Transparent display device, laminated glass, and method for manufacturing a transparent display device

Abstract

A transparent display device according to an aspect of the present invention comprises: a transparent base material (10); and light emitting diode elements (21)-(23) that are respectively provided for each pixel on the transparent base material (10), wherein the rear surface side of the transparent display device can be seen from the viewing side. Each light emitting diode element (21)-(23) is a semiconductor chip having an area of 10,000 μm2 or less, and the main surface of each light emitting diode element (21)-(23) on the rear surface side is covered with a light-shielding film (60). It is possible to prevent light which has been emitted from the light emitting diode elements (21)-(23) from leaking on the rear surface side.

Description

Technical Field

[0001] The present invention relates to a transparent display device, a laminated glass, and a method for manufacturing a transparent display device.

Background Art

[0002] A display device using a light emitting diode (LED) element as a pixel is known. Patent Document 1 discloses a transparent display device in which the size of the LED element is fine and the back side can be visually recognized through the display device.

[0003] Here, in the transparent display device, there has been a demand to prevent an image displayed on the viewing side from being visually recognized from the back side (the side opposite to the viewing side). That is, there has been a demand to suppress the light emitted from the LED element from leaking to the back side.

[0004] In the transparent display device disclosed in Patent Document 2, a light shielding member is provided to inhibit the light emitted from a bullet-shaped LED (light emitter) from passing through to the back side where the light emitters are not arranged.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, 10,000 μm 2Regarding a transparent display device using an LED element having the following area, even if the light-shielding member for bullet-shaped LEDs disclosed in Patent Document 2 is applied, light emitted from the LED element cannot be sufficiently suppressed from leaking to the back side.

[0007] The present invention has been made in view of such circumstances, and provides a transparent display device capable of suppressing light emitted from an LED element from leaking to the back side.

Means for Solving the Problems

[0008] The present invention provides a transparent display device having the configuration of [1]. [1] A transparent substrate, A light-emitting diode element arranged for each pixel on the transparent substrate, and A transparent display device capable of visually recognizing the back side from the visual recognition side, The light-emitting diode element is a semiconductor chip having an area of 10,000 μm 2 or less, The main surface on the back side of the light-emitting diode element is covered with a light-shielding film, Transparent display device.

[0009] In one aspect of the present invention, [2] The transparent display device according to [1], wherein the light-shielding film covers the entire main surface on the back side of the light-emitting diode element and is formed so as to protrude from the main surface.

[0010] [3] The transparent display device according to [1] or [2], wherein the internal transmittance of visible light in the transparent member located on the back side of the light-shielding film is 90% or less.

[0011] [4] The transparent display device according to [3], wherein the transparent substrate is the transparent member.

[0012] [5] The transparent display device according to [4], further comprising a protective layer covering the light-emitting diode element on the transparent substrate and an antireflection film formed on the protective layer.

[0013] [6] The transparent display device according to [3], further comprising a protective layer covering the light-emitting diode element on the transparent substrate. The transparent display device according to [3], wherein the protective layer is the transparent member.

[0014] [7] The transparent display device according to [6], further comprising an antireflection film formed on the main surface on the viewing side of the transparent substrate.

[0015] [8] The transparent display device according to [1] or [2], further comprising a dimming layer capable of dynamically adjusting the internal transmittance of visible light on the back side of the light-shielding film.

[0016] [9] The transparent display device according to any one of [1] to [8], further comprising a mirror structure formed so as to surround the periphery of the light-emitting diode element.

[0017]

[10] The transparent display device according to any one of [1] to [9], wherein the entire main surface on the viewing side of the light-emitting diode element is covered by a lens.

[0018] The present invention provides a laminated glass having the configuration of

[11] .

[11] A pair of glass plates, A laminated glass comprising a transparent display device provided between the pair of glass plates, wherein the transparent display device comprises a transparent substrate, and a light-emitting diode element arranged for each pixel on the transparent substrate, is a transparent display device capable of viewing from the viewing side to the back side, the light-emitting diode element is a semiconductor chip having an area of 10,000 μm 2 or less, The main surface on the back side of the light-emitting diode element is covered with a light-shielding film. Bonding glass.

[0019] The present invention provides a method for manufacturing a transparent display device having the following configuration

[12] .

[12] A method for manufacturing a transparent display device in which the back side can be visually recognized from the viewing side, On a transparent substrate, a light-emitting diode element, which is a semiconductor chip having an area of 10,000 μm 2 per pixel, is arranged, and the main surface on the back side of the light-emitting diode element is covered with a light-shielding film. A method for manufacturing a transparent display device.

Effects of the Invention

[0020] According to the present invention, a transparent display device capable of suppressing light emitted from the LED element from leaking to the back side can be provided.

Brief Description of the Drawings

[0021]

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MODE FOR CARRYING OUT THE INVENTION

[0022] Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments. Also, for clarity of explanation, the following description and drawings are appropriately simplified.

[0023] As used herein, the "transparent display device" refers to a display device that enables visual information such as a person or background located on the back side of the display device to be visible in a desired usage environment. Note that "visible" is determined at least when the display device is in a non-display state, that is, when it is not energized.

[0024] As used herein, "transparent" means that the transmittance of visible light is 40% or more, preferably 60% or more, and more preferably 70% or more. It may also mean that the transmittance is 5% or more and the haze value is 20 or less. If the transmittance is 5% or more, when looking at the outdoors during the day from indoors, the outdoors can be seen with brightness equal to or greater than that indoors, ensuring sufficient visibility.

[0025] Also, if the transmittance is 40% or more, even if the brightness on the front side and the back side of the transparent display device is the same, the back side of the transparent display device can be visually recognized substantially without problems. Also, if the haze value is 10 or less, sufficient contrast of the background can be ensured. "Transparent" means regardless of whether color is imparted, that is, it may be colorless and transparent or colored and transparent. Note that the transmittance refers to a value (%) measured by a method compliant with ISO9050. The haze value refers to a value measured by a method compliant with ISO14782.

[0026] (First Embodiment) <Configuration of Transparent Display Device> First, with reference to FIGS. 1 to 3, the configuration of the transparent display device according to the first embodiment will be described. FIG. 1 is a schematic partial plan view showing an example of the transparent display device according to the first embodiment. FIG. 2 is an enlarged view of region II in FIG. 1. FIG. 3 is a cross-sectional view taken along the cutting line III-III in FIG. 2.

[0027] As shown in FIGS. 1 to 3, the transparent display device according to the present embodiment includes a transparent substrate 10, a light emitting portion 20, an IC (Integrated Circuit) chip 30, a wiring 40, a protective layer 50, and a light shielding film 60. A display area 101 in the transparent display device is composed of a plurality of pixels and is an area where an image is displayed. Note that the image includes characters. As shown in FIG. 1, the display area 101 is composed of a plurality of pixels arranged in a row direction (x-axis direction) and a column direction (y-axis direction). FIG. 1 shows a part of the display area 101, and a total of four pixels, two pixels each in the row direction and the column direction, are shown. Here, one pixel PIX is surrounded by a dashed line.

[0028] Of course, the right-handed xyz orthogonal coordinates shown in FIGS. 1 to 3 are for convenience in explaining the positional relationship of the components. Usually, the positive direction of the z-axis is vertically upward, and the xy plane is a horizontal plane. Also, in FIGS. 1 and 2, the transparent substrate 10 and the protective layer 50 shown in FIG. 3 are omitted. Further, although FIGS. 1 and 2 are plan views, for easy understanding, the light emitting portion 20 and the IC chip 30 are dot-displayed.

[0029] <Planar Arrangement of Light Emitting Portion 20, IC Chip 30, Wiring 40, and Light Shielding Film 60> First, with reference to FIGS. 1 and 2, the planar arrangement of the light emitting portion 20, the IC chip 30, the wiring 40, and the light shielding film 60 will be described. As shown in FIG. 1, the pixels PIX surrounded by a dashed line are arranged in a matrix at a pixel pitch Px in the row direction (x-axis direction) and at a pixel pitch Py in the column direction (y-axis direction). Here, as shown in FIG. 1, each pixel PIX includes a light emitting portion 20 and an IC chip 30. That is, the light emitting portion 20 and the IC chip 30 are arranged in a matrix at a pixel pitch Px in the row direction (x-axis direction) and at a pixel pitch Py in the column direction (y-axis direction). Note that as long as they are arranged at a predetermined pixel pitch in a predetermined direction, the arrangement form of the pixels PIX, that is, the light emitting portion 20, is not limited to a matrix.

[0030] 1, the light-emitting unit 20 in each pixel PIX includes at least one light-emitting diode element (hereinafter, LED element). That is, the transparent display device according to this embodiment is a display device that uses LED elements in each pixel PIX, and is called an LED display or the like.

[0031] 1, each light-emitting section 20 includes a red LED element 21, a green LED element 22, and a blue LED element 23. The LED elements 21 to 23 correspond to sub-pixels that make up one pixel. Since each light-emitting section 20 thus includes LED elements 21 to 23 that emit light of the three primary colors of light, red, green, and blue, the transparent display device according to this embodiment can display a full-color image. Each light-emitting section 20 may include two or more LED elements of the same color, which can expand the dynamic range of the image.

[0032] The LED elements 21 to 23 are so-called micro LED elements, each having a diameter of 10,000 μm 2 It is a semiconductor chip having an area of ​​100 μm or less. Specifically, the width (length in the x-axis direction) and length (length in the y-axis direction) of the LED element 21 on the transparent substrate 10 are, for example, 100 μm or less, preferably 50 μm or less, and more preferably 20 μm or less. The same applies to the LED elements 22 and 23. The lower limits of the width and length of the LED element are, for example, 3 μm or more, depending on various manufacturing conditions, etc. Although the dimensions, ie, width and length, of the LED elements 21 to 23 in FIG. 1 are the same, they may be different from each other.

[0033] The area of ​​the LED elements 21 to 23 on the transparent substrate 10 is preferably 3,000 μm 2 Less than or equal to 500 μm, more preferably 2 The lower limit of the area occupied by one LED element is, for example, 10 μm due to various manufacturing conditions. 2The above is the case. Here, in this specification, the area of the LED element and the area of constituent members such as wiring refer to the area occupied by the LED element, wiring, and other constituent members in the xy-plane view in FIG. 1. Note that the shapes of the LED elements 21 to 23 shown in FIG. 1 are rectangular (including squares), but are not particularly limited.

[0034] Here, the transmittance of the LED elements 21 to 23 is low, for example, about 10% or less. However, in the transparent display device according to the present embodiment, as described above, the LED elements 21 to 23 with a minute size of an area of 10,000 μm 2 or less are used. Therefore, even when observing the transparent display device from a short distance of, for example, about several tens of centimeters to 2 m, the LED elements 21 to 23 can hardly be visually recognized. Further, in the display area 101, the area where the transmittance is low is narrow, and the visibility on the back side is excellent. Moreover, the degree of freedom in arranging the wiring 40 and the like is also large. Note that the "area where the transmittance is low in the display area 101" is, for example, an area where the transmittance is 20% or less. The same applies hereinafter.

[0035] Further, since the minute-sized LED elements 21 to 23 are used, even when the transparent display device is curved, the LED elements are hardly damaged. Therefore, the transparent display device according to the present embodiment can be used by being attached to a curved transparent plate such as an automotive window glass, or being enclosed between two curved transparent plates. Here, if a flexible material is used as the transparent substrate 10, the transparent display device according to the present embodiment can be curved.

[0036] The LED elements 21 to 23 are not particularly limited, but are, for example, inorganic materials. The red LED element 21 is, for example, AlGaAs, GaAsP, GaP, etc. The green LED element 22 is, for example, InGaN, GaN, AlGaN, GaP, AlGaInP, ZnSe, etc. The blue LED element 23 is, for example, InGaN, GaN, AlGaN, ZnSe, etc. Also, the LED elements 21 to 23 may not only emit non-polarized light, but also emit polarized light. The function of emitting polarized light is realized by providing a structure with a pitch shorter than the wavelength of the emitted light inside or on the surface of the LED elements 21 to 23, or by providing a chiral material inside or on the surface of the LED elements 21 to 23. Also, when the LED elements 21 to 23 emit polarized light, it is preferable to arrange a member such as a polarizing film that absorbs or reflects specific polarized light on the back side, because light leaking to the back side can be suppressed. The polarizing film may act on either linearly polarized light or circularly polarized light.

[0037] The luminous efficiency, that is, the energy conversion efficiency of the LED elements 21 to 23 is, for example, 1% or more, preferably 5% or more, and more preferably 15% or more. When the luminous efficiency of the LED elements 21 to 23 is 1% or more, sufficient luminance can be obtained even with the LED elements 21 to 23 of a small size as described above, and it can be used even in the daytime as a display device. Also, when the luminous efficiency of the LED element is 15% or more, heat generation is suppressed, and it becomes easy to enclose it inside the laminated glass using a resin adhesive layer.

[0038] The pixel pitches Px and Py are, for example, 100 to 3000 μm, preferably 180 to 1000 μm, and more preferably 250 to 400 μm, respectively. By setting the pixel pitches Px and Py within the above ranges, high transparency can be realized while ensuring sufficient display performance. Also, the diffraction phenomenon that may be caused by light from the back side of the transparent display device can be suppressed. Also, the pixel density in the display area 101 of the transparent display device according to the present embodiment is, for example, 10 ppi or more, preferably 30 ppi or more, and more preferably 60 ppi or more.

[0039] Also, the area of one pixel PIX is Px × Py. The area of one pixel is, for example, 1 × 10 4 μm 2 ~ 9 × 10 6 μm 2 , preferably 3 × 10 4 ~ 1 × 10 6 μm 2 , more preferably 6 × 10 4 ~ 2 × 10 5 μm 2 . By setting the area of one pixel to be 1 × 10 4 μm 2 ~ 9 × 10 6 μm 2 , while ensuring appropriate display performance, the transparency of the display device can be improved. The area of one pixel may be appropriately selected according to the size of the display area 101, the application, the viewing distance, etc.

[0040] The ratio of the area occupied by the LED elements 21 to 23 to the area of one pixel is, for example, 30% or less, preferably 10% or less, more preferably 5% or less, and even more preferably 1% or less. By setting the ratio of the area occupied by the LED elements 21 to 23 to the area of one pixel to be 30% or less, the transparency and the visibility from the back side are improved.

[0041] In FIG. 1, in each pixel, the three LED elements 21 to 23 are arranged in a row in the positive x-axis direction in this order, but it is not limited to this. For example, the arrangement order of the three LED elements 21 to 23 may be changed. Also, the three LED elements 21 to 23 may be arranged side by side in the y-axis direction. Alternatively, the three LED elements 21 to 23 may be arranged at the vertices of a triangle.

[0042] Also, as shown in FIG. 1, when each light-emitting part 20 includes a plurality of LED elements 21 to 23, the interval between the LED elements 21 to 23 in the light-emitting part 20 is, for example, 100 μm or less, preferably 10 μm or less. Also, the LED elements 21 to 23 may be arranged so as to be in contact with each other. Thereby, it becomes easier to share the first power branch line 41a, and the aperture ratio can be improved.

[0043] In the example of FIG. 1, the arrangement order, arrangement direction, etc. of the plurality of LED elements in each light-emitting unit 20 are the same as each other, but they may be different. Further, when each light-emitting unit 20 includes three LED elements that emit light with different wavelengths, in some light-emitting units 20, the LED elements may be arranged side by side in the x-axis direction or the y-axis direction, and in other light-emitting units 20, the LED elements of each color may be arranged at the vertices of a triangle.

[0044] In the example of FIG. 1, the IC chips 30 are arranged for each pixel PIX and drive the light-emitting units 20. Specifically, the IC chips 30 are connected to the LED elements 21 to 23 via drive lines 45 respectively, and the LED elements 21 to 23 can be driven individually. The IC chip 30 is, for example, a hybrid IC having an analog region and a logic region. The analog region includes, for example, a current control circuit, a transformer circuit, and the like.

[0045] Note that the IC chips 30 may be arranged for every plurality of pixels, and a plurality of pixels connected to each IC chip 30 may be driven. For example, if one IC chip 30 is arranged for every four pixels, the number of IC chips 30 can be reduced to 1 / 4 of that in the example of FIG. 1, and the area occupied by the IC chips 30 can be reduced. Further, the IC chip 30 is not essential.

[0046] The area of the IC chip 30 is, for example, 100,000 μm 2 Preferably 10,000 μm or less hereinafter 2 More preferably 5,000 μm or less hereinafter 2 Hereinafter. The transmittance of the IC chip 30 is as low as about 20% or less, but by using the IC chip 30 with the above size, the area with a low transmittance in the display region 101 becomes narrow, and the visibility on the back side is improved.

[0047] As shown in FIG. 1, the wiring 40 includes a plurality of power supply lines 41, ground lines 42, row data lines 43, column data lines 44, and drive lines 45. In the example of FIG. 1, the power supply lines 41, ground lines 42, and column data lines 44 extend in the y-axis direction. On the other hand, the row data lines 43 extend in the x-axis direction.

[0048] Also, in each pixel PIX, the power supply line 41 and the column data line 44 are provided on the negative x-axis side of the light emitting part 20 and the IC chip 30, and the ground line 42 is provided on the positive x-axis side of the light emitting part 20 and the IC chip 30. Here, the power supply line 41 is provided on the negative x-axis side of the column data line 44. Also, in each pixel PIX, the row data line 43 is provided on the negative y-axis side of the light emitting part 20 and the IC chip 30.

[0049] Furthermore, although it will be described in detail later, as shown in FIG. 1, the power supply line 41 includes a first power supply branch line 41a and a second power supply branch line 41b. The ground line 42 includes a ground branch line 42a. The row data line 43 includes a row data branch line 43a. The column data line 44 includes a column data branch line 44a. These respective branch lines are included in the wiring 40.

[0050] As shown in FIG. 1, each power supply line 41 extending in the y-axis direction is connected to the light emitting part 20 and the IC chip 30 of each pixel PIX arranged side by side in the y-axis direction. More specifically, in each pixel PIX, on the positive x-axis side of the power supply line 41, the LED elements 21 to 23 are arranged side by side in the positive x-axis direction in this order. Therefore, the first power supply branch line 41a branched from the power supply line 41 in the positive x-axis direction is connected to the positive y-axis side end portions of the LED elements 21 to 23.

[0051] Also, in each pixel PIX, the IC chip 30 is arranged on the negative y-axis side of the LED elements 21 to 23. Therefore, between the LED element 21 and the column data line 44, the second power supply branch line 41b branched from the first power supply branch line 41a in the negative y-axis direction extends linearly and is connected to the negative x-axis side of the positive y-axis side end portion of the IC chip 30.

[0052] As shown in FIG. 1, each ground line 42 extending in the y-axis direction is connected to the IC chip 30 of each pixel PIX arranged in parallel in the y-axis direction. Specifically, a ground branch line 42a branched from the ground line 42 in the negative x-axis direction extends linearly and is connected to the end portion on the positive x-axis side of the IC chip 30. Here, the ground line 42 is connected to the LED elements 21 to 23 via the ground branch line 42a, the IC chip 30, and the drive line 45.

[0053] As shown in FIG. 1, each row data line 43 extending in the x-axis direction is connected to the IC chip 30 of each pixel PIX arranged in parallel in the x-axis direction (row direction). Specifically, a row data branch line 43a branched from the row data line 43 in the positive y-axis direction extends linearly and is connected to the end portion on the negative y-axis side of the IC chip 30. Here, the row data line 43 is connected to the LED elements 21 to 23 via the row data branch line 43a, the IC chip 30, and the drive line 45.

[0054] As shown in FIG. 1, each column data line 44 extending in the y-axis direction is connected to the IC chip 30 of each pixel PIX arranged in parallel in the y-axis direction (column direction). Specifically, a column data branch line 44a branched from the column data line 44 in the positive x-axis direction extends linearly and is connected to the end portion on the negative x-axis side of the IC chip 30. Here, the column data line 44 is connected to the LED elements 21 to 23 via the column data branch line 44a, the IC chip 30, and the drive line 45.

[0055] The drive line 45 connects the LED elements 21 to 23 and the IC chip 30 in each pixel PIX. Specifically, in each pixel PIX, three drive lines 45 extend in the y-axis direction, and each connects the end portion on the negative y-axis side of the LED elements 21 to 23 and the end portion on the positive y-axis side of the IC chip 30.

[0056] Note that the arrangement of the power line 41, ground line 42, row data line 43, column data line 44, their branch lines, and the drive line 45 shown in FIG. 1 is merely an example and can be changed as appropriate. For example, at least one of the power line 41 and the ground line 42 may extend in the x-axis direction instead of the y-axis direction. Also, a configuration in which the power line 41 and the column data line 44 are interchanged may be used.

[0057] Also, the entire configuration shown in FIG. 1 may be a configuration that is vertically inverted or horizontally inverted. Furthermore, the row data line 43, column data line 44, their branch lines, and the drive line 45 are not essential.

[0058] The wiring 40 is made of a metal such as copper (Cu), aluminum (Al), silver (Ag), or gold (Au), for example. Among these, it is preferably a metal mainly composed of copper or aluminum from the viewpoints of low resistivity and cost. Also, the wiring 40 may be coated with a material such as titanium (Ti), molybdenum (Mo), copper oxide, or carbon for the purpose of reducing the reflectance. Also, unevenness may be formed on the surface of the coated material.

[0059] The width of the wiring 40 in the display area 101 shown in FIG. 1 is, for example, 1 to 100 μm, preferably 3 to 20 μm in all cases. Since the width of the wiring 40 is 100 μm or less, the wiring 40 is hardly visible even when observing the transparent display device from a short distance of about several tens of cm to 2 m, for example, and the visibility on the back side is excellent. On the other hand, in the case of the thickness range described later, if the width of the wiring 40 is 1 μm or more, an excessive increase in the resistance of the wiring 40 can be suppressed, and a voltage drop and a decrease in signal strength can be suppressed. Also, a decrease in heat conduction due to the wiring 40 can be suppressed.

[0060] Here, as shown in FIG. 1, when the wiring 40 mainly extends in the x-axis direction and the y-axis direction, a cross diffraction image extending in the x-axis direction and the y-axis direction is generated by the light irradiated from the outside of the transparent display device, and the visibility on the back side of the transparent display device may be reduced. By reducing the width of each wiring, this diffraction can be suppressed, and the visibility on the back side can be further improved. From the viewpoint of suppressing diffraction, the width of the wiring 40 may be 50 μm or less, preferably 10 μm or less, more preferably 5 μm or less.

[0061] The electrical resistivity of the wiring 40 is, for example, 1.0×10 -6 Ωm or less, preferably 2.0×10 -8 Ωm or less. Also, the thermal conductivity of the wiring 40 is, for example, 150 to 5,500 W / (m·K), preferably 350 to 450 W / (m·K).

[0062] The interval between adjacent wirings 40 in the display area 101 shown in FIG. 1 is, for example, 3 to 100 μm, preferably 5 to 30 μm. If there is an area where the wiring 40 is dense, it may interfere with the visibility on the back side. By setting the interval between adjacent wirings 40 to 3 μm or more, such interference with visibility can be suppressed. On the other hand, by setting the interval between adjacent wirings 40 to 100 μm or less, sufficient display performance can be ensured. In addition, when the interval between the wirings 40 is not constant due to the curvature of the wiring 40 or the like, the above-mentioned interval between adjacent wirings 40 refers to its minimum value.

[0063] The ratio of the area occupied by the wiring 40 to the area of one pixel is, for example, 30% or less, preferably 10% or less, more preferably 5% or less, and even more preferably 3% or less. The transmittance of the wiring 40 is low, for example, 20% or less, or 10% or less. However, by setting the ratio of the area occupied by the wiring 40 in one pixel to 30% or less, the area with a low transmittance in the display area 101 becomes narrower, and the visibility on the back side is improved. Furthermore, the total area occupied by the light-emitting portion 20, the IC chip 30, and the wiring 40 with respect to the area of one pixel is, for example, 30% or less, preferably 20% or less, and more preferably 10% or less.

[0064] The light-shielding film 60 is formed so as to cover the entire main surface on the back side of each of the LED elements 21 to 23. Therefore, as shown in FIG. 2, in a plan view of the xy plane, each light-shielding film 60 is formed so as to overlap with each of the LED elements 21 to 23 as a whole. In this way, by covering the main surfaces on the back sides of the LED elements 21 to 23 with the light-shielding film 60, it is possible to suppress the light emitted from the LED elements 21 to 23 from leaking to the back side. It is preferable that the light-shielding film 60 covers the entire main surface on the back side.

[0065] The light-shielding film 60 is, for example, a black resin film having insulating properties, a metal oxide film, a metal nitride film, or the like. More specifically, the light-shielding film 60 is, for example, a black resist film, a film in which carbon black or other carbon-based materials, Cr, Mo, Ti, Al, etc. are entirely or partially oxidized or nitrided, or the like. The light-shielding film 60 may be a metal film having conductivity such as a metal Cr film. Further, a resin containing a filler of such a material may be used as the light-shielding film 60. Further, it is preferable that the effective refractive index of the resin containing the filler is equal to the refractive index of the surrounding transparent base material 10 or the protective layer 50, or the difference therebetween is within 0.2. Further, in order to suppress the reflection of light by the light-shielding film 60, it is preferable that the surface of the light-shielding film 60 is not smooth.

[0066] As shown in FIG. 2, the light-shielding film 60 may be formed so as to protrude from the main surfaces on the back sides of the LED elements 21 to 23. The light-shielding film 60 protruding from the LED elements 21 to 23 can suppress the light emitted from the LED elements 21 to 23 to the viewing side and reflected to the back side from leaking to the back side.

[0067] The larger the area of the light-shielding film 60, the more effectively such reflected light can be prevented from leaking to the back side, but the visibility on the back side decreases. Therefore, the area of the light-shielding film 60 is, for example, 0.6 times or less, preferably 0.4 times or less, and more preferably 0.2 times or less, relative to the area of one pixel.

[0068] <Cross-sectional configuration of the transparent display device> Next, with reference to FIG. 3, the cross-sectional configuration of the transparent display device according to the present embodiment will be described. The transparent substrate 10 is a transparent material having insulating properties. In the example of FIG. 3, the transparent substrate 10 has a two-layer structure including a main substrate 11 and an adhesive layer 12. The main substrate 11 is, for example, a transparent resin as will be described in detail later. The adhesive layer 12 is, for example, a transparent resin adhesive such as an epoxy-based, acrylic-based, olefin-based, polyimide-based, or novolak-based adhesive. Note that the main substrate 11 may be a thin glass plate having a thickness of, for example, 200 μm or less, preferably 100 μm or less. Also, the adhesive layer 12 is not essential.

[0069] Examples of the transparent resin constituting the main substrate 11 include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), olefin resins such as cycloolefin polymer (COP) and cycloolefin copolymer (COC), cellulose resins such as cellulose, acetyl cellulose, and triacetyl cellulose (TAC), imide resins such as polyimide (PI), amide resins such as polyamide (PA), amide-imide resins such as polyamide-imide (PAI), carbonate resins such as polycarbonate (PC), sulfone resins such as polyethersulfone (PES), para-xylene-based resins such as polyp-xylylene, vinyl resins such as polyethylene (PE), polyvinyl chloride (PVC), polystyrene (PS), polyvinyl acetate (PVAc), polyvinyl alcohol (PVA), and polyvinyl butyral (PVB), acrylic resins such as polymethyl methacrylate (PMMA), urethane resins such as ethylene-vinyl acetate copolymer resin (EVA) and thermoplastic polyurethane (TPU), and epoxy resins.

[0070] Among the materials used for the main substrate 11 described above, polyethylene naphthalate (PEN) and polyimide (PI) are preferable from the viewpoint of improving heat resistance. Also, cycloolefin polymer (COP), cycloolefin copolymer (COC), polyvinyl butyral (PVB), etc. are preferable in terms of having a low birefringence and being able to reduce the distortion and bleeding of the image seen through the transparent substrate. The above materials may be used singly or in combination of two or more. Further, the main substrate 11 may be constituted by laminating flat plates of different materials.

[0071] The thickness of the entire transparent substrate 10 is, for example, 3 to 1000 μm, preferably 5 to 200 μm. Also, the transparent substrate 10 may have flexibility. Thereby, for example, a transparent display device can be attached to a curved transparent plate or sandwiched between two curved transparent plates for use. Also, it may be a material that shrinks when heated to 100 °C or higher.

[0072] As shown in Fig. 3, the LED elements 21 to 23 and the IC chip 30 are provided on the transparent base material 10, that is, on the adhesive layer 12. Here, as shown in Fig. 3, the LED elements 21 to 23 are provided on the transparent base material 10, that is, on the adhesive layer 12, via the light-shielding film 60. In other words, the light-shielding film 60 is formed on the transparent base material 10, that is, on the adhesive layer 12, and the LED elements 21 to 23 are formed on the light-shielding film 60. In the example of Fig. 3, the positive z-axis direction side is the viewing side, and the negative z-axis direction side is the back side. Therefore, in each of the LED elements 21 to 23, the entire main surface on the back side is covered by the light-shielding film 60, and it is possible to suppress the light emitted from the LED elements 21 to 23 from directly leaking to the back side. When the thickness of the light-shielding film 60 is, for example, 0.01 to 2 μm, scattering at the side walls of the light-shielding film 60 can be suppressed. The thickness of the light-shielding film 60 is preferably 0.5 μm or less, and more preferably 0.1 μm or less.

[0073] As shown in Fig. 3, the transparent base material 10 is located on the back side of the light-shielding film 60. Therefore, in order to suppress the light emitted from the LED elements 21 to 23 to the viewing side and reflected to the back side from leaking to the back side, the internal transmittance of visible light of the transparent base material 10 may be, for example, 90% or less. From such a viewpoint, the internal transmittance of visible light of the transparent base material 10 is preferably 70% or less, and more preferably 50% or less. Here, the transparent base material 10 may absorb only light in a part of the wavelength range of visible light, or may absorb light in the entire wavelength range of visible light.

[0074] As shown in Fig. 3, the LED elements 21 to 23 and the IC chip 30 are connected to the wiring 40 disposed on the transparent base material 10. In the example of Fig. 3, the wiring 40 is composed of a first metal layer M1 formed on the main substrate 11 and a second metal layer M2 formed on the adhesive layer 12. The total thickness of the wiring 40, that is, the sum of the thickness of the first metal layer M1 and the thickness of the second metal layer M2 is, for example, 0.1 to 10 μm, preferably 0.5 to 5 μm. The thickness of the first metal layer M1 is, for example, about 0.5 μm, and the thickness of the second metal layer M2 is, for example, about 3 μm.

[0075] Specifically, as shown in FIG. 3, the ground line 42 extending in the y-axis direction has a two-layer structure including the first metal layer M1 and the second metal layer M2 because of the large current amount. That is, at the site where the ground line 42 is provided, the adhesive layer 12 is removed, and the second metal layer M2 is formed on the first metal layer M1. Although not shown in FIG. 3, the power line 41, the row data line 43, and the column data line 44 shown in FIG. 1 also have a two-layer structure including the first metal layer M1 and the second metal layer M2 in the same manner.

[0076] Here, as shown in FIG. 1, the power line 41, the ground line 42, and the column data line 44 extending in the y-axis direction intersect with the row data line 43 extending in the x-axis direction. Although not shown in FIG. 3, at this intersection, the row data line 43 is composed of only the first metal layer M1, and the power line 41, the ground line 42, and the column data line 44 are composed of only the second metal layer M2. And at this intersection, an adhesive layer 12 is provided between the first metal layer M1 and the second metal layer M2, and the first metal layer M1 and the second metal layer M2 are insulated from each other. Similarly, at the intersection of the column data line 44 and the first power branch line 41a shown in FIG. 1, the first power branch line 41a is composed of only the first metal layer M1, and the column data line 44 is composed of only the second metal layer M2.

[0077] Also, in the example of FIG. 3, the ground branch line 42a, the drive line 45, and the first power branch line 41a are composed of only the second metal layer M2 and are formed to cover the ends of the LED elements 21 to 23 and the IC chip 30. Although not shown in FIG. 3, the second power branch line 41b, the row data branch line 43a, and the column data branch line 44a are also composed of only the second metal layer M2 in the same manner.

[0078] Note that, as described above, the first power branch line 41a is composed of only the first metal layer M1 at the intersection with the column data line 44, and is composed of only the second metal layer M2 at other parts. Further, metal pads made of copper, silver, gold, etc. may be arranged on the wiring 40 formed on the transparent base material 10, and at least one of the LED elements 21 to 23 and the IC chip 30 may be arranged thereon.

[0079] The protective layer 50 is a transparent resin formed on substantially the entire surface of the transparent base material 10 so as to cover and protect the light emitting portion 20, the IC chip 30, and the wiring 40. The thickness of the protective layer 50 is, for example, 3 to 1000 μm, preferably 5 to 200 μm. The elastic modulus of the protective layer 50 is, for example, 10 GPa or less. A lower elastic modulus can absorb the impact during peeling and suppress damage to the protective layer 50. The internal transmittance of visible light of the protective layer 50 is, for example, 50% or more, preferably 70% or more, and more preferably 90% or more.

[0080] For the refractive index of the protective layer 50 not to confine light within the protective layer 50 and to extract it to the viewing side (the positive z-axis direction side), it is preferable that the refractive index of the protective layer 50 is lower than that of the transparent layer (not shown in FIG. 3) that contacts the viewing side of the light emitting portion 20. On the other hand, when the in-plane average thickness of the protective layer 50 is smaller than the pitch of one pixel, it is rather preferable that the refractive index of the protective layer 50 is higher than that of the transparent layer that contacts the viewing side of the light emitting portion 20. By confining and guiding light inside the protective layer 50, light can be effectively absorbed by the light shielding film 60, the wiring 40, etc. that contact the protective layer 50 on the back side, and leakage of light to the back side can be suppressed. In this case, it is more preferable that the thickness of the protective layer 50 is thinner than the longest side of the light shielding film 60. Even if a transparent layer is further formed between the light shielding film 60, the wiring 40, etc. and the protective layer 50, if the refractive index of the transparent layer is higher than that of the protective layer 50, the same effect can be obtained.

[0081] Examples of the transparent resin constituting the protective layer 50 include vinyl resins such as polyethylene (PE), polyvinyl chloride (PVC), polystyrene (PS), polyvinyl acetate (PVAc), polyvinyl alcohol (PVA), polyvinyl butyral (PVB), olefin resins such as cycloolefin polymer (COP) and cycloolefin copolymer (COC), urethane resins such as thermoplastic polyurethane (TPU), polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), acrylic resins such as polymethyl methacrylate (PMMA), and thermoplastic resins such as ethylene-vinyl acetate copolymer resin (EVA).

[0082] As described above, in the transparent display device according to the present embodiment, in each of the LED elements 21 to 23, the entire main surface on the back side is covered with the light shielding film 60. Therefore, it is possible to suppress the light emitted from the LED elements 21 to 23 from directly leaking to the back side. Further, the light shielding film 60 is formed so as to protrude from the main surface on the back side of the LED elements 21 to 23. Therefore, it is possible to suppress the light emitted from the LED elements 21 to 23 to the viewing side and reflected to the back side from leaking to the back side. Furthermore, by setting the internal transmittance of visible light of the transparent member (transparent base material 10) located on the back side of the light shielding film 60 to 90% or less, it is possible to further suppress such reflected light from leaking to the back side.

[0083] <Manufacturing method of the transparent display device> Next, with reference to FIGS. 3 to 12, an example of the manufacturing method of the transparent display device according to the first embodiment will be described. FIGS. 4 to 12 are cross-sectional views showing an example of the manufacturing method of the transparent display device according to the first embodiment. FIGS. 4 to 12 are cross-sectional views corresponding to FIG. 3.

[0084] First, as shown in FIG. 4, after forming a first metal layer M1 on substantially the entire surface of the main substrate 11, the first metal layer M1 is patterned by photolithography to form lower-layer wirings. Specifically, lower-layer wirings are formed by the first metal layer M1 at positions where the power line 41, ground line 42, row data line 43, column data line 44, etc. shown in FIG. 1 are formed. Note that lower-layer wirings are not formed at the intersections of the power line 41, ground line 42, and column data line 44 with the row data line 43.

[0085] Next, as shown in FIG. 5, after forming an adhesive layer 12 on substantially the entire surface of the main substrate 11, a light-shielding film 60 is patterned on the adhesive layer 12 having tackiness (i.e., on the transparent substrate 10). Here, the light-shielding film 60 is formed at positions where the LED elements 21 to 23 are mounted. Next, as shown in FIG. 6, an IC chip 30 is mounted on the adhesive layer 12 (i.e., on the transparent substrate 10), and the LED elements 21 to 23 are mounted on the light-shielding film 60. The light-shielding film 60 may have tackiness similar to the adhesive layer 12.

[0086] Here, the LED elements 21 to 23 can be obtained, for example, by growing crystals on a wafer using a liquid phase growth method, HVPE (Hydride Vapor Phase Epitaxy) method, MOCVD (Metal Organic Chemical Vapor Deposition) method, etc., and then patterning. The LED elements 21 to 23 patterned on the wafer are transferred onto the transparent substrate 10 using, for example, micro-transfer printing technology. Also, for the IC chip 30, similar to the LED elements 21 to 23, the IC chip 30 patterned on, for example, a Si wafer is transferred onto the transparent substrate 10 using micro-transfer printing technology.

[0087] Next, as shown in FIG. 7, after forming a photoresist FR1 on substantially the entire surface of the transparent substrate 10 including the main substrate 11 and the adhesive layer 12, the photoresist FR1 on the first metal layer M1 is removed by patterning. Here, the photoresist FR1 at the intersection of the power line 41, the ground line 42, and the column data line 44 in the row data line 43 shown in FIG. 1 is not removed.

[0088] Next, as shown in FIG. 8, the adhesive layer 12 at the site where the photoresist FR1 has been removed is removed by dry etching to expose the first metal layer M1, that is, the lower layer wiring. Next, as shown in FIG. 9, all of the photoresist FR1 on the transparent substrate 10 is removed. Then, a plating seed layer (not shown) is formed on substantially the entire surface of the transparent substrate 10.

[0089] Next, as shown in FIG. 10, after forming a photoresist FR2 on substantially the entire surface of the transparent substrate 10, the photoresist FR2 at the site where the upper layer wiring is to be formed is removed by patterning to expose the seed layer. Next, as shown in FIG. 11, a second metal layer M2 is formed by plating on the site where the photoresist FR2 has been removed, that is, on the seed layer. Thereby, the upper layer wiring is formed by the second metal layer M2.

[0090] Next, as shown in FIG. 12, the photoresist FR2 is removed. Further, the seed layer exposed by the removal of the photoresist FR2 is removed by etching. Finally, as shown in FIG. 3, a protective layer 50 is formed on substantially the entire surface of the transparent substrate 10, whereby a transparent display device is obtained.

[0091] (Modification of the First Embodiment) Next, with reference to FIGS. 13 and 14, a transparent display device according to a modified example of the first embodiment will be described. FIG. 13 is a schematic partial plan view showing an example of a transparent display device according to a modified example of the first embodiment, and is a figure corresponding to FIG. 2. FIG. 14 is a cross-sectional view taken along the XIV-XIV cutting line in FIG. 13. In FIG. 13, the light shielding film 60 is depicted by a two-dot chain line.

[0092] In the examples shown in FIGS. 2 and 3, the upper surface side of the LED elements 21 to 23 is the viewing side. Therefore, the entire lower surface of the LED elements 21 to 23 is covered by the light shielding film 60. On the other hand, in the modified example shown in FIGS. 13 and 14, the lower surface side of the LED elements 21 to 23 is the viewing side. Therefore, the upper surfaces of the LED elements 21 to 23 are covered by the light shielding film 60. As shown in FIG. 13, the entire upper surfaces of the LED elements 21 to 23 are covered by the light shielding film 60, the first power branch line 41a, and the driving line 45. Here, the first power branch line 41a and the driving line 45 also function as light shielding films.

[0093] Also, as shown in FIG. 14, in the transparent display device according to the modified example, the protective layer 50 is located on the back side of the light shielding film 60. Therefore, in order to suppress the light emitted from the LED elements 21 to 23 to the viewing side and reflected to the back side from leaking to the back side, the internal transmittance of visible light of the protective layer 50 may be, for example, 90% or less. From such a viewpoint, the internal transmittance of visible light of the protective layer 50 is preferably 70% or less, more preferably 50% or less. Here, the protective layer 50 may absorb only light in a part of the wavelength range of visible light, or may absorb light in the entire wavelength range of visible light. On the other hand, in the transparent display device according to the modified example, the transparent base material 10 is located on the viewing side of the LED elements 21 to 23. Therefore, the internal transmittance of visible light of the transparent base material 10 is, for example, 50% or more, preferably 70% or more, more preferably 90% or more.

[0094] As described above, also in the transparent display device according to the modification example, in each of the LED elements 21 to 23, the entire main surface on the back side is covered with a light shielding film 60 having a function as a light shielding film, a first power branch line 41a, and a driving line 45. Therefore, it is possible to suppress the light emitted from the LED elements 21 to 23 from directly leaking to the back side.

[0095] Further, the light shielding film 60 is formed so as to protrude from the main surface on the back side of the LED elements 21 to 23. Therefore, it is possible to suppress the light emitted from the LED elements 21 to 23 to the viewing side and reflected to the back side from leaking to the back side. Furthermore, by setting the internal transmittance of visible light of the transparent member (protective layer 50) located on the back side of the light shielding film 60 to 90% or less, it is possible to further suppress such reflected light from leaking to the back side. Other configurations are the same as those of the transparent display device according to the first embodiment.

[0096] (Second Embodiment) Next, with reference to FIG. 15, a transparent display device according to the second embodiment will be described. FIG. 15 is a schematic partial cross-sectional view showing an example of the transparent display device according to the second embodiment, and is a view corresponding to FIG. 3.

[0097] As shown in FIG. 15, in the transparent display device according to the present embodiment, an antireflection film 70 is formed on the viewing side of the LED elements 21 to 23. Specifically, in the transparent display device shown in FIG. 15, in the transparent display device shown in FIG. 3, an antireflection film 70 is formed on the upper surface of the protective layer 50 (on the main surface on the viewing side). Therefore, it is possible to reduce the light emitted from the LED elements 21 to 23 to the viewing side and reflected to the back side on the upper surface of the protective layer 50. As a result, it is possible to suppress such reflected light from leaking to the back side more than the transparent display device according to the first embodiment. Other configurations are the same as those of the transparent display device according to the first embodiment. Note that, in the transparent display device shown in FIG. 14, the same effect can also be obtained when an antireflection film is formed on the lower surface of the transparent substrate 10 (on the main surface on the viewing side).

[0098] (Third Embodiment) Next, with reference to FIGS. 16 and 17, a transparent display device according to the third embodiment will be described. FIG. 16 is a schematic partial plan view showing an example of the transparent display device according to the third embodiment, and is a view corresponding to FIG. 2. FIG. 17 is a cross-sectional view taken along the XVII-XVII cutting line in FIG. 16.

[0099] As shown in FIG. 16, in the transparent display device according to the present embodiment, a third power branch line 41c functioning as a mirror structure is formed around each of the LED elements 21 to 23. Specifically, a pair of third power branch lines 41c branched from the first power branch line 41a in the negative y-axis direction are formed so as to surround each of the LED elements 21 to 23.

[0100] As shown in FIG. 16, each of the LED elements 21 to 23 is surrounded entirely by the first power branch line 41a, a pair of third power branch lines 41c, and the drive line 45. Note that the third power branch line 41c and the drive line 45 are separated from each other and are not electrically short-circuited.

[0101] As shown in FIG. 17, for example, light emitted from the LED element 23 toward the viewing side so as to spread in the xy plane direction is reflected by the wall surfaces of the first power branch line 41a, a pair of third power branch lines 41c, and the drive line 45 surrounding the LED element 23. Therefore, the traveling direction of the light emitted from the LED element 23 toward the viewing side can be made closer to the positive z-axis direction. The same applies to the LED elements 21 and 22.

[0102] With such a configuration, in the transparent display device according to the present embodiment, light emitted from the LED elements 21 to 23 toward the viewing side and reflected back to the back side on the upper surface of the protective layer 50 can be reduced. As a result, leakage of such reflected light to the back side can be suppressed more than in the transparent display device according to the first embodiment. Other configurations are the same as those of the transparent display device according to the first embodiment. Note that the present embodiment and the second embodiment can also be combined. That is, an antireflection film 70 shown in FIG. 15 may be formed on the upper surface of the protective layer 50 in FIG. 17.

[0103] (Modification of the Third Embodiment) Next, with reference to FIG. 18, a transparent display device according to a modification of the third embodiment will be described. FIG. 18 is a schematic partial cross-sectional view showing an example of a transparent display device according to a modification of the third embodiment, and is a view corresponding to FIG. 17.

[0104] As shown in FIG. 18, in the transparent display device according to the modification, in the transparent display device shown in FIG. 17, convex lenses 80 are formed to cover the main surfaces on the viewing side of the LED elements 21 to 23. Therefore, the traveling direction of the light emitted from the LED elements 21 to 23 toward the viewing side can be further approximated to the positive z-axis direction, and the light reflected back on the back side at the upper surface of the protective layer 50 can be reduced. As a result, leakage of such reflected light to the back side can be suppressed more than in the transparent display device shown in FIG. 17. Note that in FIG. 18, only the convex lens 80 may be provided without providing the third power branch line 41c that functions as a mirror structure.

[0105] (Fourth Embodiment) Next, with reference to FIG. 19, a transparent display device according to the fourth embodiment will be described. FIG. 19 is a schematic partial cross-sectional view showing an example of a transparent display device according to the fourth embodiment, and is a view corresponding to FIG. 3.

[0106] As shown in FIG. 19, in the transparent display device according to the present embodiment, a dimming layer 90 is formed on the back side of the light-shielding film 60. Specifically, in the transparent display device shown in FIG. 3, a dimming layer 90 is formed on the lower surface of the transparent substrate 10.

[0107] The light control layer 90 can dynamically adjust the internal transmittance of visible light. By providing the light control layer 90, it is possible to dynamically suppress the leakage of light emitted from the LED elements 21 to 23 to the viewing side and reflected to the back side to the back side. As the light control layer 90, for example, guest-host liquid crystal, polymer-dispersed liquid crystal, electric field-responsive anisotropic particles, electrochromic material, etc. can be used.

[0108] For example, while the LED elements 21 to 23 are not emitting light (i.e., while no image is being displayed), the light control layer 90 is transparent, and only while the LED elements 21 to 23 are emitting light (i.e., while an image is being displayed), the internal transmittance of visible light in the light control layer 90 is decreased. With such a configuration, it is possible to suppress the leakage of light emitted from the LED elements 21 to 23 to the viewing side and reflected to the back side to the back side without decreasing the internal transmittance of visible light of the transparent substrate 10. Since the internal transmittance of visible light of the transparent substrate 10 is high, the visibility on the back side while no image is being displayed is improved. Other configurations are the same as those of the transparent display device according to the first embodiment. Note that, in the transparent display device shown in FIG. 14, even when a light control layer is formed on the upper surface of the protective layer 50, the same effect is obtained.

[0109] (Fifth Embodiment) <Configuration of Laminated Glass Comprising a Transparent Display Device> Next, with reference to FIGS. 20 and 21, the configuration of the laminated glass according to the fifth embodiment will be described. FIG. 20 is a schematic plan view showing an example of the laminated glass according to the fifth embodiment. FIG. 21 is a schematic cross-sectional view showing an example of the laminated glass according to the fifth embodiment. The laminated glass 200 shown in FIGS. 20 and 21 is used for the windshield of an automobile, but is not particularly limited.

[0110] First, with reference to FIG. 20, the planar configuration of the laminated glass 200 will be described. As shown in FIG. 20, for example, a black shielding portion 201 is provided on the entire periphery of the laminated glass 200. The shielding portion 201 shields sunlight and protects the adhesive for assembling the laminated glass 200 to the vehicle from ultraviolet rays. Further, the shielding portion 201 makes the adhesive not visible from the outside.

[0111] As shown in FIG. 20, the transparent display device 100 includes, in addition to the display area 101 shown in FIG. 1, a non-display area 102 provided around the display area. Here, the display area 101 is composed of a large number of pixels as described in the first embodiment and is an area where an image is displayed, so a detailed description thereof is omitted. Note that FIG. 20 is a plan view, but for easy understanding, the non-display area 102 and the shielding portion 201 are shown in dot form.

[0112] The non-display area 102 does not include pixels and is an area where an image is not displayed. In the non-display area 102, thick wirings connected to the power line 41, the ground line 42, the row data line 43, and the column data line 44 shown in FIG. 1 are densely provided. The width of the wirings in the non-display area 102 is, for example, 100 to 10,000 μm, preferably 100 to 5,000 μm. The interval between the wirings is, for example, 3 to 5,000 μm, preferably 50 to 1,500 μm.

[0113] Therefore, while the display area 101 is transparent, the non-display area 102 is opaque and can be seen from inside the vehicle. Here, if the non-display area 102 can be seen, the design property of the laminated glass 200 deteriorates. Thus, in the laminated glass 200 according to the fifth embodiment, at least a part of the non-display area 102 of the transparent display device 100 is provided in the shielding portion 201. The non-display area 102 provided in the shielding portion 201 is hidden by the shielding portion 201 and cannot be seen. Therefore, the design property of the laminated glass 200 is improved as compared with the case where the entire non-display area 102 can be seen.

[0114] Next, referring to FIG. 21, the cross-sectional structure of the laminated glass 200 will be described. FIG. 21 is a cross-sectional view of the display region 101 of the transparent display device 100. As shown in FIG. 21, the laminated glass 200 according to the fifth embodiment is formed by bonding a pair of glass plates 220a and 220b via an intermediate film. And the laminated glass 200 includes the transparent display device 100 according to the first embodiment between this pair of glass plates 220a and 220b via intermediate films 210a and 210b. The intermediate films 210a and 210b are made of, for example, polyvinyl butyral (PVB). The refractive index of the intermediate film 210a in contact with the protective layer 50 is preferably higher than the refractive index of the protective layer 50 because it can suppress the confinement of light in the protective layer 50, making it difficult to be visually recognized from the back.

[0115] Also, as shown in FIG. 21, in the laminated glass 200 according to this embodiment, the intermediate film 210b and the glass plate 220b are located on the back side of the light-shielding film 60. Therefore, in order to suppress the leakage of the light emitted from the LED elements 21 to 23 to the visual side and reflected to the back side to the back side, the internal transmittance of visible light of at least one of the intermediate film 210b and the glass plate 220b may be, for example, 90% or less. From such a viewpoint, the internal transmittance of visible light of at least one of the intermediate film 210b and the glass plate 220b is preferably 70% or less, more preferably 50% or less.

[0116] Here, FIG. 22 is a schematic cross-sectional view showing another example of the laminated glass according to the fifth embodiment. In the laminated glass 200 shown in FIG. 22, the protective layer 50 in the transparent display device 100 is made of, for example, polyvinyl butyral (PVB) and also has the function of an intermediate film. Therefore, in the laminated glass 200 shown in FIG. 22, the intermediate film 210a formed on the protective layer 50 in FIG. 21 can be omitted. In this case, the refractive index of the glass plate 220a in contact with the protective layer 50 is preferably higher than the refractive index of the protective layer 50 because it can suppress the confinement of light in the protective layer 50, making it difficult to be visually recognized from the back.

[0117] Note that the present invention is not limited to the above-described embodiments and can be appropriately modified without departing from the spirit thereof.

[0118] This application claims priority based on Japanese Patent Application No. 2020-202483 filed on December 7, 2020, and incorporates the entire disclosure thereof herein.

Description of Reference Numerals

[0119] 10 Transparent substrate 11 Main substrate 12 Adhesive layer 20 Light-emitting part 21~23 LED elements 30 IC chip 40 Wiring 41 Power line 41a First power branch line 41b Second power branch line 41c Third power branch line 42 Ground line 42a Ground branch line 43 Row data line 43a Row data branch line 44 Column data line 44a Column data branch line 45 Drive line 50 Protective layer 60 Light-shielding film 70 Antireflection film 80 Convex lens 90 Dimming layer 100 Flexible transparent display device 101 Display area 102 Non-display area 200 Cover glass 201 Shielding part 210a, 210b Intermediate film 220a, 220b Glass plate FR1, FR2 Photoresist M1 First metal layer M2 Second metal layer PIX Pixel

Claims

1. A transparent substrate, and a light-emitting diode element arranged for each pixel on the transparent substrate, and is a transparent display device capable of visually recognizing the back side from the viewing side, wherein a main surface on the back side of the light-emitting diode element is covered with a light-shielding film, The light-emitting diode element is a semiconductor chip having an area of 10,000 μm ２ or less. and an internal transmittance of visible light in a transparent member located on the back side of the light-shielding film is 90% or less. A transparent display device.

2. The light-shielding film covers the entire main surface on the back side of the light-emitting diode element and protrudes from the main surface, The transparent display device according to Claim 1.

3. The transparent substrate is the transparent member, The transparent display device according to Claim 1 or 2.

4. Further comprising a protective layer covering the light-emitting diode element on the transparent substrate, and an antireflection film formed on the protective layer, The transparent display device according to Claim 3.

5. Further comprising a protective layer covering the light-emitting diode element on the transparent substrate, wherein the protective layer is the transparent member, The transparent display device according to Claim 1 or 2.

6. Further comprising an antireflection film formed on a main surface on the viewing side of the transparent substrate, The transparent display device according to Claim 5.

7. Further comprising a dimming layer capable of dynamically adjusting an internal transmittance of visible light on the back side of the light-shielding film, The transparent display device according to Claim 1 or 2.

8. Further comprising a mirror structure formed so as to surround the periphery of the light-emitting diode element, The transparent display device according to any one of Claims 1 to 7.

9. An entire main surface on the viewing side of the light-emitting diode element is covered with a lens, The transparent display device according to any one of Claims 1 to 8.

10. A laminated glass including a pair of glass plates, and a transparent display device provided between the pair of glass plates, wherein the transparent display device comprises a transparent substrate, and a light-emitting diode element arranged for each pixel on the transparent substrate, and is a transparent display device capable of visually recognizing the back side from the viewing side, wherein a main surface on the back side of the light-emitting diode element is covered with a light-shielding film, and an internal transmittance of visible light in a transparent member located on the back side of the light-shielding film is 90% or less. The light-emitting diode element is a semiconductor chip having an area of 10,000 μm ２ or less, A laminated glass.

11. A method for manufacturing a transparent display device capable of visually recognizing the back side from the viewing side, ​ ​ On a transparent substrate, a light-emitting diode element which is a semiconductor chip having an area of 10,000 μm or less per pixel is arranged. ２ ​ Cover the main surface on the back side of the light-emitting diode element with a light-shielding film, The internal transmittance of visible light in the transparent member located on the back side of the light-shielding film is 90% or less, A method for manufacturing a transparent display device.

Images