Display module and manufacturing method thereof

Abstract

The present invention provides a display module and a manufacturing method thereof, the display module comprising: a substrate on which a plurality of light emitting diodes (LEDs) are disposed, the LEDs having a non-smooth upper surface; the first dielectric layer is positioned on the substrate and surrounds the LEDs; the first dielectric layer is filled between the substrate and the second dielectric layer, and the refractive index of the second dielectric layer is greater than that of the first dielectric layer; and the plurality of color filters are positioned on one side, opposite to the first dielectric layer, of the second dielectric layer.

Description

Technical Field

[0001] The present invention relates to a display module; in particular, the present invention relates to a display module with higher light extraction efficiency and a wide viewing angle. Background Art

[0002] The display module emits light through a light emitting diode (LED), and is correspondingly provided with, for example, three primary colors (red, green, and blue) of color filters (or color filters) to form color pixels on the display panel. In the design of the display module, a sealed space may be included between the upper cover glass or the color filter and the LED array substrate, which may include air or other transparent packaging materials with a refractive index lower than that of glass to reduce the chance of total reflection, thereby increasing the light extraction efficiency. However, since a shading material (such as a black matrix) may be provided between the color filters to prevent light reflection, when the user views the display module at a larger side angle, the light emitted by the LED may be blocked by the color filter or the black matrix, causing color difference when observed by the human eye. Therefore, a display module that can improve light extraction efficiency and support a large viewing angle is currently desired by the industry. Summary of the invention

[0003] An object of the present invention is to provide a display module to improve the light extraction efficiency of light penetrating a display panel.

[0004] An object of the present invention is to provide a display module for reducing the color difference generated when a user views a display panel at a larger side viewing angle.

[0005] In one embodiment, a display module includes a substrate, a plurality of light emitting diodes (LEDs), a first dielectric layer, a second dielectric layer, and a plurality of color filters. The LEDs are disposed on the substrate and have a non-smooth upper surface; the first dielectric layer is disposed on the substrate and surrounds the LEDs, and the first dielectric layer is filled between the substrate and the second dielectric layer, and the refractive index of the second dielectric layer is greater than that of the first dielectric layer; and the color filters are disposed on a side of the second dielectric layer opposite to the first dielectric layer.

[0006] In another embodiment, a method for making a display module includes disposing a plurality of light emitting diodes (LEDs) on a substrate and forming a non-smooth upper surface on the LEDs; forming a first dielectric layer on the substrate, wherein the first dielectric layer surrounds the LEDs; forming a second dielectric layer, wherein the first dielectric layer is filled between the substrate and the second dielectric layer, and the refractive index of the second dielectric layer is greater than that of the first dielectric layer; and disposing a plurality of color filters on a side of the second dielectric layer opposite to the first dielectric layer.

[0007] Through this configuration, the display module can reduce the situation where light is blocked by internal components of the display module after being emitted from the LED, thereby reducing the light output efficiency, and improve the uniformity of light when the user views the display screen at a larger side viewing angle, thereby achieving the purpose of reducing the probability of chromatic aberration at a large viewing angle. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 A schematic diagram showing that light emitted by an LED is blocked by a color filter or a light shielding wall.

[0009] Figure 2 A schematic diagram of a display module according to an embodiment of the present invention is shown.

[0010] Figure 3 A schematic diagram showing the increased light extraction efficiency of a display module according to an embodiment of the present invention compared to a conventional design.

[0011] Figure 4 A schematic diagram of a display module including a coating layer according to another embodiment of the present invention is shown.

[0012] Figure 5A A schematic diagram of a display module including a color conversion medium according to another embodiment of the present invention is shown.

[0013] Figure 5B A schematic diagram of a display module including a color conversion medium according to another embodiment of the present invention is shown.

[0014] Figure 6 A flow chart showing a method for manufacturing a display module according to yet another embodiment of the present invention is shown.

[0015] Description of reference numerals:

[0016] 100…Display module

[0017] 101…Light Emitting Diode (LED)

[0018] 101a…Light

[0019] 101b…Light

[0020] 103…Air

[0021] 107…Color filter

[0022] 109…Glass

[0023] 111…Black Matrix

[0024] 200…Display module

[0025] 201…LED

[0026] 202…Substrate

[0027] 203…First dielectric layer

[0028] 205…Second dielectric layer

[0029] 207…Color filter

[0030] 209…Light-transmitting layer

[0031] 211…Light-shading wall

[0032] 213…Upper surface

[0033] 301…Light

[0034] 400…Display module

[0035] 401…LED

[0036] 403…First dielectric layer

[0037] 405…Second dielectric layer

[0038] 413…Upper surface

[0039] 415…Coating layer

[0040] 500…Display module

[0041] 501…LED

[0042] 501a…LED to be changed color

[0043] 502…Substrate

[0044] 503…first dielectric layer

[0045] 505…Second dielectric layer

[0046] 507…Color filter

[0047] 515…Coating layer

[0048] 517…Color transfer medium

[0049] 519…Blocking wall

[0050] 600…Method

[0051] 601…steps

[0052] 603…steps

[0053] 605…steps

[0054] 607…steps DETAILED DESCRIPTION

[0055] The following is a description of the implementation of the display module disclosed in the present invention through specific embodiments and accompanying drawings. Those skilled in the art can understand the advantages and effects of the present invention from the contents disclosed in this specification. However, the contents disclosed below are not intended to limit the scope of protection of the present invention. Without departing from the principles of the present invention, those skilled in the art can implement the present invention with other different embodiments based on different viewpoints and applications.

[0056] In the accompanying drawings, for the sake of clarity, the thickness of layers, films, panels, regions, etc. is magnified. Throughout the specification, the same reference numerals represent the same elements. It should be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" or "connected to" another element, it may be directly on or connected to another element, or an intermediate element may also exist. On the contrary, when an element is referred to as being "directly on" or "directly connected to" another element, there is no intermediate element. As used herein, "connection" may refer to physical and / or electrical connection.

[0057] It should be understood that although the terms "first", "second", "third", etc. can be used to describe various elements, components, regions, layers and / or parts in this article, these elements, components, regions, and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, the "first element", "first component", "first region", "first layer" or "first part" discussed below can be referred to as the second element, component, region, layer or part without departing from the teachings of this article.

[0058] The terms used herein are only for the purpose of describing specific embodiments and are not restrictive. As used herein, unless the content clearly indicates, the singular forms "one", "an" and "the" are intended to include plural forms, including "at least one". "Or" means "and / or". As used herein, the term "and / or" includes any and all combinations of one or more related listed items. It should also be understood that when used in this specification, the terms "comprising" and / or "including" specify the presence or addition of the features, regions, wholes, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, regions, wholes, steps, operations, elements, parts and / or their combinations.

[0059] refer to Figure 1A schematic diagram showing a light ray emitted by a light emitting diode (LED) 101 in a display module 100 being blocked is shown. Since the refractive index of the color filter 107 is greater than that of the air 103, it can be seen from the figure that when the light ray 101a is emitted from the LED 101 and passes through the air 103 and enters the color filter 107, the light ray 101a will deviate to the normal line, thereby reducing the problem of total reflection when the light ray 101a leaves the glass 109. However, when the light ray 101b is emitted to the edge of the color filter 107, even if the light ray 101b deviates to the normal line when entering the color filter 107, it may still be blocked by the adjacent color filter of another color or the black matrix 111, thereby causing color difference to be observed when the user views the display module 100 at a larger side angle.

[0060] refer to Figure 2 Schematic diagram of a display module 200 according to an embodiment of the present invention is shown. In this embodiment, the display module 200 includes a plurality of LEDs 201 disposed on a substrate 202, wherein the LEDs 201 have a rough or patterned upper surface 213, so that the light emitted from the LEDs 201 produces a scattering effect when passing through the upper surface 213, so as to increase the propagation path of the light. In addition, the display module 200 further includes a first dielectric layer 203, a second dielectric layer 205, a color filter 207, and a light-transmitting layer 209 in sequence on the substrate 202. The first dielectric layer 203 surrounds the LEDs 201 and is filled between the substrate 202 and the second dielectric layer 205, and the refractive index of the second dielectric layer 205 is greater than that of the first dielectric layer 203 (for example, the first dielectric layer 203 is air, the second dielectric layer 205 is a transparent encapsulation material having a refractive index greater than that of air, and the light-transmitting layer 209 is a material such as glass). In addition, a light shielding wall 211 (such as a black matrix) may be provided between the color filters 207, but is not limited thereto, to prevent light reflection. It should be noted that, although in the present embodiment, air is used as the first dielectric layer 203 and a transparent encapsulating material is used as the second dielectric layer, in different embodiments, the first dielectric layer 203 and the second dielectric layer 205 may also be made of other materials (for example, the first dielectric layer 203 may be any appropriate material with a refractive index between 1 and 1.4, and the second dielectric layer 205 may be any appropriate material with a refractive index between 1.5 and 2), and the present invention is not limited thereto.

[0061] refer to Figure 3 A schematic diagram illustrating how to increase the light extraction efficiency of a display module 200 according to an embodiment of the present invention. Figure 3The left side shows the light emission of the display module under conventional design, and the right side shows the light emission of the display module 200 of the present invention. Assume that the light 301 is the last light that can be emitted when it is emitted from the LED 201 to the edge of the color filter 207 at the same emission angle. That is, for example, when the LED 201 is emitted to the right edge of the color filter 207, the light 301 is the rightmost light source that can successfully leave the display module 200 when emitted at the same emission angle (that is, the light source on the right side of the LED 201 than the light 301 will be blocked by the light shielding wall 211). Then the actual light emitting length L1 is calculated as the length L of the LED 201 minus the light shielding length X, that is, L1=LX. First, under conventional design, the calculation formula of the light shielding length X is:

[0062] X=h*tanθ-D

[0063] Wherein, h represents the distance from LED 201 to color filter 207, θ represents the angle between the light and LED 201 (i.e., 90 degrees minus the exit angle), and D represents the distance from the edge of LED 201 to the vertical projection point of the edge of color filter 207 on substrate 202. Next, the calculation formula of the light shielding length X of the display module 200 of the present invention is as follows:

[0064] X=(ha)*tanθ air -D+d1

[0065] Wherein, a represents the thickness of the second dielectric layer 205, θ air is the incident angle of the light entering the second dielectric layer 205 and d1 is the distance between the incident point of the light 301 entering the second dielectric layer 205 and the incident point of the light 301 entering the color filter 207 on the same plane. The calculation formula of d1 is:

[0066] d1=a*tanθ oc ,and

[0067] θ oc =sin -1 (n air *sinθ air ) / n oc

[0068] Among them, θ oc represents the incident angle of the light 301 entering the color filter 207, n air represents the refractive index of the first dielectric layer 203 and n oc represents the refractive index of the second dielectric layer 205. Substituting the above calculation formula of d1 into the calculation formula of the shielding length X, the following formula can be obtained:

[0069] X=(ha)*tanθ air-Da*(tanθ air -tanθ oc )

[0070] The bold part (i.e. a*(tanθ air -tanθ oc )) is the portion of the display module 200 of the present invention that is reduced compared to the conventional design in the light shielding length X, that is, the portion of the actual light emitting length L1 that is increased.

[0071] In accordance with the above, through Figure 3 It can be seen from the comparison in that, while maintaining the distance (ie, h) from the LED 201 to the color filter 207 unchanged, adding the second dielectric layer 205 will improve the light extraction efficiency of the LED 201, thereby reducing the color difference problem caused by the user viewing at a larger side angle.

[0072] refer to Figure 4 The display module 400 including the coating layer 415 according to another embodiment of the present invention is described. In this embodiment, the coating layer 415 is evenly covered on the upper surface 413 of the LED 401. Since the upper surface 413 is a non-smooth surface, the coating layer 415 will also fluctuate along with the roughness of the upper surface 413 to achieve a complete coverage effect. The refractive index of the coating layer 415 is between the LED 401 and the first dielectric layer 403. For example, the coating layer 415 can be a transparent material such as silicon oxide, silicon nitride, or other appropriate materials with a refractive index greater than the first dielectric layer 403 and less than the LED 401 (for example, the refractive index of the coating layer 415 is between 1.5 and 2.5, and the refractive index of the LED 401 is between 2.2 and 3.5, etc.), and the present invention is not limited thereto. With this configuration, when the light is emitted from the LED 401 and before entering the second dielectric layer 405, it will experience a process of gradually decreasing the refractive index, thereby increasing the light entering the second dielectric layer 405 and ultimately achieving the purpose of increasing the light output rate.

[0073] refer to Figure 5AA display module 500 including a color conversion medium 517 according to another embodiment of the present invention is described. In this embodiment, the color conversion medium 517 can replace part of the first dielectric layer 503 to surround the LED 501a to be color-converted, and the remaining first dielectric layer 503 is still located between the color conversion medium 517 and the second dielectric layer 505, and the display module 500 can also include the coating layer 515 described in the above embodiment. That is, the light emitted from the LED 501 will pass through the coating layer 515, the color conversion medium 517, the first dielectric layer 503 in sequence and finally enter the second dielectric layer 505. In addition, the display module 500 further includes a barrier wall 519. In this embodiment, the barrier wall 519 can connect the substrate 502 and the second dielectric layer 505 to prevent the color conversion medium 517 from affecting other LEDs 501 except the LED 501a to be color-converted. The color conversion medium 517 can include any appropriate material such as phosphor that can convert monochromatic light into other color lights, and the present invention is not limited thereto. Through this configuration, the light emitted by the LED 501 can be converted into different three primary colors of light in coordination with the pixel arrangement of the display module 500. For example, in the present embodiment, the LED 501a to be changed in color is a blue LED, and the blue light emitted by the LED 501a to be changed in color can be converted into red light through the color conversion medium 517 to match the red filter 507 corresponding to the LED 501a to be changed in color. It should be noted that the color conversion medium 517 can also be used to convert LEDs 501 of different colors in different embodiments, such as converting a green LED into blue light or converting a red LED into green light, etc., and the present invention is not limited to this. In addition, by providing a barrier wall 519, the display module 500 can also include multiple sets of color conversion media 517 (for example, Figure 5B The present invention is not limited thereto.

[0074] refer to Figure 6 A method 600 for manufacturing a display module according to another embodiment of the present invention is described. In this embodiment, the method 600 includes arranging a plurality of light emitting diodes (LEDs) on a substrate, and forming a non-smooth upper surface (601) on the LEDs; forming a first dielectric layer on the substrate, wherein the first dielectric layer surrounds the LEDs (603); forming a second dielectric layer, wherein the first dielectric layer is filled between the substrate and the second dielectric layer, and the refractive index of the second dielectric layer is greater than that of the first dielectric layer (605); and arranging a plurality of color filters (607) on a side of the second dielectric layer opposite to the first dielectric layer. In addition, the method 600 in this embodiment may also include forming or arranging various elements as described in the aforementioned embodiments (e.g., Figure 2 As shown in the shading wall; Figure 4 The coating layer shown; Figure 5AThe color conversion medium, barrier walls, etc. shown in the figure are provided to achieve the purpose of the present invention as described in the foregoing embodiments.

Claims

1. A display module, comprising: A substrate on which a plurality of light emitting diodes are disposed, wherein the light emitting diodes have a non-smooth upper surface; A first dielectric layer, located on the substrate and surrounding the light emitting diodes; a second dielectric layer, wherein the first dielectric layer is filled between the substrate and the second dielectric layer, and the refractive index of the second dielectric layer is greater than that of the first dielectric layer; as well as A plurality of color filters are located on a side of the second dielectric layer opposite to the first dielectric layer.

2. The display module as claimed in claim 1, further comprising a plurality of light shielding walls, wherein the color filters are respectively arranged in a manner corresponding to the light emitting diodes, and the light shielding walls are located between the color filters to separate the color filters. 3 . The display module as claimed in claim 2 , further comprising a coating layer at least partially covering the upper surface of the light emitting diodes, wherein a refractive index of the coating layer is smaller than that of the light emitting diodes and larger than that of the first dielectric layer. 4 . The display module as claimed in claim 2 , further comprising a light-transmitting layer located on a side of the color filters opposite to the second dielectric layer.

5. The display module as claimed in claim 2 or 3, further comprising a color conversion medium and a barrier wall, wherein the color conversion medium is located between the second medium layer and the substrate and covers a light emitting diode to be color-changed among the light emitting diodes, and wherein the barrier wall is configured to prevent the color conversion medium from contacting the light emitting diodes other than the light emitting diode to be color-changed.

6. A method for manufacturing a display module, comprising: Disposing a plurality of light emitting diodes on a substrate, and forming a non-smooth upper surface on the light emitting diodes; forming a first dielectric layer on the substrate, wherein the first dielectric layer surrounds the light emitting diodes; forming a second dielectric layer, wherein the first dielectric layer is filled between the substrate and the second dielectric layer, and the refractive index of the second dielectric layer is greater than that of the first dielectric layer; and A plurality of color filters are arranged on a side of the second dielectric layer opposite to the first dielectric layer. 7 . The method as claimed in claim 6 , wherein disposing the color filters comprises disposing the color filters in a manner corresponding to the light emitting diodes respectively, and disposing a plurality of light shielding walls between the color filters to separate the color filters. 8 . The method of claim 7 , further comprising forming a coating layer at least partially covering the upper surface of the light emitting diodes, wherein a refractive index of the coating layer is smaller than that of the light emitting diodes and larger than that of the first dielectric layer. 9 . The method according to claim 7 , further comprising forming a light-transmitting layer, wherein the light-transmitting layer is located on a side of the color filters opposite to the second dielectric layer.

10. The method according to claim 7 or 8, further comprising forming a color conversion medium and a barrier wall, wherein the color conversion medium is located between the second medium layer and the substrate and covers a light emitting diode to be color-changed among the light emitting diodes, and wherein the barrier wall is configured to separate the color conversion medium from the light emitting diodes other than the light emitting diode to be color-changed.

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