Display panel with integrated off-axis microlens array

Abstract

To provide improved display designs that improve upon, and help to address the shortcomings of conventional display systems.SOLUTION: Various embodiments include a display panel with an integrated microlens array. The display panel typically includes an array of mesas which includes an array of pixel light sources (e.g., LEDs) electrically coupled to corresponding pixel driver circuits (e.g., FETs). The array of microlenses is off-axially aligned on the mesas including the pixel light sources, and is positioned to reduce the divergence of light produced by the pixel light sources and direct the light to a certain angle or focus point on a pixel by pixel basis. Different microlens shapes and combinations are implemented in the display panel. The display panel may also include an integrated optical spacer formed from the same microlens material layer to maintain the positioning between the microlenses and the pixel driver circuits.SELECTED DRAWING: Figure 1A

Description

[Technical field]

[0001] Related Applications

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 083,972, filed September 27, 2020, and entitled "Display Panel with Integrated Off-Axis Microlens Array," which is incorporated herein by reference.

[0002] The present disclosure relates generally to display devices, and more particularly to a system and manufacturing method for a display panel integrated with an off-axis microlens array. [Background technology]

[0003]

[0003] Display technology is becoming more and more important in today's commercial electronic devices. These display panels are widely used in stationary large screens, such as liquid crystal display televisions (LCD TVs) and organic light-emitting diode televisions (OLED TVs), as well as portable electronic devices, such as laptop personal computers, smartphones, tablets, and wearable electronic devices. Much of the development of stationary large screens is directed toward achieving a high viewing angle to accommodate and enable multiple viewers to view the screen from various angles. For example, various liquid crystal materials, such as super twisted nematic (STN) and film-compensated super twisted nematic (FSTN), have been developed to achieve a large viewing angle for every pixel light source in the display panel.

[0004]

[0004] However, most portable electronic devices are mainly designed for a single user, and the screen orientation of these portable devices should be adjusted to the best viewing angle for the corresponding user, rather than a large viewing angle to accommodate multiple viewers. For example, the appropriate viewing angle for a user may be perpendicular to the screen surface. In this case, compared with a stationary large screen, the light emitted at a large viewing angle is mostly wasted. In addition, a large viewing angle presents privacy concerns for portable electronic devices used in public areas.

[0005]

[0005] In addition, in conventional projection systems based on passive imager devices such as liquid crystal displays (LCDs), digital mirror devices (DMDs), and liquid crystal on silicon (LCOS), the passive imager devices themselves do not emit light. Specifically, conventional projection systems project images by optically modulating collimated light emitted from a light source, i.e., by transmitting a portion of the light at a pixel level, for example, by an LCD panel, or by reflecting a portion of the light, for example, by a DMD panel. However, the portion of the light that is not transmitted or reflected is lost, which reduces the efficiency of the projection system. In addition, to provide collimated light, complex illumination optics are used to collect the divergent light emitted from the light source. The illumination optics not only makes the system bulky, but also introduces additional light loss into the system, which further affects the performance of the system. In conventional projection systems, typically less than 10% of the illumination light generated by the light source is used to form the projected image.

[0006]

[0006] Light-emitting diodes (LEDs), which have the advantages of long service life and low energy consumption, are widely used in various fields. As the next generation light source, LEDs are used as backlight units for mobile phones, digital devices, liquid crystal displays, etc., as well as dashboard lighting and tail lights for vehicles, traffic signals, and other general lighting. LEDs are widely used in display fields, including indoor and outdoor electronic signs, and in biological and environmental fields, including water pollution and blood oxygen concentration. The application range of LEDs continues to expand every year due to the improvement of product performance and the reduction of manufacturing costs. In order to meet these demands, various researches are underway. There are two main methods: increasing the internal quantum efficiency and increasing the external extraction efficiency. The internal quantum efficiency can be increased by increasing the recombination rate of electron-hole pairs that emit light in the active layer of the LED and decreasing the recombination rate of electron-hole pairs that do not emit light. However, this method has technical limitations. Meanwhile, there is currently active research being conducted on increasing the external extraction efficiency. To overcome this challenge, microlens arrays are used to reduce one or more of scattering, internal reflection, waveguiding, absorption, and the like.

[0007]

[0007] LEDs made of semiconductor materials can be used in mono-color or full-color displays. In current displays employing LEDs, the LEDs are typically used as light sources to provide light that is optically modulated, for example, by an LCD or DMD panel. That is, the light emitted by the LED does not form an image by itself. LED displays using an LED panel containing multiple LED dies as an imager device are also being investigated. In such LED displays, the LED panel is a self-illuminating imager device, and each pixel may include one LED die (mono-color display) or multiple LED dies, each representing one of the primary colors (full-color display).

[0008]

[0008] However, the light emitted by the LED die is generated from self-luminescence, so it is not directional and has a large divergence angle. The large divergence angle may cause various problems in the LED display. For example, due to the large divergence angle, the light emitted by the LED die may be more likely to be scattered and / or reflected in the LED display. The scattered / reflected light may illuminate other pixels, resulting in optical crosstalk between pixels, reduced sharpness, and reduced contrast.

[0009]

[0009] In addition, the direction of light emitted from each microlens in traditional LED is the same, so that the light can only be focused on a plane, not on a single point, which limits the application field of LED. Also, an additional refractive optical structure needs to be applied in LED, which causes optical crosstalk between pixels, loss of sharpness, and loss of contrast. Summary of the Invention

[0010]

[0010] There is a need for improved display designs that help improve and address the shortcomings of conventional display systems as described above. In particular, there is a need for display panels with reduced viewing angles for better protection of user privacy, better directional focusing, or / and reduced light waste for reduced power consumption, as well as reduced light interference between pixels for better images.

[0011]

[0011] Various embodiments include a display panel having an integrated microlens array. A display panel typically includes an array of pixel light sources (e.g., LEDs, OLEDs) electrically coupled to corresponding pixel driver circuits (e.g., FETs). The array of microlenses is aligned with the pixel light sources and positioned to reduce divergence of the light generated by the pixel light sources. The display panel may also include integrated optical spacers to maintain alignment between the microlenses and the pixel driver circuits.

[0012]

[0012] The microlens array reduces the divergence angle of the light generated by the pixel light sources and the usable viewing angle of the display panel, which in turn reduces power waste, increases brightness, and / or better protects user privacy in public areas.

[0013]

[0013] Display panels with integrated microlens arrays can be manufactured using various manufacturing methods, resulting in various device designs. In one aspect, the microlens array is directly manufactured as a mesa or protrusion of the substrate together with the pixel light source. In some aspects, self-assembly, high temperature reflow, grayscale mask photolithography, molding / imprinting / stamping, and dry etching pattern transfer are techniques that can be used to manufacture the microlens array.

[0014]

[0014] Other aspects include components, devices, systems, improvements, methods and processes including methods of manufacture, applications, and other techniques related to any of the above.

[0015]

[0015] The present disclosure provides a light emitting structure having an off-axis microlens, whereby the direction of light exiting the microlens can be changed without additional optical structures.

[0016]

[0016] In some embodiments, an emissive display having an off-axis microlens array can control the light direction of each individual microlens, and light from different microlenses in the microlens array can be focused to a single point.

[0017]

[0017] The present disclosure also provides a light-detecting device having an off-axis microlens array, which can receive light from a point, and the non-collimated light from the point can be changed to a collimated light through the microlens array, which can then enter a sensor or another light-detecting unit.

[0018] In some embodiments, the present disclosure provides a light emitting structure comprising three microlenses, whereby the brightness and / or sharpness of a light emitting display using the light emitting structure can be adjusted and the usable viewing angle can be reduced.

[0019]

[0019] Some exemplary embodiments of the present disclosure include a light-emitting structure comprising three microlenses. For example, a first microlens may be formed above a first light-emitting mesa, and the central axis of the first microlens is not coaxially aligned with the central axis of the first light-emitting mesa. A portion of the light emitted from the first light-emitting region may reach and pass through the first microlens directly. A second microlens may be positioned on the second light-emitting mesa, and a third microlens may be positioned on the second microlens. A portion of the light emitted from the second light-emitting mesa may reach and pass through the second microlens directly. A portion of the light passing through the second microlens may further reach and pass through the third microlens. As a result, the path of the light may be adjusted according to the relative positions of the three microlenses. Thus, divergence may be reduced and the usable viewing angle may be reduced to the extent that displays and panels using the LED device may be viewed by a user's field of view perpendicular to the surface of the display and panel. This in turn can reduce power waste, increase brightness, and / or better protect user privacy in public areas.

[0020]

[0020] In another example, the light emitting structure may further include one or more reflecting cups, and the first light emitting mesa and the second light emitting mesa may be surrounded by the one or more reflecting cups. A part of the light emitted from the first and second light emitting mesas may reach and pass through one or more of the three microlenses directly. Another part of the light emitted from the first and second light emitting mesas may reach and be reflected by the one or more reflecting cups, and then reach and pass through one or more of the three microlenses. As a result, more light emitted from the first and second light emitting mesas may be utilized compared to a light emitting structure without a reflecting cup. Thus, divergence may be reduced, and the usable viewing angle may be reduced to an extent that displays and panels using LED devices may be viewed by several users. This may also reduce power waste, increase brightness, and / or adequately protect user privacy in public areas.

[0021] In some embodiments, the light emitting structure includes a diffractive lens, whereby the brightness and / or sharpness of the light emitting display can be adjusted. Selected wavelengths of light can also be reflected by or transmitted through the diffractive lens.

[0022]

[0022] Some exemplary embodiments of the present disclosure include a light emitting structure comprising a microlens formed on a light emitting mesa and a diffractive lens covering the microlens. The microlens may be aligned with the light emitting mesa and covered by the diffractive lens to reduce divergence of light emitting from the light emitting mesa. For example, the microlens may be aligned coaxially with the light emitting mesa and covered by the diffractive lens. A portion of the light emitted from the light emitting region may reach and pass through the microlens directly and then selectively pass through the diffractive lens. Another portion of the light emitted from the light emitting mesa may reach and selectively pass through the diffractive lens directly. One advantage of the disclosed light emitting structure is to increase the brightness of the light emitting structure. Another advantage is to increase the contrast of the light emitting structure. Thus, divergence may be reduced and the usable viewing angle may be reduced to the extent that displays and panels using the LED device can be seen by a user's field of view perpendicular to the surface of the display and panel. This, in turn, may reduce power waste, increase brightness, and / or better protect user privacy in public areas.

[0023]

[0023] In another example, the microlens may be aligned coaxially with the light-emitting region, positioned on the light-emitting mesa, covered by the diffractive lens, and surrounded by the reflecting cup. A part of the light emitted from the light-emitting region may reach and pass through the microlens and / or the diffractive lens directly. Another part of the light emitted from the light-emitting center may reach and be reflected by the reflective cup, and then reach and pass through the microlens and / or the diffractive lens. As a result, more light emitted from the light-emitting mesa may be utilized compared to a light-emitting structure without a reflective cup. Thus, the divergence may be reduced, and the usable viewing angle may be reduced to the extent that displays and panels using the LED device may be viewed by several users. This may also reduce power waste, increase brightness, and / or adequately protect user privacy in public areas.

[0024]

[0024] Accordingly, the present disclosure includes, without limitation, the following exemplary embodiments.

[0025]

[0025] Some exemplary embodiments of the present disclosure include a light emitting structure array system having an off-axis microlens array structure comprising at least one light emitting mesa and at least one microlens formed above the light emitting mesa, wherein a central axis of the at least one microlens is not coaxially aligned with the central axis of the at least one light emitting mesa.

[0026]

[0026] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure array system, the relative position of each microlens with respect to the corresponding light emitting mesa in the light emitting structure array system is the same.

[0027]

[0027] In some exemplary embodiments or any combination of exemplary embodiments, the light emitting structure array system further includes a sensor, and emitted light passing through at least one microlens from at least one light emitting mesa is collectively converted into the sensor.

[0028]

[0028] In some exemplary embodiments of the light emitting structure array system or any combination of exemplary embodiments, the sensor is positioned on a central axis of the light emitting structure array system.

[0029]

[0029] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure array system, the offset distance of each of the central axes of each microlens relative to the central axis of each light emitting mesa increases from the center of the light emitting structure array system toward either edge of the light emitting structure array system.

[0030]

[0030] In some exemplary embodiments of the light emitting structure array system or any combination of exemplary embodiments, the sensor is not positioned on the central axis of the light emitting structure array system.

[0031]

[0031] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure array system, the offset distance of the central axis of each microlens relative to the central axis of each light emitting mesa increases from the central axis of the sensor toward either edge of the light emitting structure array system.

[0032]

[0032] In some exemplary embodiments of the light emitting structure array system or any combination of exemplary embodiments, the angle of light emitted from each microlens increases from the central axis of the sensor toward either edge of the light emitting structure array system.

[0033] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure array system, the offset range of the central axis of the at least one microlens from the central axis of the at least one light emitting mesa is less than or equal to 4.5 μm.

[0034]

[0034] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure array system, the offset distance between the edge of the bottom surface of at least one light emitting mesa and the edge of the bottom surface of at least one microlens is within 30% of the diameter of the bottom surface of at least one microlens.

[0035] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure array system, the material of at least one microlens is silicon oxide or an organic material.

[0036] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure array system, the bottom surface of at least one microlens intersects with the central axis of at least one light emitting mesa.

[0037]

[0037] In some exemplary embodiments or any combination of exemplary embodiments, the light emitting structure array system further includes a semiconductor substrate and a reflector cup, wherein at least one light emitting mesa is formed on the semiconductor substrate and the at least one light emitting mesa is surrounded by the reflector cup.

[0038]

[0038] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure array system, the inner wall of the reflector cup is stepped.

[0039] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure array system, at least one light emitting mesa includes a light emitting layer, a bottom bonding layer at the bottom of the light emitting layer and bonded to the semiconductor substrate, and a top electrode layer covering the at least one light emitting mesa and electrically connected to a reflective cup. In some embodiments, the reflective cup is electrically connected to the semiconductor substrate.

[0040] In some exemplary embodiments or any combination of exemplary embodiments, the light emitting structure array system further includes a spacer formed between the at least one light emitting mesa and the at least one microlens.

[0041] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure array system, the height of the spacer is less than the height of at least one microlens.

[0042] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure array system, the semiconductor substrate is an IC substrate.

[0043]

[0043] Some exemplary embodiments of the present disclosure include a light emitting structure having at least one off-axis microlens including a light emitting mesa, a first microlens formed on the light emitting mesa, and a second microlens formed on the light emitting mesa and covering the first microlens.

[0044] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having at least one off-axis microlens, the diameter of the second microlens is larger than the diameter of the first microlens.

[0045]

[0045] In some exemplary embodiments or any combination of exemplary embodiments of a light emitting structure having at least one off-axis microlens, the central axis of the first microlens is aligned coaxially with the central axis of the light emitting mesa, and the central axis of the second microlens is not aligned coaxially with the central axis of the light emitting mesa.

[0046]

[0046] In some exemplary embodiments or any combination of exemplary embodiments of a light emitting structure having at least one off-axis microlens, the central axis of the second microlens is aligned coaxially with the central axis of the light emitting mesa, and the central axis of the first microlens is not aligned coaxially with the central axis of the light emitting mesa.

[0047]

[0047] In some exemplary embodiments or any combination of exemplary embodiments of a light emitting structure having at least one off-axis microlens, the central axis of the first microlens is not aligned coaxially with the central axis of the light emitting mesa, the central axis of the second microlens is not aligned coaxially with the central axis of the light emitting mesa, and the central axis of the first microlens is not aligned coaxially with the central axis of the second microlens.

[0048] In some example embodiments or any combination of example embodiments of a light emitting structure having at least one off-axis microlens, the light emitting structure includes more than one set of a light emitting mesa, a first microlens, and a second microlens, in some embodiments, the position of each first microlens relative to each second microlens on the light emitting structure in each set is different.

[0049]

[0049] In some exemplary embodiments or any combination of exemplary embodiments of a light emitting structure having at least one off-axis microlens, the offset distance between the central axis of the second microlens and the central axis of the light emitting mesa is 12 μm or less.

[0050]

[0050] In some exemplary embodiments or any combination of exemplary embodiments of a light emitting structure having at least one off-axis microlens, the offset distance between the central axis of the first microlens and the central axis of the light emitting mesa is 1.5 μm or less.

[0051]

[0051] In some exemplary embodiments or any combination of exemplary embodiments of a light emitting structure having at least one off-axis microlens, the offset distance between the central axis of the first microlens and the central axis of the second microlens is less than 6 μm and is greater than or equal to 4.5 μm.

[0052] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having at least one off-axis microlens, the bottom surface of the second microlens intersects with the central axis of the light emitting mesa.

[0053] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having at least one off-axis microlens, the bottom surface of the first microlens intersects with the central axis of the light emitting mesa.

[0054] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having at least one off-axis microlens, the material of the first microlens is the same as the material of the second microlens.

[0055] In some exemplary embodiments or any combination of exemplary embodiments, the light emitting structure having at least one off-axis microlens further includes a semiconductor substrate and a reflector cup. In some embodiments, a light emitting mesa is formed on the semiconductor substrate, and the light emitting mesa is surrounded by the reflector cup.

[0056] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having at least one off-axis microlens, the inner wall of the reflector cup has a stepped shape.

[0057]

[0057] In some exemplary embodiments or any combination of exemplary embodiments of a light emitting structure having at least one off-axis microlens, the light emitting mesa includes a light emitting layer, a bottom bonding layer at the bottom of the light emitting layer and bonded to the semiconductor substrate, and a top electrode layer covering the light emitting mesa and electrically connected to a reflective cup, which is electrically connected to the semiconductor substrate.

[0058]

[0058] In some exemplary embodiments or any combination of exemplary embodiments, the light emitting structure having at least one off-axis microlens further includes a spacer formed between the light emitting mesa and the first microlens.

[0059] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having at least one off-axis microlens, the height of the spacer is less than that of the first microlens.

[0060] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having at least one off-axis microlens, the semiconductor substrate is an IC substrate.

[0061]

[0061] Some exemplary embodiments of the present disclosure include a light emitting structure having at least one off-axis microlens comprising a light emitting mesa, a first microlens formed on the light emitting mesa, and a second microlens formed on the first microlens.

[0062] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having at least one off-axis microlens, the diameter of the second microlens is smaller than the diameter of the first microlens.

[0063]

[0063] In some exemplary embodiments or any combination of exemplary embodiments of a light emitting structure having at least one off-axis microlens, the central axis of the first microlens is aligned coaxially with the central axis of the light emitting mesa, and the central axis of the second microlens is not aligned coaxially with the central axis of the light emitting mesa.

[0064] In some example embodiments or any combination of example embodiments of a light emitting structure having at least one off-axis microlens, the light emitting structure includes more than one set of a light emitting mesa, a first microlens, and a second microlens, in some embodiments, the position of each first microlens relative to each second microlens on the light emitting structure in each set is different.

[0065]

[0065] In some exemplary embodiments or any combination of exemplary embodiments of a light emitting structure having at least one off-axis microlens, the offset distance between the central axis of the second microlens and the central axis of the light emitting mesa is 1.5 μm or less.

[0066] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having at least one off-axis microlens, the bottom surface of the first microlens intersects with the central axis of the light emitting mesa.

[0067] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having at least one off-axis microlens, the bottom surface of the second microlens does not intersect with the central axis of the light emitting mesa.

[0068]

[0068] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having at least one off-axis microlens, the material of the first microlens is the same as the material of the second microlens.

[0069]

[0069] In some exemplary embodiments or any combination of exemplary embodiments, the light emitting structure having at least one off-axis microlens further includes a semiconductor substrate and a reflective cup, wherein the light emitting mesa is formed on the semiconductor substrate, and the light emitting mesa is surrounded by the reflective cup.

[0070] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having at least one off-axis microlens, the inner wall of the reflector cup has a stepped shape.

[0071]

[0071] In some exemplary embodiments or any combination of exemplary embodiments of a light emitting structure having at least one off-axis microlens, the light emitting mesa includes a light emitting layer, a bottom bonding layer at the bottom of the light emitting layer and bonded to the semiconductor substrate, and a top electrode layer covering the light emitting mesa and electrically connected to a reflective cup, which is electrically connected to the semiconductor substrate.

[0072]

[0072] In some exemplary embodiments or any combination of exemplary embodiments, the light emitting structure having at least one off-axis microlens further includes a spacer formed between the light emitting mesa and the first microlens.

[0073]

[0073] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having at least one off-axis microlens, the height of the spacer is less than the height of the first microlens.

[0074] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having at least one off-axis microlens, the semiconductor substrate is an IC substrate.

[0075]

[0075] Some exemplary embodiments of the present disclosure include a light emitting structure having an off-axis microlens array structure comprising a first light emitting mesa and at least one first microlens formed above the first light emitting mesa, wherein a central axis of the first microlens is not aligned coaxially with the central axes of the first light emitting mesa, the second light emitting mesa, at least one second microlens formed above the second light emitting mesa, and at least one third microlens formed on the second light emitting mesa.

[0076]

[0076] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the third microlens covers and contacts the entire top surface of the second microlens.

[0077] In some example embodiments or any combination of example embodiments of the light emitting structure, the offset range of the central axis of the first microlens from the central axis of the first light emitting mesa is less than or equal to 4.5 μm.

[0078]

[0078] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the offset distance between the edge of the bottom surface of the first light emitting mesa and the edge of the bottom surface of the first microlens is within 30% of the diameter of the bottom surface of the first microlens.

[0079] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the material of the first microlens is silicon oxide or an organic material.

[0080] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the bottom surface of the first microlens intersects with the central axis of the first light emitting mesa.

[0081]

[0081] In some exemplary embodiments or any combination of exemplary embodiments, the light emitting structure further includes a semiconductor substrate and at least two reflector cups, wherein the first light emitting mesa and the second light emitting mesa are formed on the semiconductor substrate, and the first light emitting mesa and the second light emitting mesa are surrounded by each of the two reflector cups.

[0082]

[0082] In some exemplary embodiments of the light emitting structure or any combination of the exemplary embodiments, the inner wall of the reflector cup has a stepped shape.

[0083] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the first light emitting mesa includes a first light emitting layer, a first bottom bonding layer at the bottom of the first light emitting layer and bonded to the semiconductor substrate, and a top electrode layer at the top of the first light emitting mesa and electrically connected to a first of the two reflector cups. In some embodiments, the second light emitting mesa includes a second light emitting layer, a second bottom bonding layer at the bottom of the second light emitting layer and bonded to the semiconductor substrate, and a top electrode layer at the top of the second light emitting mesa and electrically connected to a second of the two reflector cups, and the first and second reflector cups are electrically connected to the semiconductor substrate.

[0084]

[0084] In some exemplary embodiments or any combination of exemplary embodiments, the light emitting structure further includes a spacer covering the first light emitting mesa and the second light emitting mesa, the spacer being formed between the first light emitting mesa and the first microlens, and the spacer being also formed between the second light emitting mesa and the second microlens.

[0085]

[0085] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the height of the spacer is less than the height of the first microlens.

[0086]

[0086] The light emitting structure of any one of claims 51 to 61, wherein the diameter of the third microlens is greater than the diameter of the second microlens.

[0087]

[0087] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the central axis of the second microlens is aligned coaxially with the central axis of the second light emitting mesa, and the central axis of the third microlens is not aligned coaxially with the central axis of the second light emitting mesa.

[0088]

[0088] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the central axis of the third microlens is aligned coaxially with the central axis of the second light emitting mesa, and the central axis of the second microlens is not aligned coaxially with the central axis of the second light emitting mesa.

[0089]

[0089] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the central axis of the second microlens is not aligned coaxially with the central axis of the second light emitting mesa, the central axis of the third microlens is not aligned coaxially with the central axis of the second light emitting mesa, and the central axis of the second microlens is not aligned coaxially with the central axis of the third microlens.

[0090] In some example embodiments or any combination of example embodiments of the light emitting structure, the light emitting structure includes more than one set of a light emitting mesa, a first microlens, a second microlens, and a third microlens, in some embodiments, the position of each second microlens relative to each third microlens on the light emitting structure in each set is different.

[0091]

[0091] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the offset distance between the central axis of the third microlens and the central axis of the second light emitting mesa is less than or equal to 12 μm.

[0092]

[0092] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the offset distance between the central axis of the second microlens and the central axis of the second light emitting mesa is less than or equal to 1.5 μm.

[0093]

[0093] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the offset distance between the central axis of the second microlens and the central axis of the third microlens is less than 6 μm and is greater than or equal to 4.5 μm.

[0094]

[0094] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the bottom surface of the third microlens intersects with the central axis of the second light emitting mesa.

[0095]

[0095] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the bottom surface of the second microlens does not intersect with the central axis of the second light emitting mesa.

[0096]

[0096] In some exemplary embodiments or any combination of exemplary embodiments of the light-emitting structure, the material of the second microlens is the same as the material of the third microlens, and the material of the first microlens is the same as the material of the third microlens.

[0097]

[0097] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the offset distance between the central axis of the first microlens and the central axis of the first light emitting mesa is smaller than the offset distance between the central axis of the third microlens and the central axis of the second light emitting mesa.

[0098] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the semiconductor substrate is an IC substrate.

[0099]

[0099] Some exemplary embodiments of the present disclosure include a light emitting structure comprising a first light emitting mesa, a first microlens formed above the first light emitting mesa, where a central axis of the first microlens is not coaxially aligned with a central axis of the first light emitting mesa, a second light emitting mesa, a second microlens formed above the second light emitting mesa, and a third microlens formed on the second light emitting mesa, where the third microlens does not cover the entire top surface of the second microlens.

[0100]

[0100] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the offset distance between the central axis of the first microlens and the central axis of the first light emitting mesa is less than or equal to 4.5 μm.

[0101]

[0101] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the offset distance between the edge of the bottom surface of the first light emitting mesa and the edge of the bottom surface of the first microlens is within 30% of the diameter of the bottom surface of the first microlens.

[0102]

[0102] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the material of the first microlens is silicon oxide or an organic material.

[0103]

[0103] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the bottom surface of the first microlens intersects with the central axis of the first light emitting mesa.

[0104]

[0104] In some exemplary embodiments or any combination of exemplary embodiments, the light emitting structure further includes a semiconductor substrate and a reflector cup, wherein the first light emitting mesa and the second light emitting mesa are formed on the semiconductor substrate, and the first light emitting mesa and the second light emitting mesa are surrounded by respective reflector cups.

[0105]

[0105] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the inner wall of each of the reflector cups is stepped.

[0106] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the first light emitting mesa includes a first light emitting layer, a first bottom bonding layer formed on a bottom of the first light emitting layer and bonded to the semiconductor substrate, and a top electrode layer covering the first light emitting layer and electrically connected to a first reflective cup of the reflective cups. In some embodiments, the second light emitting mesa includes a second light emitting layer, a second bottom bonding layer formed on a bottom of the second light emitting layer and bonded to the semiconductor substrate, and a top electrode layer also covering the second light emitting layer and electrically connected to a second reflective cup of the reflective cups, the reflective cup being electrically connected to the semiconductor substrate.

[0107]

[0107] In some exemplary embodiments or any combination of exemplary embodiments, the light emitting structure further includes a spacer covering the first light emitting mesa and the second light emitting mesa, the spacer being formed between the first light emitting mesa and the first microlens, and the spacer being also formed between the second light emitting mesa and the second microlens.

[0108]

[0108] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the height of the spacer is less than the height of the first microlens.

[0109]

[0109] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the horizontal dimension of the third microlens is smaller than the horizontal dimension of the base of the second microlens.

[0110]

[0110] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the central axis of the second microlens is aligned coaxially with the central axis of the second light emitting mesa, and the vertical axis of the third microlens is not aligned coaxially with the central axis of the second light emitting mesa, and the vertical axis passes through the center point of the third microlens when the third microlens is in its perfect shape.

[0111] In some example embodiments or any combination of example embodiments of the light emitting structure, the light emitting structure includes more than one set of a light emitting mesa, a first microlens, and a second microlens, in some embodiments, the position of each first microlens relative to each second microlens on the light emitting structure in each set is different.

[0112]

[0112] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the offset distance between the vertical axis of the third microlens and the central axis of the second light emitting mesa is less than or equal to 1.5 μm.

[0113]

[0113] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the bottom surface of the second microlens intersects with the central axis of the second light emitting mesa.

[0114]

[0114] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the bottom surface of the first microlens does not intersect with the central axis of the first light emitting mesa.

[0115]

[0115] In some exemplary embodiments or any combination of exemplary embodiments of the light-emitting structure, the material of the second microlens is the same as the material of the third microlens, and the material of the first microlens is the same as the material of the second microlens.

[0116]

[0116] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the offset distance between the central axis of the first microlens and the central axis of the first light emitting mesa is greater than the offset distance between the vertical axis of the third microlens and the central axis of the second light emitting mesa.

[0117]

[0117] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the semiconductor substrate is an IC substrate.

[0118]

[0118] Some exemplary embodiments of the present disclosure include a light emitting structure having coaxial microlenses, the light emitting structure comprising a light emitting mesa, a first microlens formed on the light emitting mesa, and a second microlens covering and contacting the first microlens.

[0119]

[0119] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having coaxial microlenses, the refractive index of the first microlens is higher than the refractive index of the second microlens.

[0120]

[0120] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having coaxial microlenses, the material of the second microlens is different from the material of the first microlens.

[0121]

[0121] In some exemplary embodiments or any combination of exemplary embodiments of a light emitting structure having coaxial microlenses, the first microlens has a hemispherical structure and the second microlens has a polygonal structure if there is no carve-out of the first microlens, or a composite structure if there is no carve-out of the first microlens.

[0122]

[0122] In some exemplary embodiments or any combination of exemplary embodiments of the light-emitting structure having coaxial microlenses, the composite structure is a combination of a hemispherical structure and a trapezoidal structure or a hemispherical structure and a triangular structure.

[0123]

[0123] In some exemplary embodiments or any combination of exemplary embodiments of a light-emitting structure having coaxial microlenses, a trapezoidal structure is formed at the base of a hemispherical structure, or a triangular structure is formed at the base of a hemispherical structure.

[0124]

[0124] In some exemplary embodiments or any combination of exemplary embodiments of the light-emitting structure having coaxial microlenses, the polygonal structure is a trapezoidal structure having a top surface that is inclined relative to a base surface of the trapezoidal structure.

[0125]

[0125] In some exemplary embodiments or any combination of exemplary embodiments of a light emitting structure having coaxial microlenses, the central axis of the first microlens and the central axis of the second microlens are aligned coaxially with the central axis of the light emitting mesa.

[0126]

[0126] In some exemplary embodiments or any combination of exemplary embodiments, the light emitting structure having a coaxial microlens further includes a semiconductor substrate and a reflector cup, the light emitting mesa is formed on the semiconductor substrate, and the light emitting mesa is surrounded by the reflector cup.

[0127]

[0127] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having coaxial microlenses, the inner wall of the reflector cup has a stepped shape.

[0128]

[0128] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having coaxial microlenses, the light emitting mesa includes a light emitting layer, a bottom bonding layer at the bottom of the light emitting layer and bonded to the semiconductor substrate, and a top electrode layer covering the light emitting mesa and electrically connected to a reflective cup, which is electrically connected to the semiconductor substrate.

[0129]

[0129] In some exemplary embodiments or any combination of exemplary embodiments, the light emitting structure having a coaxial microlens further includes a spacer formed above the light emitting mesa.

[0130]

[0130] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having coaxial microlenses, the height of the spacer is less than the height of the first microlens and the height of the second microlens.

[0131]

[0131] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure with coaxial microlenses, the semiconductor substrate is an IC substrate.

[0132]

[0132] Some exemplary embodiments of the present disclosure include a light emitting structure having an elliptical microlens structure comprising a light emitting mesa and at least one elliptical microlens formed above the light emitting mesa, wherein the central axis of the elliptical microlens is not coaxially aligned with the central axis of the light emitting mesa.

[0133]

[0133] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the elliptical microlens is formed by a combination of a quarter of a sphere and a quarter of an ellipsoid.

[0134]

[0134] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the radius of the sphere is less than or equal to 9 μm and the semimajor axis of the ellipsoid is less than or equal to 18 μm.

[0135]

[0135] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the offset distance of the center of the elliptical microlens from the center of the light emitting mesa at the horizontal level is less than or equal to 4.5 μm.

[0136]

[0136] In some exemplary embodiments or any combination of exemplary embodiments of the light-emitting structure, the material of the elliptical microlens is silicon oxide or an organic material.

[0137]

[0137] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the base of the elliptical microlens intersects with the central axis of the light emitting mesa.

[0138]

[0138] In some exemplary embodiments or any combination of exemplary embodiments, the light emitting structure further includes a semiconductor substrate and a reflector cup, the light emitting mesa being formed on the semiconductor substrate, and the light emitting mesa being surrounded by the reflector cup.

[0139]

[0139] In some exemplary embodiments of the light emitting structure or any combination of the exemplary embodiments, the inner wall of the reflector cup has a stepped shape.

[0140]

[0140] In some exemplary embodiments of the light emitting structure or any combination of exemplary embodiments, the light emitting mesa includes a light emitting layer, a bottom bonding layer at the bottom of the light emitting layer and bonded to the semiconductor substrate, and a top electrode layer covering the light emitting mesa and electrically connected to a reflective cup, which is electrically connected to the semiconductor substrate.

[0141]

[0141] In some exemplary embodiments or any combination of exemplary embodiments, the light emitting structure further includes a spacer formed between the light emitting mesa and the elliptical microlens.

[0142]

[0142] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the height of the spacer is less than the height of the elliptical microlens.

[0143]

[0143] In some exemplary embodiments of the light emitting structure or any combination of exemplary embodiments, the spacer height is less than 5 μm.

[0144]

[0144] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the semiconductor substrate is an IC substrate.

[0145]

[0145] Some exemplary embodiments of the present disclosure include a light emitting structure having a composite microlens structure comprising a light emitting mesa and a composite microlens structure. In some embodiments, the composite microlens structure includes at least one microlens formed above the light emitting mesa and a reflector formed on one side of the microlens.

[0146]

[0146] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having a microlens composite structure, the microlens is a sphere having a breach in the surface of the microlens.

[0147]

[0147] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having a composite microlens structure, the reflector is formed on the surface of the crack.

[0148]

[0148] In some exemplary embodiments or any combination of exemplary embodiments of a light emitting structure having a composite microlens structure, the cleft has an inclined surface relative to the bottom surface of the microlens, and the reflective portion is a planar structure attached to the inclined surface.

[0149]

[0149] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having a composite microlens structure, the crevice is a depression and the reflector is attached to a surface of the depression.

[0150]

[0150] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having a microlens composite structure, the material of the microlens is silicon oxide or an organic material.

[0151]

[0151] In some exemplary embodiments or any combination of exemplary embodiments of a light emitting structure having a composite microlens structure, the bottom surface of the microlens intersects with the central axis of the light emitting mesa.

[0152]

[0152] In some exemplary embodiments or any combination of exemplary embodiments, the light emitting structure having the composite microlens structure further includes a semiconductor substrate and a reflector cup, the light emitting mesa is formed on the semiconductor substrate, and the light emitting mesa is surrounded by the reflector cup.

[0153]

[0153] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having a composite microlens structure, the inner wall of the reflector cup has a stepped shape.

[0154]

[0154] In some exemplary embodiments or any combination of exemplary embodiments of a light emitting structure having a composite microlens structure, the light emitting mesa includes a light emitting layer, a bottom bonding layer at the bottom of the light emitting layer and bonded to the semiconductor substrate, and a top electrode layer covering the light emitting mesa and electrically connected to a reflective cup, which is electrically connected to the semiconductor substrate.

[0155]

[0155] In some exemplary embodiments or any combination of exemplary embodiments, the light emitting structure having a composite microlens structure further includes a spacer formed between the light emitting mesa and the microlens.

[0156]

[0156] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having a composite microlens structure, the height of the spacer is less than the height of the microlens.

[0157]

[0157] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having a composite microlens structure, the semiconductor substrate is an IC substrate.

[0158]

[0158] Some exemplary embodiments of the present disclosure include a light emitting structure comprising a light emitting mesa, a microlens formed on the light emitting mesa, and a diffractive lens covering the microlens.

[0159]

[0159] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the material of the microlens is different from the material of the diffractive lens.

[0160]

[0160] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the diffractive lens is a Bragg mirror.

[0161]

[0161] In some exemplary embodiments of the light emitting structure or any combination of exemplary embodiments, the center point of the top surface of the diffractive lens lies on the central axis of the microlens.

[0162]

[0162] In some exemplary embodiments or any combination of exemplary embodiments of the light-emitting structure, the central axis of the diffractive lens is inclined with respect to a vertical axis perpendicular to the substrate of the light-emitting structure, and the central axis of the microlens is perpendicular to the vertical axis perpendicular to the substrate of the light-emitting structure.

[0163]

[0163] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the microlens has a hemispherical structure and the diffractive lens has a polygonal structure or a composite structure.

[0164]

[0164] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the composite structure comprises a combination of a hemispherical structure and a trapezoidal structure or a combination of a hemispherical structure and a triangular structure.

[0165]

[0165] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, a trapezoidal structure is formed at the bottom of a hemispherical structure, or a triangular structure is formed at the bottom of a hemispherical structure.

[0166]

[0166] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the polygonal structure is a trapezoidal structure having a top surface that is inclined relative to a base surface of the trapezoidal structure.

[0167]

[0167] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the central axis of the microlens and the axis passing through the central point of the top surface of the diffractive lens are aligned coaxially with the central axis of the light emitting mesa.

[0168]

[0168] In some exemplary embodiments or any combination of exemplary embodiments, the light emitting structure further includes a semiconductor substrate and at least one reflector cup, the light emitting mesa being formed on the semiconductor substrate, and the light emitting mesa being surrounded by the at least one reflector cup.

[0169]

[0169] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the inner wall of the reflector cup has a stepped shape.

[0170]

[0170] In some exemplary embodiments of the light emitting structure or any combination of exemplary embodiments, the light emitting mesa includes a light emitting layer, a bottom bonding layer at the bottom of the light emitting layer and bonded to the semiconductor substrate, and a top electrode layer covering the light emitting mesa and electrically connected to at least one reflective cup, the at least one reflective cup being electrically connected to the semiconductor substrate.

[0171]

[0171] In some exemplary embodiments or any combination of exemplary embodiments, the light emitting structure further includes a spacer covering the light emitting mesa.

[0172]

[0172] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the height of the spacer is less than the height of the microlens.

[0173]

[0173] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure, the semiconductor substrate is an IC substrate.

[0174]

[0174] Some exemplary embodiments of the present disclosure include a light emitting structure having an off-axis microlens structure comprising a light emitting mesa and at least one microlens formed above the light emitting mesa, where the central axis of the microlens is not aligned coaxially with the central axis of the light emitting mesa.

[0175]

[0175] In some exemplary embodiments or any combination of exemplary embodiments of a light emitting structure having an off-axis microlens structure, the offset distance of the central axis of the microlens from the central axis of the light emitting mesa is 4.5 μm or less.

[0176]

[0176] In some exemplary embodiments or any combination of exemplary embodiments of a light emitting structure having an off-axis microlens structure, the offset distance between the edge of the bottom surface of the light emitting mesa and the edge of the bottom surface of the microlens is within 30% of the diameter of the bottom surface of the first microlens.

[0177]

[0177] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having an off-axis microlens structure, the material of the microlens is silicon oxide or an organic material.

[0178]

[0178] In some exemplary embodiments or any combination of exemplary embodiments of a light emitting structure having an off-axis microlens structure, the bottom surface of the microlens intersects with the central axis of the light emitting mesa.

[0179]

[0179] In some exemplary embodiments or any combination of exemplary embodiments, the light emitting structure having the off-axis microlens structure further includes a semiconductor substrate and a reflective cup, the light emitting mesa being formed on the semiconductor substrate, and the light emitting mesa being surrounded by the reflective cup.

[0180]

[0180] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having an off-axis microlens structure, the inner wall of the reflector cup has a stepped shape.

[0181]

[0181] In some exemplary embodiments or any combination of exemplary embodiments of a light emitting structure having an off-axis microlens structure, the light emitting mesa includes a light emitting layer, a bottom bonding layer at the bottom of the light emitting layer and bonded to the semiconductor substrate, and a top electrode layer covering the light emitting mesa and electrically connected to a reflective cup, which is electrically connected to the semiconductor substrate.

[0182]

[0182] In some exemplary embodiments or any combination of exemplary embodiments, the light emitting structure having an off-axis microlens structure further includes a spacer formed between the light emitting mesa and the microlens.

[0183]

[0183] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having an off-axis microlens structure, the height of the spacer is less than the height of the microlens.

[0184]

[0184] In some exemplary embodiments or any combination of exemplary embodiments of the light emitting structure having an off-axis microlens structure, the semiconductor substrate is an IC substrate.

[0185]

[0185] The design of the display device and system disclosed herein provides a reduced viewing angle and reduced light interference, which improves the luminous efficiency, resolution, and overall performance of the display system. Thus, the implementation of a display system with a microlens array can better meet the display requirements for augmented reality (AR) and virtual reality (VR), head-up displays (HUD), mobile device displays, wearable device displays, high-definition projectors, and in-vehicle displays, compared to the use of traditional displays.

[0186]

[0186] It should be noted that the above-mentioned various embodiments can be combined with any other embodiment described herein. The features and advantages described herein are not exhaustive, and many additional features and advantages will be apparent to those skilled in the art, particularly in light of the drawings, the specification, and the claims. It should also be noted that the language used in this specification is primarily selected for ease of reading and instructional purposes, and may not be selected to describe or limit the subject matter of the present invention. [Brief description of the drawings]

[0187]

[0187] In order to be able to understand the present disclosure in more detail, a more specific description may be made by referring to the features of various embodiments. Some of them are illustrated in the accompanying drawings. However, the accompanying drawings are merely illustrative of the relevant features of the present disclosure and therefore should not be considered as limiting. Because the description may allow for other useful features.

[0188]

[0188] For convenience, "up" is used to mean away from the substrate of the light-emitting structure and "down" means toward the substrate, and other directional terms such as top, bottom, above, below, under and below should be construed accordingly.

[0189] [Figure 1A]

[0189] A cross-sectional view of an exemplary light emitting structure according to some embodiments is shown. [Figure 1B]

[0190] 1 illustrates a manufacturing method for forming a display panel integrated with a microlens array using top-down pattern transfer according to some embodiments. [Figure 1C]

[0191] 1 illustrates a manufacturing method for forming a display panel integrated with a microlens array using top-down pattern transfer according to some embodiments. [Figure 2A]

[0192] 1A-1D illustrate cross-sectional views of some example embodiments of reflector cups, according to some embodiments. [Figure 2B]

[0192] Cross-sectional views of some example embodiments of reflector cups are shown, according to some embodiments. [Figure 2C]

[0192] Cross-sectional views of some example embodiments of reflector cups are shown, according to some embodiments. [Diagram 3]

[0193] 1B illustrates a cross-sectional view of an exemplary structure of a light emitting mesa on the substrate of FIG. 1A according to some embodiments. [Figure 4]

[0194] 1 illustrates a cross-sectional view of an exemplary light emitting structure having an array of microlenses and light emitting mesas according to some embodiments. [Diagram 5]

[0195] FIG. 2 is a top view of a light emitting structure array system of off-axis arranged light emitting mesas and microlenses according to some embodiments. [Figure 6]

[0196] 1 shows a cross-sectional view of a light emitting structure array system having a sensor located in a central position above the light emitting structure array system according to some embodiments. [Figure 7]

[0197] 1 shows a cross-sectional view of a light emitting structure array system having a sensor located at a lateral or non-central position above the light emitting structure array system according to some embodiments. [Figure 8]

[0198] 1 illustrates a cross-sectional view of an exemplary light emitting structure having a small microlens within a larger microlens, where the lateral dimensions of the small microlens are smaller than those of the larger microlens, according to some embodiments. [Figure 9A]

[0199] 9 shows some exemplary simulation results for light exiting the large microlens of the light emitting structure shown in FIG. 8 according to some embodiments. [Figure 9B]

[0199] Some exemplary simulation results are shown for light exiting the large microlens of the light emitting structure shown in Figure 8, according to some embodiments. [Figure 9C]

[0199] Some exemplary simulation results are shown for light exiting the large microlens of the light emitting structure shown in Figure 8, according to some embodiments. [Figure 9D]

[0199] Some exemplary simulation results are shown for light exiting the large microlens of the light emitting structure shown in Figure 8, according to some embodiments. [Figure 10]

[0200] 1 illustrates a cross-sectional view of an exemplary light emitting structure having a small microlens within a larger microlens, where the lateral dimensions of the small microlens are smaller than those of the larger microlens, according to some embodiments. [Figure 11A]

[0201] 11 shows some exemplary simulation results for light exiting a large microlens of the light emitting structure shown in FIG. 10 according to some embodiments. [Figure 11B]

[0201] Some exemplary simulation results are shown for light exiting the large microlens of the light emitting structure shown in Figure 10 according to some embodiments. [Figure 11C]

[0201] Some exemplary simulation results are shown for light exiting the large microlens of the light emitting structure shown in Figure 10 according to some embodiments. [Figure 11D]

[0201] Some exemplary simulation results are shown for light exiting the large microlens of the light emitting structure shown in Figure 10 according to some embodiments. [Figure 11E]

[0201] Some exemplary simulation results are shown for light exiting the large microlens of the light emitting structure shown in Figure 10 according to some embodiments. [Figure 12]

[0202] 1 illustrates a cross-sectional view of an exemplary light emitting structure having a small microlens within a larger microlens, where the lateral dimensions of the small microlens are smaller than those of the larger microlens, according to some embodiments. [Figure 13]

[0203] 1 illustrates a cross-sectional view of an exemplary light emitting structure having a small microlens within a larger microlens, where the lateral dimensions of the small microlens are smaller than those of the larger microlens, according to some embodiments. [Figure 14A]

[0204] 14 shows some exemplary simulation results for light exiting the large microlens of the light emitting structure shown in FIG. 13 according to some embodiments. [Figure 14B]

[0204] Some exemplary simulation results are shown for light exiting the large microlens of the light emitting structure shown in Figure 13 according to some embodiments. [Figure 15]

[0205] 1 shows a cross-sectional view of an exemplary light emitting structure having a small microlens above a larger microlens (or the small microlens is located further along the light emitting path of the light emitting structure than the large microlens), where the lateral dimensions of the small microlens are smaller than those of the large microlens, according to some embodiments. [Figure 16]

[0206] 1 shows a cross-sectional view of an exemplary light emitting structure having a small microlens above a larger microlens (or the small microlens is located further along the light emitting path of the light emitting structure than the large microlens), where the lateral dimensions of the small microlens are smaller than those of the large microlens, according to some embodiments. [Figure 17]

[0207] 1 shows a cross-sectional view of an exemplary light emitting structure having a small microlens above a larger microlens (or the small microlens is located further along the light emitting path of the light emitting structure than the large microlens), where the lateral dimensions of the small microlens are smaller than those of the large microlens, according to some embodiments. [Figure 18]

[0208] 1 shows a cross-sectional view of an exemplary light emitting structure having a small microlens above a larger microlens (or the small microlens is located further along the light emitting path of the light emitting structure than the large microlens), where the lateral dimensions of the small microlens are smaller than those of the large microlens, according to some embodiments. [Figure 19]

[0209] FIG. 1 illustrates a cross-sectional view of an exemplary light emitting structure having at least two pairs of microlenses and light emitting mesas, according to some embodiments, where at least one of the pairs has a small microlens within a large microlens, where the lateral dimension of the small microlens is smaller than that of the large microlens. [Figure 20]

[0210] FIG. 1 illustrates a cross-sectional view of an exemplary light emitting structure having at least two pairs of microlenses and light emitting mesas, according to some embodiments, where at least one of the pairs has a small microlens above a large microlens (or is located further along the light emitting path of the light emitting structure than the large microlens), and the lateral dimensions of the small microlens are smaller than those of the large microlens. [Figure 21]

[0211] 1 illustrates a cross-sectional view of an exemplary light emitting structure having at least one pair of microlens groups and light emitting mesas according to some embodiments. [Figure 22]

[0212] 1 illustrates a cross-sectional view of an exemplary light emitting structure having at least one pair of microlens groups and light emitting mesas according to some embodiments. [Diagram 23]

[0213] 1 illustrates a cross-sectional view of an exemplary light emitting structure having at least one pair of microlens groups and light emitting mesas according to some embodiments. [Figure 24]

[0214] 1 illustrates a cross-sectional view of an exemplary light emitting structure having at least one pair of microlens groups and light emitting mesas according to some embodiments. [Diagram 25]

[0215] 1 illustrates a cross-sectional view of an exemplary light emitting structure having at least one pair of microlens groups and light emitting mesas according to some embodiments. [Figure 26]

[0216] 1 illustrates a cross-sectional view of an exemplary light emitting structure having at least one pair of a microlens and a light emitting mesa according to some embodiments. [Figure 27]

[0217] 1 illustrates a cross-sectional view of an exemplary light emitting structure having at least two pairs of microlenses and light emitting mesas, where at least one of the microlenses has a cleft portion covered by a reflective portion, according to some embodiments. [Figure 28]

[0218] FIG. 2 is a top view of a micro-LED display panel according to some embodiments.

[0190]

[0219] According to common practice, the various features illustrated in the drawings may not be drawn to scale. As such, dimensions of the various features may be arbitrarily expanded or reduced for clarity. In addition, some of the drawings may not depict all of the components of a given system, method, or device. Finally, like reference numbers may be used throughout the specification and drawings to denote like features. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0191]

[0220] Numerous details are described herein to provide a thorough understanding of the exemplary embodiments shown in the accompanying drawings. However, some embodiments may be practiced without many of the specific details, and the claims are limited only by the features and aspects specifically recited in the claims. Additionally, well-known processes, components, and materials have not been described in exhaustive detail so as not to unnecessarily obscure relevant aspects of the embodiments described herein.

[0192]

[0221] As mentioned above, in some instances, the LED die has a large divergence angle, which may cause various problems such as those mentioned in the background section. Also, in a projection system employing an LED array having multiple LED dies as a self-luminous imager device, a projection lens or a set of projection lenses is required to project the image generated by the LED array, and the projection lens may have a limited numerical aperture. Thus, due to the large divergence angle of the LED die, only a small portion of the light emitted by the LED die may be collected by the projection lens. This reduces the brightness and / or increases the power consumption of the LED-based projection system.

[0193]

[0222] An embodiment consistent with the present disclosure includes an integrated display panel as a self-emissive imager device, including a substrate with an array of pixel driver circuits, an array of mesas, which may include, for example, LED dies formed on the substrate, and an array of microlenses formed on the array of mesas, and a method of making the display panel. The display panel and projection system based on the display panel combines light source, image forming, and light beam collimation functions into a single monolithic device, overcoming the shortcomings of conventional projection systems. Also, the direction and focus of light from the LEDs can be individually adjusted for each of the microlens and light emitting mesa pairs formed on the display panel.

[0194]

[0223] FIG. 1A illustrates a cross-sectional view of an exemplary light emitting structure 100 according to some embodiments. For convenience, "up" is used to mean away from the substrate 110, and "down" means toward the substrate 110, with other directional terms such as top, bottom, above, below, under, and below being interpreted accordingly. The light emitting structure 100 includes a light emitting mesa 101, as shown within the dashed rectangle in FIG. 1A. In some embodiments, the light emitting mesa 101 includes at least one single pixel light emitting device, such as an LED or micro LED, or an OLED, and light is emitted from the light emitting mesa 101. The light emitting mesa 101 has a top surface and a bottom surface. In some embodiments, the diameter or width of the top surface of the light emitting mesa 101 is in the range of 1 μm to 8 μm, and the diameter or width of the bottom surface of the light emitting mesa 101 is in the range of 3 μm to 10 μm. In some embodiments, the diameter or width of the top surface of light emitting mesa 101 is in the range of 8 μm to 25 μm, and the diameter or width of the bottom surface of light emitting mesa 101 is in the range of 10 μm to 35 μm. In some embodiments, the height of light emitting mesa 101 is in the range of 1 to 10 μm. In some embodiments, the height of light emitting mesa 101 is about 1.3 μm. In some embodiments, the diameter or width of the top surface of light emitting mesa 101 is equal to or greater than the diameter or width of the bottom surface of light emitting mesa 101.

[0195]

[0224] In some embodiments, the display panel includes an array of single pixel light emitting devices, such as light emitting mesas 101. In some embodiments, the distance between the central axes of two adjacent light emitting mesas is in the range of 1 μm to 10 μm. In some embodiments, the distance between the central axes of two adjacent light emitting mesas can vary from about 40 μm to about 20 μm, to about 10 μm, and / or to less than about 5 μm. In some embodiments, the size of the mesa and the distance between the light emitting mesas can depend on the resolution of the display. For example, for a 5000 pixel per inch (PPI) display panel, the diameter or width of the top surface of the light emitting mesa 101 is 1.5 μm and the diameter or width of the bottom surface of the light emitting mesa 101 is 2.7 μm. In some embodiments, the distance between the closest bottom edges of two adjacent light emitting mesas can be in the range of 1 μm to 10 μm. In some embodiments, the distance between the closest bottom edges of two adjacent light emitting mesas is 2.3 μm.

[0196]

[0225] In some exemplary embodiments, the light emitting structure 100 further comprises a microlens. As shown in FIG. 1A, the light emitting structure 100 may comprise a microlens 102 formed above the light emitting mesa 101. In some embodiments, the microlens 102 is positioned relative to the light emitting mesa 101 to reduce the divergence of light emitted from the light emitting mesa 101 and reduce the usable viewing angle of a single pixel LED device. As shown in FIG. 1A, the microlens 102 has a vertical central axis A-A', and the light emitting mesa 101 has a vertical central axis B-B'. The vertical central axis is perpendicular to the surface of the substrate 110. The central axis may refer to a straight line passing through any two central points in the figure. For example, the central axis of the microlens 102 (i.e., the central axis A-A') passes through the central point of the top surface of the microlens 102 and the central point of the bottom surface of the microlens 102.

[0197]

[0226] In some embodiments, the microlens 102 is stacked off-axis on the light emitting mesa 101. That is, the central axis A-A' of the microlens 102 is not coaxially aligned, overlaps, or coincides with the central axis B-B' of the light emitting mesa 101. In some embodiments, the horizontal distance between the central axis A-A' of the microlens 102 and the central axis B-B' of the light emitting mesa 101 is at least 1 μm, 2 μm, 5 μm, or 10 μm. In some embodiments, the horizontal distance between the central axis A-A' of the microlens 102 and the central axis B-B' of the light emitting mesa 101 is 4.5 μm or less. In some cases, the horizontal offset distance may be less than half the diameter of the base of the light emitting mesa 101, or less than a quarter of the diameter of the base of the light emitting mesa 101. Thus, divergence may be reduced and the usable viewing angle may be reduced to the extent that displays and panels using single pixel LED devices can be viewed by several users. It can also reduce power waste, increase brightness, and / or better protect user privacy in public areas.

[0198]

[0227] In some other embodiments (not shown in FIG. 1A ), the microlens 102 is aligned coaxially with the light-emitting mesa 101 along the A-A′ direction, and the horizontal distance between the central axis A-A′ of the microlens 102 and the central axis B-B′ of the light-emitting mesa 101 is zero. All of the light emitted from the light-emitting mesa 101 can reach and pass through the microlens 102 directly. Thus, when the central axis A-A′ of the microlens 102 and the central axis B-B′ of the light-emitting mesa 101 are identical, divergence can be reduced and the usable viewing angle can be reduced to the extent that displays and panels using single-pixel LED devices can be viewed by a user's field of view perpendicular to the surface of the display and panel. This, in turn, can reduce power waste, increase brightness, and / or better protect user privacy in public areas. In another example, a portion of the light emitted from the light emitting mesa 101 can reach and pass through the microlens 102 directly, and another portion of the light emitted from the light emitting center can pass around or bypass the microlens 102. Thus, the brightness of the light emitting structure can be adjusted.

[0199]

[0228] In some embodiments, the structure of the microlens may include a single element with one flat surface and one convex surface. For example, as shown in FIG. 1A, the structure of the microlens 102 may be a hemisphere. The structure of the microlens 102 may also be a semi-ellipsoid, a semi-ellipsoid, or other single element with one flat surface and one convex surface. In some embodiments, the structure of the microlens 102 may also be a polygonal structure or a composite structure. For example, the composite structure may comprise a hemisphere and a cylinder positioned below the plane of the hemisphere. As another example, the composite structure may be formed by a combination of a quarter of a sphere and a quarter of an ellipsoid. In this example, the radius of the sphere may be 9 μm or less, and the semi-major axis of the ellipsoid may be 18 μm or less. Furthermore, in some embodiments, the microlens may have a triangular or rectangular footprint while having a curved surface.

[0200]

[0229] In some embodiments, the microlens may further include a reflector that can adjust the path of light. For example, the microlens 102 may include an inclined surface formed on one side of the surface of the microlens 101, and the reflector may be formed on the inclined surface. In one example, the reflector may be a flat surface attached to the inclined surface. In another example, the reflector may be a curved or wavy surface.

[0201]

[0230] In some embodiments, the microlens material may comprise an inorganic material or a plastic (organic) material that is transparent to the light emitted from the light emitting structure 100. For example, a suitable material for the microlens 102 may be silicon oxide. In some embodiments, the inorganic material includes silicon oxide, silicon nitride, silicon carbide, titanium oxide, zirconium oxide, aluminum oxide, phosphosilicate glass (PSG), or borophosphosilicate glass (BPSG), or any combination thereof. In some embodiments, the plastic material includes a transparent plastic (resin) including a polymer such as SU-8, PermiNex, benzocyclobutene (BCB), or spin-on glass (SOG), or the bonding adhesive Micro Resist BCL-1200, or any combination thereof.

[0202]

[0231] In some embodiments, microlenses made of inorganic or organic materials are formed by patterning with a mask, a photolithography process, and then etching, while in some embodiments, microlenses made of organic materials are formed by patterning with a mask, a photolithography process, and then a reflow process at high temperature.

[0203]

[0232] In some embodiments, a first method for fabricating a microlens includes depositing a microlens material layer directly on at least the top of the pixelated light source and in direct physical contact with the pixelated light source. In some embodiments, the shape of the microlens material layer matches the shape of the pixelated light source and forms a hemisphere on the pixelated light source. In some embodiments, the top of the pixelated light source is generally flat and the shape of the microlens 102 formed is generally hemispherical. In some embodiments, the microlens material layer is deposited directly on the surface of the pixelated light source, such as the planarized surface of a single pixel tri-color LED device, by a chemical vapor deposition (CVD) technique. In some embodiments, the deposition parameters of the CVD process are: power from about 0 W to about 1000 W, pressure from about 100 mTorr to about 2000 mTorr, temperature from about 23° C. to about 500° C., gas flow from about 0 to about 3000 sccm (standard cubic centimeters per minute), and time from about 1 hour to about 3 hours. In some embodiments, the material of the microlens material layer is a dielectric material such as silicon dioxide.

[0204]

[0233] In some embodiments, the first method for manufacturing a microlens further comprises patterning the microlens material layer to expose electrode regions of the substrate. In some embodiments, the step of patterning the microlens material layer comprises an etching step. In some embodiments, the etching step comprises forming a mask on a surface of the microlens material. The etching step also comprises patterning the mask via a photolithography process, thereby forming an opening in the mask to expose the microlens material layer above the electrode regions of the pixel light sources. The etching step further comprises etching the portions of the microlens material layer exposed by the opening with the mask protection in place. In some embodiments, the exposed microlens material layer is etched by a wet etching method.

[0205]

[0234] In some embodiments, the second method for manufacturing a microlens also includes an optional step of forming a mark layer having marks for alignment with a microlens material layer deposited in a later step. For example, the mark layer is formed to align a unit of light-emitting pixels with the microlens material layer to form a microlens at the center of the pixel light source. In some embodiments, the mark layer is formed to align the pixel light source with layers above it, in particular the microlens material layer, to form a microlens on top of the pixel light source.

[0206]

[0235] The second method for manufacturing a microlens further includes depositing a microlens material layer directly on at least the top of one pixel light source. FIG. 1B-FIG. 1C further illustrate a manufacturing method for forming a display panel integrated with a microlens array using top-down pattern transfer according to some embodiments. In some embodiments, the microlens material layer 1145 covers the top of the pixel light source 1106M as shown in FIG. 1B, and the top surface of the microlens material layer 1145 is flat. In some embodiments, the microlens material layer 1145 is deposited on the top of the pixel light source array 1106 by spin coating. In some embodiments, the material of the microlens material layer 1145 is a photoresist. In some embodiments, the material of the microlens material layer 1145 is a dielectric material such as silicon dioxide.

[0207]

[0236] A second method for fabricating a microlens further includes patterning the microlens material layer top-down, thereby forming at least one hemisphere in the microlens material layer, as shown in Figures 1B-1C. In some embodiments, the patterning is performed without etching through or to the bottom of the microlens material layer 1145. In some embodiments, the hemisphere of the microlens 1120 is placed above at least one pixel light source 1106M.

[0208]

[0237] In some embodiments, the step of top-down patterning the microlens material layer further comprises a first step of depositing a mask layer 1130 on a surface of the microlens material layer 1145 as shown in FIG. 1B.

[0209]

[0238] The step of patterning the microlens material layer top-down also includes a second step of patterning the mask layer 1130 to form a hemispherical pattern in the mask layer 1130. In some examples, the mask layer 1130 is patterned first by a photolithography process and then by a reflow process. In some embodiments, the photosensitive polymer mask layer 1130 is patterned into isolated cells 1140, as shown by the dotted rectangular cells in FIG. 1B, in preparation for the formation of the hemispherical pattern. As an example, the isolated cells 1140 are patterned and formed through a photolithography process. The patterned photosensitive polymer mask layer 1150 with the isolated cells 1140 is then molded into the hemispherical pattern 1160 using a high-temperature reflow process. In one approach, the isolated cells 1140 are formed into the isolated hemispherical pattern 1160 through a high-temperature reflow. In some embodiments, the isolated hemispherical pattern 1160 of one pixel does not directly physically contact the hemispherical pattern of the adjacent pixel. In some embodiments, the hemispherical pattern 1160 of one pixel contacts the hemispherical pattern of the adjacent pixel only at the bottom of the hemispherical pattern 1160. The patterned photosensitive polymer mask layer 1150 is heated to a temperature above the melting point of the polymer material for a period of time. After the polymer material melts and becomes liquefied, the surface tension of the liquefied material will cause the polymer material to assume a shape with a smooth curvature surface. In the case of a cell with a round base of radius R, when the height of the cell is 2R / 3, a hemispherical shape / pattern will be formed after the reflow process. FIG. 1B shows a display panel integrated with an array of hemispherical patterns 1160 after the high temperature reflow process is completed. In some embodiments, the hemispherical pattern of the mask layer can be formed by other manufacturing methods, including the manufacturing method of the microlens described in the first method for manufacturing the microlens. In some other embodiments, the hemispherical pattern of the mask layer may be formed using grayscale mask photolithography exposure.In some other embodiments, the hemispherical pattern of the mask layer may be formed via a molding / imprinting process.

[0210]

[0239] The step of patterning the microlens material layer top-down further includes a third step of etching the microlens material layer 1145 using the hemisphere pattern 1160 as a mask to form hemispheres in the microlens material layer 1145. In some examples, etching the microlens material layer 1145 is by a photolithography process. In some examples, etching the microlens material layer 1145 is by dry etching, such as the plasma etching process 1135 shown in FIG. 1B. In some embodiments, after the microlens material layer 1145 is etched, the microlens material layer 1145 is not etched until it exposes the top surface of the pixel light source 1106M as shown in FIGS. 1B-1C, so that the spacer 1170 is formed on or covering the top of the pixel light source 1106M as shown in FIG. 1C.

[0211]

[0240] The second method for manufacturing a microlens further includes patterning the microlens material layer to expose electrode regions (not shown in FIG. 1C) of the substrate. In some embodiments, the step of patterning the microlens material layer includes an etching step. In some embodiments, the etching step includes forming a mask on the surface of the microlens material. The etching step also includes patterning the mask via a photolithography process, thereby forming an opening in the mask to expose the microlens material layer above the electrode regions of the pixel light sources. The etching step further includes etching the exposed microlens material layer with the mask protection. In some embodiments, the exposed microlens material layer is etched by a wet etching method. In some embodiments, the opening for the electrode is positioned outside the display array area.

[0212]

[0241] As mentioned above, Figures 1B-1C show various manufacturing methods for forming a display panel integrated with a microlens array. It should be understood that these are merely examples and that other manufacturing techniques may be used.

[0213]

[0242] Although the detailed description contains many details, these should not be interpreted as limiting the scope of the invention, but only as illustrating different examples and aspects of the invention. It should be understood that the scope of the invention includes other embodiments not detailed above. For example, microlenses having bases of different shapes, such as square bases or other polygonal bases, can also be used.

[0214]

[0243] In some exemplary embodiments, the light emitting structure 100 may further include a spacer covering the light emitting mesa. For example, as shown in FIG. 1A, the light emitting structure 100 may include a spacer 108 covering the light emitting mesa 101. The spacer 108 may be an optically transparent layer formed to provide an appropriate spacing between the microlens 102 and the light emitting mesa 101. Thus, the light emitted from the light emitting mesa 101 can pass through the spacer 108 before reaching the microlens 102. In some embodiments, the spacer 108 may also fill the area surrounding the light emitting mesa 101 to increase the refractive index of the medium surrounding the light emitting mesa 101. Thus, the spacer 108 may change the optical path of the light emitted from the light emitting mesa 101. In some embodiments, the spacer 108 may be positioned between the light emitting mesa 101 and the microlens 102. In some embodiments, the top surface of the spacer 108 may be flattened. In some embodiments, the spacers 108 may be formed directly on the surface of the planarized insulating layer 109, as shown in FIG. 1A. In some embodiments, the spacers 108 may cover and contact the exposed top surface of a conductive layer, such as conductive layer 115 shown in FIG. 1A. In some embodiments, the spacers 108 may be integral with the microlenses 102. In some embodiments, the spacers 108 may be the same as or part of the planarized insulating layer 109, and may be integral with the planarized insulating layer 109.

[0215]

[0244] In some embodiments, the spacer 108 extends the path of the light emitted from the light emitting mesa 101. In some embodiments, the spacer 108 modifies the path of the light emitted from the single pixel LED device by making the light emitted from the LED device more focused or more divergent according to design needs.

[0216]

[0245] In some embodiments, the dimensions of the bottom surface of microlens 102 may be smaller than the dimensions of the bottom surface of light emitting mesa 101. In some embodiments, the dimensions of the bottom surface of microlens 102 may be the same as or larger than the dimensions of the bottom surface of light emitting mesa 101, as shown in FIG. 1A.

[0217]

[0246] In some embodiments, the spacers 108 can be made from a variety of materials that are transparent at the wavelength emitted from the light emitting mesa 101. Exemplary transparent materials for the spacers 108 include polymers, dielectrics, and semiconductors. In some embodiments, the spacers 108 can comprise one or more dielectric materials. In some embodiments, the dielectric materials include one or more materials such as silicon oxide, silicon nitride, silicon carbide, titanium oxide, zirconium oxide, aluminum oxide, and the like. In some embodiments, the spacers 108 are made from photoresist. In some embodiments, the spacers 108 and the microlenses 102 have the same material. In some embodiments, the spacers 108 and the microlenses 102 have different materials.

[0218]

[0247] In some exemplary embodiments, the height of the spacer may be less than the height of the microlens. For example, as shown in FIG. 1A, the height of the spacer 108 may be less than the height of the microlens 102. In some exemplary embodiments, the height of the spacer 108 may be equal to or greater than the height of the microlens 102. In some embodiments, the height of the spacer formed between one light emitting mesa and one microlens may not be equal to the height of the spacer formed between another light emitting mesa and another microlens in the same display panel. In other embodiments, the height of the spacer formed between one light emitting mesa and one microlens may not be uniform. For example, with respect to the height of the spacer formed between the light emitting mesa 101 and the first microlens 102, the height of the spacer at the central axis A-A' may be less than the height of the spacer at the central axis B-B'.

[0219]

[0248] In some exemplary embodiments, the light emitting structure 100 may further comprise a semiconductor substrate and at least one reflector cup. The light emitting mesa may be formed on the semiconductor substrate, and an edge / surface of the light emitting mesa may be surrounded by at least one reflector cup. The reflector cup is a structure positioned relative to the light emitting mesa 101 to reflect light emitted from the light emitting mesa 101 substantially upward. In some embodiments, the reflector cup forms a rounded sidewall around the light emitting mesa 101 and includes multiple portions, such as reflector cup portions 111 and 112. For example, as shown in FIG. 1A, the light emitting structure 100 may comprise a semiconductor substrate 110 and reflector cup portions 111 and 112. The light emitting mesa 101 may be formed on the semiconductor substrate 110 and may be surrounded by the reflector cup portions 111 and 112. The reflector cup portions 111 and 112 may be formed on the semiconductor substrate 110.

[0220]

[0249] In some exemplary embodiments, the semiconductor substrate 110 may be an integrated circuit (IC) substrate. The light emitting mesas may be driven individually or collectively by an IC. In some embodiments, the semiconductor substrate 110 may be another conductive substrate.

[0221]

[0250] In some embodiments, the reflecting cups 111 and 112 can separate at least some of the light emitted from the light emitting mesa 101 or substantially all of the light emitted from the light emitting mesa 101. For example, as shown in FIG. 1A, when the height of the reflecting cups 111 and 112 is greater than the height of the light emitting mesa 101, the reflecting cups 111 and 112 can prevent some or substantially all of the light emitted from the adjacent light emitting mesas around the light emitting mesa 101 from interfering with the light emitted from the light emitting mesa 101. Thus, the reflecting cups 111 and 112 can suppress optical crosstalk between pixels to improve the overall contrast of an LED display using the light emitting structure 100. In some embodiments, reflections from the reflecting cups can also increase light emission efficiency and brightness by focusing the light emission in a direction. For example, some of the light emitted from the light emitting mesa 101 can reach and be reflected upward by the reflecting cups 111 and 112.

[0222]

[0251] In some embodiments, the height of the reflector cups 111 and 112 may be greater than the height of the light emitting mesa 101. In some embodiments, the height of the reflector cups 111 and 112 may be equal to or less than the height of the light emitting mesa 101. In some embodiments, the height of the reflector cups 111 and 112 may be between 0.5 microns and 50 microns. In some embodiments, the height of the reflector cups 111 and 112 may be between 1 micron and 20 microns. In some embodiments, the height of the reflector cups 111 and 112 may be between 2 microns and 10 microns. In one preferred embodiment, the height of the reflector cups 111 and 112 is about 2.5 microns, while the height of the light emitting mesa 101 is about 1.9 microns. In some embodiments, the height of the reflector cups may vary. For example, the height of the reflector cups 111 may be different from the height of the reflector cups 112.

[0223]

[0252] In some embodiments, the top surface of the spacer 108 may be above the top surfaces of the reflective cup portions 111 and 112. In some embodiments, the top surface of the spacer 108 may be flush with or below the top surfaces of the reflective cup portions 111 and 112. In some embodiments, the top surface of the spacer 108 may be flush with or below the top surface of the reflective cup portion 111 but higher than the top surface of the reflective cup portion 112.

[0224]

[0253] The inner wall of the reflector cup may refer to the surface facing the light emitting mesa. For example, as shown in FIG. 1A, the inner wall 113 of the reflector cup portion 111 and the inner wall 114 of the reflector cup portion 112 may face the light emitting mesa 101. The shape of the inner wall of the reflector cup may vary. In some embodiments, the inner wall of the reflector cup may be straight, such as the inner walls 113 and 114 shown in FIG. 1A. In some embodiments, the steepness of the inner walls of the reflector cup portions 111 and 112 may be designed to reduce the divergence of the light emitted from the light emitting mesa 101. For example, the angle of the inner wall of the reflector cup 111 with respect to a vertical axis perpendicular to the semiconductor substrate 110 may be at least 5 degrees and at most 75 degrees. In another example, the angle of the inner wall of the reflector cup 111 with respect to a vertical axis perpendicular to the semiconductor substrate 110 may be at least 10 degrees and at most 50 degrees.

[0225]

[0254] In some embodiments, the inner wall of the reflector cup can be curved, wavy, multi-lined, or a combination thereof. The detailed structure of the inner wall of the reflector cup will be further described below with the aid of some exemplary embodiments in Figures 2A to 2C.

[0226]

[0255] In some embodiments, the reflector cup may comprise a metal. In some embodiments, the reflector cup may comprise a dielectric material, such as silicon oxide. In some embodiments, the reflector cup may comprise a photosensitive dielectric material. In some embodiments, the photosensitive dielectric material may comprise SU-8, photosensitive polyimide (PSPI), or benzocyclobutene (BCB). In other embodiments, the reflector cup may comprise a photoresist material.

[0227]

[0256] In some exemplary embodiments, light emitting mesa 101 may include a conductive electrode layer 115 as a capping layer on top of light emitting mesa 101. In some embodiments, light emitting mesa 101 includes a light emitting layer 120. Generally, an LED light emitting layer includes a PN junction / diode with a p-type region / layer and an n-type region / layer, and an active layer between the p-type region / layer and the n-type region / layer.

[0228]

[0257] The conductive electrode layer may be electrically connected to the reflector cup including the reflector cup portions 111 and 112 and may further be electrically connected to a light emitting layer such as the light emitting layer 120 of the light emitting mesa 101. In one example, as shown in FIG. 1A, the conductive electrode layer 115 may be electrically connected to the reflector cup portions 111 and 112 at the bottom of each of the reflector cup portions 111 and 112, respectively. In another example not shown in FIG. 1A, the conductive electrode layer 115 may be electrically connected to the reflector cup portions 111 and 112 at the top of each of the reflector cup portions 111 and 112, respectively. The conductive electrode layer may cover the light emitting layer 120 and may further be electrically connected to the light emitting layer 120 at its top. In another example, the conductive electrode layer 115 may be electrically connected to the reflector cup portions 111 and 112 at the inner walls such as 113 and 114 of each of the reflector cup portions 111 and 112, respectively. In some embodiments, the conductive electrode layer 115 may be formed between the light emitting layer 120 and the microlens 102. In some embodiments, the conductive electrode layer 115 may be formed between the spacer 108 and the light emitting layer 120. In some embodiments, the conductive electrode layer 115 may be made of a material such as graphene, indium tin oxide (ITO), aluminum doped zinc oxide (AZO), or fluorine doped tin oxide (FTO), or any combination thereof. In some embodiments, the conductive electrode layer 115 may be transparent, and some of the light emitted from the light emitting layer 120 may pass through the conductive electrode layer 115.

[0229]

[0258] In some exemplary embodiments, the light emitting mesa 101 may further include one or more metal bonding layers (e.g., metal bonding layer 116) formed on the semiconductor substrate 110. The metal bonding layer may be electrically connected to the light emitting mesa 101. For example, as shown in FIG. 1A, the light emitting mesa 101 may include a metal bonding layer 116 at the bottom of the light emitting mesa 101. The metal bonding layer 116 may be formed on the semiconductor substrate 110. The metal bonding layer 116 may further be formed at the bottom of the light emitting mesa 101 and may be electrically connected to the light emitting layer 120. In some embodiments, the metal bonding layer 116 has a sloping side. The sloping side may increase the ease of connecting different connectors to the LED light emitting layer, prevent the connectors from being disconnected due to sharp angles, and increase the overall stability of the device. In some embodiments, the metal bonding layer 116 may also be used as a reflector to reflect light emitted from the LED layer above.

[0230]

[0259] In some embodiments, the metal bonding layer 116 is electrically connected to both the driver circuitry on the semiconductor substrate 110 and the light emitting layer 120 above the metal bonding layer 116, and acts as a P electrode. In some embodiments, the metal bonding layer 116 has a thickness of about 0.1 microns to about 3 microns. In other embodiments, the metal bonding layer 116 has a thickness of about 0.3 μm. The metal bonding layer 116 may include an ohmic contact layer and a metal bonding layer. In some embodiments, the metal bonding layer 116 may include two metal layers. One of the metal layers may be deposited above the metal bonding layer in the light emitting structure 100. A corresponding bonding metal layer may also be deposited on the semiconductor substrate 110.

[0231]

[0260] In some embodiments, the composition of the metal bonding layer 116 includes Au-Au bonding, Au-Sn bonding, Au-In bonding, Ti-Ti bonding, Cu-Cu bonding, or a mixture thereof. For example, if Au-Au bonding is selected, two layers of Au each require a Cr coating as an adhesion layer and a Pt coating as a diffusion barrier layer. And the Pt coating is between the Au layer and the Cr layer. The Cr layer and the Pt layer are positioned on the top and bottom of the two bonded Au layers. In some embodiments, when the thicknesses of the two Au layers are approximately the same, the interdiffusion of Au on both layers bonds the two layers together under high pressure and high temperature. Eutectic bonding, thermocompression bonding, and transient liquid phase (TLP) bonding are examples of techniques that can be used.

[0232]

[0261] In some exemplary embodiments, light emitting structure 100 may further include several isolation structures, such as 118, on substrate 110 between light emitting mesas, such as light emitting mesa 101. Isolation structures 118 are formed on substrate 110. In some embodiments, isolation structures 118 are thinner than bonding layer 116. In some embodiments, isolation structures 118 are made of a dielectric material, such as SiO2. In some embodiments, the dielectric material of isolation structures 118 may be an inorganic material or an organic material.

[0233]

[0262] In some exemplary embodiments, the light emitting structure 100 may further include an insulating layer 117 on a surface of the light emitting layer 120 and on the surfaces of the isolation structure 118 and the bonding layer 116. In some embodiments, a conductive electrode layer 115 is then formed on a surface of the insulating layer 117. In some embodiments, the insulating layer 117 is made of a dielectric material such as SiO2. In some embodiments, the dielectric material of the insulating layer 117 may be an inorganic material or an organic material.

[0234]

[0263] 2A-2C each show a cross-sectional view of some example embodiments of a reflector cup that may correspond to reflector cup portion 111 and / or 112 of FIG. 1A, according to some embodiments. In some embodiments, as shown in FIG. 2A, reflector cup 201 may include an inner wall 201a facing light emitting mesa 101. Inner wall 201a may be curved to reflect some of the light emitted from light emitting mesa 101 upward. In some embodiments, as shown in FIG. 2B, the inner wall of reflector cup 202 may be a multi-line including sub-walls 202A, 202B, and 202C. Sub-walls 202A, 202B, and 202C face toward light emitting mesa 101 such that some of the light emitted from the light emitting mesa may be reflected upward by sub-walls 202A, 202B, and 202C. Each of the sub-walls may also focus the light emitted in a different pattern (especially in the horizontal direction). In some embodiments, the steepness (angle of the inner wall of the reflector cup relative to a vertical axis perpendicular to the semiconductor substrate 110) of each of the sub-inner walls (relative to the bottom of the reflector cup 202) may increase from the bottom to the top of the reflector cup 202. In other embodiments, the steepness of each of the sub-inner walls (relative to the bottom of the reflector cup 202) may decrease from the bottom to the top of the reflector cup 202. In other embodiments, the steepness of each of the sub-inner walls (relative to the bottom of the reflector cup 202) may be randomly selected from the bottom to the top of the reflector cup 202.

[0235]

[0264] Further, in some embodiments, the inner wall of the reflector cup 203 may be stepped, as shown in FIG. 2C. The reflector cup 203 may include one or more step structures (e.g., step structures 203-1, 203-2, and 203-3). Each of the one or more step structures may include sub-walls (e.g., sub-walls 203a, 203b, and 203c, respectively). Similar to the reflector cup 202 mentioned above, the reflector cup 203 may also reflect some of the light emitted from the light emitting mesa upwards and adjust the focus of the emitted light in different patterns (e.g., in the horizontal direction) by, for example, changing the steepness and height of each of the sub-walls.

[0236]

[0265] In some embodiments, the reflector cup can be manufactured by a combination of deposition, photolithography, and etching processes. In some embodiments, the reflector cup can be manufactured by other suitable methods. In one example, the reflector cup can be manufactured by the following steps: 1) PSPI is formed into a reflector cup shape by photolithography process; 2) a metal layer (Pt, Rh, Al, Au, Ag), TiO2 / SiO2 stack (distributed Bragg reflector (DBR)), or any other layer with total reflection property (ODR) is deposited on the entire surface by evaporation; and 3) the reflector layer is shielded by photoresist, while the reflector layer in other areas is etched to expose the light-emitting area to air. In another example, the reflector cup can be fabricated by the following steps: 1) an isolation layer (SiO2, SiN, or SU8) thicker than the light emitting structure is deposited or spun onto the light emitting structure; 2) using photoresist as a mask, the reflector cup shape is etched into the isolation layer; 3) a metal layer with high reflectivity (Pt, Rh, Al, Au, Ag), a TiO2 / SiO2 stack (DBR), or any other layer with total reflection properties (ODR) is deposited over the entire surface by evaporation; and 4) the reflector layer is shielded by photoresist while the reflector layer in other areas is etched to expose the light emitting area.

[0237]

[0266] In some embodiments, the reflector cup may further include one or more reflective coatings. The one or more reflective coatings may be disposed on one or more inner walls of the reflector cup, such as inner walls 113, 114, and 201a, sub-inner walls 202A, 202B, and 202C, and sub-inner walls 203a, 203b, and 203c. The bottom of each of the one or more reflective coatings does not contact the light-emitting mesa, such as the light-emitting mesa 101 described in FIG. 1A (not shown in FIG. 2). The one or more reflective coatings may reflect light emitted from the light-emitting mesa, and thus increase the brightness and light-emitting efficiency of the micro-LED panel or display. For example, light emitted from the light-emitting mesa may reach the one or more reflective coatings and be reflected upward by the one or more reflective coatings.

[0238]

[0267] In some embodiments, the one or more reflective coatings can work with the reflector cup to reflect the direction and / or strength of the light emitted from the light emitting mesa. For example, the sub-inner walls 203a, 203b, and 203c can be inclined at an angle, and thus the one or more reflective coatings disposed on the sub-inner walls 203a, 203b, and 203c can be inclined at the same angle as the sub-inner walls 203a, 203b, and 203c. When the light emitted from the light emitting mesa reaches the one or more reflective coatings, the light emitted from the light emitting mesa will be reflected by the one or more reflective coatings depending on the angle of the sub-inner walls 203a, 203b, and 203c.

[0239]

[0268] The material of the one or more reflective coatings may be highly reflective, having a reflectivity greater than 60%, 70%, or 80%, so that most of the light emitted from the light emitting mesa may be reflected. In some embodiments, the one or more reflective coatings may comprise one or more metallic conductive materials having a high reflectivity. In these embodiments, the one or more metallic conductive materials may comprise one or more of aluminum, gold, or silver. In some other embodiments, the one or more reflective coatings may be multi-layered. More specifically, the one or more reflective coatings may comprise a stack of one or more reflective material layers and one or more dielectric material layers. For example, the one or more reflective coatings may comprise a reflective material layer and a dielectric material layer. In some other embodiments, the one or more reflective coatings may comprise two reflective material layers and a dielectric material layer positioned between the two reflective material layers. In still other embodiments, the one or more reflective coatings may comprise two dielectric material layers and a reflective material layer positioned between the two dielectric material layers. In some embodiments, the multi-layer structure may comprise two or more metal layers, which may comprise one or more of TiAu, CrAl, or TiWAg.

[0240]

[0269] In some embodiments, the one or more reflective coatings may be a multi-layer omni-directional reflector (ODR) comprising a metal layer and a transparent conductive oxide (TCO) layer. For example, the multi-layer structure may include a dielectric material layer, a metal layer, and a TCO layer. In some embodiments, the one or more reflective coatings may comprise two or more dielectric material layers arranged in alternation to form a DBR. For example, the one or more reflective coatings may comprise a dielectric material layer, a metal layer, and a transparent dielectric layer. The transparent dielectric layer may comprise one or more of SiO2, Si3N4, Al2O3, or TiO2. The one or more reflective coatings may further comprise a dielectric material layer, a TCO, and a DBR. In other embodiments, the one or more reflective coatings may comprise one or more metallic conductive materials having high reflectivity. In these embodiments, the one or more metallic conductive materials may comprise one or more of aluminum, gold, or silver.

[0241]

[0270] In some embodiments, the one or more reflective coatings may be electrically conductive, such that the one or more reflective coatings may also serve as electrical contacts to the light emitting structure 100. For example, the light emitting mesa 101 may be electrically connected to the one or more reflective coatings. The one or more reflective coatings may be patterned so as not to block light emitted from the light emitting mesa. The one or more reflective coatings may then also serve as a common electrode for the LED device and / or LEDs on the display panel.

[0242]

[0271] FIG. 3 illustrates a cross-sectional view 300 of an exemplary structure of light emitting mesa 101 on substrate 110 of FIG. 1A, according to some embodiments. As illustrated in FIG. 1A, light emitting mesa 101 may include at least one light emitting layer (e.g., light emitting layer 120) and a bottom bonding layer (e.g., bottom bonding layer 116) at the bottom of light emitting layer 120 and bonded to semiconductor substrate 110. In some embodiments, light emitting mesa 101 includes a top electrode layer (e.g., top electrode layer 115) covering light emitting layer 120 and electrically connected to at least one reflector cup (e.g., reflector cup portion 111 and / or 112) as illustrated in FIG. 1A. In some embodiments, at least one reflector cup (e.g., reflector cup portion 111 or 112) may be electrically connected to semiconductor substrate 110. For example, as shown in FIG. 3, light emitting mesa 101 may include light emitting layer 120, bottom bonding layer 116 at the bottom of light emitting layer 120 and bonded to semiconductor substrate 110, and top electrode layer 115 covering light emitting layer 120 and electrically connected to at least one reflector cup 111 and / or 112 (described in FIGS. 1-2 and not shown in FIG. 3).

[0243]

[0272] In some embodiments, the light emitting layer 120 may emit green, blue, or red light. Light emitted from the light emitting layer 120 may pass through and / or around the top electrode layer 115 to reach the microlens 102 (described in FIG. 1A and not shown in FIG. 3). Light emitted from the light emitting layer 120 may also reach at least one reflector cup 111 and / or 112 and be reflected upward to the microlens 102 or / and another lens (not shown in FIG. 3). In some embodiments, the light emitting mesa 101 may comprise two or more light emitting layers that emit different colors. The two or more light emitting layers may be stacked vertically or arranged parallel to the same level. For example, a light emitting layer that emits green light may be disposed above a light emitting layer that emits red light, or a light emitting layer that emits green light may be arranged horizontally parallel to a light emitting layer that emits red light. In some embodiments, the light emitting structure 100 may include two or more light emitting mesas. In some embodiments, each of the light emitting mesas can include at least one light emitting layer that emits a separate color. When there are two light emitting mesas in light emitting structure 100, two colors and combinations of the two colors can be emitted from light emitting structure 100. When there are three light emitting mesas in light emitting structure 100, three colors and combinations of the three colors can be emitted from light emitting structure 100.

[0244]

[0273] In some embodiments, a light emitting layer such as 301 may include many epitaxial sublayers with different compositions. Examples of LED epitaxial layers may include III-V nitride epitaxial structures, III-V arsenide epitaxial structures, III-V phosphide epitaxial structures, and III-V antimonide epitaxial structures. Examples of microLEDs may include GaN-based UV / blue / green microLEDs, AlInGaP-based red / orange microLEDs, and GaAs or InP-based infrared (IR) microLEDs.

[0245]

[0274] In some embodiments, the bottom bonding layer 116 may be a conductive transparent layer, such as a metal layer or an ITO layer, formed on the bottom of the light emitting layer 120 to improve conductivity and transparency. In some embodiments, when there is more than one light emitting layer in the light emitting mesa, the light emitting layers are bonded to each other with respective bonding layers therebetween. Light emitted from the light emitting layers may pass through the bonding layer above the current light emitting layer and be reflected by the bonding layer below the current light emitting layer. In some embodiments, the bottom bonding layer 116 is bonded to the semiconductor substrate 110.

[0246]

[0275] In some embodiments, the top electrode layer 115 may be a conductive transparent layer, such as a metal layer or an ITO layer, formed on the light-emitting layer 120 to improve conductivity and transparency. In addition, in some embodiments, there are additional conductive layers at the bottom and top of each of the light-emitting layers, such as a conductive layer 302 at the bottom of the light-emitting layer 120 and a conductive layer 303 at the top of the light-emitting layer 120. Each of the conductive layers is electrically connected to either the top electrode layer or the IC circuitry in the substrate. The top electrode layer 115 may be electrically connected to another circuit or component. In some embodiments, there may be a contact pad 304 positioned between the top electrode layer 115 and the conductive layer 303, as shown in FIG. 3. The contact pad 304 may be made of a material such as graphene, ITO, TCO, AZO, or FTO, or any combination thereof. In some embodiments, the conductive layer 303 may be electrically connected to at least one reflective cup through the conductive electrode layer 115 (as described in FIG. 1A).

[0247]

[0276] In some embodiments, a reflective layer, such as reflective layer 301, may be positioned above bottom bonding layer 116 and at the bottom of each light emitting layer, such as light emitting layer 120. In some embodiments, a reflective layer, such as reflective layer 301, may be positioned below a conductive layer, such as conductive layer 302, at the bottom of each light emitting layer, such as light emitting layer 120. The reflective layer may improve light transmission efficiency. For example, light emitted from light emitting layer 120 may be reflected by reflective layer 301. In some embodiments, the material of the reflective layer may have a high reflectivity, especially for light emitted by one or more light emitting layers above the current reflective layer. For example, the reflectivity of the reflective layer is greater than 60%. In another example, the reflectivity of the reflective layer is greater than 70%. In yet another example, the reflectivity of the reflective layer is greater than 80%. In some embodiments, the material of the reflective layer may be a metal selected from one or more of Rh, Al, Ag, and Au. In some embodiments, the reflective layer may include at least two sublayers having different refractive indices. Each of the sub-layers also has a high reflectivity, such as more than 60%, 70%, or 80%. In some embodiments, the reflective layer may include a DBR structure. For example, the reflective layer may be formed from multiple layers of alternating or different materials with varying refractive index. In some cases, each layer boundary of the DBR structure causes partial reflection of the light wave. The reflective layer may be used to reflect several selected wavelengths. In some embodiments, the reflective layer may be made of multiple layers, for example at least two layers of SiO2 and Ti3O5, respectively. By varying the thickness and number of the SiO2 and Ti3O5 layers, respectively, selective reflection or transmission of light of different wavelengths can be formed.

[0248]

[0277] In some embodiments, at least one reflective cup may be electrically connected to the semiconductor substrate, for example through a top electrode layer.

[0249]

[0278] FIG. 4 illustrates a cross-sectional view of an exemplary light emitting structure 400 having an array of microlenses and light emitting mesas, according to some embodiments. In some exemplary embodiments, the light emitting structure comprises a first light emitting mesa. For example, as shown in FIG. 4, the light emitting structure 400 comprises a first light emitting mesa 401. In some embodiments, the first light emitting mesa 401 has the same or similar dimensions, shape, structure, composition, positioning, and fabrication (including other associated structures such as reflector cups and optional spacers) as the light emitting mesa 101 and associated structures described in FIG. 1A. The first light emitting mesa 401 may include an LED or micro LED, and light may be emitted from the first light emitting mesa 401. The first light emitting mesa 401 may have a top surface and a bottom surface. In some embodiments, the diameter or width of the top surface of the first light emitting mesa 401 and the diameter or width of the bottom surface of the first light emitting mesa 401 may be in a similar range as described above with reference to FIG. 1A.

[0250]

[0279] In some exemplary embodiments, the light emitting structure 400 further includes a first microlens. As shown in FIG. 4, the light emitting structure 400 comprises a first microlens 402 formed on a first light emitting mesa 401. In some embodiments, the first microlens 402 may have the same or similar dimensions, shape, structure, composition, positioning, and fabrication as the microlens 102 described in FIG. 1A. In some embodiments, the first microlens 402 may be coaxially aligned with the first light emitting mesa 401 along a C-C' direction (not shown in FIG. 4) and positioned above the first light emitting mesa 401. The axis C-C' illustrated in FIG. 4 refers to the central axis of the first light emitting mesa 401, and the axis D-D' illustrated in FIG. 4 refers to the central axis of the first microlens 402. In those embodiments (not shown in FIG. 4 ) with coaxially aligned central axes, all of the light emitted from the first light-emitting mesa 401 can reach and pass through the first microlens 402 directly. Thus, divergence can be reduced and the usable viewing angle can be reduced to the extent that displays and panels using single pixel LED devices can be seen by a user's field of view perpendicular to the surface of the display and panel. This in turn can reduce power waste, increase brightness, and / or better protect user privacy in public areas. In another example, a portion of the light emitted from the first light-emitting mesa 401 can reach and pass through the first microlens 402 directly, and another portion of the light emitted from the light-emitting center can pass around or bypass the microlens 402. Thus, the brightness from the first light-emitting mesa 401 can be adjusted.

[0251]

[0280] In yet another example, the central axis of the first microlens 402 is stacked off-axis on the central axis of the first light emitting mesa 401, as shown in FIG. 4. In other words, the central axis D-D' of the first microlens 402 is not coaxially aligned, overlapping, or coinciding with the central axis C-C' of the first light emitting mesa 401, as shown in FIG. 4. In some embodiments, the offset distance between the central axis D-D' of the first microlens 402 and the central axis C-C' of the first light emitting mesa 401 is 4.5 μm or less. In this example, the vertical light array 440 from the center of the light emitting mesa 401 is redirected by the microlens as light array 442 at an angle to the vertical light array 440. The light array 444 from the edge of the light emitting mesa 401 toward the center of the microlens 402 is redirected by the microlens as light array 446 at a larger angle than the light array 444 with respect to the axis perpendicular to the substrate 410. In this embodiment, divergence may be reduced and the usable viewing angle may be reduced to the extent that displays and panels using single pixel LED devices may only be seen by a user's field of view at an angle to the surface of the display and panel, which may also reduce power waste, increase brightness, and / or adequately protect user privacy in public areas.

[0252]

[0281] In FIG. 4, the light emitting structure includes a plurality of light emitting mesas distributed in an array. For example, FIG. 5 is a top view of a light emitting structure array system 500 of off-axis light emitting mesas and microlenses according to some embodiments. The shape of the array can be a matrix, a circle, a rectangle, a square, a hexagon, or another shape. The array includes one microlens above each light emitting mesa. The off-axis light emitting mesa and microlens array includes light emitting mesa 501 and microlens 502 above light emitting mesa 501. In some embodiments, the edge of the first light emitting mesa is near the edge of the first microlens, for example, the offset distance between the edge of the bottom surface of the first light emitting mesa and the edge of the bottom surface of the first microlens is within 30% of the diameter of the bottom surface of the first microlens. For example, as shown in FIG. 4, line E-E' refers to a perpendicular line passing through the extreme end point of the edge of the bottom surface of first light emitting mesa 401 (the extreme end point 504 of first light emitting mesa 501 in the cross-sectional view along G-G' in FIG. 5). Similarly, line F-F' refers to a perpendicular line passing through the extreme end point of the edge of the bottom surface of first microlens 402 (the extreme end point 506 of first microlens 502 in the cross-sectional view along G-G' in FIG. 5). The offset distance between the edge of the bottom surface of first light emitting mesa 401 and the edge of the bottom surface of first microlens 402 refers to the offset distance between line E-E' and line F-F'. In some embodiments, as shown in FIG. 5, the offset distance between the edge of the bottom surface of first light emitting mesa 401 and the edge of the bottom surface of first microlens 402 is zero, e.g., 504 and 506 are the same point. 4, the offset distance between the edge 504 of the bottom surface of the first emitting mesa 401 / 501 and the edge 506 of the bottom surface of the first microlens 402 / 502 can be very small, for example, the offset distance between line E-E' and line F-F' can be within 30% of the diameter of the bottom surface of the first microlens 402. In some embodiments, the offset distance between line E-E' and line F-F' can be more than 30% but less than 50% of the diameter of the bottom surface of the first microlens 402.In some embodiments, the offset distance between line EE′ and line FF′ may be greater than 50% of the diameter of the base of the first microlens 402 .

[0253]

[0282] In some embodiments, the bottom surface of the first microlens 402 covers the position of the central axis CC' of the first light emitting mesa 401. In other words, the central axis CC' of the first light emitting mesa 401 intersects with the bottom surface of the first microlens 402, as shown in FIG.

[0254]

[0283] In some embodiments, the structure of the first microlens 402 may include one element having one flat surface and one convex surface. For example, as shown in FIG. 4, the structure of the first microlens 402 may be a hemisphere. Other structures of the first microlens 402 may be other structures / shapes similar to those described above with reference to FIG. 1A. In some embodiments, the first microlens 402 may further include a reflector that can adjust the path of light. The reflector may be similar to the reflector described above.

[0255]

[0284] In some embodiments, the material of the first microlens 402 comprises an inorganic material or an organic material. For example, the material of the first microlens 402 may comprise silicon oxide. Other materials and manufacturing methods of the first microlens 402 may be the same as or similar to the materials and manufacturing of the microlens 102 described above with reference to FIG. 1A.

[0256]

[0285] In some embodiments, the light emitting structure 400 further comprises a second light emitting mesa and a second microlens formed above the second light emitting mesa. For example, as shown in FIG. 4, the light emitting mesa 400 comprises a second light emitting mesa 403 and a second microlens 404 formed above the second light emitting mesa 403. In some embodiments, the second light emitting mesa 403 may be similar to the first light emitting mesa 401 described above, and the second microlens 404 may be similar to the first microlens 402 described above. In some embodiments, the second light emitting mesa 403 may be adjacent to the first light emitting mesa 401. For example, as shown in FIG. 4, the second light emitting mesa 403 is adjacent to the first light emitting mesa 401 at the same horizontal level. In another example, the second light emitting mesa 403 may be adjacent to the first light emitting mesa 401 at a higher or lower horizontal level.

[0257]

[0286] In some embodiments, the structure of the second microlens 404 may include one element having one flat surface and one convex surface. For example, as shown in FIG. 4, the structure of the second microlens 404 may be a hemisphere. Other structures of the second microlens 404 may be other structures / shapes similar to those described above with reference to FIG. 1A. In some embodiments, the second microlens 404 may further include a reflector that can adjust the path of the light. The reflector may be similar to the reflector described above.

[0258]

[0287] In some embodiments, the offset distance between the central axis of the first microlens 402 and the central axis of the first emitting mesa 401 is the same as the offset distance between the central axis of the second microlens 404 and the central axis of the second emitting mesa 403. In some embodiments, the offset distance between the central axis of the first microlens 402 and the central axis of the first emitting mesa 401 is not the same as the offset distance between the central axis of the second microlens 404 and the central axis of the second emitting mesa 403. As shown in FIG. 5, in some embodiments, the relative position of each microlens, such as 502, and each corresponding emitting mesa, such as 501, is the same within the light emitting structure array system 500. For example, the offset distance of the central axis of a microlens relative to the central axis of the corresponding emitting mesa (such as the distance between lines D-D' and C-C' shown in FIG. 4) is the same across all light emitting mesa and microlens pairs on the light emitting structure array system 500. In this manner, all light emitted from the light emitting mesa and microlens pairs on the light emitting structure array system 500 is directed towards a user or device at the same angle or a similar range of angles.

[0259]

[0288] FIG. 6 shows a cross-sectional view of a light emitting structure array system 600 having a sensor 602 located at a central position above the light emitting structure array system 600, according to some embodiments. The light emitting structure array system 600 includes one or more light emitting mesas, such as 604, 608, 612, 616, and 620, and one or more microlenses, such as 606, 610, 614, 618, and 622, each of which may be similar to those described in any one of FIGs. 1 to 5. In some embodiments, the emitted light passing through one or more microlenses from one or more light emitting mesas is collectively converted into the sensor 602. In some embodiments, the sensor 602 (or the central axis of the sensor 602) is located at a location on the central axis H-H' of the light emitting structure array system 600.

[0260]

[0289] In some embodiments, the offset distance of a microlens relative to a corresponding light emitting mesa varies within the light emitting structure array system 600. In some embodiments, the offset distance of a microlens relative to a corresponding light emitting mesa is determined by the location of the sensor and the location of the microlens relative to the sensor. In some embodiments, as shown in FIG. 6, the offset distance of a central axis of a microlens relative to a central axis of a corresponding light emitting mesa (such as the distance between lines D-D' and C-C' shown in FIG. 4) increases from the center of the light emitting structure array system where the sensor 602 is located to the edge of the light emitting structure array system 600. In other words, when the sensor 602 is closer in distance from both a first microlens and a first light emitting mesa to the sensor 602 than the same sensor 602 is from both a second microlens and a second light emitting mesa to the same sensor 602, the offset distance of the central axis of a first microlens, such as 610, relative to the central axis of a first light emitting mesa, such as 608, is smaller than the offset distance of the central axis of a second microlens, such as 614, relative to the central axis of a second light emitting mesa, such as 612. In some embodiments, the offset distance of a central axis of a microlens, such as 606, relative to a central axis of a corresponding emitting mesa, such as 604, is zero when both the central axis of the microlens and the central axis of the emitting mesa are coaxially aligned with the central axis of the sensor 602. In some embodiments, the offset distance range of a microlens and emitting mesa pair on the emitting structure array system 600 is 4.5 μm or less.

[0261]

[0290] In some embodiments, the offset distance of the central axis of each microlens relative to the central axis of each corresponding light-emitting mesa is symmetrical about the central axis of the light-emitting structure array system 600 in which the sensor 602 is located. For example, the offset distance of the central axis of the microlens 610 relative to the central axis of the corresponding light-emitting mesa 608 is the same as the offset distance of the central axis of the microlens 618 relative to the central axis of the corresponding light-emitting mesa 616. The offset distance of the central axis of the microlens 614 relative to the central axis of the corresponding light-emitting mesa 612 is the same as the offset distance of the central axis of the microlens 622 relative to the central axis of the corresponding light-emitting mesa 620. In some embodiments, to the right of the central axis of the sensor, the microlenses are displaced left relative to the corresponding light-emitting mesa below the microlenses (see, e.g., microlenses 610 and 614 in FIG. 6). In some embodiments, to the left of the central axis of the sensor, the microlenses are displaced right relative to the corresponding light-emitting mesa below the microlenses (see, e.g., microlenses 618 and 622 in FIG. 6).

[0262]

[0291] The light emitting structure array system 600 shown in FIG. 6 can direct light emitted from each of the light emitting mesas to a sensor 602 at a central location. For example, light emitted from light emitting mesa 604 at a central axis at the center of the light emitting structure array system 600 does not change direction after passing through microlens 606. Light emitted from light emitting mesa 608 at a central axis changes direction after passing through microlens 610 toward sensor 602. Light emitted from light emitting mesa 612 at a central axis changes direction after passing through microlens 614 toward sensor 602. The angle of light emitted from microlenses located toward the edge of the light emitting structure array system 600 with respect to a normal axis perpendicular to the surface of the substrate is larger than the angle of light emitted from microlenses located toward the center of the light emitting structure array system 600 with respect to a normal axis perpendicular to the surface of the substrate. For example, the angle of light emitted from a microlens 614 located toward the edge of the light emitting structure array system 600 relative to a vertical axis normal to the surface of the substrate is greater than the angle of light emitted from a microlens 610 located toward the center of the light emitting structure array system 600 relative to a vertical axis normal to the surface of the substrate.

[0263]

[0292] FIG. 7 shows a cross-sectional view of a light emitting structure array system 700 having a sensor 702 located at a side or non-center position above the light emitting structure array system 700, according to some embodiments. The light emitting structure array system 700 includes one or more light emitting mesas, such as 704, 708, 712, 716, and 720, and one or more microlenses, such as 706, 710, 714, 718, and 722, each of which may be similar to those described in any one of FIG. 1 to FIG. 5. In some embodiments, the emitted light passing through one or more microlenses from one or more light emitting mesas is collectively converted into the sensor 702. In some embodiments, the sensor 702 (or the central axis of the sensor 702) is located at a location that is not on the central axis of the light emitting structure array system 700. For example, the central axis I-I′ of the sensor 702 passes through a side of the light emitting structure array system 700.

[0264]

[0293] In some embodiments, the offset distance of a microlens relative to a corresponding light emitting mesa varies within the light emitting structure array system 700. In some embodiments, the offset distance of a microlens relative to a corresponding light emitting mesa is determined by the position of the sensor and the position of the microlens relative to the sensor. In some embodiments, as shown in FIG. 7, the offset distance of a central axis of a microlens relative to a central axis of a corresponding light emitting mesa (such as the distance between lines D-D' and C-C' shown in FIG. 4) increases for each microlens and mesa pair as the position progresses from the central axis I-I' of the sensor 702 to the edge of the light emitting structure array system 700, i.e., in the horizontal direction to the left from the central axis I-I' in FIG. 7. In other words, when both a first microlens and a first emitting mesa are closer in distance to the sensor 702 than are both a second microlens and a second emitting mesa to the same sensor 702, the offset distance of the central axis of the first microlens, such as 706, relative to the central axis of the first emitting mesa, such as 704, is less than the offset distance of the central axis of the second microlens, such as 710, relative to the central axis of the second emitting mesa, such as 708. In some embodiments not shown in FIG. 7, when both the central axis of the microlens and the central axis of the emitting mesa are aligned coaxially with the central axis of the sensor 702, the offset distance of the central axis of the microlens relative to the central axis of the corresponding emitting mesa is zero. In some embodiments, the offset distance range of the microlens and emitting mesa pairs on the light emitting structure array system 700 is 4.5 μm or less.

[0265]

[0294] 7, the offset distance of the central axis of each microlens relative to the central axis of each corresponding emitting mesa is symmetric about the central axis of the sensor 702. In some embodiments, to the right of the central axis of the sensor, the microlenses are displaced to the left relative to the corresponding emitting mesa below the microlenses. In some embodiments, to the left of the central axis of the sensor, the microlenses are displaced to the right relative to the corresponding emitting mesa below the microlenses.

[0266]

[0295] The light emitting structure array system 700 shown in FIG. 7 can direct light emitted from each of the light emitting mesas to a sensor 702 at a non-center location. For example, light emitted from the light emitting mesa 708 on the central axis changes direction after passing through the microlens 710 toward the sensor 702. Light emitted from the light emitting mesa 712 on the central axis changes direction after passing through the microlens 714 toward the sensor 702. The angle of the light emitted from the microlens located further from the central axis of the sensor 702 with respect to a normal axis perpendicular to the surface of the substrate is greater than the angle of the light emitted from the microlens located closer to the central axis of the sensor 702 with respect to a normal axis perpendicular to the surface of the substrate. For example, the angle of the light emitted from the microlens 714 located further from the central axis of the sensor 702 with respect to a normal axis perpendicular to the surface of the substrate is greater than the angle of the light emitted from the microlens 710 located closer to the central axis of the sensor 702 with respect to a normal axis perpendicular to the surface of the substrate.

[0267]

[0296] When the offset distances of the microlenses to their corresponding emitting mesas are the same, the light emitted from the microlens array is parallel and forms an illumination plane. When the offset distances of the microlenses to their corresponding emitting mesas are different, the light emitted from the microlens array may be focused to a point rather than a plane.

[0268]

[0297] FIG. 8 illustrates a cross-sectional view of an exemplary light emitting structure 800 having a small microlens within a large microlens, where the lateral dimension of the small microlens is smaller than that of the large microlens, according to some embodiments. The array structure, dimensions, shape, fabrication, and materials of the large microlens and light emitting mesa pair (including associated reflector cups and optional spacers) are the same as or similar to the light emitting structures described in any one of FIGS. 1-7. The materials, shapes, and fabrication of the small microlens are similar to the large microlenses of FIGS. 1-7 described above. In some embodiments, the light emitting structure 800 includes a small microlens, such as 806 or 808, and a large microlens, such as 802 or 804, in the same microlens group and light emitting mesa pair. The small microlens, such as 806 or 808, is formed on the light emitting mesa, such as 401 or 403. The large microlens is formed on the light emitting mesa, such as 401 or 403, and covers the small microlens, such as 806 or 808. The diameter of the larger microlenses, such as 802, is larger than the diameter of the smaller microlenses, such as 806, to improve the light extraction efficiency.

[0269]

[0298] 8, the central axis J-J' of small microlens 806 is displaced from the central axis K-K' of light emitting mesa 401 to redirect the light, while the central axis of large microlens 802 is coaxially aligned (or is the same) as the central axis K-K' of light emitting mesa 401. In some embodiments, the offset distance between the central axis of small microlens 806 and the central axis of light emitting mesa 401 is 9 μm or less, preferably 1.5 μm or less.

[0270]

[0299] In some embodiments, as shown in FIG. 8, the edge of the small microlens 806 may not cover the central axis of the light emitting mesa 401, while the edge of the large microlens 802 covers the central axis of the light emitting mesa 401, as also described above in FIG. 4. In other words, the central axis K-K' of the light emitting mesa 401 may not intersect with the bottom surface of the small microlens 806, while the central axis K-K' of the light emitting mesa 401 intersects with the bottom surface of the large microlens 802. In some other embodiments, not shown in FIG. 8, the edges of both the small microlens 806 and the large microlens 802 cover the central axis of the light emitting mesa 401. In other words, the central axis K-K' of the light emitting mesa 401 intersects with the bottom surface of the small microlens 806, and the central axis K-K' of the light emitting mesa 401 intersects with the bottom surface of the large microlens 802.

[0271]

[0300] In some embodiments, light ray 840 emitted from light emitting mesa 401 is redirected to exit large microlens 802 as 842. Light ray 844 emitting from light emitting mesa 401 is redirected as 846 while traveling through small microlens 806 and exits large microlens 802 as 848. By adding small microlenses within the large microlens, the light within a particular portion of the LED pixel structure can be further directed and tuned to a particular angle. For example, in FIG. 8, the light ray from the large microlens is more focused in a particular direction after it exits.

[0272]

[0301] 9A-9D show some exemplary simulation results of light output from the large microlens of the light emitting structure 800 shown in FIG. 8 according to some embodiments. FIG. 9A-9D show the change in output light intensity from the light emitting structure 800 when the offset distance between the central axis K-K' of the light emitting mesa such as 401 and the central axis J-J' of the small microlens such as 806 is changed while the central axis of the large microlens such as 802 is coaxially aligned (or is the same) as the central axis K-K' of the light emitting mesa such as 401. The output light intensity was measured in a vertical plane passing through the vertical central axis of the light emitting mesa such as the central axis K-K' of the light emitting mesa 401. X and Y indicate the offset distance in micrometers on a horizontal plane parallel to the substrate 410 in two orthogonal directions, the X direction and the Y direction. In this example, the maximum horizontal dimension (e.g., the bottom surface) of the light emitting mesa such as 401 is 8 μm. The maximum horizontal dimension (e.g., bottom) of small microlenses such as 806 is 18 μm. The maximum horizontal dimension (e.g., bottom) of large microlenses such as 802 is 36 μm. Figures 9A-9D also show the change in output light intensity from light emitting structure 800 as the angle of the output light ray with respect to an axis normal to substrate 410 (output angle θ expressed in degrees) is changed.

[0273]

[0302] For example, in FIG. 9A, when the offset distance between the central axis of the light-emitting mesa and the central axis of the small microlens is 1.5 μm in the X direction and 1.5 μm in the Y direction, the maximum normalized output light intensity at an output angle of 0 degrees is about 0.3 arbitrary units (au). There are two other secondary peak normalized output light intensity at output angles of approximately +30 degrees and -30 degrees. The secondary peak intensity is about 0.15 AU. When the absolute value of the output angle is greater than 30 degrees, the light intensity gradually decreases to zero as the absolute value of the output angle increases. When the absolute value of the output angle is less than 30 degrees, the light intensity gradually decreases as the absolute value of the output angle decreases, with a minimum intensity value of about 0.05 AU near the output angle of 0 degrees.

[0274]

[0303] For example, in FIG. 9B, when the offset distance between the central axis of the light-emitting mesa and the central axis of the small microlens is 3 μm in the X direction and 3 μm in the Y direction, the maximum normalized output light intensity at an output angle of 0 degrees is about 0.3 arbitrary units. There are two other secondary peak normalized output light intensity at output angles of approximately +35 degrees and -35 degrees. The secondary peak intensity is about 0.16 arbitrary units. When the absolute value of the output angle is greater than 35 degrees, the light intensity gradually decreases to zero as the absolute value of the output angle increases. When the absolute value of the output angle is less than 35 degrees, the light intensity gradually decreases as the absolute value of the output angle decreases, with a minimum intensity value of about 0.05 arbitrary units near an output angle of 0 degrees.

[0275]

[0304] For example, in FIG. 9C, when the offset distance between the central axis of the light-emitting mesa and the central axis of the small microlens is 4.5 μm in the X direction and 4.5 μm in the Y direction, the maximum normalized output light intensity at an output angle of 0 degrees is about 0.2 arbitrary units. There are two other secondary peak normalized output light intensity at output angles of approximately +30 degrees and -30 degrees. The secondary peak intensity is about 0.16 arbitrary units. When the absolute value of the output angle is greater than 30 degrees, the light intensity gradually decreases to zero as the absolute value of the output angle increases. When the absolute value of the output angle is less than 30 degrees, the light intensity gradually decreases as the absolute value of the output angle decreases, with a minimum intensity value of about 0.01 arbitrary units near an output angle of 0 degrees.

[0276]

[0305] For example, in FIG. 9D, when the offset distance between the central axis of the light-emitting mesa and the central axis of the small microlens is 9 μm in the X direction and 9 μm in the Y direction, the maximum normalized output light intensity at an output angle of 0 degrees is about 0.275 arbitrary units. There are two other secondary peak normalized output light intensity at output angles of approximately +40 degrees and -40 degrees. The secondary peak intensity is about 0.16 arbitrary units. When the absolute value of the output angle is greater than 40 degrees, the light intensity gradually decreases to zero as the absolute value of the output angle increases. When the absolute value of the output angle is less than 40 degrees, the light intensity gradually decreases as the absolute value of the output angle decreases, with a minimum intensity value of about 0.075 arbitrary units near an output angle of 0 degrees.

[0277]

[0306] FIG. 10 shows a cross-sectional view of an exemplary light emitting structure 1000 having a small microlens within a large microlens, where the lateral dimension of the small microlens is smaller than that of the large microlens, according to some embodiments. The array structure, dimensions, shape, fabrication, and materials of the large microlens and light emitting mesa pair (including associated reflector cups and optional spacers) are the same as or similar to the light emitting structures described in any one of FIGS. 1-7. The materials, shapes, and fabrication of the small microlens are similar to the large microlenses of FIGS. 1-7 described above. In some embodiments, the light emitting structure 1000 includes a small microlens, such as 1006 or 1008, and a large microlens, such as 1002 or 1004, in the same microlens group and light emitting mesa pair. The small microlens, such as 1006 or 1008, is formed on the light emitting mesa, such as 401 or 403. A large microlens is formed on the light emitting mesa, such as 401 or 403, and covers a small microlens, such as 1006 or 1008. The diameter of the large microlens, such as 1002, is larger than the diameter of the small microlens, such as 1006, to improve the light extraction efficiency.

[0278]

[0307] 10, the central axis M-M' of the large microlens 1002 is displaced from the central axis L-L' of the light emitting mesa 401 to redirect the light, while the central axis of the small microlens 1006 is coaxially aligned (or is the same) as the central axis L-L' of the light emitting mesa 401. Preferably, the offset distance between the central axis of the large microlens 1002 and the central axis of the light emitting mesa 401 is 12 μm or less, and in some embodiments is 1.5 μm or less.

[0279]

[0308] 10, an edge of the small microlens 1006 covers the central axis of the light emitting mesa 401, and an edge of the large microlens 1002 covers the central axis of the light emitting mesa 401, as also described above in FIG. 4. In other words, the central axis L-L' of the light emitting mesa 401 intersects the bottom surface of the small microlens 1006, and the central axis L-L' of the light emitting mesa 401 intersects the bottom surface of the large microlens 1002.

[0280]

[0309] In some embodiments, light ray 1038 emanating from light emitting mesa 401 is redirected as 1040 as it travels through large microlens 1002 and exits large microlens 1002 as 1042. Light ray 1044 emitted from light emitting mesa 401 travels through small microlens 1006 and is then redirected and exits large microlens 1002 as 1046. By adding small microlenses within the large microlens, the light within a particular portion of the LED pixel structure can be further directed and tuned to a particular angle. For example, in FIG. 10, the light ray from the large microlens is more focused in a particular direction after it exits.

[0281]

[0310] 11A-11E show some exemplary simulation results of light output from the large microlens of the light emitting structure 1000 shown in FIG. 10 according to some embodiments. FIG. 11A-11E show the change in output light intensity from the light emitting structure 1100 when the offset distance between the central axis L-L' of the light emitting mesa such as 401 and the central axis J-J' of the large microlens such as 1002 is changed while the central axis of the small microlens such as 1006 is coaxially aligned (or is the same) as the central axis L-L' of the light emitting mesa such as 401. The output light intensity was measured in a vertical plane passing through the vertical central axis of the light emitting mesa such as the central axis L-L' of the light emitting mesa 401. X and Y indicate the offset distance in micrometers on a horizontal plane parallel to the substrate 410 in two orthogonal directions, the X direction and the Y direction. In this example, the maximum horizontal dimension (e.g., the bottom surface) of the light emitting mesa such as 401 is 8 μm. The maximum horizontal dimension (e.g., bottom) of a small microlens such as 1006 is 18 μm. The maximum horizontal dimension (e.g., bottom) of a large microlens such as 1002 is 36 μm. Figures 11A-11E also show the change in output light intensity from light emitting structure 1000 as the angle of the output light ray with respect to an axis normal to substrate 410 (output angle θ expressed in degrees) is changed.

[0282]

[0311] For example, in FIG. 11A, when the offset distance between the central axis of the light-emitting mesa and the central axis of the large microlens is 3 μm in the X direction and 3 μm in the Y direction, the maximum normalized output light intensity at an output angle of 0 degrees is about 0.28 arbitrary units. There is one secondary peak normalized output light intensity at an output angle of about +40 degrees, and the secondary peak intensity is about 0.175 arbitrary units. When the output angle value is greater than 40 degrees, the light intensity gradually decreases to zero as the output angle value increases. When the output angle value is less than 40 degrees and greater than 0 degrees, the light intensity gradually decreases as the output angle value decreases, with a minimum intensity value of about 0.05 arbitrary units near the output angle of 0 degrees. When the output angle value is less than 0 degrees, the light intensity is stable up to about −30 degrees, and then gradually decreases to zero as the output angle value decreases.

[0283]

[0312] For example, in FIG. 11B, when the offset distance between the central axis of the light emitting mesa and the central axis of the large microlens is 4.5 μm in the X direction and 4.5 μm in the Y direction, the maximum normalized output light intensity at an output angle of 0 degrees is about 0.2 arbitrary units. There is one peak normalized output light intensity at an output angle of approximately +45 degrees, and the peak intensity is about 0.2 arbitrary units. When the output angle value is greater than 45 degrees, the light intensity gradually decreases to zero as the output angle value increases. When the output angle value is less than 45 degrees and greater than 0 degrees, the light intensity gradually decreases as the output angle value decreases, with a minimum intensity value of about 0.025 arbitrary units near the output angle of 0 degrees. When the output angle value is less than 0 degrees, the light intensity gradually decreases to zero as the output angle value decreases.

[0284]

[0313] For example, in FIG. 11C, when the offset distance between the central axis of the light-emitting mesa and the central axis of the large microlens is 6 μm in the X direction and 6 μm in the Y direction, the maximum normalized output light intensity at an output angle of 0 degrees is about 0.21 arbitrary units. There is a secondary peak normalized output light intensity at an output angle of approximately +50 degrees, and the secondary peak intensity is about 0.18 arbitrary units. When the output angle value is greater than 50 degrees, the light intensity gradually decreases to zero as the output angle value increases. When the output angle value is less than 50 degrees and greater than 0 degrees, the light intensity gradually decreases as the output angle value decreases, with a minimum intensity value of about 0.025 arbitrary units near the output angle of 0 degrees. When the output angle value is less than 0 degrees, the light intensity is stable up to about −20 degrees, and then gradually decreases to zero as the output angle value decreases.

[0285]

[0314] For example, in FIG. 11D, when the offset distance between the central axis of the light-emitting mesa and the central axis of the large microlens is 9 μm in the X direction and 9 μm in the Y direction, the maximum normalized output light intensity at an output angle of 0 degrees is about 0.15 arbitrary units. There is a secondary peak normalized output light intensity at an output angle of approximately +55 degrees, and the secondary peak intensity is about 0.09 arbitrary units. When the output angle value is greater than 55 degrees, the light intensity gradually decreases to zero as the output angle value increases. When the output angle value is less than 55 degrees and greater than 0 degrees, the light intensity gradually decreases as the output angle value decreases to a minimum intensity value of about 0.03 arbitrary units near 25 degrees, and the light intensity gradually increases as the output angle value decreases. When the output angle value is less than 0 degrees, the light intensity is stable up to about −20 degrees, and then gradually decreases to zero as the output angle value decreases.

[0286]

[0315] For example, in FIG. 11E, when the offset distance between the central axis of the light emitting mesa and the central axis of the large microlens is 12 μm in the X direction and 12 μm in the Y direction, the maximum normalized output light intensity at an output angle of 0 degrees is about 0.2 arbitrary units. When the output angle value is smaller than 0 degrees, the light intensity gradually decreases to zero as the output angle value becomes smaller. When the output angle value is larger than 0 degrees, the light intensity gradually decreases to zero as the output angle value becomes larger.

[0287]

[0316] FIG. 12 shows a cross-sectional view of an exemplary light emitting structure 1200 having a small microlens within a large microlens, where the lateral dimension of the small microlens is smaller than that of the large microlens, according to some embodiments. The array structure, dimensions, shape, fabrication, and materials of the large microlens and light emitting mesa pair (including associated reflector cups and optional spacers) are the same as or similar to the light emitting structures described in any one of FIGS. 1-7. The materials, shapes, and fabrication of the small microlens are similar to the large microlenses of FIGS. 1-7 described above. In some embodiments, the light emitting structure 1200 includes a small microlens, such as 1206 or 1208, and a large microlens, such as 1202 or 1204, in the same microlens group and light emitting mesa pair. The small microlens, such as 1206 or 1208, is formed on the light emitting mesa, such as 401 or 403. A large microlens is formed on the light emitting mesa, such as 401 or 403, and covers a small microlens, such as 1206 or 1208. The diameter of the large microlens, such as 1202, is larger than the diameter of the small microlens, such as 1206, to improve the light extraction efficiency.

[0288]

[0317] 12, the central axis N-N' of the small microlens 1206 and the central axis of the large microlens 1202 are displaced from the central axis O-O' of the light emitting mesa 401 to redirect the light, while the central axis of the small microlens 1206 is coaxially aligned (or is the same) as the central axis of the large microlens 1202. Preferably, the offset distance between the central axis of the large microlens 1202 and the central axis of the light emitting mesa 401 is 12 μm or less.

[0289]

[0318] 12, an edge of small microlens 1206 covers the central axis of light emitting mesa 401, and an edge of large microlens 1202 covers the central axis of light emitting mesa 401, as also described above in FIG. 4. In other words, central axis O-O' of light emitting mesa 401 intersects the bottom surface of small microlens 1206, and central axis O-O' of light emitting mesa 401 intersects the bottom surface of large microlens 1202.

[0290]

[0319] In some embodiments, light ray 1236 emanating from light emitting mesa 401 is redirected as 1238 while traveling through small microlens 1206, then redirected as 1240 while traveling through large microlens 1202, and exits large microlens 1202 as 1242. Light ray 1244 emanating from light emitting mesa 401 is redirected as 1246 while traveling through large microlens 1202, and exits large microlens 1202 as 1248. Adding small microlenses within large microlenses can further direct and tune the light in a particular portion of the LED pixel structure to a particular angle, especially when the first microlens and the large microlens have different refractive indices. For example, in FIG. 12, the light rays from the large microlens are focused in a particular direction around the light emitting mesa after emission.

[0291]

[0320] FIG. 13 shows a cross-sectional view of an exemplary light emitting structure 1300 having a small microlens within a large microlens, where the lateral dimension of the small microlens is smaller than that of the large microlens, according to some embodiments. The array structure, dimensions, shape, fabrication, and materials of the large microlens and light emitting mesa pair (including associated reflector cups and optional spacers) are the same as or similar to the light emitting structures described in any one of FIGS. 1-7. The materials, shapes, and fabrication of the small microlens are similar to the large microlenses of FIGS. 1-7 described above. In some embodiments, the light emitting structure 1300 includes a small microlens, such as 1306 or 1308, and a large microlens, such as 1302 or 1304, in the same microlens group and light emitting mesa pair. The small microlens, such as 1306 or 1308, is formed on the light emitting mesa, such as 401 or 403. A large microlens is formed on the light emitting mesa, such as 401 or 403, and covers a small microlens, such as 1306 or 1308. The diameter of the large microlens, such as 1302, is larger than the diameter of the small microlens, such as 1306, to improve the light extraction efficiency.

[0292]

[0321] In some embodiments, as shown in FIG. 13, the central axis Q-Q' of the small microlens 1306 and the central axis R-R' of the large microlens 1302 are displaced from the central axis P-P' of the light emitting mesa 401 to change the light direction, while the central axis of the small microlens 1306 is not coaxially aligned (or is not the same) as the central axis of the large microlens 1302. Preferably, the offset distance between the central axis Q-Q' of the small microlens 1306 and the central axis R-R' of the large microlens 1302 is 6 μm or less and 4.5 μm or more. In some embodiments, the central axis of the large microlens 1302 and the central axis of the light emitting mesa 401 are 12 μm or less. Also, the position of the small microlens relative to the large microlens of each microlens group and light emitting mesa pair may be different within the same display panel to obtain various light directions and light angles.

[0293]

[0322] 13, an edge of the small microlens 1306 covers the central axis P-P' of the light emitting mesa 401, and an edge of the large microlens 1302 covers the central axis P-P' of the light emitting mesa 401, as also shown above in FIG. 4. In other words, the central axis P-P' of the light emitting mesa 401 intersects with the bottom surface of the small microlens 1306, and the central axis P-P' of the light emitting mesa 401 intersects with the bottom surface of the second microlens 1302. In another embodiment, only the edge of the small microlens 1306 covers the central axis P-P' of the light emitting mesa 401.

[0294]

[0323] In some embodiments, light ray 1338 emanating from light emitting mesa 401 is redirected as 1340 while traveling through large microlens 1302 and exits large microlens 1302 as 1342. Light ray 1344 emitted from light emitting mesa 401 travels through small microlens 1306 and then is redirected as 1346 while traveling through large microlens 1302 and exits large microlens 1302 as 1348. Adding small microlenses within large microlenses can further direct and tune the light in a particular portion of the LED pixel structure to a particular angle, especially when the first microlens and the large microlens have different refractive indices. For example, in FIG. 13, the light rays from the large microlens are focused in a particular direction around the light emitting mesa after exiting.

[0295]

[0324] 14A-14B show some exemplary simulation results for light output from the large microlens of the light emitting structure 1300 shown in FIG. 13 according to some embodiments. FIG. 14A-14B show the variation of the output light intensity from the light emitting structure 1300 when both the offset distance between the central axis P-P' of the light emitting mesa such as 401 and the central axis Q-Q' of the small microlens such as 1306 and the offset distance between the central axis P-P' of the light emitting mesa such as 401 and the central axis R-R' of the large microlens such as 1302 are changed. The output light intensity was measured in a vertical plane passing through the vertical central axis of the light emitting mesa such as the central axis P-P' of the light emitting mesa 401. X and Y indicate the offset distance in micrometers on a horizontal plane parallel to the substrate 410 in two orthogonal directions, the X direction and the Y direction. In this example, the maximum horizontal dimension (e.g., the bottom surface) of the light emitting mesa such as 401 is 8 μm. The maximum horizontal dimension (e.g., bottom) of small microlenses such as 1306 is 18 μm. The maximum horizontal dimension (e.g., bottom) of large microlenses such as 1302 is 36 μm. Figures 14A-14B also show the change in output light intensity from light emitting structure 1300 as the angle of the output light ray with respect to an axis normal to substrate 410 (output angle θ expressed in degrees) is changed.

[0296]

[0325] For example, in FIG. 14A, when the offset distance between the central axis of the light-emitting mesa and the central axis of the small microlens is 3 μm in the X direction and 3 μm in the Y direction, and the offset distance between the central axis of the light-emitting mesa and the central axis of the large microlens is 9 μm in the X direction and 9 μm in the Y direction, the maximum normalized output light intensity at an output angle of 0 degrees is about 0.06 arbitrary units. There is a peak normalized output light intensity at an output angle of approximately +55 degrees, and the peak intensity is about 0.095 arbitrary units. When the output angle value is greater than +55 degrees, the light intensity gradually decreases to zero as the output angle value increases. When the output angle value is less than 55 degrees and greater than 0 degrees, the light intensity gradually decreases as the output angle value decreases, with a minimum intensity value of about 0.015 arbitrary units near an output angle of 0 degrees. For exit angle values ​​less than 0 degrees, the light intensity is stable at 0.025 arbitrary units up to approximately -55 degrees, and then gradually decreases to zero for smaller exit angle values.

[0297]

[0326] For example, in FIG. 14B, when the offset distance between the central axis of the light-emitting mesa and the central axis of the small microlens is 4.5 μm in the X direction and 4.5 μm in the Y direction, and the offset distance between the central axis of the light-emitting mesa and the central axis of the large microlens is 9 μm in the X direction and 9 μm in the Y direction, the maximum normalized output light intensity at an output angle of 0 degrees is about 0.08 arbitrary units. There is a peak normalized output light intensity at an output angle of approximately +55 degrees, and the peak intensity is about 0.09 arbitrary units. When the output angle value is greater than +55 degrees, the light intensity gradually decreases to zero as the output angle value increases. When the output angle value is less than +55 degrees and greater than 0 degrees, the light intensity gradually decreases as the output angle value decreases, with a minimum intensity value of about 0.015 arbitrary units near an output angle of 0 degrees. For exit angle values ​​less than 0 degrees, the light intensity is stable at 0.025 arbitrary units up to approximately -55 degrees, and then gradually decreases to zero for smaller exit angle values.

[0298]

[0327] In some embodiments of Figures 8 to 13, the edge of the large microlens covers the central axis of the light emitting mesa, thereby avoiding a reduction in light extraction efficiency. In some embodiments of Figures 8 to 13, the material of the small microlens is different from the material of the large microlens, for example, the large and small microlenses have different refractive indices due to different optical properties. In some embodiments of Figures 8 to 13, the material of the small microlens is the same as the material of the large microlens to avoid light loss at the interface.

[0299]

[0328] FIG. 15 shows a cross-sectional view of an exemplary light emitting structure 1500 with a small microlens above a large microlens (or further along the light emitting path of the light emitting structure than the large microlens), where the small microlens has a smaller lateral dimension than the large microlens, according to some embodiments. The array structure, dimensions, shape, fabrication, and materials of the large microlens and light emitting mesa pair (including associated reflector cups and optional spacers) are the same as or similar to the light emitting structures described in any one of FIGS. 1-7. The materials, shape, and fabrication of the small microlens are similar to the large microlenses of FIGS. 1-7 described above. In some embodiments, the light emitting structure 1500 includes a small microlens, such as 1506 or 1508, and a large microlens, such as 1502 or 1504, in the same microlens group and light emitting mesa pair. The large microlens, such as 1502 or 1504, is formed on the light emitting mesa, such as 401 or 403. A small microlens is formed above a large microlens such as 1502 or 1504, covering a portion of the surface of the large microlens, but not the entire surface of the large microlens. The diameter of the large microlens such as 1502 is larger than the diameter of the small microlens such as 1506 to improve light extraction efficiency. In some embodiments, such as shown in FIG. 15, a small microlens such as 1506 is formed directly on a large microlens such as 1502, such that the top surface of the large microlens is perfect (having its original shape, such as a hemisphere) and the bottom surface of the small microlens matches the shape of the surface of the large microlens. In some embodiments, the overall shape of the small microlens is a hemisphere whose bottom surface matches the shape of a portion of the top surface of the large microlens.

[0300]

[0329] 15, the central axis of the small microlens 1506 is defined as an axis perpendicular to the surface of the substrate 410 that passes through the center of the perfect sphere or other shape (as an imperfect sphere or other shape) that forms the small microlens. In some embodiments, the central axis J-J' of the small microlens 1506 is displaced from the central axis K-K' of the light emitting mesa 401 to redirect the light, while the central axis of the large microlens 1502 is coaxially aligned (or is the same) as the central axis K-K' of the light emitting mesa 401. In some embodiments, the offset distance between the central axis of the small microlens 1506 and the central axis of the light emitting mesa 401 is 9 μm or less, preferably 1.5 μm or less.

[0301]

[0330] In some embodiments, as shown in FIG. 15, the edge of the small microlens 1506 may not cover the central axis of the light emitting mesa 401, while the edge of the large microlens 1502 covers the central axis of the light emitting mesa 401, as also described above in FIG. 4. In other words, the central axis K-K' of the light emitting mesa 401 may not intersect with the bottom surface of the small microlens 1506, while the central axis K-K' of the light emitting mesa 401 intersects with the bottom surface of the large microlens 1502. In some other embodiments, not shown in FIG. 15, the edges of both the small microlens 1506 and the large microlens 1502 cover the central axis of the light emitting mesa 401. In other words, the central axis K-K' of the light emitting mesa 401 intersects with the bottom surface of the small microlens 1506, and the central axis K-K' of the light emitting mesa 401 intersects with the bottom surface of the large microlens 1502.

[0302]

[0331] In some embodiments, light ray 1540 emitted from light emitting mesa 401 is redirected to exit large microlens 1502 as 1542. Light ray 1544 emitting from light emitting mesa 401 is redirected as 1546 as it travels through large microlens 1502, then redirected as 1548 as it travels through small microlens 1506, exiting small microlens 1506 as 1550. Adding a small microlens above the large microlens can further direct and tune the light in a particular portion of the LED pixel structure to a particular angle. For example, in FIG. 15, the light ray from the large microlens is more focused in a particular direction after it exits.

[0303]

[0332] In some embodiments, the simulation results for light output from the large and small microlenses of the light emitting structure 1500 shown in FIG. 15 are very similar to the situation shown in FIG. 9A-9D for the embodiment in which the small microlenses are within the large microlenses as shown in FIG. 8. For example, the output light intensity from the light emitting structure 1500 changes when the central axis of the large microlens, such as 1502, is aligned (or is the same) with the central axis K-K' of the light emitting mesa, such as 401, while the offset distance between the central axis K-K' of the light emitting mesa, such as 401, and the central axis J-J' of the small microlens, such as 1506, is changed. The output light intensity was measured in a vertical plane passing through the vertical central axis of the light emitting mesa, such as the central axis K-K' of the light emitting mesa 401. X and Y indicate the offset distance in micrometers on a horizontal plane parallel to the substrate 410 in two orthogonal directions, the X direction and the Y direction. In this example, the maximum horizontal dimension (e.g., the bottom surface) of the light emitting mesa, such as 401, is 8 μm. Small microlenses such as 1506 have a maximum horizontal dimension of 18 μm. Larger microlenses such as 1502 have a maximum horizontal dimension (e.g., bottom) of 36 μm. The output light intensity from light emitting structure 1500 also changes as the angle of the output light ray with respect to an axis normal to substrate 410 (output angle θ expressed in degrees) changes.

[0304]

[0333] FIG. 16 shows a cross-sectional view of an exemplary light emitting structure 1600 with a small microlens above a large microlens (or further along the light emitting path of the light emitting structure than the large microlens), where the small microlens has a smaller lateral dimension than the large microlens, according to some embodiments. The array structure, dimensions, shape, fabrication, and materials of the large microlens and light emitting mesa pair (including associated reflector cups and optional spacers) are the same as or similar to the light emitting structures described in any one of FIGS. 1-7. The materials, shape, and fabrication of the small microlens are similar to the large microlenses of FIGS. 1-7 described above. In some embodiments, the light emitting structure 1600 includes a small microlens, such as 1606 or 1608, and a large microlens, such as 1602 or 1604, in the same microlens group and light emitting mesa pair. The large microlens, such as 1602 or 1604, is formed on the light emitting mesa, such as 401 or 403. A small microlens is formed above a large microlens such as 1602 or 1604, covering a portion of the surface of the large microlens, but not the entire surface of the large microlens. The diameter of the large microlens such as 1602 is larger than the diameter of the small microlens such as 1606 to improve light extraction efficiency. In some embodiments, such as shown in FIG. 16, a small microlens such as 1606 is formed directly on a large microlens such as 1602, such that the top surface of the large microlens is perfect (having its original shape, such as a hemisphere) and the bottom surface of the small microlens matches the shape of the surface of the large microlens. In some embodiments, the overall shape of the small microlens is a hemisphere whose bottom surface matches the shape of a portion of the top surface of the large microlens.

[0305]

[0334] In some embodiments, as shown in FIG. 16, the central axis of the small microlens 1606 is defined as an axis perpendicular to the surface of the substrate 410 that passes through the center of the perfect sphere or other shape (as an imperfect sphere or other shape) that forms the small microlens. In some embodiments, as shown in FIG. 16, the central axis M-M' of the large microlens 1602 is displaced from the central axis L-L' of the light emitting mesa 401 to redirect the light, while the central axis of the small microlens 1606 is coaxially aligned (or is the same) as the central axis L-L' of the light emitting mesa 401. Preferably, the offset distance between the central axis of the large microlens 1602 and the central axis of the light emitting mesa 401 is 12 μm or less. In some embodiments, the offset distance between the central axis of the large microlens 1602 and the central axis of the light emitting mesa 401 is 1.5 μm or less.

[0306]

[0335] 16, an edge of the small microlens 1606 covers the central axis of the light emitting mesa 401, and an edge of the large microlens 1602 covers the central axis of the light emitting mesa 401, as also described above in FIG. 4. In other words, the central axis L-L' of the light emitting mesa 401 intersects the bottom surface of the small microlens 1606, and the central axis L-L' of the light emitting mesa 401 intersects the bottom surface of the large microlens 1602.

[0307]

[0336] In some embodiments, light ray 1638 emitted from light emitting mesa 401 is redirected as 1640 while traveling through large microlens 1602, and then redirected to exit large microlens 1602 as 1642. Light ray 1644 emitted from light emitting mesa 401 is redirected as 1646 while traveling through small microlens 1606, and then redirected to exit small microlens 1606 as 1648. Adding small microlenses above the large microlenses can further direct and tune the light in certain portions of the LED pixel structure to specific angles. For example, in FIG. 16, the light rays from the large microlens are more focused in a specific direction after exiting.

[0308]

[0337] In some embodiments, simulation results for light exiting the large and small microlenses of the light emitting structure 1600 shown in FIG. 16 are very similar to the situation shown in FIGS. 11A to 11E for an embodiment in which the small microlens is within the large microlens as shown in FIG. 10.

[0309]

[0338] FIG. 17 shows a cross-sectional view of an exemplary light emitting structure 1700 with a small microlens above a large microlens (or further along the light emitting path of the light emitting structure than the large microlens), where the small microlens has a smaller lateral dimension than the large microlens, according to some embodiments. The array structure, dimensions, shape, fabrication, and materials of the large microlens and light emitting mesa pair (including associated reflector cups and optional spacers) are the same as or similar to the light emitting structures described in any one of FIGS. 1-7. The materials, shape, and fabrication of the small microlens are similar to the large microlenses of FIGS. 1-7 described above. In some embodiments, the light emitting structure 1700 includes a small microlens, such as 1706 or 1708, and a large microlens, such as 1702 or 1704, in the same microlens group and light emitting mesa pair. The large microlens, such as 1702 or 1704, is formed on the light emitting mesa, such as 401 or 403. A small microlens is formed above a large microlens, such as 1702 or 1704, covering a portion of the surface of the large microlens, but not the entire surface of the large microlens. The diameter of the large microlens, such as 1702, is larger than the diameter of the small microlens, such as 1706, to improve light extraction efficiency. In some embodiments, such as shown in FIG. 17, a small microlens, such as 1706, is formed directly on a large microlens, such as 1702, such that the top surface of the large microlens is perfect (having its original shape, such as a hemisphere) and the bottom surface of the small microlens matches the shape of the surface of the large microlens. In some embodiments, the overall shape of the small microlens is a hemisphere whose bottom surface matches the shape of a portion of the top surface of the large microlens.

[0310]

[0339] In some embodiments, the central axis of the small microlens 1706 is defined as an axis perpendicular to the surface of the substrate 410 that passes through the center of the perfect sphere or other shape (as an imperfect sphere or other shape) that forms the small microlens, as shown in FIG 17. In some embodiments, the central axis N-N' of the small microlens 1706 and the central axis of the large microlens 1702 are displaced from the central axis O-O' of the light emitting mesa 401 to redirect the light, while the central axis of the small microlens 1706 is coaxially aligned (or is the same) with the central axis of the large microlens 1702, as shown in FIG 17. Preferably, the offset distance between the central axis of the large microlens 1702 and the central axis of the light emitting mesa 401 is 12 μm or less.

[0311]

[0340] 17, an edge of small microlens 1706 covers the central axis of light emitting mesa 401, and an edge of large microlens 1702 covers the central axis of light emitting mesa 401, as also described above in FIG. 4. In other words, the central axis O-O' of light emitting mesa 401 intersects the bottom surface of small microlens 1706, and the central axis O-O' of light emitting mesa 401 intersects the bottom surface of large microlens 1702.

[0312]

[0341] In some embodiments, light ray 1738 emanating from light emitting mesa 401 is redirected as 1740 as it travels through large microlens 1702 and exits large microlens 1702 as 1742. Light ray 1744 emanating from light emitting mesa 401 travels through large microlens 1702 and then is redirected as 1746 as it travels through small microlens 1706 and exits small microlens 1706 as 1748. Adding small microlenses above the large microlenses can further direct and tune the light in specific portions of the LED pixel structure to specific angles. For example, in FIG. 17, the light rays from the large microlens are more focused in specific directions around the light emitting mesa after they exit.

[0313]

[0342] FIG. 18 shows a cross-sectional view of an exemplary light emitting structure 1800 with a small microlens above a large microlens (or further along the light emitting path of the light emitting structure than the large microlens), where the small microlens has a smaller lateral dimension than the large microlens, according to some embodiments. The array structure, dimensions, shape, fabrication, and materials of the large microlens and light emitting mesa pair (including associated reflector cups and optional spacers) are the same as or similar to the light emitting structures described in any one of FIGS. 1-7. The materials, shape, and fabrication of the small microlens are similar to the large microlenses of FIGS. 1-7 described above. In some embodiments, the light emitting structure 1800 includes a small microlens, such as 1806 or 1808, and a large microlens, such as 1802 or 1804, in the same microlens group and light emitting mesa pair. The large microlens, such as 1802 or 1804, is formed on the light emitting mesa, such as 401 or 403. A small microlens is formed above a large microlens such as 1802 or 1804, covering a portion of the surface of the large microlens, but not the entire surface of the large microlens. The diameter of the large microlens such as 1802 is larger than the diameter of the small microlens such as 1806 to improve light extraction efficiency. In some embodiments, such as shown in FIG. 18, a small microlens such as 1806 is formed directly on a large microlens such as 1802, such that the top surface of the large microlens is perfect (having its original shape, such as a hemisphere) and the bottom surface of the small microlens matches the shape of the surface of the large microlens. In some embodiments, the overall shape of the small microlens is a hemisphere whose bottom surface matches the shape of a portion of the top surface of the large microlens.

[0314]

[0343] In some embodiments, as shown in FIG. 18, the central axis of the small microlens 1806 is defined as an axis perpendicular to the surface of the substrate 410 that passes through the center of the perfect sphere or other shape (as an imperfect sphere or other shape) that forms the small microlens. In some embodiments, as shown in FIG. 18, the central axis Q-Q' of the small microlens 1806 and the central axis R-R' of the large microlens 1802 are displaced from the central axis P-P' of the light emitting mesa 401 to change the light direction, while the central axis of the small microlens 1806 is not coaxially aligned (or is not the same) as the central axis of the large microlens 1802. Preferably, the offset distance between the central axis Q-Q' of the small microlens 1806 and the central axis R-R' of the large microlens 1802 is 6 μm or less and 4.5 μm or more. In some embodiments, the central axis of the large microlens 1802 and the central axis of the light emitting mesa 401 are 12 μm or less. Also, the position of the small microlens relative to the large microlens in each microlens group and light emitting mesa pair may be different within the same display panel to obtain different light directions and angles.

[0315]

[0344] 18, an edge of the small microlens 1806 covers the central axis P-P' of the light emitting mesa 401, and an edge of the large microlens 1802 covers the central axis of the light emitting mesa 401, as also described above in FIG. 4. In other words, the central axis P-P' of the light emitting mesa 401 intersects the bottom surface of the small microlens 1806, and the central axis P-P' of the light emitting mesa 401 intersects the bottom surface of the second microlens 1802. In another embodiment, only the edge of the large microlens 1802 covers the central axis P-P' of the light emitting mesa 401.

[0316]

[0345] In some embodiments, light ray 1838 emanating from light emitting mesa 401 is redirected as 1840 as it travels through large microlens 1802 and exits large microlens 1802 as 1842. Light ray 1844 emanating from light emitting mesa 401 travels through large microlens 1802 and then is redirected as 1846 as it travels through small microlens 1806 and exits small microlens 1806 as 1848. Adding small microlenses above the large microlenses can further direct and tune the light within a particular portion of the LED pixel structure to a particular angle. For example, in FIG. 18, the light rays from the large microlens are more focused in a particular direction around the light emitting mesa after they exit.

[0317]

[0346] In some embodiments, simulation results for light exiting the large and small microlenses of the light emitting structure 1800 shown in FIG. 18 are very similar to the situation shown in FIGS. 14A-14B for an embodiment in which the small microlens is within the large microlens as shown in FIG. 13.

[0318]

[0347] In some embodiments of Figures 15-18, the edge of the large microlens covers the central axis of the light emitting mesa, thereby avoiding a reduction in light extraction efficiency. In some preferred embodiments of Figures 15-18, the material of the small microlens is the same as that of the large microlens to avoid light loss at the interface. In some embodiments of Figures 15-18, the material of the small microlens is different from that of the large microlens, e.g., the large and small microlenses have different refractive indices due to different optical properties.

[0319]

[0348] FIG. 19 shows a cross-sectional view of an exemplary light emitting structure 1900 having at least two pairs of microlenses and light emitting mesas, according to some embodiments, where at least one of the pairs has a small microlens within a large microlens, and the lateral dimension of the small microlens is smaller than that of the large microlens. The array structure, dimensions, shape, fabrication, and materials of the large microlens and light emitting mesa pairs (including associated reflector cups and optional spacers) are the same as or similar to the light emitting structures described in any one of FIGS. 1 to 7, particularly FIG. 4. The materials, shapes, and fabrication of the small microlenses are similar to the large microlenses of FIGS. 1 to 7 described above. The light emitting structure 1900 includes a first pair of large microlenses 402 and light emitting mesas 401. The light emitting structure 1900 includes a second pair of large microlenses 404 and light emitting mesas 403, and a small microlens 1902 within the large microlenses 404.

[0320]

[0349] Similar to that shown above in any one of Figures 8, 10, 12, and 13, light emitting structure 1900 includes a small microlens such as 1902 and a large microlens such as 404 in the same microlens group and light emitting mesa pair. The small microlens such as 1902 is formed on the light emitting mesa such as 403 and within the large microlens such as 404. The large microlens such as 404 is formed on the light emitting mesa such as 403 and covers the small microlens such as 1902. The diameter of the large microlens such as 404 is larger than the diameter of the small microlens such as 1902 to improve light extraction efficiency.

[0321]

[0350] Within the same microlens group and light-emitting mesa pair of light-emitting structure 1900, the relative positions and offset distances between the central axis S-S' of light-emitting mesa 403, the central axis T-T' of small microlens 1902, and the central axis U-U' of large microlens 404 are the same as or similar to those described above in any one of Figures 8, 10, 12, and 13.

[0322]

[0351] In some embodiments, in FIG. 19 , the offset distance between the central axis D-D' of a microlens 402 and the central axis C-C' of the corresponding light-emitting mesa 401 is smaller than the offset distance between the central axis U-U' of a large microlens 404 and the central axis S-S' of the corresponding light-emitting mesa 403.

[0323]

[0352] FIG. 20 shows a cross-sectional view of an exemplary light emitting structure 2000 having at least two pairs of microlenses and light emitting mesas, according to some embodiments, where at least one of the pairs has a small microlens above a large microlens (or the small microlens is located further along the light emitting path of the light emitting structure than the large microlens), and the lateral dimension of the small microlens is smaller than that of the large microlens. The array structure, dimensions, shape, fabrication, and materials of the large microlens and light emitting mesa pairs (including associated reflector cups and optional spacers) are the same as or similar to the light emitting structures described in any one of FIGS. 1 to 7, particularly FIG. 4. The materials, shape, and fabrication of the small microlenses are similar to the large microlenses of FIGS. 1 to 7 described above. The light emitting structure 1900 includes a first pair of large microlenses 402 and light emitting mesa 401. Light emitting structure 1900 includes a second pair of large microlens 404 and light emitting mesa 403 , and a small microlens 1902 above the large microlens 404 .

[0324]

[0353] Similar to that shown above in Figures 15-18, the light emitting structure 2000 includes a small microlens, such as 2002, and a large microlens, such as 404, in the same microlens group and light emitting mesa pair. The large microlens, such as 404, is formed on the light emitting mesa, such as 403. The small microlens, such as 2002, is formed above the large microlens, such as 404, to cover a portion of the surface of the large microlens, but not the entire surface of the large microlens. The diameter of the large microlens, such as 404, is larger than the diameter of the small microlens, such as 2002, to improve light extraction efficiency. In some embodiments, such as shown in Figure 20, the small microlens, such as 2002, is formed directly on the large microlens, such as 404, such that the top surface of the large microlens is perfect (having its original shape, such as a hemisphere) and the bottom surface of the small microlens matches the shape of the surface of the large microlens. In some embodiments, the overall shape of the small microlens is a hemisphere whose bottom surface matches the shape of a portion of the top surface of the large microlens.

[0325]

[0354] Within the same microlens group and light-emitting mesa pair of the light-emitting structure 2000, the relative positions and offset distances between the central axis S-S' of the light-emitting mesa 403, the central axis T-T' of the small microlens 2002, and the central axis U-U' of the large microlens 404 are the same or similar to those described above in any one of Figures 15 to 18.

[0326]

[0355] In some embodiments, in FIG. 20 , the offset distance between the central axis D-D' of a microlens 402 and the central axis C-C' of the corresponding light-emitting mesa 401 is greater than the offset distance between the central axis T-T' of a small microlens 2002 and the central axis S-S' of the corresponding light-emitting mesa 403.

[0327]

[0356] In some embodiments, the material of the small microlens 1902 or 2002 in any one of Figures 19-20 is the same as that of the large microlens 404 in the same microlens group and emitting mesa pair. In some embodiments, the material of the large microlens 402 is the same as that of the small microlens 1902 or 2002 in another microlens group and emitting mesa pair.

[0328]

[0357] FIG. 21 illustrates a cross-sectional view of an exemplary light emitting structure 2100 having at least one pair of microlenses and light emitting mesas according to some embodiments. The structure, size, shape, fabrication, and materials of the array of pairs of microlenses 102 and light emitting mesas 101 (including associated reflector cups and optional spacers) are the same as or similar to the light emitting structures described in any one of FIG. 1 to FIG. 7, particularly FIG. 1A. In FIG. 21, a microlens 2102 is formed above the microlens 102. In some embodiments, the microlens 2102 covers the top surface of the microlens 102 and contacts the microlens 102. The material and fabrication of the microlens 2102 are similar to the microlens 102 described above in FIG. 1 to FIG. 7. In some embodiments, the central axis of the microlens 102 and the central axis of the microlens 2102 are coaxially aligned or are the same. In some embodiments described above, the central axis of microlens 102 is not coaxially aligned or is not the same as the central axis B-B' of emitting mesa 101. In a preferred embodiment, the central axis of microlens 102 is coaxially aligned or is the same as the central axis B-B' of emitting mesa 101. In some embodiments, the horizontal dimension of microlens 2102 is the same as or larger than the horizontal dimension of microlens 102.

[0329]

[0358] In some embodiments, the material of microlens 2102 is different from the material of microlens 102. In some embodiments, the refractive index of microlens 102 is higher than that of microlens 2102, improving light extraction efficiency. The direction of light rays from light emitting mesa 101 is changed through microlens 102 and microlens 2102. For example, light ray 2104 emanating from the central axis of light emitting mesa 101 travels through microlens 102 and microlens 2102, is redirected and exits microlens 2102 as 2106. Light ray 2108 emanating from light emitting mesa 101 travels through microlens 102, is redirected as 2110 as it travels through microlens 2102, and is redirected and exits microlens 2102 as 2112.

[0330]

[0359] 21, in some embodiments, the bottom of the microlens 2102 coincides with the top curved surface of the microlens 102. In some embodiments, the microlens 102 has a hemispherical shape. In some embodiments, the microlens 2102 has a cylindrical structure with a polygonal shaped cross section when not considering the cutout of the microlens 102. When viewed from a cross-sectional view without considering the cutout of the microlens 102, the polygonal structure can be a planar figure described by a finite number of straight line segments connected to form a closed polygonal chain. For example, the planar figure may be a unilateral, dilateral, triangular, quadrilateral, pentagon, hexagon, heptagon, octagon, decagon, eleven-sided, dodecagon, ten-sided, tetralateral, pentagon, sixteen-sided, seventeen-sided, octagon, nineteen-sided, icosagon, twenty-four-sided, triadic, tetraadic, pentagon, hexagon, heptagon, octagon, nineteen-sided, hundred-sided, or other regular or irregular shape.

[0331]

[0360] 21, in some embodiments, the cross section of the polygonal shape, not considering the cutting out of the microlenses 102, is a trapezoid with a slanted top surface 2130. In some embodiments, the slanted top surface 2130 has an angle in the range of 10-80 degrees with respect to an axis perpendicular to the surface of the substrate 110. In some embodiments, the slanted top surface 2130 has an angle in the range of 30-60 degrees with respect to an axis perpendicular to the surface of the substrate 110. In some embodiments, the slanted top surface can be curved, wavy, or a combination thereof.

[0332]

[0361] By adding a microlens 2102 above the microlens 102, the light from the light emitting mesa can be further directed and adjusted to a specific angle. For example, in FIG. 21, the light from the microlens 102 is focused in a specific direction around the light emitting mesa after emitting. Therefore, even when the central axis of the light emitting mesa 101 and the central axis of the microlens 102 are the same, the light exiting from the microlens 102 can still be redirected to a specific angle when it travels through the microlens 2102 and exits. Also, when the offset of the central axis of the microlens 102 and the microlens 2102 relative to the central axis of the light emitting mesa 101, respectively, is changed, the exit angle and intensity of the light can be further adjusted. For example, the central axis of the microlens 2102 may not be the same as the central axis of the microlens 102 or the central axis of the light emitting mesa 101, and the offset may vary within the same display.

[0333]

[0362] FIG. 22 illustrates a cross-sectional view of an exemplary light emitting structure 2200 having at least one pair of microlenses and light emitting mesas, according to some embodiments. The structure, size, shape, fabrication, and materials of the array of pairs of microlenses 102 and light emitting mesas 101 (including associated reflector cups and optional spacers) are the same as or similar to the light emitting structures described in any one of FIG. 1 to FIG. 7, particularly FIG. 1A. In FIG. 22, a microlens 2202 is formed above the microlens 102. In some embodiments, the microlens 2202 covers the top surface of the microlens 102 and contacts the microlens 102. The material and fabrication of the microlens 2202 are similar to the microlens 102 described above in FIG. 1 to FIG. 7. In some embodiments, the central axis of the microlens 102 and the central axis of the microlens 2202 are coaxially aligned or are the same. In some embodiments described above, the central axis of microlens 102 is not coaxially aligned or is not the same as the central axis B-B' of emitting mesa 101. In a preferred embodiment, the central axis of microlens 102 is coaxially aligned or is the same as the central axis B-B' of emitting mesa 101. In some embodiments, the horizontal dimension of microlens 2202 is the same as or larger than the horizontal dimension of microlens 102.

[0334]

[0363] In some embodiments, the material of microlens 2202 is different from the material of microlens 102. In some embodiments, the refractive index of microlens 102 is higher than that of microlens 2202, improving light extraction efficiency. The direction of light rays from light emitting mesa 101 is changed through microlens 102 and microlens 2202. For example, light ray 2204 emanating from the central axis of light emitting mesa 101 travels through microlens 102 and microlens 2202, is redirected and exits microlens 2202 as 2206. Light ray 2208 emanating from light emitting mesa 101 travels through microlens 102, is redirected as 2210 as it travels through microlens 2202, and is redirected and exits microlens 2202 as 2212.

[0335]

[0364] In FIG. 22, in some embodiments, the bottom of the microlens 2202 matches the top curved surface of the microlens 102. In some embodiments, the microlens 102 has a hemispherical shape. In some embodiments, the microlens 2202 has a cylindrical structure with a triangular cross section when not considering the cutting of the microlens 102. As shown in FIG. 22, in some embodiments, the microlens 2202 has a slanted top surface 2230. In some embodiments, the slanted top surface 2230 has an angle ranging from 10 to 80 degrees with respect to an axis perpendicular to the surface of the substrate 110. In some embodiments, the slanted top surface 2230 has an angle ranging from 30 to 60 degrees with respect to an axis perpendicular to the surface of the substrate 110.

[0336]

[0365] By adding a microlens 2202 above the microlens 102, the light from the light emitting mesa can be further directed and adjusted to a specific angle. For example, in FIG. 22, the light from the microlens 102 is focused in a specific direction around the light emitting mesa after emitting. Therefore, even when the central axis of the light emitting mesa 101 and the central axis of the microlens 102 are the same, the light exiting from the microlens 102 can still be redirected to a specific angle when it travels through the microlens 2202 and exits. Also, when the offset of the central axis of the microlens 102 and the microlens 2202 relative to the central axis of the light emitting mesa 101, respectively, is changed, the exit angle and intensity of the light can be further adjusted. For example, the central axis of the microlens 2202 may not be the same as the central axis of the microlens 102 or the central axis of the light emitting mesa 101, and the offset may vary within the same display.

[0337]

[0366] FIG. 23 illustrates a cross-sectional view of an exemplary light emitting structure 2300 having at least one pair of microlenses and light emitting mesas according to some embodiments. The structure, size, shape, fabrication, and materials of the array of pairs of microlenses 102 and light emitting mesas 101 (including associated reflector cups and optional spacers) are the same as or similar to the light emitting structures described in any one of FIG. 1 to FIG. 7, particularly FIG. 1A. In FIG. 23, a microlens 2302 is formed above the microlens 102. In some embodiments, the microlens 2302 covers the top surface of the microlens 102 and contacts the microlens 102. The material and fabrication of the microlens 2302 are similar to the microlens 102 described above in FIG. 1 to FIG. 7. In some embodiments, the central axis of the microlens 102 and the central axis of the microlens 2302 are coaxially aligned or are the same. In some embodiments described above, the central axis of microlens 102 is not coaxially aligned or is not the same as the central axis B-B' of emitting mesa 101. In a preferred embodiment, the central axis of microlens 102 is coaxially aligned or is the same as the central axis B-B' of emitting mesa 101. In some embodiments, the horizontal dimension of microlens 2302 is the same as or larger than the horizontal dimension of microlens 102.

[0338]

[0367] In some embodiments, the material of microlens 2302 is different from the material of microlens 102. In some embodiments, the refractive index of microlens 102 is higher than that of microlens 2302, improving light extraction efficiency. The direction of light rays from light emitting mesa 101 is changed through microlens 102 and microlens 2302. For example, light ray 2304 emanating from the central axis of light emitting mesa 101 travels through microlens 102 and microlens 2302, is redirected and exits microlens 2302 as 2306. Light ray 2308 emanating from light emitting mesa 101 travels through microlens 102, is redirected as 2310 as it travels through microlens 2302, and is redirected and exits microlens 2302 as 2312.

[0339]

[0368] In FIG. 23, in some embodiments, the bottom of the microlens 2302 matches the top curved surface of the microlens 102. In some embodiments, the microlens 102 has a hemispherical shape. In some exemplary embodiments, a composite structure can be a combination of two or more structures. In some embodiments, the microlens 2302 is a composite structure having two shaped components 2302-1 and 2302-2. The microlens component 2302-1 is formed at the bottom of the microlens component 2302-2. In some embodiments, the microlens component 2302-1 has a cylindrical structure with a polygonal cross section when not considering the cutting of the microlens 102. As shown in FIG. 23, in some embodiments, the polygonal cross section is a trapezoid with a slanted top surface 2330 when not considering the cutting of the microlens 102. As shown in FIG. 23, in some embodiments, the microlens component 2302-1 has a slanted top surface 2330. In some embodiments, the inclined top surface 2330 has an angle in the range of 10 to 80 degrees with respect to an axis perpendicular to the surface of the substrate 110. In some embodiments, the inclined top surface 2330 has an angle in the range of 30 to 60 degrees with respect to an axis perpendicular to the surface of the substrate 110. As shown in FIG. 23, in some embodiments, the microlens component 2302-2 has a hemispherical shape with a flat bottom side and a convex top side. The flat bottom side of the microlens component 2302-2 seamlessly contacts and covers the inclined top surface 2330 of the microlens component 2302-1. The flat bottom side of the microlens component 2302-2 and the inclined top surface 2330 of the microlens component 2302-1 have the same shape and dimensions, and both are inclined at the same angle with respect to an axis perpendicular to the surface of the substrate 110. The two microlens components 2302-1 and 2302-2 are integral parts of the microlens 2302 and form the composite shape of the microlens 2302.

[0340]

[0369] By adding a microlens 2302 above the microlens 102, the light from the light emitting mesa can be further directed and adjusted to a specific angle. For example, in FIG. 23, the light from the microlens 102 is focused in a specific direction around the light emitting mesa after emitting. Therefore, even when the central axis of the light emitting mesa 101 and the central axis of the microlens 102 are the same, the light exiting from the microlens 102 can still be redirected to a specific angle when it travels through the microlens 2302 and exits. Also, when the offset of the central axis of the microlens 102 and the microlens 2302 relative to the central axis of the light emitting mesa 101, respectively, is changed, the exit angle and intensity of the light can be further adjusted. For example, the central axis of the microlens 2302 may not be the same as the central axis of the microlens 102 or the central axis of the light emitting mesa 101, and the offset may vary within the same display.

[0341]

[0370] FIG. 24 illustrates a cross-sectional view of an exemplary light emitting structure 2400 having at least one pair of microlenses and light emitting mesas according to some embodiments. The structure, size, shape, fabrication, and materials of the array of pairs of microlenses 102 and light emitting mesas 101 (including associated reflector cups and optional spacers) are the same as or similar to the light emitting structures described in any one of FIG. 1 to FIG. 7, particularly FIG. 1A. In FIG. 24, a microlens 2402 is formed above the microlens 102. In some embodiments, the microlens 2402 covers the top surface of the microlens 102 and contacts the microlens 102. The material and fabrication of the microlens 2402 are similar to the microlens 102 described above in FIG. 1 to FIG. 7. In some embodiments, the central axis of the microlens 102 and the central axis of the microlens 2402 are coaxially aligned or are the same. In some embodiments described above, the central axis of microlens 102 is not coaxially aligned or is not the same as the central axis B-B' of emitting mesa 101. In a preferred embodiment, the central axis of microlens 102 is coaxially aligned or is the same as the central axis B-B' of emitting mesa 101. In some embodiments, the horizontal dimension of microlens 2402 is the same as or larger than the horizontal dimension of microlens 102.

[0342]

[0371] In some embodiments, the material of microlens 2402 is different from the material of microlens 102. In some embodiments, the refractive index of microlens 102 is higher than that of microlens 2402, improving light extraction efficiency. The direction of light rays from light emitting mesa 101 is changed through microlens 102 and microlens 2402. For example, light ray 2404 emanating from the central axis of light emitting mesa 101 travels through microlens 102 and microlens 2402, is redirected and exits microlens 2402 as 2406. Light ray 2408 emanating from light emitting mesa 101 travels through microlens 102, is redirected as 2410 as it travels through microlens 2402, and is redirected and exits microlens 2402 as 2412.

[0343]

[0372] In FIG. 24, in some embodiments, the bottom of the microlens 2402 matches the top curved surface of the microlens 102. In some embodiments, the microlens 102 has a hemispherical shape. In some embodiments, the microlens 2402 is a composite structure having two shaped components 2402-1 and 2402-2. The microlens component 2402-1 is formed at the bottom of the microlens component 2402-2. The microlens component 2402-1 has a cylindrical structure with a triangular cross section when not considering the cutting of the microlens 102. As shown in FIG. 24, in some embodiments, the microlens component 2402-1 has a slanted top surface 2430. In some embodiments, the slanted top surface 2430 has an angle ranging from 10 to 80 degrees with respect to an axis perpendicular to the surface of the substrate 110. In some embodiments, the slanted top surface 2430 has an angle ranging from 30 to 60 degrees with respect to an axis perpendicular to the surface of the substrate 110. 24, in some embodiments, the microlens component 2402-2 has a hemispherical shape with a flat bottom side and a convex top side. The flat bottom side of the microlens component 2402-2 seamlessly contacts and covers the inclined top surface 2430 of the microlens component 2402-1. The flat bottom side of the microlens component 2402-2 and the inclined top surface 2430 of the microlens component 2402-1 have the same shape and dimensions, and both are inclined at the same angle with respect to an axis perpendicular to the surface of the substrate 110. The two microlens components 2402-1 and 2402-2 are integral parts of the microlens 2402 and form the composite shape of the microlens 2402.

[0344]

[0373] By adding a microlens 2402 above the microlens 102, the light from the light emitting mesa can be further directed and adjusted to a specific angle. For example, in FIG. 24, the light from the microlens 102 is focused in a specific direction around the light emitting mesa after emitting. Therefore, even when the central axis of the light emitting mesa 101 and the central axis of the microlens 102 are the same, the light exiting from the microlens 102 can still be redirected to a specific angle when it travels through the microlens 2402 and exits. Also, when the offset of the central axis of the microlens 102 and the microlens 2402 relative to the central axis of the light emitting mesa 101, respectively, is changed, the exit angle and intensity of the light can be further adjusted. For example, the central axis of the microlens 2402 may not be the same as the central axis of the microlens 102 or the central axis of the light emitting mesa 101, and the offset may vary within the same display.

[0345]

[0374] FIG. 25 illustrates a cross-sectional view of an exemplary light emitting structure 2500 having at least one pair of microlenses and light emitting mesas, according to some embodiments. The structure, dimensions, shape, fabrication, and materials of the array of pairs of microlenses 102 and light emitting mesas 101 (including associated reflector cups and optional spacers) are the same as or similar to the light emitting structures described in any one of FIGS. 1-7, particularly FIG. 1A. In FIG. 25, a microlens 2502 is formed above the microlens 102. In some embodiments, the microlens 2502 covers the top surface of the microlens 102 and contacts the microlens 102. In some embodiments, the material and fabrication of the microlens 2502 are similar to the microlens 102 described above in FIGS. 1-7. In some embodiments, the microlens 2502 is a diffractive microlens. In some embodiments, the central axis of the microlens 102 and the center point of the top surface 2540 of the diffractive microlens 2502 intersect. In a preferred embodiment, the central axis of microlens 102 is coaxially aligned or identical to the central axis B-B' of light emitting mesa 101. In some embodiments, the horizontal dimension of microlens 2502 is the same as or larger than the horizontal dimension of microlens 102.

[0346]

[0375] In some embodiments, the material of microlens 2502 is different from the material of microlens 102. In some embodiments, the refractive index of microlens 102 is higher than that of microlens 2502, improving light extraction efficiency. In some embodiments, the refractive index of microlens 102 is lower than that of microlens 2502. The direction of light rays from light emitting mesa 101 is changed through microlens 102 and microlens 2502. For example, light ray 2504 emanating from the central axis of light emitting mesa 101 travels through microlens 102 and microlens 2502, is redirected and exits microlens 2502 as 2506. Light ray 2508 emanating from light emitting mesa 101 travels through microlens 102, is redirected as 2510 as it travels through microlens 2502, and is redirected and exits microlens 2502 as 2512.

[0347]

[0376] In FIG. 25, in some embodiments, the bottom of the microlens 2502 coincides with the top curved surface of the microlens 102. In some embodiments, the microlens 102 has a hemispherical shape. In some embodiments, the microlens 2502 is a composite structure having four shaped components 2502-1, 2502-2, 2502-3, and 2502-4. In some embodiments, the microlens component 2502-1 has a cylindrical structure with a cross section of a polygonal shape when not considering the cutting of the microlens 102. As shown in FIG. 25, in some embodiments, the cross section of the polygonal shape is a trapezoid with a slanted top surface 2530 when not considering the cutting of the microlens 102. In some other embodiments not shown in FIG. 25, the microlens component 2502-1 has a cylindrical structure with a cross section of a triangular shape when not considering the cutting of the microlens 102, similar to the microlens components described above in FIGS. 22 and 24. Microlens component 2502-1 is formed at the bottom of microlens components 2502-2, 2502-3, and 2502-4.

[0348]

[0377] As shown in FIG. 25, in some embodiments, the microlens component 2502-1 has a slanted top surface 2530. In some embodiments, the slanted top surface 2530 has an angle in the range of 10-80 degrees with respect to an axis normal to the surface of the substrate 110. In some embodiments, the slanted top surface 2530 has an angle in the range of 30-60 degrees with respect to an axis normal to the surface of the substrate 110. As shown in FIG. 25, in some embodiments, the microlens component 2502-2 has a hemispherical shape with a flat bottom side and a convex top side. In some embodiments, the microlens component 2502-2 has a central axis V-V' passing through the center point of the top surface and the center point of the bottom surface of the hemispherical shaped microlens component 2502-2. In some embodiments, a central point may refer to a point related to a geometric figure such that for any point on the figure, another point on the figure exists such that a line connecting the two points is bisected by the central point. For example, the diffractive microlens 2502 may be a hemispherical structure, and thus the center point of the top surface of the diffractive microlens 2502 may refer to the apex of the top surface of the hemispherical structure.

[0349]

[0378] The central axis V-V' of the microlens component 2502-2 is perpendicular to the inclined top surface 2530 of the microlens component 2502-1. The flat bottom side of the microlens component 2502-2 contacts and covers the center of the inclined top surface 2530 of the microlens component 2502-1 seamlessly. The flat bottom side of the microlens component 2502-2 and the inclined top surface 2530 of the microlens component 2502-1 contact each other and are both inclined at the same angle with respect to an axis perpendicular to the surface of the substrate 110. In some embodiments, several polygonal structures are formed around the microlens component 2502-2 to increase diffraction, such as the microlens components 2502-3 and 2502-4 in the cross section of FIG. 25. In some embodiments, the polygonal structures are similar to the staircase structure described in FIG. 2C. In some embodiments, the stepped microlens components 2502-3 and 2502-4 have stepped top surfaces that increase toward the edge of the microlens 2502. In some embodiments, the microlens components 2502-3 and 2502-4 have multiple surfaces that are inclined at different angles to redirect light from the light emitting structure 2500 in different directions. The four microlens components 2502-1, 2502-2, 2502-3, and 2502-4 are integral parts of the microlens 2502 and form the composite shape of the microlens 2502. In some embodiments, the microlens 2502 has multiple surfaces that are inclined at different angles to redirect light from the light emitting structure 2500 in different directions.

[0350]

[0379] By adding a diffractive microlens 2502 above the microlens 102, the light from the light emitting mesa can be further directed and adjusted to a specific angle. For example, in FIG. 25, the light from the microlens 102 is diffracted in a specific direction around the light emitting mesa after it is emitted. Therefore, even when the central axis of the light emitting mesa 101 and the central axis of the microlens 102 are the same, the light exiting the microlens 102 can still be redirected to multiple angles as it travels through the microlens 2502 and exits. Also, the exit angle and intensity of the light can be further adjusted when the offset of the central axis of the microlens 102 and the microlens 2502 relative to the central axis of the light emitting mesa 101, respectively, is changed. For example, the central axis of the microlens 2502 may not be the same as the central axis of the microlens 102 or the central axis of the light emitting mesa 101, and the offset may vary within the same display.

[0351]

[0380] In some embodiments, light having certain wavelengths may selectively pass through or be reflected by diffractive microlens 2502 depending on the design of diffractive microlens 2502. In some embodiments, the diffractive lens may be on microlens 102, and the base of diffractive microlens 2502 is not larger than the base of microlens 102.

[0352]

[0381] In some embodiments, the diffractive microlens 2502 may comprise a single slit, where a diffraction effect may occur. In some embodiments, the diffractive microlens 2502 may comprise a double slit, where a diffraction effect may occur. In some embodiments, the diffractive microlens 2502 may comprise one or more circular apertures, where a diffraction effect may occur. In some embodiments, the diffractive microlens 2502 may comprise one or more periodic and / or non-periodic structures, where a diffraction effect may occur.

[0353]

[0382] In some exemplary embodiments, the diffractive microlens 2502 can be a Bragg mirror. The Bragg mirror can include a series of alternating layers of two different optical materials. For example, the Bragg mirror can be a quarter-wave mirror. Each layer of optical material can have a different thickness corresponding to a quarter of the wavelength for which the Bragg mirror is designed. When the Bragg mirror is designed for a larger angle of incidence, correspondingly thicker layers will be required. Thus, selected wavelengths of light emitted from the light emitting mesa and / or passing through the microlens can be reflected by the Bragg mirror. In some embodiments, the Bragg mirror is mounted on the top surface of the microlens 2502. In some embodiments, the Bragg mirror is mounted only on the surfaces of the microlens components 2502-3 and 2502-4.

[0354]

[0383] In some embodiments, a Bragg mirror for a red light LED includes multiple layers of Au and / or indium tin oxide (ITO).

[0355]

[0384] In one example, the Bragg mirror may comprise alternating TiO2 and SiO2 layers. In one example, the following distributed Bragg reflector (DBR) structure shown in Table 1 may be used to reflect green light from a green light LED.

[0356]

[0385] [Table 1]

[0357]

[0386] In one example, the following DBR structure shown in Table 2 can be used to reflect blue light from a blue light LED.

[0358]

[0387] [Table 2]

[0359]

[0388] The light emitting structure 2500 may use Bragg mirrors with different structures. In some embodiments, the Bragg mirrors may be dielectric mirrors based on thin film coating techniques, for example, fabricated by electron beam evaporation or ion beam sputtering. In these embodiments, the Bragg mirrors may comprise amorphous materials. In some embodiments, the Bragg mirrors may be fiber Bragg gratings, including long period fiber gratings. In these embodiments, the fiber Bragg gratings may be fabricated by irradiating a fiber with spatially patterned ultraviolet light. In some embodiments, the Bragg mirrors may be volume Bragg gratings, which may be fabricated in photosensitive bulk glass. In some embodiments, the Bragg mirrors may be semiconductor Bragg mirrors, which may be produced by lithographic methods. Other types of Bragg mirrors may be used, for example, based on corrugated waveguide structures, which may be fabricated via lithography.

[0360]

[0389] In some embodiments, the Bragg mirror may use other multi-layer mirror designs that differ from a simple quarter wave design. In these embodiments, the Bragg mirror may have a lower reflectivity for the same number of layers, but may be optimized, for example, as a dichroic mirror or as a dispersive chirped mirror for dispersion compensation.

[0361]

[0390] In some embodiments, the microlens 102 can be formed in many different or composite shapes, as described in FIG. 1A. FIG. 26 shows a cross-sectional view of an exemplary light emitting structure 2600 having at least one microlens-light emitting mesa pair, according to some embodiments. The structure, dimensions, shape, fabrication, and materials of the array of microlens 2602-light emitting mesa 2601 pairs (including associated reflector cups and optional spacers) are the same as or similar to the light emitting structures described in any one of FIGS. 1-7, particularly FIG. 1A. In some embodiments, the microlens 2602 is an elliptical microlens formed by a combination of a quarter of a sphere and a quarter of an ellipsoid. In some embodiments not shown in FIG. 26, other microlenses, as described in FIGS. 8-25, may be formed above or within the microlens 2602.

[0362]

[0391] In a preferred embodiment, the central axis of microlens 2602 (the axis passing through the center point of the bottom surface of microlens 2602 perpendicular to the surface of the substrate) is not coaxially aligned or coincident with the central axis of light emitting mesa 2601 .

[0363]

[0392] In some embodiments, the microlens 2602 is a composite structure having two shaped components 2602-1 and 2602-2. In some embodiments, the microlens component 2602-1 is a quarter of a sphere. In some embodiments, the microlens component 2602-2 is a quarter of an ellipsoid. The two shaped components 2602-1 and 2602-2 are seamlessly formed and integrated with each other. For example, the diameter of the microlens component 2602-1 matches the diameter of the microlens component 2602-2 along the Z direction and along the direction perpendicular to the cross section 2600. The two microlens components 2602-1 and 2602-2 are an integral part of the microlens 2602 and form the composite shape of the microlens 2602.

[0364]

[0393] The direction of light rays from light emitting mesa 2601 is redirected through microlens 2602 to different angles from different surfaces of microlens 2602. Figure 26 shows a simulation of the ray paths of many different light rays from light emitting mesa 2601 into microlens 2602, including the effects of diffraction and reflection. For example, light ray 2604 emanating from the central axis of light emitting mesa 2601 travels through microlens 2602, is redirected and exits microlens 2602 as 2606. Light ray 2608 emanating from light emitting mesa 2601 travels through microlens 2602, is redirected and exits microlens 2602 as 2610.

[0365]

[0394] In some embodiments, the radius of the sphere is 9 μm or less and the semimajor axis of the ellipsoid is 18 μm or less. In some embodiments, similar to FIG. 1A for microlens 102, the offset distance of the central axis of microlens 2602 from the central axis of emitting mesa 2601 at the horizontal level is 4.5 μm or less to improve light extraction efficiency. In some embodiments, similar to FIG. 1A for microlens 102, the edge of microlens 2602 covers the central axis of emitting mesa 2601.

[0366]

[0395] The compound asymmetric shape of the microlens 2602 can further direct and adjust the light from the light emitting mesa to a specific angle. For example, in FIG. 26, the light from the microlens 2602 is diffracted in certain directions around the light emitting mesa and focused in other directions after emission. Therefore, even when the central axis of the light emitting mesa 2601 and the central axis of the microlens 2602 are the same, the light exiting the microlens 2602 can still be redirected to multiple angles as it travels through the microlens 2602 and exits. Also, the exit angle and intensity of the light can be further adjusted when the offset of the central axis of the microlens 2602 and the microlens above the microlens 2602 relative to the central axis of the light emitting mesa 2601, respectively, is changed. For example, the central axis of the microlens above the microlens 2602 may not be the same as the central axis of the microlens 2602 or the central axis of the light emitting mesa 2601, and the offset may vary within the same display.

[0367]

[0396] 27 shows a cross-sectional view of an exemplary light emitting structure 2700 having at least two pairs of microlenses and light emitting mesas, where at least one of the microlenses has a cleft portion covered by a reflector portion, according to some embodiments. The array structure, dimensions, shape (not considering the cleft), fabrication, and materials of the microlens and light emitting mesa pairs (including associated reflector cups and optional spacers) are the same as or similar to the light emitting structures described in any one of FIGS. 1 to 7, particularly FIG. 4. The light emitting structure 2700 includes a first pair of microlenses 2702 and light emitting mesa 401. The light emitting structure 2700 includes a second pair of microlenses 2704 and light emitting mesa 403.

[0368]

[0397] In some embodiments, microlens 2702 or 2704 has a cutout as a cleft on one side of the top surface of the microlens. In one example, cleft 2710 leaves a sloping flat surface on microlens 2702. In another example, cleft 2720 leaves a curved surface on microlens 2704. In some embodiments, a reflector is formed or attached on the surface of the cleft. For example, reflector 2712 is formed on the surface of cleft 2710. Reflector 2722 is formed on the surface of cleft 2720. The reflector is a surface that matches the shape of the surface of the cleft of the microlens. For example, reflector 2712 on microlens 2702 is a sloping flat layer. Reflector 2722 on microlens 2704 is a curved layer. The shapes of the cleft and reflector are not limited to flat and curved shapes, other shapes such as portions of the surfaces of rectangles, triangles, squares, polygons, and other compound shapes may be possible.

[0369]

[0398] In some embodiments, the reflector 2712 or 2722 may include a reflective layer to enhance the reflection of light within a particular portion of the microlens. In these embodiments, the reflective layer may have a high reflectivity. For example, the reflectivity of the reflective layer may be greater than 60%. In another example, the reflectivity of the reflective layer may be greater than 70%. In yet another example, the reflectivity of the reflective layer may be greater than 80%. In these embodiments, the material of the reflective layer may further comprise a metal selected from one or more of Rh, Al, Ag, and Au, or may comprise two sublayers with different refractive indices. In some embodiments, the reflective layer may be a Bragg mirror as described above in FIG. 25.

[0370]

[0399] In some embodiments, the light ray direction from light emitting mesa 401 is redirected via microlens 2702 and reflector 2712 to different angles from different surfaces of microlens 2702. For example, light ray 2714 emanating from light emitting mesa 401 travels through microlens 2702, is redirected within microlens 2702 as 2716, and is redirected as 2718 before exiting microlens 2702. In some embodiments, the light ray direction from light emitting mesa 403 is redirected via microlens 2704 and reflector 2722 to different angles from different surfaces of microlens 2704. For example, light ray 2724 emanating from light emitting mesa 403 travels through microlens 2704, is redirected within microlens 2704 as 2726, and is redirected as 2728 before exiting microlens 2704.

[0371]

[0400] The asymmetric shape of the microlens with the clefts combined with the reflectors can further direct and tune the light from the emitting mesa to a specific angle. For example, in FIG. 27, the light from microlens 2702 or 2704 is diffracted in certain directions around the emitting mesa and focused in other directions after emission. Thus, even when the central axis of the emitting mesa such as 401 and the central axis of the microlens such as 2702 are the same, the light exiting from microlens 2702 can still be redirected to multiple angles as it travels through and exits microlens 2702. Also, the exit angle and intensity of the light can be further tuned when the offset of the central axis of the microlens such as 2702 relative to the central axis of the emitting mesa such as 401 and the position of the cleft such as 2710 on the microlens are changed, respectively. For example, the offset of the central axis of the microlens and the central axis of the emitting mesa, the position of the cleft, and the shape and type of the cleft may be varied within the same display.

[0372]

[0401] Although the detailed description contains many details, these should not be interpreted as limiting the scope of the present invention, but only as illustrating different examples and aspects of the present invention. It should be understood that the scope of the present invention includes other embodiments not detailed above. Microlenses having different shaped bases, such as square bases or other polygonal bases, can also be used. Various other modifications, changes, and variations that will be apparent to those skilled in the art can be made in the arrangement, operation, and details of the methods and apparatus of the present invention disclosed herein without departing from the spirit and scope of the present invention as defined in the appended claims. Therefore, the scope of the present invention should be determined by the appended claims and their legal equivalents.

[0373]

[0402] Further embodiments include various subsets of the above embodiments, including those shown in Figures 1-27, combined or otherwise rearranged in various other embodiments. For example, each embodiment of the microlens(s) and light emitting mesa pair structure described in any one of Figures 1-27 may be mixed with any other embodiment described in Figures 1-27 within the same display panel.

[0374]

[0403] FIG. 28 is a top view of a micro LED display panel 2800, according to some embodiments. The display panel 2800 includes a data interface 2810, a control module 2820, and a pixel area 2850. The data interface 2810 receives data defining an image to be displayed. The source or sources and format of this data will vary depending on the application. The control module 2820 receives the incoming data and converts it into a form suitable for driving pixels of the display panel. The control module 2820 may include digital logic and / or state machines to convert from the received format to one suitable for the pixel area 2850, shift registers or other types of buffers and memories to store and transfer data, digital to analog converters and level shifters, and a scan controller including clock circuits.

[0375]

[0404] The pixel area 2850 includes an array of mesas (not shown separately from the LEDs 2834 in FIG. 28) that contain pixels. The pixels include micro LEDs, such as single or multi-color LEDs 2834 integrated with pixel drivers, as described above. An array of micro lenses (not shown separately from the LEDs 2834 in FIG. 28) covers the top of the array of mesas. In this example, the display panel 2800 is a color RGB display panel. It includes red, green, and blue pixels. Within each pixel, the LEDs 2834 are controlled by a pixel driver. According to the previously shown embodiment, the pixels are in contact with a power supply voltage (not shown) and ground via a ground pad 2836, as well as a control signal. Although not shown in FIG. 28, the p-electrode of the LEDs 2834 and the output of the drive transistor are electrically connected. The LED current drive signal connections (between the p-electrode of the LED and the output of the pixel driver), the ground connection (between the n-electrode and system ground), the supply voltage Vdd connection (between the source of the pixel driver and system Vdd), and the control signal connections to the gate of the pixel driver are made according to various embodiments. Any of the microlens arrays disclosed herein may be implemented with the micro LED display panel 2800.

[0376]

[0405] FIG. 28 is a representative diagram only. Other designs will be apparent. For example, the colors need not be red, green, and blue. They also need not be arranged in columns or stripes. As an example, apart from the square matrix arrangement of pixels shown in FIG. 28, a hexagonal matrix arrangement of pixels can also be used to form the display panel 2800.

[0377]

[0406] In some applications, a fully programmable rectangular array of pixels is not necessary. Display panels of other designs with various shapes and displays can also be formed using the device structures described herein. One class of examples is specialized applications including signs and automobiles. For example, multiple pixels may be arranged in a star or spiral to form a display panel, and different patterns can be generated on the display panel by turning LEDs on and off. Another specialized example is automobile headlights and smart lighting, where certain pixels are grouped together to form various lighting shapes, and each group of LED pixels can be turned on or off or otherwise adjusted by an individual pixel driver.

[0378]

[0407] Even the lateral placement of devices within each pixel can vary. In Figure 1A, the LEDs and pixel driver are arranged vertically; that is, each LED is located on top of its corresponding pixel driver circuit. Other arrangements are possible. For example, the pixel driver could be located "behind," "in front," or "to the side" of the LEDs.

[0379]

[0408] Different types of display panels may be manufactured. For example, the resolution of the display panel may typically range from 8x8 to 3840x2160. Common display resolutions include QVGA with a resolution of 320x240 and an aspect ratio of 4:3, XGA with a resolution of 1024x768 and an aspect ratio of 4:3, D with a resolution of 1280x720 and an aspect ratio of 16:9, FHD with a resolution of 1920x1080 and an aspect ratio of 16:9, UHD with a resolution of 3840x2160 and an aspect ratio of 16:9, and 4K with a resolution of $326x2160. There may also be a variety of pixel sizes ranging from sub-micron to 10mm or more. The size of the overall display area may also vary widely, ranging from as little as tens of microns or less to hundreds of inches or more diagonally.

[0380]

[0409] Different applications will also have different requirements for optical brightness and viewing angle. Exemplary applications include direct-view display screens, light engines for home / office projectors, and portable electronics such as smartphones, laptops, wearable electronics, AR and VR glasses, and retinal projection. Power consumption can vary from as low as a few milliwatts for retinal projectors to as high as kilowatts for large-screen outdoor displays, projectors, and smart car headlights. In terms of frame rate, due to the fast response (nanoseconds) of inorganic LEDs, the frame rate can be as high as KHz, or even MHz for small resolutions.

[0381]

[0410] Further embodiments include various subsets of the above-described embodiments, including the embodiments illustrated in Figures 1 through 28, combined or otherwise rearranged in various other embodiments.

[0382]

[0411] Although the detailed description includes many details, these should not be interpreted as limiting the scope of the present invention, but only as illustrating different examples and aspects of the present invention. It should be understood that the scope of the present invention includes other embodiments not detailed above. For example, the above-described approach can be applied to the integration of functional devices other than LEDs and OLEDs with control circuits other than pixel drivers. Examples of non-LED devices include vertical cavity surface emitting lasers (VCSELs), photodetectors, microelectromechanical systems (MEMS), silicon optical devices, power electronic devices, and distributed feedback lasers (DFBs). Examples of other control circuits include current drivers, voltage drivers, transimpedance amplifiers, and logic circuits.

[0383]

[0412] The preceding description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the embodiments described herein and variations thereof. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the spirit or scope of the subject matter disclosed herein. Thus, the present disclosure is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the following claims and the principles and novel features disclosed herein.

[0384]

[0413] Features of the present invention may be implemented in, using, or with the aid of a computer program product, such as one or more storage media or one or more computer-readable storage media having stored thereon instructions that can be used to program a processing system to perform any of the features presented herein. The storage media may include high-speed random access memory, such as, but not limited to, DRAM, SRAM, DDR RAM, or other random access solid-state memory devices, and may include non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid-state storage devices. The memory optionally includes one or more storage devices located remotely from the one or more CPUs. The memory, or alternatively the one or more non-volatile memory devices in the memory, comprises a non-transitory computer-readable storage medium.

[0385]

[0414] Features of the present invention may be embodied in software and / or firmware stored on any one or more machine-readable media for controlling the hardware of a processing system and for enabling the processing system to utilize the results of the present invention and interact with other mechanisms. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments / containers.

[0386]

[0415] It will be understood that terms such as "first", "second", etc. may be used herein to describe various elements or steps, but these elements or steps should not be limited by these terms. These terms are used only to distinguish one element or step from another element or step.

[0387]

[0416] The terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the claims. When used in the description of the embodiments and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise. It will also be understood that the term "and / or" as used herein refers to and includes any and all possible combinations of one or more of the associated listed items. It will be further understood that the terms "comprises" and / or "comprising," when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0388]

[0417] As used herein, the term "if" may be interpreted to mean "when" a stated precondition is true or "upon" a stated precondition is true or "in accordance with a determination" that a stated precondition is true or "in response to detecting" that a stated precondition is true, depending on the context. Similarly, the phrases "if it is determined that a stated precondition is true" or "if a stated precondition is true" or "when a stated precondition is true" may be interpreted to mean "upon determining" that a stated precondition is true or "in response to determining" that a stated precondition is true or "in accordance with a determination" that a stated precondition is true or "upon detecting" that a stated precondition is true or "in response to detecting" that a stated precondition is true, depending on the context.

[0389]

[0418] The foregoing description has been described with reference to specific embodiments for purposes of explanation. However, the illustrative discussion above is not intended to be exhaustive or to limit the scope of the claims to the precise forms disclosed. Many modifications and variations are possible in light of the above teachings. The embodiments have been selected and described in order to best explain the principles of operation and practical applications so as to enable others skilled in the art to best utilize the invention and various embodiments.

Claims

1. 1. A light emitting structure array system having an off-axis microlens array structure, comprising: at least one light emitting mesa; at least one microlens formed above the light emitting mesa; A light emitting structure array system, wherein a central axis of the at least one microlens is not coaxially aligned with a central axis of the at least one light emitting mesa.

2. The light emitting structure array system of claim 1 , wherein the relative position of each microlens with respect to a corresponding light emitting mesa in the light emitting structure array system is the same.

3. Further comprising a sensor, 3. The light emitting structure array system of claim 1 or 2, wherein emitted light from said at least one light emitting mesa passing through said at least one microlens is collectively converted into said sensor.

4. The light emitting structure array system of claim 3 , wherein the sensor is disposed on a central axis of the light emitting structure array system.

5. 5. The light emitting structure array system of claim 4, wherein the offset distance of each of the central axes of each of the microlenses relative to the central axis of each of the light emitting mesas increases from the center of the light emitting structure array system toward the edge of the light emitting structure array system.

6. The light emitting structure array system according to claim 3 , wherein the sensor is not positioned on a central axis of the light emitting structure array system.

7. 7. The light emitting structure array system of claim 6, wherein an offset distance of a central axis of each microlens relative to a central axis of each light emitting mesa increases from a central axis of the sensor toward an edge of the light emitting structure array system.

8. 8. The light emitting structure array system of claim 6 or 7, wherein the angle of light emitted from each microlens increases from a central axis of the sensor towards an edge of the light emitting structure array system.

9. 9. The light emitting structure array system of claim 1, wherein an offset range of the central axis of the at least one microlens from the central axis of the at least one light emitting mesa is less than or equal to 4.5 μm.

10. 10. The light emitting structure array system of claim 1 , wherein an offset distance between an edge of a bottom surface of the at least one light emitting mesa and an edge of a bottom surface of the at least one microlens is within 30% of a diameter of the bottom surface of the at least one microlens.

11. The light emitting structure array system according to claim 1 , wherein the material of the at least one microlens is silicon oxide or an organic material.

12. The light emitting structure array system of claim 1 , wherein a bottom surface of the at least one microlens intersects with the central axis of the at least one light emitting mesa.

13. Further comprising a semiconductor substrate and a reflector cup; the at least one light emitting mesa is formed on the semiconductor substrate; The light emitting structure array system of claim 1 , wherein the at least one light emitting mesa is surrounded by the reflector cup.

14. 14. The light emitting structure array system of claim 13, wherein an inner wall of the reflector cup is stepped.

15. The at least one light emitting mesa comprises: A light-emitting layer; a bottom bonding layer located at the bottom of the light emitting layer and bonded to the semiconductor substrate; a top electrode layer covering the at least one light emitting mesa and electrically connected to the reflector cup; 15. The light emitting structure array system of claim 13 or 14, wherein the reflector cup is electrically connected to the semiconductor substrate.

16. 16. The light emitting structure array system of claim 1, further comprising a spacer formed between the at least one light emitting mesa and the at least one microlens.

17. 17. The light emitting structure array system of claim 16, wherein a height of the spacer is less than a height of the at least one microlens.

18. 18. The light emitting structure array system of claim 13, wherein the semiconductor substrate is an IC substrate.

19. 1. A light emitting structure having at least one off-axis microlens, A luminous mesa; a first microlens formed on the light emitting mesa; a second microlens formed on the light emitting mesa and covering the first microlens; A light emitting structure comprising:

20. 20. The light emitting structure having at least one off-axis microlens of claim 19, wherein a diameter of the second microlens is greater than a diameter of the first microlens.

21. a central axis of the first microlens is aligned coaxially with a central axis of the light emitting mesa; 21. A light emitting structure having at least one off-axis microlens according to claim 19 or 20, wherein a central axis of the second microlens is not coaxially aligned with the central axis of the light emitting mesa.

22. a central axis of the second microlens is aligned coaxially with a central axis of the light emitting mesa; 22. A light emitting structure having at least one off-axis microlens according to claim 19, wherein a central axis of the first microlens is not coaxially aligned with the central axis of the light emitting mesa.

23. a central axis of the first microlens is not coaxially aligned with a central axis of the light emitting mesa; a central axis of the second microlens is not coaxially aligned with the central axis of the light emitting mesa; 23. A light emitting structure having at least one off-axis microlens according to claim 19, wherein the central axis of the first microlens is not coaxially aligned with the central axis of the second microlens.

24. the light emitting structure includes more than one set of a light emitting mesa, a first microlens, and a second microlens; 24. A light emitting structure having at least one off-axis microlens as described in any one of claims 19 to 23, wherein the positions of each first microlens relative to each second microlens on the light emitting structure in each set are different.

25. 25. A light emitting structure having at least one off-axis microlens as described in any one of claims 21 to 24, wherein an offset distance between the central axis of the second microlens and the central axis of the light emitting mesa is 12 μm or less.

26. 26. A light emitting structure having at least one off-axis microlens as described in any one of claims 22 to 25, wherein an offset distance between the central axis of the first microlens and the central axis of the light emitting mesa is 1.5 μm or less.

27. 27. A light emitting structure having at least one off-axis microlens according to claim 23, wherein an offset distance between the central axis of the first microlens and the central axis of the second microlens is less than or equal to 6 μm and greater than or equal to 4.5 μm.

28. 28. The light emitting structure having at least one off-axis microlens according to claim 19, wherein a bottom surface of the second microlens intersects with the central axis of the light emitting mesa.

29. 30. The light emitting structure having at least one off-axis microlens of claim 28, wherein a bottom surface of the first microlens intersects with the central axis of the light emitting mesa.

30. 30. A light emitting structure having at least one off-axis microlens according to claim 28, wherein a material of the first microlens is the same as a material of the second microlens.

31. Further comprising a semiconductor substrate and a reflector cup; the light emitting mesa is formed on the semiconductor substrate; 31. The light emitting structure having at least one off-axis microlens according to claim 19, wherein the light emitting mesa is surrounded by the reflector cup.

32. 32. The light emitting structure having at least one off-axis microlens of claim 31, wherein an inner wall of the reflector cup has a stepped shape.

33. The light emitting mesa is A light-emitting layer; a bottom bonding layer located at the bottom of the light emitting layer and bonded to the semiconductor substrate; a top electrode layer covering the light emitting mesa and electrically connected to the reflector cup; 33. The light emitting structure having at least one off-axis microlens according to claim 31 or 32, wherein the reflector cup is electrically connected to the semiconductor substrate.

34. 34. A light emitting structure having at least one off-axis microlens according to claim 19, further comprising a spacer formed between the light emitting mesa and the first microlens.

35. 35. The light emitting structure having at least one off-axis microlens of claim 34, wherein a height of the spacer is less than that of the first microlens.

36. 36. A light emitting structure having at least one off-axis microlens according to claim 31, wherein the semiconductor substrate is an IC substrate.

37. A luminous mesa; a first microlens formed on the light emitting mesa; a second microlens formed on the first microlens; 1. A light emitting structure having at least one off-axis microlens comprising:

38. 38. The light emitting structure having at least one off-axis microlens of claim 37, wherein a diameter of the second microlens is smaller than a diameter of the first microlens.

39. a central axis of the first microlens is aligned coaxially with a central axis of the light emitting mesa; 39. A light emitting structure having at least one off-axis microlens as described in claim 37 or 38, wherein a central axis of the second microlens is not coaxially aligned with the central axis of the light emitting mesa.

40. the light emitting structure includes more than one set of a light emitting mesa, a first microlens, and a second microlens; 40. A light emitting structure having at least one off-axis microlens as described in any one of claims 37 to 39, wherein the positions of each first microlens relative to each second microlens on the light emitting structure in each set are different.

41. 41. A light emitting structure having at least one off-axis microlens as described in claim 39 or 40, wherein an offset distance between the central axis of the second microlens and the central axis of the light emitting mesa is 1.5 μm or less.

42. 42. A light emitting structure having at least one off-axis microlens according to claim 37, wherein a bottom surface of the first microlens intersects with a central axis of the light emitting mesa.

43. 43. The light emitting structure having at least one off-axis microlens of claim 42, wherein a bottom surface of the second microlens does not intersect with the central axis of the light emitting mesa.

44. 44. A light emitting structure having at least one off-axis microlens according to any one of claims 37 to 43, wherein a material of the first microlens is the same as a material of the second microlens.

45. Further comprising a semiconductor substrate and a reflector cup; the light emitting mesa is formed on the semiconductor substrate; 45. A light emitting structure having at least one off-axis microlens according to claim 37, wherein the light emitting mesa is surrounded by the reflector cup.

46. 46. ​​The light emitting structure having at least one off-axis microlens of claim 45, wherein an inner wall of the reflector cup has a stepped shape.

47. The light emitting mesa is A light-emitting layer; a bottom bonding layer located at the bottom of the light emitting layer and bonded to the semiconductor substrate; a top electrode layer covering the light emitting mesa and electrically connected to the reflector cup; 47. A light emitting structure having at least one off-axis microlens according to claim 45 or 46, wherein the reflector cup is electrically connected to the semiconductor substrate.

48. 48. A light emitting structure having at least one off-axis microlens according to any one of claims 37 to 47, further comprising a spacer formed between the light emitting mesa and the first microlens.

49. 49. The light emitting structure having at least one off-axis microlens of claim 48, wherein a height of the spacer is less than a height of the first microlens.

50. 50. A light emitting structure having at least one off-axis microlens according to any one of claims 45 to 49, wherein the semiconductor substrate is an IC substrate.

51. a first light emitting mesa; at least one first microlens formed above the first light emitting mesa, the central axis of the first microlens not being coaxially aligned with the central axis of the first light emitting mesa; a second light emitting mesa; at least one second microlens formed above the second light emitting mesa; at least one third microlens formed on the second light emitting mesa; 1. A light emitting structure having an off-axis microlens structure comprising:

52. 52. The light emitting structure of claim 51, wherein the third microlens covers and contacts the entire top surface of the second microlens.

53. 53. The light emitting structure of claim 51 or 52, wherein the offset range of the central axis of the first microlens from the central axis of the first light emitting mesa is 4.5 μm or less.

54. 54. The light emitting structure of claim 51, wherein an offset distance between an edge of a bottom surface of the first light emitting mesa and an edge of a bottom surface of the first microlens is within 30% of a diameter of the bottom surface of the first microlens.

55. 55. The light emitting structure of claim 51, wherein the material of the first microlens is silicon oxide or an organic material.

56. 56. The light emitting structure of claim 51, wherein a bottom surface of the first microlens intersects with the central axis of the first light emitting mesa.

57. Further comprising a semiconductor substrate and at least two reflector cups; the first light emitting mesa and the second light emitting mesa are formed on the semiconductor substrate; 57. The light emitting structure of claim 51, wherein the first light emitting mesa and the second light emitting mesa are surrounded by respective ones of the two reflector cups.

58. 58. The lighting structure of claim 57, wherein an inner wall of the reflector cup is stepped.

59. The first light emitting mesa includes: A first light-emitting layer; and a first bottom bonding layer located at the bottom of the first light emitting layer and bonded to the semiconductor substrate; a top electrode layer on a top surface of the first light emitting mesa and electrically connected to a first of the two reflector cups; The second light emitting mesa includes: A second light-emitting layer; and a second bottom bonding layer at the bottom of the second light emitting layer and bonded to the semiconductor substrate; the top electrode layer also on a top surface of the second light emitting mesa and electrically connected to a second one of the two reflector cups; 60. The light emitting structure of claim 57 or 58, wherein the first and second reflector cups are electrically connected to a semiconductor substrate.

60. a spacer covering the first light emitting mesa and the second light emitting mesa; the spacer is formed between the first light emitting mesa and the first microlens; 60. The light emitting structure of claim 51, wherein the spacer is also formed between the second light emitting mesa and the second microlens.

61. 61. The light emitting structure of claim 60, wherein a height of the spacer is less than a height of the first microlens.

62. 62. The light emitting structure of claim 51, wherein a diameter of the third microlens is greater than a diameter of the second microlens.

63. a central axis of the second microlens is aligned coaxially with a central axis of the second light emitting mesa; 63. The light emitting structure of claim 51, wherein a central axis of the third microlens is not coaxially aligned with the central axis of the second light emitting mesa.

64. a central axis of the third microlens is aligned coaxially with a central axis of the second light emitting mesa; 64. The light emitting structure of claim 51, wherein a central axis of the second microlens is not coaxially aligned with the central axis of the second light emitting mesa.

65. a central axis of the second microlens is not coaxially aligned with a central axis of the second light emitting mesa; a central axis of the third microlens is not coaxially aligned with the central axis of the second light emitting mesa; 65. The light emitting structure of claim 51, wherein the central axis of the second microlens is not coaxially aligned with the central axis of the third microlens.

66. the light emitting structure includes more than one set of a light emitting mesa, a first microlens, a second microlens, and a third microlens; 66. The light emitting structure of claim 51, wherein a position of each second microlens relative to a respective third microlens on the light emitting structure in each set is different.

67. 67. The light emitting structure of claim 63, wherein an offset distance between the central axis of the third microlens and the central axis of the second light emitting mesa is less than or equal to 12 μm.

68. 68. The light emitting structure of claim 67, wherein an offset distance between the central axis of the second microlens and the central axis of the second light emitting mesa is 1.5 μm or less.

69. 69. The light emitting structure of claim 68, wherein an offset distance between the central axis of the second microlens and the central axis of the third microlens is less than or equal to 6 μm and greater than or equal to 4.5 μm.

70. 70. The light emitting structure of claim 51, wherein a bottom surface of the third microlens intersects with a central axis of the second light emitting mesa.

71. 71. The light emitting structure of claim 70, wherein a bottom surface of the second microlens does not intersect with a central axis of the second light emitting mesa.

72. the material of the second microlens is the same as the material of the third microlens; 72. The light emitting structure of claim 70 or 71, wherein the material of the first microlens is the same as the material of the third microlens.

73. 73. The light emitting structure of claim 51, wherein an offset distance between the central axis of the first microlens and the central axis of the first light emitting mesa is smaller than an offset distance between the central axis of the third microlens and the central axis of the second light emitting mesa.

74. 74. The light emitting structure of any one of claims 57 to 73, wherein the semiconductor substrate is an IC substrate.

75. a first light emitting mesa; a first microlens formed above the first light emitting mesa, the first microlens having a central axis that is not coaxially aligned with a central axis of the first light emitting mesa; a second light emitting mesa; a second microlens formed above the second light emitting mesa; a third microlens formed on the second microlens, the third microlens not covering an entire top surface of the second microlens; A light emitting structure comprising:

76. 76. The light emitting structure of claim 75, wherein an offset distance between the central axis of the first microlens and the central axis of the first light emitting mesa is 4.5 μm or less.

77. 77. The light emitting structure of claim 75 or 76, wherein an offset distance between an edge of a bottom surface of the first light emitting mesa and an edge of a bottom surface of the first microlens is within 30% of a diameter of the bottom surface of the first microlens.

78. 78. The light emitting structure of claim 75, wherein the material of the first microlens is silicon oxide or an organic material.

79. 79. The light emitting structure of claim 75, wherein a bottom surface of the first microlens intersects with the central axis of the first light emitting mesa.

80. Further comprising a semiconductor substrate and a reflector cup; the first light emitting mesa and the second light emitting mesa are formed on the semiconductor substrate; 80. The light emitting structure of any one of claims 75 to 79, wherein the first light emitting mesa and the second light emitting mesa are surrounded by respective reflector cups.

81. 81. The light emitting structure of claim 80, wherein an inner wall of each of the reflector cups is stepped.

82. The first light emitting mesa includes: A first light-emitting layer; and a first bottom bonding layer formed on a bottom of the first light emitting layer and bonded to the semiconductor substrate; a top electrode layer covering the first light emitting layer and electrically connected to a first one of the reflector cups; The second light emitting mesa includes: A second light-emitting layer; and a second bottom bonding layer formed on a bottom of the second light emitting layer and bonded to the semiconductor substrate; the top electrode layer also covering the second light emitting layer and electrically connected to a second one of the reflector cups; 82. The light emitting structure of claim 80 or 81, wherein the reflector cup is electrically connected to the semiconductor substrate.

83. a spacer covering the first light emitting mesa and the second light emitting mesa; the spacer is formed between the first light emitting mesa and the first microlens; 83. The light emitting structure of any one of claims 75 to 82, wherein the spacer is also formed between the second light emitting mesa and the second microlens.

84. 84. The light emitting structure of claim 83, wherein a height of the spacer is less than a height of the first microlens.

85. 85. The light emitting structure of any one of claims 75 to 84, wherein a horizontal dimension of the third microlens is smaller than a horizontal dimension of a base of the second microlens.

86. a central axis of the second microlens is aligned coaxially with a central axis of the second light emitting mesa; a vertical axis of the third microlens is not coaxially aligned with the central axis of the second light emitting mesa; 86. The light emitting structure of claim 75, wherein the vertical axis passes through a center point of the third microlens when the third microlens is perfectly aligned.

87. the light emitting structure includes more than one set of a light emitting mesa, a first microlens, and a second microlens; 87. The light emitting structure of claim 75, wherein a position of each first microlens relative to each second microlens on the light emitting structure in each set is different.

88. 88. The light emitting structure of claim 86 or 87, wherein an offset distance between the vertical axis of the third microlens and the central axis of the second light emitting mesa is 1.5 μm or less.

89. 89. The light emitting structure of any one of claims 75 to 88, wherein a bottom surface of the second microlens intersects with a central axis of the second light emitting mesa.

90. 90. The light emitting structure of claim 89, wherein a bottom surface of the first microlens does not intersect with a central axis of the first light emitting mesa.

91. the material of the second microlens is the same as the material of the third microlens; 91. The light emitting structure of claim 89 or 90, wherein the material of the first microlens is the same as the material of the second microlens.

92. 92. The light emitting structure of claim 86, wherein an offset distance between the central axis of the first microlens and the central axis of the first light emitting mesa is greater than an offset distance between the vertical axis of the third microlens and the central axis of the second light emitting mesa.

93. 93. The light emitting structure of any one of claims 80 to 92, wherein the semiconductor substrate is an IC substrate.

94. A luminous mesa; a first microlens formed on the light emitting mesa; a second microlens covering and in contact with the first microlens; 1. A light emitting structure having a coaxial microlens comprising:

95. 95. The light emitting structure having coaxial microlenses of claim 94, wherein the refractive index of the first microlens is higher than the refractive index of the second microlens.

96. 96. A light emitting structure having coaxial microlenses as claimed in claim 94 or 95, wherein a material of the second microlens is different from a material of the first microlens.

97. the first microlens has a hemispherical structure; 97. A light emitting structure having a coaxial microlens as claimed in any one of claims 94 to 96, wherein the second microlens has a polygonal structure when there is no cutting of the first microlens, or a composite structure when there is no cutting of the first microlens.

98. 98. The light emitting structure having coaxial microlenses according to claim 97, wherein the composite structure is a combination of a hemispherical structure and a trapezoidal structure or a hemispherical structure and a triangular structure.

99. 99. The light emitting structure having a coaxial microlens of claim 98, wherein the trapezoidal structure is formed at the bottom of the hemispherical structure or the triangular structure is formed at the bottom of the hemispherical structure.

100. 100. A light emitting structure having a coaxial microlens as claimed in any one of claims 97 to 99, wherein the polygonal structure is a trapezoidal structure having a top surface inclined relative to a base surface of the trapezoidal structure.

101. 101. A light emitting structure having coaxial microlenses as described in any one of claims 94 to 100, wherein a central axis of the first microlens and a central axis of the second microlens are aligned coaxially with a central axis of the light emitting mesa.

102. Further comprising a semiconductor substrate and a reflector cup; the light emitting mesa is formed on the semiconductor substrate; 102. The light emitting structure having a coaxial microlens according to any one of claims 94 to 101, wherein the light emitting mesa is surrounded by the reflector cup.

103. 103. The light emitting structure having a coaxial microlens as described in claim 102, wherein an inner wall of the reflector cup has a stepped shape.

104. The light emitting mesa is A light-emitting layer; a bottom bonding layer located at the bottom of the light emitting layer and bonded to the semiconductor substrate; a top electrode layer covering the light emitting mesa and electrically connected to the reflector cup; 104. The light emitting structure having a coaxial microlens according to claim 102 or 103, wherein the reflector cup is electrically connected to the semiconductor substrate.

105. 105. The light emitting structure having a coaxial microlens according to any one of claims 94 to 104, further comprising a spacer formed above the light emitting mesa.

106. 106. The light emitting structure having coaxial microlenses of claim 105, wherein a height of the spacer is less than a height of the first microlens or a height of the second microlens.

107. 107. The light emitting structure having a coaxial microlens according to any one of claims 102 to 106, wherein the semiconductor substrate is an IC substrate.

108. A light emitting structure having an elliptical microlens structure, A luminous mesa; at least one elliptical microlens formed above the light emitting mesa; A light emitting structure, wherein a central axis of the elliptical microlens is not coaxially aligned with a central axis of the light emitting mesa.

109. 109. The light emitting structure of claim 108, wherein the elliptical microlenses are formed by a combination of a quarter of a sphere and a quarter of an ellipsoid.

110. The radius of the sphere is 9 μm or less, 110. The light emitting structure of claim 109, wherein the semimajor axis of the ellipsoid is 18 μm or less.

111. 111. The light emitting structure of claim 109 or 110, wherein an offset distance of a center of the elliptical microlens from a center of the light emitting mesa at a horizontal level is 4.5 μm or less.

112. 112. The light emitting structure of any one of claims 108 to 111, wherein the material of the elliptical microlenses is silicon oxide or an organic material.

113. 113. The light emitting structure of any one of claims 108 to 112, wherein a base of the elliptical microlens intersects with the central axis of the light emitting mesa.

114. Further comprising a semiconductor substrate and a reflector cup; the light emitting mesa is formed on the semiconductor substrate; 114. The light emitting structure of any one of claims 108 to 113, wherein the light emitting mesa is surrounded by the reflector cup.

115. 115. The light emitting structure of claim 114, wherein an inner wall of the reflector cup is stepped.

116. The light emitting mesa is A light-emitting layer; a bottom bonding layer located at the bottom of the light emitting layer and bonded to the semiconductor substrate; a top electrode layer covering the light emitting mesa and electrically connected to the reflector cup; 116. The light emitting structure of claim 114 or 115, wherein the reflector cup is electrically connected to the semiconductor substrate.

117. 117. The light emitting structure of any one of claims 108 to 116, further comprising a spacer formed between the light emitting mesa and the elliptical microlens.

118. 118. The light emitting structure of claim 117, wherein a height of the spacers is less than a height of the elliptical microlenses.

119. 119. The light emitting structure of claim 117 or 118, wherein the spacer has a height of less than 5 μm.

120. 120. The light emitting structure of any one of claims 114 to 119, wherein the semiconductor substrate is an IC substrate.

121. A luminous mesa; a composite microlens structure having at least one microlens formed above the light emitting mesa and a reflector formed on one side of the microlens; A light emitting structure having a composite microlens structure comprising:

122. 122. The light emitting structure of claim 121, wherein the microlens is a sphere having a crack in a surface of the microlens.

123. 123. The light emitting structure of claim 122, wherein the reflector is formed on a surface of the crack.

124. the crack has an inclined surface with respect to a bottom surface of the microlens, 124. The light emitting structure of claim 123, wherein the reflector is a planar structure attached to the inclined surface.

125. The crack is a depression, 125. The light emitting structure of claim 123 or 124, wherein the reflector is attached to a surface of the recess.

126. 126. The light emitting structure of any one of claims 121 to 125, wherein the material of the microlenses is silicon oxide or an organic material.

127. 127. The light emitting structure of any one of claims 121 to 126, wherein a bottom surface of the microlens intersects with a central axis of the light emitting mesa.

128. Further comprising a semiconductor substrate and a reflector cup; the light emitting mesa is formed on the semiconductor substrate; 128. The light emitting structure of any one of claims 121 to 127, wherein the light emitting mesa is surrounded by the reflector cup.

129. 129. The light emitting structure of claim 128, wherein an inner wall of the reflector cup is stepped.

130. The light emitting mesa is A light-emitting layer; a bottom bonding layer located at the bottom of the light emitting layer and bonded to the semiconductor substrate; a top electrode layer covering the light emitting mesa and electrically connected to the reflector cup; 130. The light emitting structure of claim 128 or 129, comprising: the reflector cup electrically connected to the semiconductor substrate.

131. 131. The light emitting structure of any one of claims 121 to 130, further comprising a spacer formed between the light emitting mesa and the microlens.

132. 132. The light emitting structure of claim 131, wherein a height of the spacers is less than a height of the microlenses.

133. 133. The light emitting structure of any one of claims 128 to 132, wherein the semiconductor substrate is an IC substrate.

134. A luminous mesa; a microlens formed on the light emitting mesa; a diffractive lens covering the microlens; A light emitting structure comprising:

135. 135. The light emitting structure of claim 134, wherein the material of the microlenses is different from the material of the diffractive lenses.

136. 136. The light emitting structure of claim 134 or 135, wherein the diffractive lens is a Bragg mirror.

137. 137. The light emitting structure of any one of claims 134 to 136, wherein the center point of the top surface of the diffractive lens is on the central axis of the microlens.

138. a central axis of the diffractive lens is inclined with respect to a vertical axis perpendicular to a substrate of the light emitting structure; 138. The light emitting structure of claim 137, wherein the central axis of the microlens is perpendicular to the vertical axis that is perpendicular to the substrate of the light emitting structure.

139. The microlens has a hemispherical structure, 139. The light emitting structure of any one of claims 134 to 138, wherein the diffractive lens has a polygonal structure or a composite structure.

140. 140. The light emitting structure of claim 139, wherein the composite structure comprises a combination of hemispherical and trapezoidal structures or a combination of hemispherical and triangular structures.

141. 141. The light emitting structure of claim 140, wherein the trapezoidal structure is formed at the base of the hemispherical structure or the triangular structure is formed at the base of the hemispherical structure.

142. 142. The light emitting structure of any one of claims 139 to 141, wherein the polygonal structure is a trapezoidal structure with a top surface that is inclined relative to a base surface of the trapezoidal structure.

143. 143. The light emitting structure of any one of claims 134 to 142, wherein a central axis of the microlens and an axis passing through a central point of the top surface of the diffractive lens are aligned coaxially with a central axis of the light emitting mesa.

144. Further comprising a semiconductor substrate and at least one reflector cup; the light emitting mesa is formed on the semiconductor substrate; 144. The light emitting structure of any one of claims 134 to 143, wherein the light emitting mesa is surrounded by the at least one reflector cup.

145. 145. The light emitting structure of claim 144, wherein an inner wall of the reflector cup is stepped.

146. The light emitting mesa is A light-emitting layer; a bottom bonding layer located at the bottom of the light emitting layer and bonded to the semiconductor substrate; a top electrode layer covering the light emitting mesa and electrically connected to the at least one reflector cup; 146. The light emitting structure of claim 144 or 145, wherein the at least one reflector cup is electrically connected to the semiconductor substrate.

147. 147. The light emitting structure of any one of claims 134 to 146, further comprising a spacer covering the light emitting mesa.

148. 148. The light emitting structure of claim 147, wherein the height of the spacers is less than the height of the microlenses.

149. 149. The light emitting structure of any one of claims 144 to 148, wherein the semiconductor substrate is an IC substrate.

150. A luminous mesa; at least one microlens formed above the light emitting mesa, the central axis of the microlens not being coaxially aligned with the central axis of the light emitting mesa; 1. A light emitting structure having an off-axis microlens structure comprising:

151. 151. The light emitting structure of claim 150, wherein an offset distance between the central axis of the microlens and the central axis of the light emitting mesa is 4.5 μm or less.

152. 152. The light emitting structure of claim 150 or 151, wherein an offset distance between an edge of the base of the light emitting mesa and an edge of the base of the microlens is within 30% of a diameter of the base of the first microlens.

153. 153. The light emitting structure of any one of claims 150 to 152, wherein the material of the microlens is silicon oxide or an organic material.

154. 154. The light emitting structure of any one of claims 150 to 153, wherein a bottom surface of the microlens intersects with the central axis of the light emitting mesa.

155. Further comprising a semiconductor substrate and a reflector cup; the light emitting mesa is formed on the semiconductor substrate; 155. The light emitting structure of any one of claims 150 to 154, wherein the light emitting mesa is surrounded by the reflector cup.

156. 156. The light emitting structure of claim 155, wherein an inner wall of the reflector cup is stepped.

157. The light emitting mesa is A light-emitting layer; a bottom bonding layer located at the bottom of the light emitting layer and bonded to the semiconductor substrate; a top electrode layer covering the light emitting mesa and electrically connected to the reflector cup; 157. The light emitting structure of claim 155 or 156, wherein the reflector cup is electrically connected to the semiconductor substrate.

158. 158. The light emitting structure of any one of claims 150 to 157, further comprising a spacer formed between the light emitting mesa and the microlens.

159. 159. The light emitting structure of claim 158, wherein the height of the spacers is less than the height of the microlenses.

160. 160. The light emitting structure of any one of claims 155 to 159, wherein the semiconductor substrate is an IC substrate.

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