Transparent display device

Abstract

A transparent display device according to the present disclosure comprises: a first substrate; an internal layer; and a second substrate. The first substrate can transmit visible light. The internal layer is provided on a main surface of the first substrate, and has arranged therein, in different positions in plan view, the following: a plurality of light emitting pixels configured so that each can independently emit light; and a plurality of light modulating pixels each of which independently changes the transmission rate with respect to visible light. The second substrate can transmit visible light and is provided on the side of the internal layer which is opposite the first substrate.

Description

[Technical Field]

[0001] The present disclosure relates to a transparent display device. [Background technology]

[0002] BACKGROUND ART Conventionally, there is known technology relating to a transparent display device that has a light-emitting layer sandwiched between a pair of transparent electrodes, is capable of displaying images and text information on a display surface based on light from the light-emitting layer, and is also capable of transmitting external light from the back surface to the display surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-041100 Summary of the Invention

[0004] Further improvements are needed in transparent display devices.

[0005] The transparent display device according to the present disclosure comprises a first substrate, an internal layer, and a second substrate. The first substrate is capable of transmitting visible light. The internal layer is provided on a main surface of the first substrate, and has a plurality of light-emitting pixels, each configured to be capable of independently emitting light, and a plurality of light-modulating pixels, each having independently variable transmittance for visible light, arranged at different positions in a planar view. The second substrate is provided on the opposite side of the internal layer from the first substrate, and is capable of transmitting visible light. Each of the plurality of light-adjusting pixels is provided between the plurality of light-emitting pixels in the internal layer. The internal layer has a first electrode, a second electrode, and a light-adjusting member. The first electrode is provided at a position different from the plurality of light-emitting pixels in a planar view and is capable of transmitting visible light. The second electrode is provided on a side of the second substrate facing the first electrode and spaced apart from the first electrode and is capable of transmitting visible light. The light-adjusting member is provided between the first electrode and the second electrode and its transmittance for visible light changes depending on a voltage applied between the first electrode and the second electrode. The light-adjusting member covers at least one of the plurality of light-emitting pixels in a planar view.

[0006] The present disclosure can provide a transparent display device that can achieve further improvements. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a cross-sectional view schematically showing an example of the configuration of a transparent display device according to the first embodiment. [Figure 2] FIG. 2 is a plan view schematically illustrating an example of the configuration of the transparent display device according to the first embodiment. [Figure 3] FIG. 3 is a plan view schematically showing another example of the configuration of the transparent display device according to the first embodiment. [Figure 4] FIG. 4 is a cross-sectional view schematically illustrating an example of the configuration of the transparent display device according to the first embodiment in a transmissive mode. [Figure 5] FIG. 5 is a cross-sectional view schematically illustrating an example of the configuration of the transparent display device according to the first embodiment in a dimming mode. [Figure 6] FIG. 6 is a cross-sectional view schematically illustrating an example of the configuration of the transparent display device according to the second embodiment in a transmissive mode. [Figure 7] FIG. 7 is a cross-sectional view schematically illustrating an example of the configuration of the transparent display device according to the second embodiment in a dimming mode. [Figure 8] FIG. 8 is a cross-sectional view schematically illustrating an example of the configuration of the transparent display device according to the third embodiment in a transmissive mode. [Figure 9] FIG. 9 is a cross-sectional view schematically illustrating an example of the configuration of the transparent display device according to the third embodiment in the dimming mode. [Figure 10] FIG. 10 is a cross-sectional view schematically illustrating an example of the configuration of the transparent display device according to the fourth embodiment in the transmissive mode. [Figure 11] FIG. 11 is a cross-sectional view schematically illustrating an example of the configuration of the transparent display device according to the fourth embodiment in a dimming mode. [Figure 12] FIG. 12 is a cross-sectional view schematically illustrating an example of the configuration of a transparent display device according to a fifth embodiment in a transmissive mode. [Figure 13] FIG. 13 is a cross-sectional view schematically illustrating an example of the configuration of the transparent display device according to the fifth embodiment in a dimming mode. [Figure 14]FIG. 14 is a cross-sectional view schematically illustrating an example of the configuration of a transparent display device according to the sixth embodiment in a transmissive mode. [Figure 15] FIG. 15 is a cross-sectional view schematically illustrating an example of the configuration of the transparent display device according to the sixth embodiment in the dimming mode. [Figure 16] FIG. 16 is a cross-sectional view schematically illustrating an example of the configuration of a transparent display device according to the seventh embodiment in a transmissive mode. [Figure 17] FIG. 17 is a cross-sectional view schematically illustrating an example of the configuration of the transparent display device according to the seventh embodiment in the dimming mode. [Figure 18] FIG. 18 is a cross-sectional view schematically illustrating an example of the configuration of a transparent display device according to the eighth embodiment in a transmissive mode. [Figure 19] FIG. 19 is a cross-sectional view schematically illustrating an example of the configuration of the transparent display device according to the eighth embodiment in a dimming mode. [Figure 20] FIG. 20 is a cross-sectional view schematically illustrating an example of the configuration of a transparent display device according to a ninth embodiment in a transmissive mode. [Figure 21] FIG. 21 is a cross-sectional view schematically illustrating an example of the configuration of the transparent display device according to the ninth embodiment in a dimming mode. [Figure 22] FIG. 22 is a cross-sectional view schematically showing an example of a circuit configuration of the transparent display device according to the embodiment. [Figure 23] FIG. 23 is a signal waveform diagram schematically showing an example of light control of the transparent display device according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] (Knowledge that formed the basis of the invention) In a transparent display device, when the amount of external light is greater than the amount of light from the light-emitting layer, the display based on the light from the light-emitting layer may become difficult to see.

[0009] Hereinafter, embodiments of a transparent display device according to the present disclosure will be described with reference to the drawings. In the present embodiments, a transparent display device used as a video playback device or a navigation device mounted on an automobile will be exemplified. Note that the configuration of the transparent display device according to each embodiment described below is merely an example, and is not limited to the following description.

[0010] In the following description, components having the same or substantially the same functions as those described above with respect to the previously mentioned drawings may be given the same reference numerals, and their description may be omitted as appropriate. Furthermore, even when the same or substantially the same parts are shown, the dimensions and proportions may be different depending on the drawing. Furthermore, for example, in order to ensure the visibility of the drawings, reference numerals may be given to only the main components in the description of each drawing, and reference numerals may not be given to components having the same or substantially the same functions as those described above with respect to the previously mentioned drawings.

[0011] In the following description, "transparent" includes the concept of "transparent or translucent." In other words, "transparent" does not necessarily mean that transmitted light is not absorbed, but also means that the degree to which transmitted light is absorbed is small. Furthermore, "opaque" includes the concept of "opaque or low translucency." In other words, "opaque" does not necessarily mean that light is not transmitted, i.e., blocked, but also means that the degree to which transmitted light is absorbed is large. Furthermore, in this specification, "transmittance" refers to the ratio of the brightness (amount of light) of visible light passing through a panel to the brightness (amount of light) of visible light incident on the panel. In other words, "transmittance" is the transmittance of visible light.

[0012] In the following description, for the sake of simplicity, the front and back surfaces of the transparent display device are assumed to be parallel to the xy plane. table The direction toward the surface is the z+ direction. In other words, in the following description, the front side refers to the z+ side. Similarly, the back side refers to the z- side.

[0013] (First embodiment) FIG. 1 is a cross-sectional view schematically illustrating an example of the configuration of a transparent display device 1 according to the first embodiment. The transparent display device 1 according to this embodiment is an organic light-emitting diode (OLED) display. The transparent display device 1 according to this embodiment is also a bottom-emission type transparent display. That is, the display surface of the transparent display device 1 according to this embodiment is provided on the back side.

[0014] 1, the transparent display device 1 has a pair of glass substrates 3a and 3b. The pair of glass substrates 3a and 3b are arranged substantially parallel to each other and spaced apart from each other. A TFT (Thin Film Transistor) substrate 5 and a light control layer 7 are provided between the pair of glass substrates 3a and 3b.

[0015] The glass substrate 3a is provided on the back side of the transparent display device 1. The glass substrate 3b is provided on the front side of the transparent display device 1. Each of the glass substrates 3a and 3b is transparent to visible light. Each of the glass substrates 3a and 3b has, for example, a rectangular flat plate shape. Here, the glass substrate 3a is an example of a first substrate. Furthermore, the glass substrate 3b is an example of a second substrate.

[0016] The TFT substrate 5 is provided on the front surface side of the glass substrate 3a on the back side. The TFT substrate 5 can be made of a-Si, LTPS, IGZO, or the like. The TFT substrate 5 is formed, for example, from a plate-like member, but may also be formed from a film-like member. The TFT substrate 5 has a plurality of TFTs 102 (see FIG. 22) arranged in a matrix. Each of the plurality of TFTs 102 has a gate electrode 53a and a source-drain electrode 53b. The source-drain electrode 53b is provided on the front surface at a position corresponding to the gate electrode 53a. In the TFT substrate 5, each of the plurality of TFTs 102 is covered with an insulating member 51. The insulating member 51 may be made of a material that is transparent to visible light and electrically insulating. The insulating member 51 can be made, for example, of silicon nitride (SiN).

[0017] The TFT substrate 5 is provided with a plurality of light-emitting sections 6. Each of the light-emitting sections 6 corresponds to a corresponding one of the plurality of light-emitting pixels 100 (see FIG. 22 ) of the transparent display device 1. Each of the light-emitting sections 6 is configured to be able to emit light independently of one another. Each of the light-emitting sections 6 is electrically connected to a source-drain electrode 53b of the TFT 102 via a transparent electrode 61a extending in the z-direction inside the insulating member 51. The transparent electrode 61a is an electrode transparent to visible light. Each of the light-emitting sections 6 is separated from the TFT 102 by, for example, the insulating member 51. Each of the light-emitting sections 6 includes a transparent electrode 61b, a reflective electrode 63, and a light-emitting layer 65. The transparent electrode 61b and the reflective electrode 63 are arranged substantially parallel to each other and spaced apart from each other. The light-emitting layer 65 is provided between the transparent electrode 61b and the reflective electrode 63. Here, the TFT substrate 5 is an example of a first internal layer.

[0018] The transparent electrode 61b is provided on the rear surface side of each of the plurality of light-emitting sections 6. The transparent electrode 61b is electrically connected to the transparent electrode 61a. The transparent electrode 61b is transparent to visible light. The transparent electrode 61b has, for example, a rectangular plate shape.

[0019] The reflective electrode 63 is provided on the front surface side of each of the plurality of light-emitting sections 6. The reflective electrode 63 is provided in a position facing the transparent electrode 61b. The reflective electrode 63 has, for example, the same shape as the transparent electrode 61b. The reflective electrode 63 is opaque to visible light. The reflective electrode 63 is formed of, for example, a metal. Alternatively, the reflective electrode 63 is formed of glass or resin with a metal layer provided on its surface.

[0020] The light-emitting layer 65 is a light-emitting diode (LED) made of an organic compound. The light-emitting layer 65 emits light when a voltage exceeding a threshold voltage is applied between the transparent electrode 61b and the reflective electrode 63.

[0021] Each of the light-emitting units 6 is covered with an insulating member 55. The insulating member 55 may be made of a material that is transparent to visible light and electrically insulating. Silicon nitride (SiN), for example, can be used as the insulating member 55.

[0022] A light control layer 7 is provided on the front surface side of the TFT substrate 5. The light control layer 7 has a transparent electrode 71a, a transparent electrode 71b, a transparent electrode 73, a light control member 75, and a spacer 77. Here, the light control layer 7 is an example of a second internal layer.

[0023] The transparent electrode 71b is provided on the surface side of the insulating member 55. The transparent electrode 71b is electrically connected to the source-drain electrodes 53b of the TFT 102 via the transparent electrode 71a extending in the z-direction inside the insulating member 51 and the insulating member 55. The transparent electrode 71b is transparent to visible light. The transparent electrode 71b has, for example, a rectangular flat plate shape.

[0024] The transparent electrode 73 is provided on the surface side of the insulating member 55 via a spacer 77. In other words, the transparent electrode 73 is provided approximately parallel to the transparent electrode 71b, spaced apart from the transparent electrode 71b by the length of the spacer 77 in the z direction. b The transparent electrode 73 is transparent to visible light and has, for example, a rectangular plate shape.

[0025] A light-adjusting material 75 is filled between the transparent electrode 71b and the transparent electrode 73. In other words, the spacer 77 is a member for forming a gap between the transparent electrode 71b and the transparent electrode 73, into which the light-adjusting material 75 is filled. The light-adjusting material 75 is transparent to visible light when no voltage is applied between the transparent electrode 71b and the transparent electrode 73. Hereinafter, the state in which the light-adjusting material 75 is transparent to visible light will be referred to as a transmissive mode. When a voltage exceeding a threshold voltage is applied between the transparent electrode 71b and the transparent electrode 73, the light-adjusting material 75 is opaque to visible light between the transparent electrode 71b and the transparent electrode 73. Hereinafter, the state in which the light-adjusting material 75 is opaque to visible light will be referred to as a light-adjusting mode. As the light-adjusting material 75, a guest-host liquid crystal, a PNLC (polymer dispersed liquid crystal), an SPD (suspensed particle diode), an electrochromic material, or the like can be appropriately used. The light-adjusting material 75 may be appropriately selected depending on, for example, the operating voltage and response speed characteristics. For example, the light adjusting member 75 transitions between a transmissive mode and a dimming mode in response to a voltage applied between the transparent electrode 71b and the transparent electrode 73 by the TFT substrate 5. In other words, the light adjusting member 75 changes its transmittance for visible light in response to a voltage applied between the transparent electrode 71b and the transparent electrode 73 by the TFT substrate 5. Therefore, it is preferable that the operating voltage required for mode transition of the light adjusting member 75 is low enough to be driven by the TFT substrate 5. A structure in which the light adjusting member 75 is sandwiched between the transparent electrode 71b and the transparent electrode 73 is sometimes referred to as a dimming pixel.

[0026] Fig. 2 is a plan view schematically showing an example of the configuration of the transparent display device 1 according to the first embodiment. Fig. 3 is a plan view schematically showing another example of the configuration of the transparent display device 1 according to the first embodiment. As shown in Figs. 2 and 3, the transparent display device 1 has a light-emitting region R1 and a dimming region R2. As shown in Figs. 2 and 3, the light-emitting region R1 and the dimming region R2 are different regions from each other in a plan view.

[0027] The light-emitting region R1 is a region in the TFT substrate 5 where the pixels are arranged. In other words, the light-emitting region R1 is a region in which the light-emitting unit 6 is provided. Fig. 2 illustrates a case where R pixels, G pixels, and B pixels are provided in the light-emitting region R1. Note that, as shown in Fig. 3, R pixels, G pixels, B pixels, and W pixels may also be provided in the light-emitting region R1.

[0028] The dimming region R2 is a region of the dimming layer 7 that corresponds to a portion located between the transparent electrode 71b and the transparent electrode 73. In other words, the dimming region R2 is a region of the dimming layer 7 that corresponds to a portion where the transparent electrode 71b is provided. The dimming region R2 is also a region where dimming pixels are provided. Here, the dimming region R2 is provided in a transparent region that is provided at least between each pixel of the TFT substrate 5 in a planar view. More specifically, in the example shown in FIG. 1, the light-emitting section 6 and the transparent electrode 71b are different regions from each other in a planar view.

[0029] Next, the operation of the transparent display device 1 according to the embodiment will be described. Here, it is assumed that the light-emitting section 6a corresponds to an R pixel and emits red light, and the light-emitting section 6b emits green light.

[0030] FIG. 4 is a cross-sectional view schematically illustrating an example of the configuration of the transparent display device 1 according to the first embodiment in the transmissive mode. The light-emitting unit 6a emits red light from the light-emitting layer 65 toward the rear surface, as indicated by the arrow Ar in FIG. 4. Similarly, the light-emitting unit 6b emits green light from the light-emitting layer 65 toward the rear surface, as indicated by the arrow Ag in FIG. 4. Furthermore, when no voltage is applied between the transparent electrodes 71b and 73, the light-adjusting member 75 is transparent to visible light. Therefore, external light Ac incident on the transparent display device 1 from the front surface passes through the light-adjusting member 75a in the transmissive mode and is emitted from the rear surface. Furthermore, external light incident on the transparent display device 1 from the rear surface passes through the light-adjusting member 75a in the transmissive mode and is emitted from the front surface.

[0031] FIG. 5 is a cross-sectional view schematically illustrating an example of the configuration of the transparent display device 1 according to the first embodiment in the dimming mode. As shown in FIG. 5, the light-emitting units 6a and 6b emit visible light to the rear surface side, as in the transmissive mode. On the other hand, when a voltage exceeding the threshold voltage is applied between the transparent electrodes 71b and 73, the dimming member 75 is opaque to visible light between the transparent electrodes 71b and 73. Therefore, external light Ac incident on the transparent display device 1 from the front surface side is blocked by the dimming member 75b in the dimming mode. Note that external light incident on the transparent display device 1 from the rear surface side is also blocked by the dimming member 75b in the dimming mode.

[0032] In this way, light from the light-emitting unit 6 and external light transmitted through the transparent display device 1 are emitted from the display surface, i.e., the back side, of the transparent display device 1 in the transmissive mode. Therefore, a user can see the background scenery on the opposite side of the display surface, i.e., the front side, of the transparent display device 1, along with the display on the transparent display device 1. This allows the transparent display device 1 to display an image superimposed on the background scenery, for example.

[0033] In such an environment, in which the amount of external light is greater than the amount of light emitted from the light-emitting unit 6, past In the transparent display device 1 in the transparent display mode, the visibility of the displayed image decreases.

[0034] In a conventional self-luminous transparent display having a light-emitting region and a transparent region within each pixel, a light-adjusting device that changes the transmittance of visible light is attached to the back side of the display. However, if the transmittance of visible light is changed over the entire display area, areas other than the displayed image are also dimmed, making it impossible to achieve partial dimming in accordance with the displayed image.

[0035] In response to this, there is a technology in which a light control device capable of changing the transmittance of visible light pixel by pixel is attached to the back side of a transparent display. However, depending on the accuracy of the attachment, misalignment may occur between the transparent pixels of the transparent display and the light control pixels of the light control device, resulting in a problem of large variations in transmittance across the display area. Furthermore, this misalignment can cause interference fringes (moiré) due to diffraction caused by the grid pattern of the transparent display and the grid pattern of the light control device. Here, the grid pattern of the transparent display is a pattern based on the structure between the pixels of the transparent display or between the light-emitting region and the transparent region. Furthermore, the grid pattern of the light control device is a pattern based on the structure between the pixels of the light control device. Furthermore, there is a problem in that the transmittance changes significantly depending on the viewing angle due to the gap of about several millimeters between the transparent display and the light control device.

[0036] On the other hand, in the transparent display device 1 according to this embodiment, the transparent electrode 71b of the light control layer 7 is provided in a region between the pixels of the TFT substrate 5, i.e., a region that overlaps in plan view with a region that is transmissive to external light. A transparent electrode 73 is provided on the side of the glass substrate 3b facing the transparent electrode 71b. A liquid crystal material for changing the transmittance is sealed between the transparent electrode 71b and the transparent electrode 73. With this configuration, by applying a voltage exceeding the threshold voltage between the transparent electrode 71b and the transparent electrode 73, the transmittance of the liquid crystal for visible light can be changed in a region that overlaps in plan view with a region that is transmissive to external light.

[0037] In this way, further improvements can be achieved according to the transparent display device 1 of the first embodiment. According to the transparent display device 1 of the first embodiment, for example, visibility can be improved.

[0038] Furthermore, in the transparent display device 1 according to this embodiment, the light control layer 7 is formed on the TFT substrate 5. In other words, the TFT substrate 5 and the light control layer 7 are integrally formed. Therefore, compared to the case where a transparent display and a light control device that are formed independently are bonded together, it is possible to suppress misalignment between the transparent region between the light-emitting regions R1 of the TFT substrate 5 and the light control region R2 of the light control layer 7.

[0039] Furthermore, in the transparent display device 1 according to this embodiment, the TFT substrate 5 and the light control layer 7 are integrally formed, so there is no need to provide a glass substrate between the TFT substrate 5 and the light control layer 7. Therefore, according to the technology according to this embodiment, compared to the case where an independently formed transparent display and a light control device are bonded together, the number of glass substrates can be reduced from four to two, thereby achieving a thinner and lighter device.

[0040] (Second embodiment) Fig. 6 is a cross-sectional view schematically showing an example of the configuration of the transparent display device 1 according to the second embodiment in a transmission mode. Fig. 7 is a cross-sectional view schematically showing an example of the configuration of the transparent display device 1 according to the second embodiment in a dimming mode.

[0041] The light control layer 7 of the transparent display device 1 according to this embodiment does not necessarily have to include the spacers 77.

[0042] As an example, the gap in the light-controlling layer 7 that is filled with the light-controlling member 75 is formed by the insulating member 55 that covers the light-emitting section 6 of the TFT substrate 5, as shown in FIGS. 6 and 7 . Specifically, the transparent electrode 71b is provided on the surface side of the insulating member 51. The transparent electrode 71b is electrically connected to the source-drain electrodes 53b of the TFT 102 via a transparent electrode 71a that extends inside the insulating member 51 in the z-direction. The transparent electrode 73 is provided on the surface side of the insulating member 51 via the insulating member 55. In other words, the transparent electrode 73 is provided approximately parallel to the transparent electrode 71b, spaced apart from the transparent electrode 71b by the length in the z-direction of the insulating member 55 that covers the light-emitting section 6.

[0043] Even with this configuration, it is possible to improve visibility, similarly to the transparent display device 1 according to the first embodiment. Furthermore, since the layer on which the insulating member 55 of the TFT substrate 5 is provided and the light-controlling layer 7 are integrally formed, it is possible to achieve a thinner and lighter display device than the transparent display device 1 according to the first embodiment.

[0044] (Third embodiment) Fig. 8 is a cross-sectional view schematically showing an example of the configuration of the transparent display device 1 according to the third embodiment in a transmission mode. Fig. 9 is a cross-sectional view schematically showing an example of the configuration of the transparent display device 1 according to the third embodiment in a dimming mode.

[0045] The transparent display device 1 according to this embodiment may be a top-emission transparent display, that is, the display surface of the transparent display device 1 according to this embodiment is provided on the front surface side.

[0046] 8 and 9, the transparent electrode 61b is provided on the front surface side of each of the plurality of light-emitting sections 6. On the other hand, the reflective electrode 63 is provided on the rear surface side of each of the plurality of light-emitting sections 6 at a position facing the transparent electrode 61b. The reflective electrode 63 is electrically connected to the transparent electrode 61a.

[0047] The light-emitting unit 6a emits red light from the light-emitting layer 65 toward the front surface side, as indicated by arrows Ar in Figures 8 and 9. Similarly, the light-emitting unit 6b emits green light from the light-emitting layer 65 toward the front surface side, as indicated by arrows Ag in Figures 8 and 9. Furthermore, external light Ac incident on the transparent display device 1 from the front surface side passes through the light-adjusting member 75a in the transmission mode and is emitted from the back surface side. On the other hand, external light Ac incident on the transparent display device 1 from the front surface side is blocked by the light-adjusting member 75b in the light-adjusting mode.

[0048] As described above, the transparent display device 1 according to this embodiment is configured as a top-emission transparent display. Here, the light control layer 7 is provided on the display surface side. Even with this configuration, visibility can be improved, similar to the transparent display device 1 according to the first embodiment.

[0049] In the transparent display device 1 according to this embodiment, the layer on which the insulating member 55 of the TFT substrate 5 is provided and the dimming layer 7 may be formed integrally, as in the transparent display device 1 according to the second embodiment.

[0050] (Fourth embodiment) Fig. 10 is a cross-sectional view schematically showing an example of the configuration of the transparent display device 1 according to the fourth embodiment in a transmission mode. Fig. 11 is a cross-sectional view schematically showing an example of the configuration of the transparent display device 1 according to the fourth embodiment in a dimming mode.

[0051] Each of the plurality of light-emitting sections 6 according to this embodiment has, for example, the same light-emitting layer 65. As an example, each of the plurality of light-emitting sections 6c emits white light as indicated by an arrow Aw in FIGS.

[0052] The transparent display device 1 according to this embodiment further includes a plurality of color filters 79. Each of the plurality of color filters 79 is provided between the transparent electrode 73 and the glass substrate 3b. Each of the plurality of color filters 79 is provided at a position overlapping with a plurality of light-emitting units 6 in a planar view. Each of the plurality of color filters 79 has a predetermined wavelength selectivity. The color filter 79a is a color filter that transmits, for example, red light. The color filter 79b is a color filter that transmits, for example, green light.

[0053] As described above, in the transparent display device 1 according to this embodiment, white light from the plurality of light-emitting units 6c is incident on the corresponding color filters 79. Each of the plurality of color filters 79 emits visible light containing wavelengths according to its wavelength selectivity to the rear surface side. Even with this configuration, visibility can be improved, similar to the transparent display device 1 according to the first embodiment.

[0054] Each of the light-emitting units 6c may be an OLED that emits visible light in any wavelength range, not limited to white light. In this case, the wavelength selectivity of the color filter 79 may be determined according to the wavelength range of the visible light from the light-emitting unit 6c.

[0055] The transparent display device 1 according to this embodiment, like the transparent display device 1 according to the first or second embodiment, bottom The display may be configured as an emission-type transparent display, in which case each of the plurality of color filters 79 may be provided on the rear surface side of the corresponding light-emitting portion 6c.

[0056] In the transparent display device 1 according to this embodiment, the layer on which the insulating member 55 of the TFT substrate 5 is provided and the dimming layer 7 may be formed integrally, as in the transparent display device 1 according to the second embodiment.

[0057] In the transparent display device 1 according to this embodiment, the light-controlling member 75 of the light-controlling layer 7 may be filled between the plurality of color filters 79.

[0058] (Fifth embodiment) Fig. 12 is a cross-sectional view schematically illustrating an example of the configuration of the transparent display device 1 according to the fifth embodiment in a transmission mode. Fig. 13 is a cross-sectional view schematically illustrating an example of the configuration of the transparent display device 1 according to the fifth embodiment in a dimming mode.

[0059] The transparent display device 1 according to this embodiment may be a transparent display having display surfaces on both the front and back sides.

[0060] As shown in FIGS. 12 and 13, the transparent electrode 61b is provided on the back surface side of each of the plurality of light-emitting sections 6. The transparent electrode 61b is electrically connected to the transparent electrode 61a. Here, the transparent display device 1 according to this embodiment has a transparent electrode 61c instead of the reflective electrode 63. The transparent electrode 61c is provided on the front surface side of each of the plurality of light-emitting sections 6 in a position facing the transparent electrode 61b. The transparent electrode 61c is transparent to visible light. The transparent electrode 61c has, for example, the same shape as the transparent electrode 61b.

[0061] The light-emitting unit 6a emits red light from the light-emitting layer 65 to both the front and back sides, as indicated by arrows Ar in FIGS. 12 and 13. Similarly, the light-emitting unit 6b emits green light from the light-emitting layer 65 to both the front and back sides, as indicated by arrows Ag in FIGS. 12 and 13. Furthermore, external light Ac incident on the transparent display device 1 from the front side passes through the light-adjusting member 75a in the transmission mode and is emitted from the back side. Meanwhile, external light Ac incident on the transparent display device 1 from the front side is blocked by the light-adjusting member 75b in the dimming mode. Furthermore, external light incident on the transparent display device 1 from the back side is also blocked by the light-adjusting member 75b in the dimming mode.

[0062] In this way, the transparent display device 1 according to this embodiment is configured as a transparent display having display surfaces on both the front and back sides. Even with this configuration, visibility can be improved, similar to the transparent display device 1 according to the first embodiment.

[0063] In the transparent display device 1 according to this embodiment, the layer on which the insulating member 55 of the TFT substrate 5 is provided and the dimming layer 7 may be formed integrally, as in the transparent display device 1 according to the second embodiment.

[0064] The transparent display device 1 according to this embodiment may be provided with a plurality of color filters 79, similarly to the transparent display device 1 according to the fourth embodiment. In this case, the plurality of color filters 79 may be provided not only between the transparent electrode 73 and the glass substrate 3b but also on the back surface side of the corresponding light-emitting portion 6c.

[0065] (Sixth embodiment) Fig. 14 is a cross-sectional view schematically illustrating an example of the configuration of the transparent display device 1 according to the sixth embodiment in a transmission mode. Fig. 15 is a cross-sectional view schematically illustrating an example of the configuration of the transparent display device 1 according to the sixth embodiment in a dimming mode.

[0066] The transparent display device 1 according to this embodiment may be a transparent display configured to block visible light from each of the plurality of light emitting units 6 in the dimming mode.

[0067] The transparent electrode 71b is provided over the entire light-controlling layer 7, as shown in FIGS.

[0068] As shown by the arrow Ar in FIG. 14, the light-emitting unit 6a transmits red light from the light-emitting layer 65 through the light-adjusting member 75a in the transmissive mode and emits it toward the front side. Furthermore, as shown by the arrow Ar in FIG. 14, the light-emitting unit 6a also emits red light from the light-emitting layer 65 toward the back side. Similarly, as shown by the arrow Ag in FIG. 14, the light-emitting unit 6b transmits green light from the light-emitting layer 65 through the light-adjusting member 75a in the transmissive mode and emits it toward the front side. Furthermore, as shown by the arrow Ag in FIG. 14, the light-emitting unit 6b also emits green light from the light-emitting layer 65 toward the back side. Furthermore, external light Ac incident on the transparent display device 1 from the front side transmits through the light-adjusting member 75a in the transmissive mode and is emitted from the back side.

[0069] On the other hand, the red light emitted from the light-emitting unit 6a to the front side, the green light emitted from the light-emitting unit 6b to the front side, and the external light Ac incident on the transparent display device 1 from the front side or the back side are each blocked by the dimming member 75b in the dimming mode, as shown in FIG. 15.

[0070] In this way, the transparent display device 1 according to this embodiment is configured as a transparent display having display surfaces on both the front and back sides. Even with this configuration, the visibility of the display surface on the back side can be improved, similar to the transparent display device 1 according to the first embodiment.

[0071] In the transparent display device 1 according to this embodiment, the layer on which the insulating member 55 of the TFT substrate 5 is provided and the dimming layer 7 may be formed integrally, as in the transparent display device 1 according to the second embodiment.

[0072] The transparent display device 1 according to this embodiment may be provided with a plurality of color filters 79, similarly to the transparent display device 1 according to the fourth embodiment. In this case, the plurality of color filters 79 may be provided not only between the transparent electrode 73 and the glass substrate 3b but also on the back surface side of the corresponding light-emitting portion 6c.

[0073] (Seventh embodiment) Fig. 16 is a cross-sectional view schematically illustrating an example of the configuration of the transparent display device 1 according to the seventh embodiment in a transmission mode. Fig. 17 is a cross-sectional view schematically illustrating an example of the configuration of the transparent display device 1 according to the seventh embodiment in a dimming mode.

[0074] The light adjusting member 75 according to this embodiment may have a light adjusting function in combination with a polarizing plate 81.

[0075] As shown in FIGS. 16 and 17, the transparent display device 1 according to this embodiment further includes a polarizing plate 81a and a polarizing plate 81b. The polarizing plate 81a is provided on the rear surface side of the glass substrate 3a. The polarizing plate 81b is provided on the front surface side of the glass substrate 3b. The polarizing plate 81a and the polarizing plate 81b may each be formed of a plate-like member or a film-like member. Here, the polarizing plate 81a is an example of a first polarizing layer. The polarizing plate 81b is an example of a second polarizing layer.

[0076] In the transparent display device 1 provided with the polarizing plate 81, it is preferable that visibility caused by external light can be improved even when the user is wearing polarized sunglasses, for example. Hereinafter, cases where liquid crystal of each of the TN (Twisted Nematic) type, VA (Vertical Alignment) type, and IPS (In Plane Switching) type is used as the light control member 75 will be described.

[0077] Here, the absorption axis of the polarized sunglasses is assumed to be, for example, 0° (horizontal). Furthermore, it is assumed that users are present on both the front and back sides of the transparent display device 1. Generally, in a transmissive liquid crystal display (LCD), the polarizing plates are arranged with a 90° offset between the front and back. However, if the absorption axis of the polarizing plate is arranged at 90° (vertical), the light from the display cannot pass through the polarized sunglasses with an absorption axis of 0°, and the user cannot see the display.

[0078] Therefore, in the transparent display device 1 according to this embodiment, the polarizing plate 81a and the polarizing plate 81b are arranged so that both of their absorption axes are at 0°. With this configuration, the transmittance through polarized sunglasses with an absorption axis of 0° can be made the highest compared to other combinations of absorption axes.

[0079] Alternatively, in the transparent display device 1 according to this embodiment, the polarizing plate 81a and the polarizing plate 81b are arranged so that their absorption axes are both at an angle of 45°. In this case, the absorption axis of the polarizing plate 81a and the absorption axis of the polarizing plate 81b can be shifted by 90°.

[0080] The following description will be continued taking as an example a case where the absorption axis of the polarizing plate 81b on the front side is at 45° and the absorption axis of the polarizing plate 81a on the back side is at −45°.

[0081] (When the dimming component is a TN LCD) Unpolarized external light incident on the front-side polarizer 81b is polarized by the polarizer 81b, which has an absorption axis of 45°, into linearly polarized light with a tilt of -45°. When no voltage is applied between the transparent electrodes 71b and 73, the TN liquid crystal molecules are twisted and aligned at 90°. The phase difference of the liquid crystal is λ / 2. Therefore, light transmitted through the light control component 75 has a linear polarization of 45°. Linearly polarized light with a tilt of 45° incident on the rear-side polarizer 81a can be transmitted through the polarizer 81a, which has an absorption axis of -45°, as shown in FIG. 16.

[0082] On the other hand, when a voltage is applied between transparent electrode 71b and transparent electrode 73, the TN liquid crystal molecules are aligned vertically. The phase difference of the liquid crystal is 0. Therefore, the light transmitted through light control member 75 has linear polarization with an inclination of -45°, and therefore cannot transmit through polarizer 81a with an absorption axis of -45°, as shown in FIG.

[0083] That is, the transparent display device 1 using the TN liquid crystal as the light control member 75 can block external light by applying a voltage between the transparent electrode 71b and the transparent electrode 73. This allows the transparent display device 1 to improve the visibility of the display.

[0084] (When the dimming component is a VA LCD) When using VA liquid crystal, if the absorption axes of the polarizer 81 are arranged at the same angle on both the front and back sides to make it normally white, the black will not be subdued, i.e., no contrast will be produced, so it is preferable to shift the absorption axes on the front and back sides by 90° to make it normally black.

[0085] When no voltage is applied between transparent electrode 71b and transparent electrode 73, VA liquid crystal molecules are aligned vertically. The phase difference of the liquid crystal is 0. Therefore, the light transmitted through light control component 75 has linear polarization with an inclination of -45°, and therefore cannot transmit through polarizer 81a on the rear surface side, which has an absorption axis of -45°, as shown in FIG.

[0086] On the other hand, when a voltage is applied between transparent electrode 71b and transparent electrode 73, the VA-type liquid crystal molecules are oriented in the 0° and / or 90° directions. The phase difference of the liquid crystal is λ / 2. Therefore, the light transmitted through light control component 75 contains right-handed elliptically polarized light and left-handed elliptically polarized light with an inclination of 45°, and as shown in FIG. 16, the linearly polarized light component with an inclination of 45° can be transmitted through polarizer 81a on the rear surface side, which has an absorption axis of -45°.

[0087] That is, the transparent display device 1 using the VA liquid crystal as the light control member 75 can block external light by not applying a voltage between the transparent electrode 71b and the transparent electrode 73. This allows the transparent display device 1 to improve the visibility of the display.

[0088] (When the dimming component is an IPS LCD) When using IPS liquid crystal, it is preferable to shift the absorption axes of the polarizing plate 81 by 90° between the front and back sides to make it normally black, as in the case of using VA liquid crystal.

[0089] When no voltage is applied between transparent electrode 71b and transparent electrode 73, the IPS liquid crystal molecules are aligned at 45°. The phase difference of the liquid crystal is λ / 2. Therefore, the light transmitted through light control component 75 has linear polarization with an inclination of -45°, and therefore cannot transmit through polarizer 81a on the rear surface side, which has an absorption axis of -45°, as shown in FIG.

[0090] On the other hand, when a voltage is applied between transparent electrode 71b and transparent electrode 73, the IPS liquid crystal molecules are oriented in the 0° and / or 90° directions. The phase difference of the liquid crystal is λ / 2. Therefore, the light transmitted through light control component 75 contains right-handed elliptically polarized light and left-handed elliptically polarized light with an inclination of 45°, and as shown in FIG. 16, the linearly polarized light component with an inclination of 45° can be transmitted through polarizer 81a on the back side, which has an absorption axis of -45°.

[0091] That is, the transparent display device 1 using the IPS liquid crystal as the light control member 75 can block external light by not applying a voltage between the transparent electrode 71b and the transparent electrode 73. This allows the transparent display device 1 to improve the visibility of the display.

[0092] As described above, in the transparent display device 1 according to the seventh embodiment, the absorption axes of the polarizers 81a and 81b are determined according to the orientation of the liquid crystal used as the light control member 75. Therefore, according to the technology according to this embodiment, by combining the light control member 75 and the polarizers 81, it is possible to achieve pixel-by-pixel light control in the same manner as in the above-described embodiments.

[0093] In the transparent display device 1 according to this embodiment, the layer on which the insulating member 55 of the TFT substrate 5 is provided and the dimming layer 7 may be formed integrally, as in the transparent display device 1 according to the second embodiment.

[0094] The transparent display device 1 according to this embodiment may be configured as a top-emission type transparent display, similar to the transparent display device 1 according to the third embodiment.

[0095] In addition, the transparent display device 1 according to this embodiment may be provided with a plurality of color filters 79, similarly to the transparent display device 1 according to the fourth embodiment.

[0096] The transparent display device 1 according to this embodiment may be configured as a transparent display having display surfaces on both the front and back sides, similar to the transparent display device 1 according to the fifth or sixth embodiment.

[0097] In addition, the transparent display device 1 of this embodiment may be a transparent display configured to block visible light from each of the multiple light-emitting units 6 in dimming mode, similar to the transparent display device 1 of the sixth embodiment.

[0098] (Eighth embodiment) Fig. 18 is a cross-sectional view schematically illustrating an example of the configuration of the transparent display device 1 according to the eighth embodiment in a transmission mode. Fig. 19 is a cross-sectional view schematically illustrating an example of the configuration of the transparent display device 1 according to the eighth embodiment in a dimming mode.

[0099] The light control member 75 according to this embodiment may have a light control function and a low reflection function in combination with a polarizing plate 81 and a λ / 4 retardation plate 83 .

[0100] As shown in FIGS. 18 and 19 , the transparent display device 1 according to this embodiment further includes a λ / 4 retardation plate 83a and a λ / 4 retardation plate 83b. The λ / 4 retardation plate 83a is provided between the glass substrate 3a and the polarizing plate 81a. The λ / 4 retardation plate 83b is provided between the glass substrate 3b and the polarizing plate 81b. The λ / 4 retardation plate 83a and the λ / 4 retardation plate 83b may each be formed of a plate-like member or a film-like member. Here, the λ / 4 retardation plate 83a is an example of a first retardation layer. The λ / 4 retardation plate 83b is an example of a second retardation layer.

[0101] In the transparent display device 1 provided with the polarizing plate 81, it is preferable that the decrease in visibility caused by external light can be suppressed even when the user is wearing polarized sunglasses, for example. It is also more preferable that the decrease in visibility caused by external light reflected by wiring such as electrodes and light-emitting units 6 such as OLEDs provided on the TFT substrate 5 can be suppressed. Below, cases where TN (Twisted Nematic) and VA (Vertical Alignment) liquid crystals are used as the light-adjusting member 75 will be described.

[0102] In a configuration using a λ / 4 retarder 83, the light incident on the dimming member 75, i.e., the light transmitted through the λ / 4 retarder 83, becomes circularly polarized light, so it is preferable to specify the liquid crystal alignment direction for each liquid crystal type.

[0103] Below, we will explain an example where the absorption axes of the polarizing plates 81a and 81b on the front and back sides are both 0°, and the slow axes of the λ / 4 phase difference plates 83a and 83b on the front and back sides are both 45°.

[0104] (When the dimming component is a TN LCD) Unpolarized external light incident on the front-side polarizer 81b is polarized by the polarizer 81b with an absorption axis of 0° into linearly polarized light with a tilt of 90°, and then polarized by the λ / 4 retarder 83b with a slow axis of 45° into left-handed circularly polarized light. When no voltage is applied between the transparent electrodes 71b and 73, the TN liquid crystal molecules are twisted and aligned by 90°. The phase difference of the liquid crystal is λ / 2. Therefore, the light transmitted through the light control component 75 contains right-handed circular polarization, and the linearly polarized light component with a tilt of 90° is transmitted through the rear-side λ / 4 retarder 83a with a slow axis of 45°. As a result, the linearly polarized light with a tilt of 90° incident on the rear-side polarizer 81a can be transmitted through the polarizer 81a with an absorption axis of 0°, as shown in FIG. 18 .

[0105] Furthermore, the light that has passed through the light adjusting member 75 has right-handed circular polarization. Therefore, the light that has been reflected by the TFT substrate 5 on the back side of the light adjusting member 75 has left-handed circular polarization. Therefore, the light that has passed through the light adjusting member 75 has right-handed circular polarization, and the linearly polarized light component with a tilt of 0° passes through the λ / 4 retarder 83b with a slow axis of 45° on the front side. As a result, the linearly polarized light with a tilt of 0° that has entered the λ / 4 retarder 83b with a slow axis of 45° on the front side cannot pass through the polarizer 81b with an absorption axis of 0°.

[0106] Furthermore, when a voltage is applied between transparent electrode 71b and transparent electrode 73, TN liquid crystal molecules are vertically aligned. The phase difference of the liquid crystal is 0. Therefore, the light transmitted through light control member 75 contains left-handed circularly polarized light, and the linearly polarized light component with an inclination of 0° is transmitted through λ / 4 retardation plate 83a on the back surface side, which has a slow axis of 45°. As a result, the linearly polarized light with an inclination of 0° that is incident on polarizing plate 81a on the back surface side cannot be transmitted through polarizing plate 81a with an absorption axis of 0°, as shown in FIG. 19.

[0107] That is, the transparent display device 1 using the TN liquid crystal as the light control member 75 can block external light by applying a voltage between the transparent electrode 71b and the transparent electrode 73. This can improve the visibility of the display in the transparent display device 1. In addition, it can prevent external light from the front surface side from being reflected by the TFT substrate 5 and emitted to the front surface side.

[0108] The slow axis of either the front-side or rear-side λ / 4 retarder 83a or λ / 4 retarder 83b can be set to -45°. In this case, the transparent display device 1 using TN liquid crystal as the light control member 75 can block external light by not applying a voltage between the transparent electrode 71b and the transparent electrode 73. This allows the transparent display device 1 to improve the visibility of the display. Also, as in the above case, it is possible to prevent external light from the front side from being reflected by the TFT substrate 5 and emitted to the front side.

[0109] (When the dimming component is a VA LCD) When no voltage is applied between transparent electrode 71b and transparent electrode 73, VA liquid crystal molecules are vertically aligned. The phase difference of the liquid crystal is 0. Therefore, the light transmitted through light control member 75 contains left-handed circular polarization, and the linearly polarized light component with an inclination of 0° is transmitted through λ / 4 retardation plate 83a on the back side with a slow axis of 45°. As a result, the linearly polarized light with an inclination of 0° that is incident on polarizing plate 81a on the back side cannot be transmitted through polarizing plate 81a with an absorption axis of 0°, as shown in FIG. 19.

[0110] Furthermore, the light that has passed through the light adjusting member 75 has left-handed circular polarization. Therefore, the light that has been reflected by the TFT substrate 5 on the back side of the light adjusting member 75 has right-handed circular polarization. Therefore, the light that has passed through the light adjusting member 75 has right-handed circular polarization, and the linearly polarized light component with a tilt of 0° passes through the λ / 4 retarder 83b with a slow axis of 45° on the front side. As a result, the linearly polarized light with a tilt of 0° that has entered the λ / 4 retarder 83b with a slow axis of 45° on the front side cannot pass through the polarizer 81b with an absorption axis of 0°.

[0111] Furthermore, when a voltage is applied between the transparent electrode 71b and the transparent electrode 73, the VA-type liquid crystal molecules are aligned at 45° and / or −45°. The phase difference of the liquid crystal is λ / 2. Therefore, the light transmitted through the light control component 75 contains right-handed circularly polarized light and left-handed circularly polarized light, and the right-handed elliptically polarized light and left-handed elliptically polarized light are transmitted through the rear-side λ / 4 retarder 83a with a slow axis of 45°. As a result, of the right-handed elliptically polarized light and left-handed elliptically polarized light incident on the rear-side polarizer 81a, the linearly polarized light component with an inclination of 90° can be transmitted through the polarizer 81a with an absorption axis of 0°, as shown in FIG. 18 .

[0112] That is, the transparent display device 1 using the VA liquid crystal as the light control member 75 can block external light by not applying a voltage between the transparent electrode 71b and the transparent electrode 73. This can improve the visibility of the display in the transparent display device 1. In addition, it can prevent external light from the front surface side from being reflected by the TFT substrate 5 and emitted to the front surface side.

[0113] The slow axis of either the front-side or rear-side λ / 4 retarder 83a or λ / 4 retarder 83b can be set to -45°. In this case, the transparent display device 1 using VA liquid crystal as the light control member 75 can block external light by applying a voltage between the transparent electrode 71b and the transparent electrode 73. This allows the transparent display device 1 to improve the visibility of the display. Also, as in the above case, it is possible to prevent external light from the front side from being reflected by the TFT substrate 5 and emitted to the front side.

[0114] As described above, the transparent display device 1 according to the seventh embodiment can achieve pixel-by-pixel dimming in the same manner as the above-described embodiments by combining the dimming member 75, the polarizing plate 81, and the λ / 4 retarder 83. In addition, it is possible to prevent a decrease in visibility due to reflection of external light on the TFT substrate 5.

[0115] In the transparent display device 1 according to this embodiment, the layer on which the insulating member 55 of the TFT substrate 5 is provided and the dimming layer 7 may be formed integrally, as in the transparent display device 1 according to the second embodiment.

[0116] The transparent display device 1 according to this embodiment may be configured as a top-emission type transparent display, similar to the transparent display device 1 according to the third embodiment.

[0117] In addition, the transparent display device 1 according to this embodiment may be provided with a plurality of color filters 79, similarly to the transparent display device 1 according to the fourth embodiment.

[0118] The transparent display device 1 according to this embodiment may be configured as a transparent display having display surfaces on both the front and back sides, similar to the transparent display device 1 according to the fifth or sixth embodiment.

[0119] In addition, the transparent display device 1 of this embodiment may be a transparent display configured to block visible light from each of the multiple light-emitting units 6 in dimming mode, similar to the transparent display device 1 of the sixth embodiment.

[0120] (Ninth embodiment) Fig. 20 is a cross-sectional view schematically illustrating an example of the configuration of the transparent display device 1 according to the ninth embodiment in a transmission mode. Fig. 21 is a cross-sectional view schematically illustrating an example of the configuration of the transparent display device 1 according to the ninth embodiment in a dimming mode.

[0121] The transparent display device 1 according to this embodiment may be a transparent display configured using LEDs 85 such as mini LEDs or micro LEDs, instead of OLEDs, as the light-emitting units 6. Figures 20 and 21 illustrate LEDs 85a and LEDs 85b as examples of the LEDs 85.

[0122] The LED 85 of the light-emitting unit 6 is electrically connected to the transparent electrodes 61b and 61c. For example, the LED 85a of the light-emitting unit 6a is a red light-emitting diode. For example, the LED 85b of the light-emitting unit 6b is a green light-emitting diode.

[0123] As described above, the transparent display device 1 according to this embodiment has LEDs 85 such as mini LEDs or micro LEDs instead of OLEDs as the light-emitting units 6. Even with this configuration, visibility can be improved, as with the transparent display device 1 according to the first embodiment. Furthermore, the occurrence of burn-in can be reduced compared to OLEDs. Furthermore, the life of the light-emitting units 6 can be extended compared to OLEDs.

[0124] In the transparent display device 1 according to this embodiment, the layer on which the insulating member 55 of the TFT substrate 5 is provided and the dimming layer 7 may be formed integrally, as in the transparent display device 1 according to the second embodiment.

[0125] The transparent display device 1 according to this embodiment may be configured as a top-emission type transparent display, similar to the transparent display device 1 according to the third embodiment.

[0126] In addition, the transparent display device 1 according to this embodiment may be provided with a plurality of color filters 79, similarly to the transparent display device 1 according to the fourth embodiment.

[0127] The transparent display device 1 according to this embodiment may be configured as a transparent display having display surfaces on both the front and back sides, similar to the transparent display device 1 according to the fifth or sixth embodiment.

[0128] In addition, the transparent display device 1 of this embodiment may be a transparent display configured to block visible light from each of the multiple light-emitting units 6 in dimming mode, similar to the transparent display device 1 of the sixth embodiment.

[0129] The transparent display device 1 according to this embodiment may have a configuration in which the light control function is realized by combining a light control member 75 and a polarizing plate 81, similar to the transparent display device 1 according to the seventh embodiment.

[0130] In addition, the transparent display device 1 of this embodiment may have a configuration that achieves dimming function and reflection reduction function by combining a dimming member 75, a polarizing plate 81, and a λ / 4 retardation plate 83, similar to the transparent display device 1 of the eighth embodiment.

[0131] (Light control in transparent display devices) Here, the light control in the transparent display device 1 according to each of the above-described embodiments will be described with reference to the drawings.

[0132] FIG. 22 is a diagram schematically illustrating an example of a circuit configuration of the TFT substrate 5 of the transparent display device 1 according to the embodiment.

[0133] As shown in Fig. 22, the TFT substrate 5 has a plurality of light-emitting pixels 100 and a plurality of dimming pixels 110. The plurality of light-emitting pixels 100 and the plurality of dimming pixels 110 are arranged in a matrix on the TFT substrate 5. The plurality of light-emitting pixels 100 are configured to be able to emit light independently. The plurality of dimming pixels 110 each have a variable transmittance for visible light independently. The plurality of dimming pixels 110 are arranged at positions different from the plurality of light-emitting pixels 100 in a planar view.

[0134] Each of the plurality of pixels 100 includes a light emitting element 101, a TFT 102, a TFT 105, a storage capacitor 106, and a storage capacitor 107, as shown in FIG.

[0135] The anode of the light-emitting element 101 is electrically connected to the drain of the TFT 102 via the transparent electrodes 61a and 61b. The cathode of the light-emitting element 101 is electrically connected to the power supply wiring 104 on the Vss side via the reflective electrode 63. The light-emitting element 101 emits light with a brightness that corresponds to the value of the current flowing between the anode and the cathode.

[0136] The TFT 102 is a driving transistor for the light-emitting element 101. The TFT 102 is, for example, a P-type TFT. The source and drain of the TFT 102 are realized by source-drain electrodes 53b. The gate of the TFT 102 is realized by a gate electrode 53a. The source of the TFT 102 is electrically connected to the power supply wiring 103 on the Vdd side. The gate of the TFT 102 is electrically connected to the drain of the TFT 105. The gate of the TFT 102 is also electrically connected to the power supply wiring 103 on the Vdd side via a storage capacitor 106 and a storage capacitor 107. The TFT 102 supplies a current to the light-emitting element 101 according to the voltages held in the storage capacitors 106 and 107.

[0137] The TFT 105 is a switch transistor of the light emitting element 101. The TFT 105 is, for example, a P-type TFT. The source of the TFT 105 is electrically connected to the video signal line 130. The TFT 105 is turned on or off in response to a voltage applied by the scanning line driving circuit 121.

[0138] The storage capacitors 106 and 107 store the potential difference between the potential of the power supply wiring 103 on the Vdd side when the TFT is turned off and the potential of the gate of the TFT 102. In other words, the storage capacitors 106 and 107 store a voltage corresponding to the signal voltage.

[0139] Each of the plurality of light-modulating pixels 110 includes a liquid crystal element 111, a TFT 113, a storage capacitor 114, and a storage capacitor 115, as shown in FIG.

[0140] The liquid crystal element 111 corresponds to the light control member 75 of the light control layer 7. Specifically, it corresponds to the light control member 75 located between the transparent electrode 71b and the transparent electrode 73 among the light control members 75. One end of the liquid crystal element 111 is electrically connected to the power supply wiring 112 on the Vcom side via the transparent electrode 73. The other end of the liquid crystal element 111 is electrically connected to the drain of the TFT 113.

[0141] The TFT 113 is a switch transistor of the liquid crystal element 111. The TFT 113 is, for example, a P-type TFT. A storage capacitor 114 is electrically connected between the gate and drain of the TFT 113. The TFT 113 is turned on or off in response to a voltage applied by the scanning line driving circuit 121.

[0142] As shown in FIG. 22, the TFT substrate 5 has a plurality of scanning lines 120, a scanning line driving circuit 121, a plurality of video signal lines 130, a video signal line driving circuit 131, a plurality of dimming signal lines 140, a dimming signal line driving circuit 141, and an image signal timing control circuit 150.

[0143] The scanning line driving circuit 121 is electrically connected to the plurality of scanning lines 120. FIG. 22 illustrates scanning line Gate_n and scanning line Gate_n+1 as examples of the plurality of scanning lines 120. The scanning line Gate_n is electrically connected to the gate of the TFT 105 of each of the plurality of light-emitting pixels 100 and the gate of the TFT 113 of each of the plurality of dimming pixels 110. The scanning line Gate_n+1 is electrically connected to the drain of each of the TFTs 113 via the storage capacitors 115 of each of the plurality of dimming pixels 110. The scanning line driving circuit 121 is electrically connected to the drain of the TFT 113 via the storage capacitors 115.

[0144] The scanning line driving circuit 121 sequentially scans the plurality of luminescent pixels 100 by outputting scanning signals to the plurality of scanning lines 120. Specifically, it turns on or off the TFTs 105 row by row. As a result, the scanning line driving circuit 121 applies signal voltages output from the video signal line driving circuit 131 to the plurality of video signal lines 130 to the plurality of luminescent pixels 100 in the selected row, causing the luminescent pixels 100 to emit light at a luminance corresponding to the video data.

[0145] Similarly, the scanning line drive circuit 121 sequentially scans the multiple dimming pixels 110 by outputting scanning signals to the multiple scanning lines 120. Specifically, it turns on or off the TFTs 113 row by row. As a result, the scanning line drive circuit 121 applies the signal voltage output from the dimming signal line drive circuit 141 to the multiple dimming pixels 110 in the selected row, and changes the transmittance of the liquid crystal element 111 of the dimming pixel 110 in accordance with the dimming data.

[0146] The video signal line drive circuit 131 is electrically connected to a plurality of video signal lines 130. FIG. 22 illustrates Sig_nR, Sig_nG, Sig_nB, Sig_n+1R, Sig_n+1G, and Sig_n+1B as examples of the plurality of video signal lines 130. The video signal line Sig_nR is electrically connected to the source of the TFT 105 of the OLED-R light-emitting pixel 100. The video signal line Sig_nG is electrically connected to the source of the TFT 105 of the OLED-G light-emitting pixel 100. The video signal line Sig_nB is electrically connected to the source of the TFT 105 of the OLED-B light-emitting pixel 100. Here, OLED-R is an OLED that emits red light. OLED-G is an OLED that emits green light. OLED-B is an OLED that emits blue light.

[0147] The video signal line driving circuit 131 applies a signal voltage corresponding to video data to each of the plurality of luminescence pixels 100 via the plurality of video signal lines 130 .

[0148] The dimming signal line drive circuit 141 is electrically connected to a plurality of dimming signal lines 140. Fig. 22 illustrates a dimming signal line Sig_nLC and a dimming signal line Sig_n+1LC as examples of the plurality of dimming signal lines 140. The dimming signal line Sig_nLC and the dimming signal line Sig_n+1LC are electrically connected to the sources of the TFTs 113 of the corresponding dimming pixels 110.

[0149] The dimming signal line driver circuit 141 applies a signal voltage corresponding to the dimming data to each of the dimming pixels 110 via the dimming signal lines 140 .

[0150] The image signal timing control circuit 150 is electrically connected to each of the scanning line drive circuit 121, the video signal line drive circuit 131, and the dimming signal line drive circuit 141. The image signal timing control circuit 150 controls the operation timing of the scanning line drive circuit 121, the video signal line drive circuit 131, and the dimming signal line drive circuit 141 based on an input image signal. Here, the image signal timing control circuit 150 is an example of a control circuit.

[0151] FIG. 23 is a signal waveform diagram schematically showing an example of light control of the transparent display device 1 according to the embodiment.

[0152] 23, the image signal timing control circuit 150 controls the scanning line drive circuit 121 to raise the scanning line signal Vg at a timing according to the input image signal. The scanning line drive circuit 121 generates, for example, a rectangular pulse signal at a timing according to the control of the image signal timing control circuit 150, and sequentially scans the plurality of luminescence pixels 100 and the plurality of dimming pixels 110. Therefore, the pulse width of the pulse signal corresponds to one scanning period.

[0153] In addition, based on the input image signal, the image signal timing control circuit 150 supplies a signal voltage corresponding to the video data to the video signal line drive circuit 131, and also supplies a signal voltage corresponding to the dimming data to the video signal line drive circuit 131.

[0154] Here, as shown in FIG. 23, the image signal timing control circuit 150 controls the amplitude of the dimming signal Vsig applied from the dimming signal line drive circuit 141 to each of the multiple dimming pixels 110 for each frame based on the input image signal.

[0155] In this way, based on the input image signal, the image signal timing control circuit 150 controls, for each frame, the amplitude of the dimming signal Vsig applied to each of the multiple dimming pixels 110. In other words, the image signal timing control circuit 150 controls the transmittance of the liquid crystal element 111 of the dimming pixel 110 based on the input image signal.

[0156] Furthermore, the image signal timing control circuit 150 controls the timing at which the scanning line signal Vg rises based on the input image signal, thereby controlling the light emission of each of the plurality of light-emitting pixels 100 and the dimming of each of the plurality of dimming pixels 110. In other words, the image signal timing control circuit 150 can control the light emission and dimming of each pixel in the transparent display device 1 using a single gate pulse signal. This configuration makes it possible to easily achieve dimming on a pixel-by-pixel basis according to image data to be displayed.

[0157] As the hardware of the image signal timing control circuit 150, for example, a processor such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array) can be used as appropriate.

[0158] The image signal timing control circuit 150 may include a processor such as a CPU (Central Processing Unit) and a memory such as RAM (Random Access Memory), and the processor may execute a control program loaded into the memory to achieve the above-described control. In this case, the control program may be provided in advance in a read-only memory (ROM). The control program may also be provided by being recorded in an installable or executable file format on a computer-readable recording medium such as a CD-ROM, a flexible disk (FD), a CD-R, or a digital versatile disk (DVD). The control program may also be provided by being stored on a computer connected to a network such as the Internet and downloaded via the network. The control program may also be provided or distributed via a network such as the Internet.

[0159] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention described in the claims and their equivalents.

[0160] The techniques described in the above embodiments can also be understood as follows. (1) a first substrate that is transmissive to visible light; a first internal layer provided on a first main surface of the first substrate, in which a plurality of light-emitting pixels each configured to be able to emit light independently and a region capable of transmitting visible light are arranged; a second internal layer provided on the opposite side of the first internal layer from the first substrate, in which a plurality of light-modulating pixels, each having a transmittance for visible light that independently changes, are arranged at positions different from the plurality of light-emitting pixels in a plan view; a second substrate that is provided on the opposite side of the second internal layer from the first internal layer and that is capable of transmitting visible light; A transparent display device comprising: (2) the first internal layer has a circuit configuration electrically connected to each of the plurality of light-emitting pixels, The second inner layer is a first electrode electrically connected to the circuit configuration, provided at a position different from the plurality of light-emitting pixels in a plan view, and capable of transmitting visible light; a second electrode that is capable of transmitting visible light and is provided on a side of the second substrate facing the first electrode and spaced apart from the first electrode; a light-controlling member provided between the first electrode and the second electrode, the light-controlling member having a transmittance for visible light that changes in response to a voltage applied between the first electrode and the second electrode; having The transparent display device according to (1) above. (3) The transparent display device according to (1) or (2), wherein each of the plurality of light-modulating pixels is provided between the plurality of light-emitting pixels in the first internal layer. (4) a first polarizing layer that is provided on the opposite side of the first substrate from the first internal layer and polarizes visible light; a second polarizing layer that is provided on the second substrate opposite to the second internal layer and polarizes visible light; Furthermore, Each of the plurality of light-modulating pixels has a liquid crystal element, an absorption axis of the first polarizing layer and an absorption axis of the second polarizing layer are defined according to the orientation of the liquid crystal element; A transparent display device according to any one of (1) to (3) above. (5) A transparent display device described in any of (1) to (4) above, further comprising a control circuit that controls the on / off timing of switches provided in each of the plurality of light-emitting pixels and the plurality of dimming pixels based on an image signal. [Explanation of symbols]

[0161] 1 Transparent display device 3a, 3b Glass substrate 5 TFT substrate 51 Insulating material 53a Gate electrode 53b Source-drain electrode 55 Insulating materials 6, 6a, 6b, 6c Light-emitting part 61a,61b,61c Transparent electrode 63 Reflecting electrode 65 Light-emitting layer 7 Photochromic Layer 71a,71b,73 Transparent electrode 75 Light control components 77 Spacer 79a, 79b Color filters 81a, 81b Polarizing plate 83a,83b λ / 4 retardation plate 85, 85a, 85b LEDs 100 luminous pixels 101 Light-emitting element 102,105,113 TFT 106,107,114,115 holding capacity 110 dimming pixels 111 Liquid crystal element 120 scan lines 121 Scanning line driving circuit 130 Video signal line 131 Video signal line driver circuit 140 Dimming signal line 141 Dimming signal line driver circuit 150 Image signal timing control circuit R1 Light-emitting area R2 dimming area

Claims

1. a first substrate that is transmissive to visible light; provided on a main surface of the first substrate, a plurality of light-emitting pixels each configured to be able to emit light independently; Multiple dimming pixels, each of which independently changes its transmittance to visible light, However, internal layers are arranged at different positions in a plan view, and a second substrate that is provided on the opposite side of the internal layer from the first substrate and is capable of transmitting visible light; Equipped with Each of the plurality of light-modulating pixels is provided between the plurality of light-emitting pixels in the internal layer, The inner layer is a first electrode that is provided at a position different from the plurality of light-emitting pixels in a plan view and that is capable of transmitting visible light; a second electrode that is provided on a side of the second substrate facing the first electrode and spaced apart from the first electrode, and that is capable of transmitting visible light; a light-adjusting member provided between the first electrode and the second electrode, the light-adjusting member having a transmittance for visible light that changes in response to a voltage applied between the first electrode and the second electrode; and the light adjusting member covers at least one of the plurality of light-emitting pixels in a plan view; Transparent display device.

2. A first substrate that is transmissive to visible light; provided on a main surface of the first substrate, a plurality of light-emitting pixels each configured to be able to emit light independently; Multiple dimming pixels, each of which independently changes its transmittance to visible light, However, internal layers are arranged at different positions in a plan view, and a second substrate that is provided on the opposite side of the internal layer from the first substrate and is capable of transmitting visible light; Equipped with The inner layer is a first internal layer provided on the first substrate side, in which the plurality of light-emitting pixels and an area capable of transmitting visible light are arranged; a second internal layer provided on the second substrate side, in which the plurality of light-modulating pixels are arranged at positions corresponding to the region capable of transmitting visible light; and The second inner layer is a first electrode that is provided at a position different from the plurality of light-emitting pixels in a plan view and that is capable of transmitting visible light; a second electrode that is provided on a side of the second substrate facing the first electrode and spaced apart from the first electrode, and that is capable of transmitting visible light; a light-adjusting member provided between the first electrode and the second electrode, the light-adjusting member having a transmittance for visible light that changes in response to a voltage applied between the first electrode and the second electrode; and the first electrode is provided in each of the plurality of light-modulating pixels and extends to a position covering an adjacent one of the plurality of light-emitting pixels; Transparent display device.

3. the second internal layer is located between the first internal layer and the second substrate in a cross-sectional view. The transparent display device of claim 2 .

4. the plurality of light-emitting pixels include a first light-emitting pixel, the first light-emitting pixel is located between the second internal layer and the first substrate in a cross-sectional view; The transparent display device according to claim 2 or 3.

5. the first electrode is provided on the first internal layer; The transparent display device according to any one of claims 2 to 4.

6. the first internal layer has a transistor electrically connected to the first electrode; The transparent display device according to claim 4 or 5.

7. 3. The transparent display device according to claim 1, wherein the first electrode is provided for each of the plurality of light-modulating pixels.

8. A first substrate that is transmissive to visible light; provided on a main surface of the first substrate, a plurality of light-emitting pixels each configured to be able to emit light independently; Multiple dimming pixels, each of which independently changes its transmittance to visible light, However, internal layers are arranged at different positions in a plan view, and a second substrate that is provided on the opposite side of the internal layer from the first substrate and is capable of transmitting visible light; Equipped with Each of the plurality of light-modulating pixels is provided between the plurality of light-emitting pixels in the internal layer, The inner layer is a first electrode that is provided at a position different from the plurality of light-emitting pixels in a plan view and that is capable of transmitting visible light; a second electrode that is provided on a side of the second substrate facing the first electrode and spaced apart from the first electrode, and that is capable of transmitting visible light; a light-adjusting member provided between the first electrode and the second electrode, the light-adjusting member having a transmittance for visible light that changes in response to a voltage applied between the first electrode and the second electrode; and the first electrode is provided in each of the plurality of light-modulating pixels and extends to a position covering an adjacent one of the plurality of light-emitting pixels; Transparent display device.

9. The transparent display device according to claim 1 , wherein a light-emitting surface of each of the plurality of light-emitting pixels is provided on a side facing the first substrate.

10. each of the plurality of light-emitting pixels includes a transparent electrode that is transparent to visible light, a reflective electrode that is opaque to visible light, and a light-emitting layer located between the transparent electrode and the reflective electrode; the reflective electrode is located between the second internal layer and the transparent electrode in a cross-sectional view. The transparent display device according to any one of claims 2 to 6.

11. The transparent display device according to claim 9 , further comprising a plurality of color filters, each having a predetermined wavelength selectivity, provided between the light-emitting surface of each of the plurality of light-emitting pixels and the first substrate.

12. The transparent display device according to claim 1 , wherein a light-emitting surface of each of the plurality of light-emitting pixels is provided on a side facing the second substrate.

13. each of the plurality of light-emitting pixels includes a transparent electrode that is transparent to visible light, a reflective electrode that is opaque to visible light, and a light-emitting layer located between the transparent electrode and the reflective electrode; the transparent electrode is located between the second internal layer and the reflective electrode in a cross-sectional view; The transparent display device according to any one of claims 2 to 6.

14. The transparent display device according to claim 12 , further comprising a plurality of color filters, each having a predetermined wavelength selectivity, provided between the light-emitting surface of each of the plurality of light-emitting pixels and the second substrate.

15. The transparent display device according to claim 14 , wherein each of the plurality of color filters is provided between the second substrate and the internal layer.

16. 9. The transparent display device according to claim 1, wherein the light-emitting surface of each of the plurality of light-emitting pixels is provided on a side facing the first substrate and a side facing the second substrate.

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