Optical data transmission in light emitting modules

Abstract

A light-emitting module includes a first surface and a second surface comprising a plurality of light-emitting elements, configured to receive drive signals and transfer such signals to the light-emitting elements on the first surface. The second surface includes a plurality of optical transmitters, each of which is associated with an associated optical receiver arranged on the first surface. The optical transmitters and the associated corresponding optical receivers are separated by an optical medium such that an optical signal containing a drive signal transmitted by the optical transmitter is received by the corresponding optical receiver. Each optical receiver is connected to at least one light-emitting element and configured to convert the optical signal into an electrical signal that drives the at least one light-emitting element to generate an image on the display.

Description

Technical Field

[0001] Invention Field

[0002] This disclosure relates to the field of light-emitting modules for use in light-emitting displays, and more particularly to the transmission of signal data within such light-emitting modules. These light sources are typically solid-state light-emitting elements, such as LEDs or micro-LEDs. Prior Technology

[0003] Background of the Invention

[0004] The use of LEDs (light-emitting diodes) in display technology has a long history. LEDs have proven to be reliable, durable, time-consistent, powerful, and stable, making them a perfect technology for direct-view displays. For efficient and low-cost operation, modern LED displays are driven in an active matrix mode, similar to how LCD displays are driven.

[0005] To understand this type of display, TFT (thin-film transistor) technology can be used. These LEDs are mounted on a carrier or light-emitting module of a specific size, such as an on-glass TFT on which electronic driving circuitry is implemented (e.g., a reference current source for fixed current driving, a level shifter for voltage correction, a pipeline logic flip-flop, a shift register, etc.).

[0006] This technology is used in high-resolution displays. A large number of contacts need to be rerouted to the back end of the light-emitting module. The number of contacts depends on the integration level of the electronic components on the TFT light-emitting module; however, all such connections need to be rerouted to the back end of the light-emitting module. Planar contact technology used in LCD panels is not feasible because these light-emitting modules need to be seamlessly tiled. Therefore, the space between adjacent modules used to relay these contacts from the front end of the light-emitting module to the back end is quite limited and inevitably becomes the tolerance space between the edges of these adjacent modules.

[0007] To relay these contacts from the front to the back of the light-emitting module, a current-side contact technology is required, which must be suitable for the narrow space between adjacent light-emitting modules. WO2015079058A1 discloses a solution that saves space by placing the conductive material of the light-emitting module on the sidewall to create a narrower edge between adjacent light-emitting modules. This solution is no longer suitable for microLEDs when the LED display is in good working order, for example, when an additional number of electrical connections must be added. In fact, thousands of contacts (e.g., 40 micrometers wide and 2 micrometers thick) at the front of the light-emitting module need to be contacted on both the front and back sides, which can double the net number of contacts.

[0008] In addition to data signals, power, reference points, and grounding also need to be made accessible. These contacts are typically large and located above the edge of the light-emitting module, thus occupying space for these data signals.

[0009] One remaining challenge is to provide a light-emitting module with a narrow edge and thousands of contacts, from which data signals, in addition to power, reference points and ground, are transmitted between the front and rear sides of the light-emitting module. Summary of the Invention

[0010] Invention Summary

[0011] One object of the present invention is to provide a light-emitting module comprising a first surface and a second surface. The first surface includes a plurality of light-emitting elements, and the second surface is configured to receive driving signals and transfer such signals to the light-emitting elements on the first surface. The second surface further includes a plurality of optical transmitters, each of which is associated with an optical receiver arranged on the first surface. The optical transmitters and the associated optical receivers are separated by an optical medium such that an optical signal transmitted by the optical transmitter is received by the associated optical receiver. Each optical receiver is connected to at least one light-emitting element and is configured to convert the optical signal into an electrical signal. The electrical signal is configured to drive the at least one light-emitting element to generate an image for a display.

[0012] Providing optical transmitters and receivers eliminates the need for electrical connections to transmit such data signals. It offers a new method for transferring data within a light-emitting module. Furthermore, these optical transmitters and receivers can be implemented anywhere on the first and second surfaces of the light-emitting module. This solution requires only one optical medium between each pair of optical transmitters and receivers.

[0013] The optical receiver can be an optical photosensitive device. The optical photosensitive device can be easily implemented on a TFT, for example, as a transistor, similar to a photosensitive device used for fingerprint detection.

[0014] The optical transmitter may be a light-emitting element, preferably an LED, OLED and its variations, QD-LED, EL-QLED, AMOLED, mini LED, micro LED, or a laser.

[0015] When LEDs are used as point light sources, there are advantages to using LEDs in the optical transmitter. Furthermore, LEDs are energy-efficient, compact, and provide easily adjustable high radiation intensity. Any spectral bandwidth can be used, thus the optical receiver can be easily tuned to be highly sensitive to the spectral bandwidth of the light emitted by the optical transmitter. In addition to the visible spectrum, IR and UV LEDs can be used. LEDs can also provide a collimated beam with simple collimating optics.

[0016] These light-emitting elements can be any type of LED, OLED and its variations, QD-LED, EL-QLED, AMOLED, mini LED, or micro LED.

[0017] Although this invention has been fabricated to provide easy transfer of data signals when the light-emitting module is filled with thousands of micro-LEDs, this invention is not limited to micro-LEDs. This novel optical method for transferring signal data can be used with any type of display as defined above.

[0018] The first surface and / or the second surface may preferably be any type of TFT on glass, TFT on polyimide, or PCB.

[0019] This invention is not limited to the type of surface used. However, TFTs or PCBs are commonly used in this display field. It is quite important that an optical medium separates the first and second surfaces at at least the locations of the optical receivers and transmitters. The first and second surfaces are preferably optically connected at these locations. Glass can also be used as the optical medium. Any surface, such as a PCB or TFT on a substrate, can also be used, suitable for carrying the light-emitting elements and related electronic components, as well as the optical receiver for the first surface and the optical transmitter for the second surface. Therefore, the first and second surfaces can also be provided by the same PCB, wherein holes can be made at the locations of the optical receivers and transmitters. The first and second surfaces can then be the top and bottom surfaces of the PCB.

[0020] The refractive indices of the first and second surfaces can be selected to minimize the total internal reflection of light.

[0021] In fact, the goal is to reduce stray light to achieve the desired effect on these optical receivers.

[0022] An aperture can be set along the optical path between each optical transmitter and its associated optical receiver. This aperture can then be configured so that the beam emitted by the optical transmitter reaches the optical receiver in a mirror image.

[0023] Setting an aperture can further reduce stray light and prevent light from an optical transmitter from reaching a non-directly corresponding or unrelated optical receiver. Furthermore, mirroring the beam can reduce interference between the optical signals received by these optical receivers.

[0024] The aperture can be arranged in an aperture layer disposed between the first surface and the second surface. The aperture layer is preferably laminated or attached. The aperture layer may also contain light-absorbing properties.

[0025] Such porous layers can be easily manufactured and can be readily implemented between the first and second surfaces.

[0026] The refractive index of the aperture layer and the refractive indices of the first and second surfaces can be selected to minimize the total internal reflection of light.

[0027] Stray light can therefore be significantly reduced.

[0028] An optical lens can be further positioned along the optical path between each pair of optical receivers and optical transmitters. The optical lens can be assembled to focus the beam emitted by the optical transmitter onto the optical receiver. The optical lens can also be provided by collimating optics on the optical transmitter.

[0029] The optical lens can also be arranged within a miniature biconvex lens. This arrangement is easily achieved.

[0030] The optical lens can be placed within the aperture of the aperture layer.

[0031] The aperture layer may further have a thickness of at least the diameter of the aperture, such that each aperture is a light guide funnel for selectively transmitting a mirrored beam emitted by the optical transmitter toward the optical receiver.

[0032] The advantage of placing a funnel between the optical receiver and the transmitter is that it further reduces stray light in the optical medium and at the entrance of the optical receiver.

[0033] Two adjacent optical transmitters are preferably coupled to emit radiation of a different type. The corresponding optical receiver is then coupled to receive the radiation from its associated optical transmitter.

[0034] This has the advantage of further reducing unwanted signals reaching each optical receiver.

[0035] For example, an optical receiver is preferably configured to receive the same spectral bandwidth as its associated optical transmitter.

[0036] Two adjacent optical transmitters preferably emit light with different spectral bandwidths.

[0037] An optical transmitter is preferably configured to transmit light with at least two different spectral bandwidths, and the two associated optical receivers are configured to be highly sensitive to the two different spectral bandwidths.

[0038] Each spectral bandwidth of the associated optical receiver may also include an output, so that an optical receiver can provide an additional drive signal.

[0039] For example, the optical transmitter can be provided by a white LED that emits red, green, and blue light. An optical receiver can then be assembled to receive the red, green, and blue components of the optical signal, thus enabling a single optical transmitter to send three more pieces of information. Therefore, different wavelengths can be used to modulate different signals.

[0040] The optical receiver has good sensitivity and can be modulated to selectively respond to incident mirror light from the associated optical transmitter.

[0041] A neutral density layer may also be disposed between the optical transmitter and the optical receiver.

[0042] The power consumption of the optical transmitter can be further reduced to increase the signal-to-noise ratio of the optical receiver.

[0043] All these options provide methods for altering the sensitivity of the optical receiver and improving its reception of data signals. By reducing the power consumption of the optical transmitter, noise can also be reduced for the unrelated optical receiver. The optical receiver can be more selective in receiving its desired signal. Interference from adjacent stray light can therefore be minimized.

[0044] The sensitivity of the optical receiver can also be modulated by matching the critical level of the analog signal received by the optical receiver.

[0045] This is similar to what was described above, but it is located at the level of the optical receiver.

[0046] The optical receiver is preferably covered by a protective layer to reduce the penetration of ambient light into the inside of the light-emitting module.

[0047] Covering the optical receiver can reduce contamination from stray light or even unwanted light from the display's light-emitting elements.

[0048] The optical transmitters are advantageously covered by a protective cover to reduce the penetration of ambient light into the light-emitting module.

[0049] The optical transmitters and associated optical receivers are preferably arranged to optimize the space on the first and second surfaces.

[0050] The optical transmitters and receivers can therefore be arranged in a matrix configuration on the first and second surfaces, respectively. One advantage of using optical data transmission is that the optical transmitters and receivers can be placed anywhere on the first and second surfaces, and do not require a periodic arrangement. They can be installed in locations with sufficient space to accommodate other specific circuitry.

[0051] It should be understood that both the foregoing general description and the following detailed description are exemplary and intended to provide further explanation of the invention as requested. Other advantages and features of the invention will become more apparent from the following description, drawings, and claims. Simple Explanation of the Diagram

[0052] The novel features of this invention are believed to be presented in accordance with the characteristics described in the appended claims. However, the invention itself can be best understood by referring to the following detailed description of the invention, which illustrates an exemplary embodiment, and in conjunction with the accompanying drawings, wherein: Figure 1A illustrates a light-emitting module for fixing to a display, which is one of the basic carriers. Figure 1B illustrates multiple light-emitting modules mounted on a display. Figure 2 is a detailed view of the light-emitting module in Figure 1A. Figure 3A illustrates the second surface of an LED light-emitting module, which has one of its electronic components. Figure 3B illustrates the first surface of a light-emitting module, wherein the light source is an LED. Figure 4 illustrates the first and second surfaces of a stacked LED module. Figure 5A illustrates a ball grid array used to connect a light-emitting module to a basic carrier according to the prior art. Figure 5B shows different layers in an exploded view of an LED module and one of its basic carriers. Figure 6A shows one of the OPDs on a TFT backplane. Figure 6B is a schematic representation showing that a threshold value is applied to the analog signal transmitted by the optical transmitter to generate a digital signal to be fed to the light-emitting elements. Figure 7 is a side view of a light-emitting module having a first and a second surface of a TFT backplane that transfers electrical signals to a sequence of optical transmitters and associated optical receivers of the display light-emitting elements. Figure 8A is a schematic representation of the Lambertian emission of the LED optical transmitter, wherein an aperture layer is provided to make the beam appear as a mirror image when it reaches the optical receiver. Figure 8B shows one representation of this aperture, which has a thickness such that the optical signal emitted by the optical transmitter travels in a funnel when it reaches the optical receiver. [Definitions and Abbreviations]

[0053] [Active Matrix]

[0054] An active matrix is ​​a type of addressing scheme used in flat panel displays. In this method of switching individual elements (pixels), each pixel is attached to a transistor and capacitor that actively maintain the state of the pixel when other pixels are addressed.

[0055] Active matrix circuits are typically constructed using thin-film transistors (TFTs) in a semiconductor layer formed on a display substrate, and each emitting pixel in the display is controlled by a separate TFT circuit. The semiconductor layer is typically amorphous silicon or polycrystalline silicon and is distributed across the entire flat panel display substrate. An active matrix display can also be, for example, an LCD, an electrophoretic reflective transmissive emission display, or a similar display.

[0056] A subpixel of a display can be controlled by a control element, and each control element includes at least one transistor. For example, in a simple active-matrix LED display, each control element includes two transistors (a select transistor and a power transistor) and a capacitor for storing a charge specifying the brightness of that subpixel. Each LED element uses a separate control electrode connected to the power transistor and a common electrode. Control of the light-emitting element in a well-known active matrix display is typically provided through a data signal line, a select signal line, a power or supply connection (see, for example, VDD), and a ground connection.

[0057] A backplane is a panel that contains electronic components assembled to drive a light-emitting display. A backplane can be, for example, a PCB backplane or a TFT backplane. [BGA] [Ball grid array]

[0058] [Carrier board] Refers to a panel assembled to receive at least one display module. It serves as a support structure for a tiled display. The carrier board can be a back panel or a mechanical support structure. It can also serve as a distribution panel for power, grounding, and for distributing the signals to the optical transmitters to arrange the individual modules.

[0059] [Drive signal or data signal] is a signal that contains information for driving the light-emitting elements to generate an image on the display. Depending on which stage of the transmission process it is in, it can be a digital signal, an analog signal, an optical pulse signal, etc. [monitor]

[0060] A display screen may be composed of a structure of light-emitting pixels referred to as "display pixels" or "pixels," wherein the number of display pixels determines the "display resolution," sometimes referred to as the "natural display resolution" or the "natural pixel resolution." One measure of display resolution may be the total number of display pixels in a display, for example, 1920x1080 pixels. Each display pixel can emit light in all colors of the display's color gamut (i.e., all color combinations the display can provide).

[0061] Each [Display pixels] can be referenced as " A display pixel is composed of light-emitting elements called "subpixels," which typically emit red (R), green (G), or blue (B) (but may also emit white, yellow, or other colors). A display pixel may consist of at least three subpixels: a red subpixel, a green subpixel, and a blue subpixel. Furthermore, the display pixel may include other subpixels of any of the aforementioned colors (to further expand the color gamut). Depending on the type of these subpixels, the display pixel may subsequently be referred to as an RGB-, RGGB-, RRGB-, etc. A single display pixel can produce all the colors of the display's color gamut, whereas a single subpixel cannot.

[0062] The emission of a single pixel can be individually controlled, allowing each display pixel to emit the brightness and color required to form the desired image.

[0063] A display module is a module that includes at least one light-emitting module arranged on a carrier. The carrier system of the display module is configured to transfer drive signals and power signals to the at least one light-emitting module.

[0064] Multiple display modules can be placed on a larger carrier plate (mechanical interface) to create a tiled display and connected to an external device or the display module. The function of the driver can also be embedded in the display module.

[0065] [Duty Cycle] The term duty cycle describes the ratio of 'operating' time to a regular interval or time 'cycle'; a low duty cycle is equivalent to low power, because the power is off most of the time. Duty cycles are expressed as a percentage, with 100% representing full operation. [LED] [Light Emitting Diode]

[0066] [Light-emitting element] A light-emitting element may be, for example, a solid-state light-emitting element, such as an LED or an OLED (organic LED) light-emitting diode. [Light-emitting module]

[0067] A light-emitting module is an optomechanical carrier of a specific size that carries and guides light-emitting elements to a viewfinder, as well as possible light-emitting elements for driving and controlling electronic components. These light-emitting elements are driven to create a static or dynamic (video) image. Hereinafter, this light-emitting module will be referred to as an "LED module," although the invention is not limited to LEDs. Several LED modules or OLED modules can be placed adjacent to each other to form a display module. Several display modules can be tiled together to form a larger tiled display.

[0068] A single atomic element, that is, an indivisible small LED module, can be referred to as a "stamp". This light-emitting module can have any size and shape. If it is suitable for placement in a robot on a display module, it can be rectangular or square, hexagonal, triangular, or any shape. It may also contain a pixel comprising a red, green, and blue LED.

[0069] The light-emitting module includes at least one backplane. The top surface of the backplane includes the light-emitting elements and associated conductive tracks, which connect various light-emitting elements to various electronic components (e.g., current drivers, power supply contacts, etc.). The backplane can be a PCB, a TFT on glass, a TFT on PI, etc.

[0070] The following patent applications from the same applicant provide definitions of LED displays and related terms. These definitions are therefore incorporated herein by reference. - US7972032B2 “LED Assembly” - US7176861B2 "Pixel structure with optimized subpixel size for light-emitting displays" - US7450085 "Smart lighting modules and operating methods of such smart lighting modules" - US7071894 "Method and apparatus for displaying images on a display device".

[0071] one [Optical path] is the path that a ray of light follows when it passes through an optical medium or system.

[0072] one [Optical media] are materials through which electromagnetic waves propagate.

[0073] one A photosensitive device is a semiconductor device that converts light into an electric current. This current is generated when photons are absorbed by the device. The device may include filters, built-in lenses, and may have a large or small surface area. [TGV] [Penetrating glass hole]

[0074] [Thin Film Technology] Referring to the use of thin films: a thin film, several molecules thick, is deposited on a glass, ceramic, or semiconductor substrate to form, for example, a capacitor, resistor, coil, cooler, or other circuit component. A thin film or material, ranging from one to several hundred molecules thick, is deposited on a solid substrate such as glass or ceramic, or as a layer on a supporting liquid. TFTs can be deposited on a substrate such as glass or PI. They comprise multiple circuit layers, semiconductors, and isolation layers. Implementation

[0075] Detailed Description of Preferred Embodiments

[0076] The terminology used to describe specific embodiments is not intended to be limiting of the invention. As used herein, unless the context clearly indicates otherwise, the singular forms "a," "an," and "the" are intended to include the plural forms as well. The terms "and / or" include any and all combinations of one or more of the associated items listed. It should be understood that the terms "comprising" and / or "comprising of" specify the presence of the stated feature but do not exclude the presence or addition of one or more other features. It should be further understood that when a particular step of a method refers to another step, it may directly follow the other step or one or more intermediate steps may be performed before the particular step, unless otherwise specified. Similarly, it should be understood that when describing a connection between structures or components, unless otherwise specified, the connection may be established directly or through intermediate structures or components.

[0077] While the invention may be described with reference to specific embodiments and certain drawings, it is not limited thereto, but is limited only by the claims. These illustrative drawings are for illustrative purposes only and are not limiting. The dimensions of certain elements in these drawings may be exaggerated and are not drawn to scale for illustrative purposes. The term "comprising" is used in this description and claims and does not exclude other elements or steps.

[0078] Furthermore, the terms "first," "second," "third," etc., used in this description and claim are for distinguishing between similar elements and are not intended to describe a sequence or chronological order. It should be understood that such terms are interchangeable where appropriate, and the embodiments of the invention described herein can operate in other orders than those described or illustrated herein.

[0079] The terms "approximately" or "closely" are synonyms and are used to indicate that the numerical value modified by the term has an associated comprehensible range, which may be +20%, +15%, +10%, +5%, or +1%. The term "substantially" is used to indicate that a result (e.g., a measurement) is close to a target value, where close can be expressed as, for example, the result being within 80%, 90%, 95%, or 99% of the value.

[0080] Figures 1A and 1B illustrate a light-emitting module 110 for a display 100. These light-emitting elements can be any light-emitting element provided in the defined section. However, for clarity, LEDs can be used in these illustrated examples. Therefore, an LED display 100 comprising multiple LED modules 110 (light-emitting modules) is shown here. Figure 1A provides a side view of the display, and Figure 1B provides a front view. Each module 110 is secured to a carrier 120 via wiring 130, which provides mechanical and electrical connections. The carrier can be further connected to an external driver 140 via a flexible connection to an external driver connector 150.

[0081] The carrier 120 can be a PCB with or without driver electronics or a TFT backplane. In the figure above, the basic carrier is a TFT backplane, which is connected to a driver PCB with driver electronics via a flexible connection, such as a flexible PCB.

[0082] Figure 2 shows a detailed view of an LED module 110. In this example, the LED module includes a first TFT backplane 170 and a second TFT backplane 180. The first and second backplanes can also be PCBs. Thus, any combination of front / back TFT backplane / PCB backplane is possible. This example is illustrated using a TFT backplane.

[0083] The connection from the first 170 to the second 180 backplate can be accomplished using a contact strip 210 on the edge. This contact strip can replace the aperture in a single stacked LED module. A sphere 230 between the two TFT backplates acts as a spacer to control the distance between them. The LED module 110 is also connected to a carrier 120 via a connector 240. Here, in this example, the carrier 120 is a PCB. After assembly, the first and second TFT glass pieces are bonded together with the spacer to maintain the planarity and parallelism between them.

[0084] Figures 3A and 3B further illustrate the second 180 and the first 170 TFT backplanes of an LED module, respectively. The first TFT backplane includes the LED and TFT electronic components and functions. The second TFT backplane includes TFT electronic components, which may be separately mounted semiconductor electronic components and a contact array 250 to contact the carrier 120.

[0085] As further illustrated in Figure 4, the connection between the first and second TFT backplanes, that is, the addition of a current connection at the edge of both the first and second TFT backplanes, requires a large number of side contacts 210.

[0086] As shown in Figure 5B, the LED module with side connections is then mounted on a carrier. The contact of the carrier of the light-emitting module can be achieved through an FPC or a planar contact array (as shown in Figure 5A, similar to a ball grid array).

[0087] One object of the present invention is to replace the number of side contacts 210 between the first and second TFT backplanes shown in FIG4. As will be explained later, instead of using a first and second backplane, we will refer to a first and second surface throughout the description.

[0088] Instead of using a current connection to transmit data signals from the second surface to the first surface, the inventors have developed a system for optically transmitting such data signals to light-emitting elements disposed on the first surface of a light-emitting module. To achieve this optical data transmission, the light-emitting module includes an optical receiver disposed on the first surface and an associated optical transmitter arranged on the second surface, such that an optical signal transmitted by the optical transmitter is received by the associated optical receiver and converted into a driving signal for the light-emitting elements. Each optical receiver is thus connected to at least one light-emitting element and configured to convert the optical signal into an electrical signal that drives the at least one light-emitting element to generate an image on the display.

[0089] Therefore, optical transmitters and receivers are preferably operated in pairs. Throughout this description, reference is made to an optical transmitter and its corresponding or associated optical receiver. Conversely, if an optical transmitter / receiver is not paired for operation, it may be referred to as an unassociated or uncorresponding optical receiver / transmitter.

[0090] For example, in TFT technology, it is possible to implement an element called an optical photodiode (OPD), that is, a photodiode. Such photodiodes are well-known to those skilled in the industry and can be easily implemented in TFT technologies (e.g., LTP, IGZO, amorphous silicon). These photodiodes are commonly used for fingerprint capture. The photodiode or OPD can be freely combined with other circuitry on the TFT glass.

[0091] One advantage is that the OPD can be designed with different spectral sensitivities. For example, the OPD can be designed to intercept light only in the visible range (425-650 nanometers) or any specific wavelength range. The OPD can be guided for measurement off-port or in-port. An example of such an OPD arranged on a TFT glass backplane is illustrated in Figure 6A. The OPD can be quite compact (7 micrometers x 5 micrometers) and therefore can be easily fitted between other circuits on the TFT glass.

[0092] The object of this invention is to use an optical receiver, such as an OPD. As illustrated in FIG6A, the OPD 600 is embedded in the first surface 670 to receive an optical signal from an optical transmitter. As illustrated in FIG7A, the OPD 600 in this example is arranged to look inward from the first surface 670 toward a second surface, facing the optical transmitter arranged on the second surface.

[0093] Figure 7 shows a cross-section of a light-emitting module 7000. Multiple optical transmitters 7110 and 7120 are disposed on a first surface 7170. Corresponding optical receivers 7210 and 7220 are disposed on a second surface 7180. Each optical receiver 7210 and 7220 is connected to at least one light-emitting element 7010, 7020, or 7030.

[0094] The optical signal emitted by the optical transmitter can be a pulsed optical signal. After the pulsed optical signal emitted by the transmitter on the second surface 7180 is received, it is used as an optical pulse of a certain wavelength (or wavelength range) and directly converted into an electrical signal. It is then further processed in the electronic components of the first surface 7170 to drive the light source of the first surface and to generate an image on a display having such light-emitting elements.

[0095] The optical transmitter arranged on the first surface can be any light-emitting element as defined above, such as LED, or any type of mini LED, micro LED, OLED, EL, laser, etc. LEDs have advantages such as being a single light source, being quite compact, and being highly energy efficient.

[0096] In Figure 7, the light-emitting elements are provided by red (R) 7010, green (G) 7020, and blue (B) 7030 micro-LEDs. Both the first surface 7170 and the second surface 7180 are TFT glass in this example. Furthermore, the optical transmitters are embodied by micro-LEDs 7110 and 7120.

[0097] As described above, the first surface 7170 and the second surface 7180 can be, for example, a backed TFT glass, but can also be a PCB. One advantage of using a backed TFT glass for the first and second surfaces is that the medium between the optical transmitters and optical receivers (OPDs) is an optical medium, i.e., glass. However, the invention is not limited to TFT glass when other types of first and second surfaces can be provided as an optical medium between the optical transmitters and receivers. A PCB with holes at the locations of the receivers / transmitters can also be used as an optical medium, wherein the optical transmitters can be disposed on the bottom layer and the optical receivers on the top layer.

[0098] A drive circuit connected to or embedded in the second surface 7180, or even possibly an external driver panel, is configured to send a drive signal to the second surface 7180, which further processes the digital data and then modulates the optical transmitters, i.e., the microLEDs. The electrical signal is converted into an optical signal. This optical signal is transmitted as an optical pulse to the corresponding associated optical receiver, OPD. The signal triggers the photosensitive sensitivity of the OPD from a certain threshold (see Figure 6B). The OPDs 7210 and 7220 then transfer the optical signal back to an electrical signal for further processing on the front TFT glass 7170 and to drive the light-emitting elements, i.e., the microLEDs. In this manner, an optical data transfer between the second surface 7180 and the first surface 7170 can be established.

[0099] In Figure 6B, the optical signals are received as an optical pulse 620, which is converted into a digital binary signal after a threshold 610 is applied in the driver 600. This digital signal is then fed to various electronic components 630 so that it finally reaches the light-emitting elements as a driving signal to generate an image on the display.

[0100] The digital data stream is transmitted normally through the electrical connections at these sides.

[0101] As shown in Figure 6A, where OPD 600 is illustrated on a TFT substrate, these OPDs can be arranged anywhere on the substrate, for example, without following a periodic configuration, or arranged in rows and columns. Regarding the use of current connections, for example, when arranged on a substrate, they require a certain spacing, which provides additional flexibility. Therefore, these optical receivers and associated transmitters can be arranged anywhere on the surface with available space and can be distributed arbitrarily. The only limitation is that two optical receivers should preferably not be too close to each other to avoid interference.

[0102] The number of optical transmitters and associated optical receivers can be determined by the amount of data signals transmitted.

[0103] Using this type of optical transmission for all data signals maintains a single current coupling between the first and second surfaces, providing the power, ground, and reference voltage required to operate the light-emitting module. While these connections may still require appropriate spacing between adjacent light-emitting modules, these requirements become less stringent as the available space for these current connections increases dramatically. These connections can therefore be distributed more widely and with less restriction along the edges of the light-emitting module.

[0104] To ensure the integrity, quality, and reliability of the transmission from the optical transmitter to the optical receiver, the following additional methods may be provided.

[0105] When the optical transmitters 7110 and 7120 emit Lambertian radiation, the light emitted by one optical transmitter may be transmitted beyond the associated optical receiver, i.e., OPD, thus causing signal distortion in the receivers of other OPDs.

[0106] To reduce signal crosstalk, as illustrated in Figure 7, a pinhole 7200 or aperture 7200 can be provided along the optical path between the optical transmitters 7110 and 7120 and the optical receivers 7210 and 7220. The pinhole 7200 can filter a portion of the Lambertian radiation emitted by the optical transmitter, i.e., the micro-LED. These pinholes can be implemented as a pinhole aperture layer 7060 in the interlayer lamination between the first 7170 and the second 7180 surfaces of the light-emitting module.

[0107] Such apertures (or pinholes) should be suitable for the dimensions of such contact pads, or suitable for the spaces between such LEDs. Therefore, such apertures should have a diameter of at most one 50 micrometers.

[0108] As shown in Figure 7, the aperture layer sheet is sandwiched between the first and second surfaces. The aperture layer is a sheet containing an aperture / pinhole matrix, with each aperture dedicated to a pair of optical transmitters / optical receivers.

[0109] As a result, the optical transmitters 7110 and 7120, i.e., the micro-LEDs, emit a mirror-shaped beam of light. The light from these transmitting LEDs will be more prominently present at the associated OPD, and wide stray light will be reduced.

[0110] Reducing Lambertian radiation and allowing mirrored light to propagate from the rear end to the front end is achieved by significantly reducing the reflection of light rays due to the TIR (Total Internal Reflection) within the optical medium, such as in examples where the first and second surfaces are TFT glass, which is a glass medium. TIR occurs when the light rays are incident at an angle exceeding a certain angle determined by the refractive index of the optical medium and its adjacent media, such as air. At these critical angles, the transition surfaces of the optical medium, such as the glass medium and its adjacent media, act as a mirror, propagating the light beam further into the medium as uncontrollable stray light. Stray light from an adjacent emitter may fall into an uncorrelated OPD, triggering a spurious pulse. As shown in Figures 8A and 8B, the apertures or pinholes 7200 at all levels significantly reduce the propagation of uncontrollable stray light, thus improving the overall integrity of the data transmission.

[0111] Stray light generated by TIR can also be reduced by optimizing the aperture layer that maximizes the absorption of emitted light outside the OPD aperture.

[0112] Furthermore, the aperture layer can be attached to or laminated onto the glass surface, and the refractive index of the aperture layer can be matched with the refractive indices of the first and second surfaces. As illustrated in Figures 8A and 8B, this maximizes the absorption of non-aperture light entering the aperture layer and thus minimizes the TIR of the glass medium.

[0113] These light-emitting elements can be further configured with pre-collimation optics, thus reducing unwanted side radiation with simple collimation.

[0114] The light emitted by these optical transmitters can be further focused onto the optical receiver by an optical lens (e.g., a microlens collimating or condenser lens) disposed in the optical path between the optical transmitter and its associated optical receiver. The optical lens can be arranged in a micro-biconvex lens disposed between the first and second surfaces. For example, the optical lens can also be arranged in each aperture of the aperture layer 7060 disposed between the first and second surfaces of the light-emitting module.

[0115] Advantageously, by increasing the thickness of the aperture layer to, for example, at least the diameter of the aperture, as shown in FIG8B, a light-guiding funnel 810 can be automatically established, thus selectively transmitting the mirrored light emitted by the optical transmitter toward the associated optical receiver. The light funnel absorbs incident light entering the funnel at various angles. This can improve the reliability of the optical transfer by reducing the influence of stray light in the medium of the first and second surfaces, i.e., the front TFT glass and the back TFT glass.

[0116] To increase detection efficiency, two adjacent optical transmitters can emit different types of radiation, either in parallel or alternately. For example, as illustrated in Figure 7, two adjacent LEDs 7110 and 7120 can be paired to emit different wavelengths λ1 and λ2. The corresponding OPD at the receiver can also select the associated transmitting LED. Therefore, due to the wavelength selectivity of the transmitter and receiver, a pair of optical receivers / transmitters is less sensitive to crosstalk between adjacent optical transmitters / receivers.

[0117] Thus, each optical receiver can be configured to receive the same spectral bandwidth as its associated optical transmitter. Alternatively, two adjacent optical transmitters can emit light with a different spectral bandwidth, allowing the associated optical receiver to receive that specific spectral bandwidth.

[0118] An optical transmitter, assembled to emit light with at least two different spectral bandwidths, can also be provided. For example, a white LED (comprising three LEDs) emits a red, a green, and a blue component. An optical receiver can then be adapted to receive each of these emitting components. In this way, additional signals can be transmitted by a transmitter. Thus, the signals transmitted by the optical transmitters can be modulated with different wavelengths. The optical receiver may further include an output for each receiving component.

[0119] The transmitter can be advantageously provided by a three-in-one LED (R, G, B), wherein the three wavelengths can be combined into a single color depending on the contents of R, G, and B.

[0120] The receiver can select wavelengths and divide the information into R, G, and B channels.

[0121] Advantageously, an optical transmitter that emits light outside the visible spectrum can be further provided, along with an optical receiver configured to be highly sensitive to such wavelengths. For example, the optical transmitter can be embedded in a UV micro-LED, and the associated optical receiver in a UV photodiode. A similar example could be provided with IR. This is advantageous when the optical receiver is not sensitive to the light emitted by the display, and the light emitted by the optical transmitter does not interfere with the image emitted by the display.

[0122] The reliability of optical data transmission can be further improved by modulating the sensitivity of the OPD to respond more selectively to incident mirror light from the associated optical transmitter and less to residual stray light from different, unassociated optical transmitters. Through TIR, light can also propagate in the glass medium between the first surface (e.g., TFT glass) and the second surface (e.g., TFT glass). This can be achieved by providing a neutral density layer between the OPD and the incident received light. A similar effect can be achieved by adjusting the power of the optical transmitters.

[0123] Furthermore, as shown in Figure 6B, the sensitivity of the OPD can be adjusted by modulating the electrical threshold 610 or trigger level of the analog signal 620 from the OPD 600 itself.

[0124] In addition to the aforementioned improvements, it is also necessary to protect the interior of the light-emitting module from stray light, such as ambient light, as well as light emitted by the display itself.

[0125] In fact, in most cases, these displays are RGB emitting displays where the light is emitted quite close to the OPD itself. Therefore, it is preferable to protect the interior of the light-emitting module from visible light interference to avoid interference with the display's light-emitting elements. There are also different possibilities for avoiding stray light.

[0126] These optical receivers, i.e., these OPDs, are preferably protected from incident light from the environment (e.g., incident light at the front of the display) and light from the display's LEDs. These OPDs may be covered by a protective layer, which may be integrated with the secondary optical elements of the light-emitting film assembly, or integrated with a separate screen 7140 that directly covers and protects one of the optical receivers, as shown in Figure 7.

[0127] The secondary optical element may be provided, for example, by an additional optical layer disposed on top of the LEDs. This additional layer (or secondary layer) may retain additional optical functions, such as anti-reflective patterns, contrast enhancement solutions, etc.

[0128] As shown in Figure 7, these optical transmitters can also be further separated by adding a protective cover 7120, preferably a non-transmission material or layer, to the top of these optical transmitters.

[0129] Although the invention has been illustrated with TFTs on glass for the first and second surfaces, the same effect can be achieved with any type of backplane having single-sided circuitry. For example, non-glass carriers, such as FR4 PCB material or ceramic material, can be used for the first and second surfaces. TFTs on polyimide (PI) can also be used. If a non-permeable material is used, pinholes or funnels between the optical transmitters and their associated optical receivers may need to be arranged in the medium to provide an optical medium for light traveling from the optical transmitter to its associated optical receiver.

[0130] Advantageously, the teachings of this invention can be applied when a large amount of data signals need to be transferred.

[0131] Although the present invention has been described in terms of OPD, the advantages of using OPD can also be achieved with separate OPD devices (e.g., semiconductor photovoltaic elements). Modifications

[0132] It will be appreciated that the embodiments described above can be modified in various ways. Such modifications may include equivalent elements and other features known in the design, the manufacture and use of the light-emitting module and its component parts, and the omission or additional use of features described herein. Features of one embodiment may be replaced or supplemented by features of another embodiment.

[0133] The same principle can be implemented with other non-optical radiation techniques. For example, the same principle can be applied to sound waves due to the use of piezoelectric transducers for transmission and reception, and due to inductive transmitters and receivers (e.g., RF).

[0134] This invention is not limited to light-emitting modules for displays; it can be further applied to any application where data needs to be transferred from a first surface to a second surface. The second surface must include a plurality of optical transmitters, and the first surface must include a plurality of optical receivers, each optical receiver being associated with an associated optical transmitter, and an optical medium may be further disposed between each pair of optical receivers and transmitters. Therefore, instead of sending the data to a light-emitting element to generate an image on the display, other types of devices besides light-emitting elements can be used.

[0135] Furthermore, instead of transmitting the data to multiple light-emitting elements, such optical devices can be used to transfer, for example, data already acquired by a sensor. These sensors can thus be implemented on the second surface close to the optical transmitters, allowing the acquired data to be transferred from the optical transmitters to an associated optical receiver, and then further transferred to a base carrier or any other processing device. These sensors can be, for example, a photodiode, a photovoltaic, a light guide device, a photoelectric crystal, etc. This can be used in applications such as contactless optical sensing of fingerprints, facial recognition lenses, thermal sensing (IR sensing), iris / eye recognition, biometric applications, vein matching, (vascular technology), etc.

[0136] In interpreting these appended claims, it should be understood that the word "comprising" does not exclude the presence of other elements or actions not listed in a given claim; the word "a" or "an" preceding an element does not exclude the presence of multiple such elements; any reference numerals in these claims do not limit their scope; several "methods" may be represented by the same or different items or implementations of structures or functions; unless otherwise specifically stated, any of these disclosed devices or portions thereof may be combined together or separated into other parts. Reference to one claim to another may indicate synergistic advantages achieved by a combination of their individual features. However, the mere fact that certain measures are listed in different claims does not imply that any combination of such measures cannot be used to have an advantage. This embodiment may therefore include all operational combinations of these claims, wherein each claim may, in principle, refer to any of the foregoing claims unless explicitly excluded by the context.

[0137] Although the present invention has been described above with reference to specific embodiments, this is for illustrative purposes and not for limiting the invention. Those skilled in the art will recognize that various modifications and combinations of the disclosed features can be made without departing from the spirit of the invention.

[0138] 100: Monitor 110: Light-emitting module 120: Carrier 130: Wiring 140: External drive 150: External driver connector 170: First TFT backplane 180: Second TFT backplane 210: Contact strip, side contact point 230: Sphere 240: Connection 250: Contact Array 600: Optical sensor, driver 610: Critical value 620: Optical Pulse 630: Electronic Components 670, 7170: First surface 7000: Light-emitting module 7010: Red light-emitting element 7020: Green light-emitting element 7030: Blue light-emitting element 7060: Pinhole diameter layer 7110, 7120: Optical transmitters, miniature LEDs 7120: Protective Shield 7140: Screen 7180: Second Surface 7200: Pinhole, aperture 7210, 7220: Optical receiver 810: Light-guiding funnel λ1, λ2: Wavelength

Claims

1. A light-emitting module comprising: a first surface including a plurality of light-emitting elements; a second surface configured to receive a drive signal and transfer the signal to the light-emitting elements of the first surface; wherein the second surface includes a plurality of optical transmitters, each of the optical transmitters being associated with a corresponding optical receiver arranged on the first surface, the optical transmitters and the associated corresponding optical receivers being separated by an optical medium such that an optical signal including a drive signal transmitted by the optical transmitters is received by the associated corresponding optical receiver; each optical receiver being connected to at least one light-emitting element and configured to convert the optical signal into an electrical signal, the electrical signal being configured to drive the at least one light-emitting element to generate an image for a display.

2. As in request item 1, the light-emitting module, wherein, The optical receiver is an optical photosensitive device, or the optical transmitter is a light-emitting element, which is any one of LED, OLED, QD-LED, EL-QLED, AMOLED, mini LED, micro LED, or laser, or the light-emitting element on the first surface is any one of LED, OLED, QD-LED, EL-QLED, AMOLED, mini LED, or micro LED.

3. As in request item 1, the light-emitting module, wherein, The first surface is any one of a thin-film transistor on glass (TFT), a TFT on polyimide, or a printed circuit board (PCB), or the second surface is any one of a thin-film transistor on glass (TFT), a TFT on polyimide, or a printed circuit board (PCB).

4. The light-emitting module of claim 1, wherein an aperture is provided along the optical path between each optical transmitter and its associated optical receiver, the aperture being configured such that the light beam emitted by the optical transmitter is mirrored when it reaches the optical receiver.

5. The light-emitting module of claim 4, wherein the aperture is arranged in an aperture layer disposed between the first surface and the second surface, wherein the aperture layer may be laminated or attached, and / or wherein the aperture layer contains light-absorbing properties.

6. The light-emitting module of claim 5, wherein the aperture layer has a thickness of at least the diameter of the aperture, such that each aperture is a light-guiding funnel for selectively transmitting a mirrored beam emitted by the optical transmitter toward the optical receiver.

7. The light-emitting module of claim 1, wherein an optical lens is provided for each pair of optical receivers and optical transmitters along the optical path between the optical transmitter and its associated optical receiver, the optical lenses being assembled to focus the light beam emitted by the optical transmitter onto the optical receiver.

8. The light-emitting module of claim 7, wherein the optical lens is disposed in the aperture of the aperture layer.

9. The light-emitting module of claim 1, wherein two adjacent optical transmitters are configured to emit radiation of a different type, and the associated optical receiver is configured to receive the radiation of its associated optical transmitter.

10. The light-emitting module of claim 9, wherein two adjacent optical transmitters emit light with different spectral bandwidths.

11. The light-emitting module of claim 9, wherein an optical transmitter is configured to transmit light having at least two different spectral bandwidths, and the associated optical receiver is configured to be sensitive to the two different spectral bandwidths.

12. The light-emitting module of claim 11, wherein the associated optical receiver includes an output per spectral bandwidth.

13. The light-emitting module of claim 1, wherein the sensitivity of the optical receiver is modulated to selectively respond to incident mirror light from the associated optical transmitter.

14. The light-emitting module of claim 13, wherein a neutral density layer is disposed between the optical transmitter and the optical receiver.

15. The light-emitting module of claim 13, wherein the sensitivity of the optical receiver is modulated by means of a critical level adapted to the analog signal received by the optical receiver.

16. The light-emitting module of claim 1, wherein the optical receiver is covered by a protective layer to reduce the penetration of ambient light into the interior of the light-emitting module, or the optical transmitters are covered by a protective cover to reduce the penetration of ambient light into the light-emitting module.

Images