Transmission type display

Abstract

The invention provides a transmission-type display capable of suppressing light irradiated when a light source is turned on from leaking to the back surface of the display. In the transmissive display, a plurality of LEDs (4) are disposed between a plurality of groups of electrodes (2, 3) disposed in an array on a transparent substrate (1), and a plurality of openings (20) in which the electrodes (2, 3) are not disposed are disposed in an array, whereby light can be transmitted through the plurality of openings (20). A light shielding layer (11) is disposed in a target region including a region that shields an optical path on the optical path in the direction of the transparent substrate (1) from a portion of the back surface of the LED (4) facing the gap between the electrodes (2, 3), whereby light irradiated in the direction of the transparent substrate (1) from the back surface of the LED (4) can be prevented from being shielded by the light shielding layer (11), and the irradiation light of the LED (4) can be prevented from leaking to the back surface of the display.

Description

Technical Field

[0001] The present invention relates to a transmissive display, which is particularly suitable for a transmissive display that can transmit light through a plurality of openings by arranging a plurality of light sources between a plurality of sets of electrodes arranged in an array on a transparent substrate and providing a plurality of openings where no electrodes are arranged. Background Art

[0002] Conventionally, different from general displays, a transmissive display formed in a manner that can see through the back is known. The transmissive display can transmit light from the back of the display to the front through the openings by arranging a plurality of light sources in an array on a transparent substrate and providing a plurality of openings where no electrodes or the like are arranged. The ratio of the area of the openings to the area of one pixel is called the aperture ratio. The larger the aperture ratio, the more background light can be introduced, and a display that is visually close to transparent can be achieved.

[0003] There are various types of transmissive displays. Among them, the transmissive LED display can achieve a high transmittance of 70% or more, so it is expected to be applied to various uses. When constructing a transmissive LED display, it is preferable to use a technology called micro-LED in which LEDs used as light sources are miniaturized and arranged in an array. Displays using micro-LEDs are disclosed in Patent Documents 1 to 3, for example.

[0004] Figure 7 It is a diagram simply showing the structure of the light-emitting part of the transmissive LED display. Figure 7 (a) of FIG. shows the state of observing the light-emitting part of the transmissive LED display from the front side, Figure 7 (b) of FIG. shows the state of observing the light-emitting part of the transmissive LED display from the back side. As Figure 7 shown, a plurality of LEDs 101 are arranged in an array, and a plurality of openings 102 are arranged in an array adjacent to the plurality of LEDs 101. The plurality of LEDs 101 are respectively arranged between an anode electrode 103 and a cathode electrode 104.

[0005] However, in such a transmissive LED display thus configured, there is a problem that the light of the LED 101 that emits light to display information on the front leaks from the gap between the anode electrode 103 and the cathode electrode 104 to the back side. That is, as Figure 7As shown in (b), when the transmissive LED display is viewed from the back side, a part of the LED 101 can be seen through the gap between the anode electrode 103 and the cathode electrode 104. In the transmissive LED display, not only the substrate disposed on the front side of the LED 101 is made of a transparent substrate, but also the substrate disposed on the back side of the LED 101 is made of a transparent substrate. Therefore, when the LED 101 is lit, light leaks from the back of the LED 101 through the gap between the electrodes 102 and 103 to the back of the display.

[0006] [Prior Art Documents]

[0007] [Patent Documents]

[0008] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2021-052156

[0009] [Patent Document 2] Japanese Unexamined Patent Application Publication No. 2022-093393

[0010] [Patent Document 3] WO2023-127585 Summary of the Invention

[0011] The present invention has been completed to solve such problems, and an object thereof is to suppress light irradiated when a light source is lit from leaking to the back of a transmissive display.

[0012] To solve the above technical problems, in the transmissive display of the present invention, a plurality of light sources are arranged between a plurality of sets of electrodes arranged in an array on a transparent substrate, and a plurality of openings where no electrodes are arranged are arranged in an array, whereby light can be transmitted through the plurality of openings. In this transmissive display, on the optical path from the portion of the back of the light source that faces the gap between the electrodes toward the transparent substrate, a light-shielding layer is arranged in an object region including a region that shields the optical path.

[0013] [Effects of the Invention]

[0014] According to the present invention configured as described above, in the transmissive display, light irradiated from the back of the light source toward the transparent substrate when the light source is lit is shielded by the light-shielding layer, so that light irradiated from the light source can be suppressed from leaking to the back of the display. Brief Description of the Drawings

[0015] Figure 1 It is a diagram showing a structural example of a light-emitting structure with a leakage suppression function applied in the transmissive LED display of the present embodiment.

[0016] Figure 2 It is a diagram schematically showing the light-shielding effect of the light-emitting structure with a leakage suppression function of the present embodiment.

[0017] Figure 3 This is a diagram showing an example of the manufacturing process of the light-emitting structure with leakage suppression function according to the present embodiment.

[0018] Figure 4 This is a diagram schematically showing an example of the array configuration of the light-emitting structure with leakage suppression function according to the present embodiment.

[0019] Figure 5 This is a diagram schematically showing another example of the array configuration of the light-emitting structure with leakage suppression function according to the present embodiment.

[0020] Figure 6 This is a diagram showing a modified example of the light-emitting structure with leakage suppression function having the light-shielding layer according to the present embodiment.

[0021] Figure 7 This is a diagram showing the structure of the light-emitting portion of the transmissive LED display. Detailed Embodiment

[0022] Hereinafter, an embodiment of the present invention will be described based on the drawings. The transmissive display of the present embodiment is a transmissive display in which a plurality of light sources are arranged between a plurality of sets of electrodes arranged in an array on a transparent substrate, and a plurality of openings where no electrodes are arranged are provided, so that light can be transmitted through the plurality of openings. Thus, the background light is transmitted from the back surface of the display to the front surface, and the back of the display can be seen through from the front side.

[0023] In the present embodiment, a structure for suppressing light leakage to the back surface is applied to the light-emitting structure of a transmissive LED display using a micro LED element as an example of a light source. When referred to as a "light-emitting structure with leakage suppression function" in the following description, it means a light-emitting structure including the light leakage suppression structure of the present embodiment, which is distinguished from a light-emitting structure not including the light leakage suppression structure.

[0024] Figure 1 This is a diagram showing a structural example of the light-emitting structure 10 with leakage suppression function applied in the transmissive LED display of the present embodiment. Figure 1 This shows the cross-sectional structure of the light-emitting structure 10 with leakage suppression function when observing the transmissive LED display from the side. The upper part of the figure is the front surface of the display, and the lower part of the figure is the back surface of the display. In Figure 1 , two light-emitting structures 10 with leakage suppression function arranged side by side are shown, but actually these light-emitting structures 10 with leakage suppression function are arranged in an array (refer to the following Figure 4 , Figure 5 , etc.).

[0025] As Figure 1As shown, in a light-emitting structure 10 with a leakage suppression function, a set of anodic electrodes 2 and cathodic electrodes 3 are arranged at a prescribed interval above a transparent substrate 1, and an LED 4 is arranged and electrically connected between the electrodes 2 and 3. In Figure 1 In the example of

[0026] Two contact holes 5 formed on two insulating layers 8 and insulating layer 9 above the electrodes 2 and 3 are provided with two electrode pads 6, and the LED 4 is mounted through a conductive adhesive 7 formed above the electrode pads 6.

[0027] In the present embodiment, a light-shielding layer 11 is provided for the light-emitting structure configured as described above. The light-shielding layer 11 is a light leakage suppression structure. The light-shielding layer 11 is arranged in an object area including a region that shields the optical path in the optical path direction from the portion of the back surface of the LED 4 that faces the gap between the electrodes 2 and 3 toward the transparent substrate 1. In Figure 1 In the example of

[0028] The light-shielding layer 11 preferably has high light-shielding property in order to be able to shield high-energy light emission. For example, the optical density (OD value), which is an index indicating the light transmittance (transmittance), can be “3” or more (transmittance 0.1% or less). This is in consideration of the fact that the standard of the OD value of the black matrix formed to prevent light leakage or RGB color mixing in the backlight of the liquid crystal display device is set to be approximately “3”.

[0029] Figure 2 It is a diagram schematically showing the light-shielding effect of the light-emitting structure 10 with a leakage suppression function of the present embodiment configured as described above compared with the conventional light-emitting structure.

[0030] Figure 2 (a) of Figure 2 shows the conventional light-emitting structure, Figure 2 and (b) of

[0031] In Figure 2 In the case of the conventional light-emitting structure shown in (a) ofFigure 2 In the case of the light-emitting structure 10 with leakage suppression function shown in FIG. (b), the light irradiated from the back surface of the LED 4 toward the transparent substrate 1 is blocked by the light-shielding layer 11 disposed so as to cover the gap between the electrodes 2 and 3. Therefore, the light irradiated from the back surface of the LED 4 is prevented from leaking to the back surface of the transparent substrate 1 through the gap between the electrodes 2 and 3.

[0032] Figure 3 It represents Figure 1 FIG. showing an example of the manufacturing process of the light-emitting structure 10 with leakage suppression function. In addition, the materials and processes described below are examples and are not limited thereto.

[0033] First, an anode electrode 2 and a cathode electrode 3 are formed on the transparent substrate 1 (step S1). As the materials for the electrodes 2 and 3, for example, Au, Ag, Cu, AgMg, Al, ITO, etc. can be used. The process mainly uses a photolithography process. The arrangement of the electrodes 2 and 3 is not limited to a simple matrix or an active matrix, and can also be an irregular arrangement.

[0034] Next, a first insulating layer 8 is formed on the transparent substrate 1 so as to cover the electrodes 2 and 3 by evaporation, sputtering, spin coating, etc. (step S2). As the material for the first insulating layer 8, for example, SiNx, SiOx, acrylic resin, etc. can be used.

[0035] Next, a light-shielding layer 11 is formed in the target area covering the gap between the electrodes 2 and 3 on the first insulating layer 8 (step S3). For example, a light-shielding material is coated on the first insulating layer 8 by evaporation or spin coating, etc., and the light-shielding layer 11 is formed in the target area covering between the anode electrode 2 and the cathode electrode 3 in the photolithography process. As the light-shielding material, for example, a photosensitive resin containing a black pigment, chromium oxide, etc. can be used.

[0036] Next, a second insulating layer 9 is formed on the first insulating layer 8 so as to cover the light-shielding layer 11 by evaporation, sputtering, spin coating, etc. (step S4). As the material for the second insulating layer 9, for example, SiNx, SiOx, acrylic resin, etc. can be used. The second insulating layer 9 also has a planarizing effect, so the film thickness is preferably thicker than that of the first insulating layer 8.

[0037] Next, contact holes 5 are formed on the electrodes 2 and 3 through a photolithography process and etching (step S5). Further, electrode pads 6 are formed in the contact holes 5 mainly through a photolithography process, and the electrode pads 6 are electrically connected to the electrodes 2 and 3 (step S6). As the material for the electrode pads 6, for example, Au, Ag, Cu, AgMg, Al, ITO, etc. can be used.

[0038] Finally, after forming the conductive adhesive 7 on the electrode pad 6, the LED 4 is mounted (step S7). As the conductive adhesive 7, for example, solder, ACF (anisotropic conductive film), a material in which conductive particles are dispersed in resin, etc. can be used. The mounting is performed by placing the LED 4 at the correct position and then, in the case of solder, performing reflow, and in the case of other materials, applying pressure and heating for curing.

[0039] Figure 4 FIG. is a schematic diagram comparing an example of the array configuration of the light-emitting structure 10 with leakage suppression function with the array configuration of the conventional light-emitting structure. Figure 4 (a) of FIG. shows the array configuration of the conventional light-emitting structure and represents the state of observing the light-emitting structure from the back side. Figure 4 (b) of FIG. shows the array configuration of the light-emitting structure 10 with leakage suppression function and represents the state of observing the light-emitting structure 10 with leakage suppression function from the back side.

[0040] In Figure 4 In the array configuration of the conventional light-emitting structure shown in (a) of FIG., one pixel is composed of three sub-pixels each having an LED 4 (red LED, green LED, and blue LED) according to RGB, and a light-emitting structure is provided for each sub-pixel. In addition, openings 20 are formed between adjacent sub-pixels and between adjacent pixels, respectively. In Figure 4 In (a) of FIG., it is the electrode pattern in the case of lighting up (fully lighting up) a plurality of LEDs 4 arranged in a line all at once, and openings 20 are also formed between the lines. No light-shielding layer 11 is arranged between the anode electrode 2 and the cathode electrode 3, and a part of the back surface of the LED 4 is seen through the gap between the electrodes 2 and 3 from the back side of the light-emitting structure. Therefore, the light irradiated from the back side of the LED 4 toward the transparent substrate 1 leaks to the back side through the gap between the electrodes 2 and 3.

[0041] In Figure 4 In the array configuration of the present embodiment shown in (b) of FIG., the light-emitting structure itself is also the same as Figure 4 (a) of FIG. That is, one pixel is composed of three sub-pixels each having an LED 4 according to each RGB, and openings 20 are formed between adjacent sub-pixels, between adjacent pixels, and between lines, respectively. In Figure 4 In the case of (b) of FIG., a light-emitting structure 10 with a leakage suppression function is provided for each sub-pixel. In each light-emitting structure 10 with a leakage suppression function, a light-shielding layer 11 is arranged in the target area covering the gap between the anode electrode 2 and the cathode electrode 3, thereby being able to significantly suppress the light leakage to the back side.

[0042] In addition, here, a structural example in which three sub-pixels of RGB are arranged in one pixel is shown, but it may also be a structure without sub-pixels in which one LED 4 is arranged in one pixel.

[0043] Here, in order to improve the effect of suppressing light leakage, the length of the object area where the light-shielding layer 11 is disposed in the direction connecting the anode electrode 2 and the cathode electrode 3 (the L direction in the figure) may be set to be equal to or greater than the interval between the electrodes 2 and 3. However, the length that does not overlap with the adjacent object area is set as the upper limit. That is, in Figure 4 (b) of, the length where the light-shielding layers 11 adjacent in the L direction do not overlap each other is set as the upper limit. In addition, the width of the object area where the light-shielding layer 11 is disposed in the direction orthogonal to the direction connecting the anode electrode 2 and the cathode electrode 3 (the W direction in the figure) may be set to be equal to or greater than the width of the narrower one of the widths of the electrodes 2 and 3 and the width of the LED 4. Among them, the width that does not overlap with the adjacent object area is used as the upper limit. That is, in Figure 4 (b) of, the width where the light-shielding layers 11 adjacent in the W direction do not overlap each other is set as the upper limit.

[0044] In addition, the length of the light-shielding layer 11 in the L direction may be set to the length extending from the electrodes 2 and 3 toward the opening 20, or the width of the light-shielding layer 11 in the W direction may be set to the width extending from the electrodes 2 and 3 toward the opening 20. However, in this case, a part of the opening 20 is shielded by the light-shielding layer 11, and the aperture ratio of the pixel is reduced. Therefore, it is preferable that the portion of the light-shielding layer 11 extending from the electrodes 2 and 3 toward the opening 20 does not become too wide. The length of the light-shielding layer 11 may be set to the width, or the object area where the light-shielding layer 11 is disposed may be set to an area that does not extend from the electrodes 2 and 3 toward the opening 20.

[0045] In Figure 4 , the electrode pattern in the case where a plurality of LEDs 4 arranged in a line are lit up together is shown, but the light-emitting structure 10 with a leakage suppression function of the present embodiment can also be applied to other electrode patterns. For example, it can also be applied to the case where a plurality of LEDs 4 are arranged in a matrix as in Figure 5 . In the example of the array configuration shown in Figure 5 , the anode electrode 2 and the cathode electrode 3 that protrude like branches from the vertically and horizontally intersecting electrodes 2A and 3A are connected to the LED 4. In this case, the light-shielding layer 11 is also disposed in the gap between the anode electrode 2 and the cathode electrode 3.

[0046] In addition, in Figure 1 , a structure in which the object area where the light-shielding layer 11 is disposed is set to an area including the area that shields the optical path and covers the gap between the electrodes 2 and 3 on the front side of the gap is shown. However, as long as it is an area including the area that shields the optical path, the light-shielding layer 11 may be located at any layer of the cross section of the light-emitting structure. In addition, the light-emitting structure to which the light-shielding layer 11 is applied is not limited to the structure shown in Figure 1 . Figure 6Several modified examples of a light-emitting structure with a leakage suppression function including a light-shielding layer 11 are shown.

[0047] Figure 6 (a) of shows that in a light-emitting structure 10 with a leakage suppression function shown in Figure 1 where the height of the electrode pad 6 is reduced and the second insulating layer 9 is eliminated, in a light-emitting structure 10A with a leakage suppression function where a light-shielding layer 11 is disposed in an object region to block the gap between two electrode pads 6 connected to the anode electrode 2 and the cathode electrode 3. In this structural example, the object region where the light-shielding layer 11 is disposed also includes a region that blocks the light path, and becomes a region that covers the gap between the electrodes 2 and 3 on the front side of the gap.

[0048] Figure 6 (b) of represents a light-emitting structure 10B with a leakage suppression function without Figure 1 the contact holes 5, electrode pads 6, and insulating layers 8 and 9 shown in the light-emitting structure 10 with a leakage suppression function. In a light-emitting structure where a conductive adhesive 7 is directly formed on the electrodes 2 and 3 to mount the LED 4, a structural example of the light-emitting structure 10B with a leakage suppression function where a light-shielding layer 11 is disposed in an object region to block the gap between the anode electrode 2 and the cathode electrode 3. In addition, in the same light-emitting structure as Figure 1 、 Figure 6 (a) of, a light-shielding layer 11 can also be disposed in an object region to block the gap between the electrodes 2 and 3.

[0049] Figure 6 (c) of represents a structural example of a light-emitting structure 10C with a leakage suppression function where a light-shielding layer 11 is disposed on the back surface of the transparent substrate 1 in the same light-emitting structure as Figure 6 (b) of. In this case, the object region where the light-shielding layer 11 is disposed includes a region that blocks the light path, and becomes a region that covers the gap between the electrodes 2 and 3 on the back side of the gap. In addition, in the same light-emitting structure as Figure 1 or Figure 6 (a) of, a light-shielding layer 11 can also be disposed on the back surface of the transparent substrate 1.

[0050] Figure 6 (d) of represents a structural example of a light-emitting structure 10D with a leakage suppression function where a light-shielding layer 11 is disposed on the back surface of the LED 4 in the same light-emitting structure as Figure 6 (b) of. In addition, in the same light-emitting structure as Figure 1 or Figure 6 (a) of, a light-shielding layer 11 can also be disposed on the back surface of the LED 4.

[0051] As described in detail above, in the present embodiment, in the light emitting structure of the transmissive LED display using the micro LED element, a light shielding layer 11 is arranged in a target area including an area shielding the light path in the light path from the portion of the back side of the LED 4 that is opposite to the gap between the electrodes 2 and 3 toward the transparent substrate 1. Thus, when the LED 4 is lit, the light irradiated from the back side of the LED 4 toward the transparent substrate 1 is shielded by the light shielding layer 11, so that the irradiated light of the LED 4 can be prevented from leaking to the back side of the display.

[0052] In addition, in the above-mentioned embodiment, the structure of applying the shading layer 11 to a transmissive LED display using micro-LED elements is described, but as long as it is a transmissive display with a structure in which the irradiated light from the light source leaks from the gap between the electrodes, the light-emitting structure with leakage suppression function of this embodiment can be applied.

[0053] In addition, the above-mentioned embodiments are merely examples of specific implementations of the present invention, and the technical scope of the present invention should not be interpreted as being limited. That is, the present invention can be implemented in various forms without departing from the gist or main features thereof.

[0054] [Explanation of Reference Numerals]

[0055] 1 transparent substrate

[0056] 2 Anode electrode

[0057] 3 Cathode electrode

[0058] 4LED(light source)

[0059] 10, 10A, 10B, 10C, 10D Light-emitting structures with leakage suppression function

[0060] 11 Shading layer

[0061] 20 Opening.

Claims

1. A transmissive display, wherein a plurality of light sources are arranged between a plurality of groups of electrodes arranged in an array on a transparent substrate, and a plurality of openings are provided where the electrodes are not arranged, so that light can be transmitted through the plurality of openings, wherein the transmissive display is characterized in that: A light shielding layer is disposed in a target region including a region shielding the light path in a direction from a portion of the back surface of the light source facing the gap between the electrodes toward the transparent substrate.

2. The transmissive display according to claim 1, characterized in that: The target region is a region including a region shielding the light path and covering the gap between the electrodes.

3. The transmissive display according to claim 2, characterized in that: The target region has a length in a direction connecting the electrodes that is equal to or greater than the interval between the electrodes and does not overlap with an adjacent target region.

4. The transmissive display according to claim 2, characterized in that: The target region has a width in a direction perpendicular to a direction connecting the electrodes that is equal to or greater than the narrower width of the electrode and the light source and does not overlap with an adjacent target region.

5. The transmissive display according to claim 1, wherein: The target region is a region including a region shielding the light path and blocking a gap between the electrodes.

6. The transmissive display according to claim 1, characterized in that: The optical density of the light-shielding layer is 3 or more.

7. The transmissive display according to any one of claims 1 to 6, characterized in that: A micro LED element is used as the light source.

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