Display device

A display device according to the present disclosure includes first and second substrates transmitting visible light, light emitting pixels, a first internal layer, a liquid crystal layer, a first electrode reflecting visible light, and second to fourth electrodes transmitting visible light. The light emitting pixels independently emit light. The liquid crystal layer is located between the first and second substrates. The first electrode is located between at least one of the light emitting pixels and the liquid crystal layer. The second electrode is located between the liquid crystal layer and the first substrate without overlapping the first electrode in plan view. The third electrode is located between the liquid crystal layer and the second substrate while overlapping the first electrode in plan view. The fourth electrode is located between the liquid crystal layer and the second substrate while overlapping the second electrode in plan view.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2023-013221, filed on Jan. 31, 2023, the entire contents of which are incorporated herein by reference.

FIELD

BACKGROUND

There has been known a technique of configuring a display device as a transparent display that includes a double-sided light emission type light emitting layer, and that can display an image or character information on both surfaces based on light from the light emitting layer and transmit external light from one display surface side to the other display surface side (e.g., JP 2016-184175 A).

However, when an amount of external light is larger compared with an amount of light from the light emitting layer, it may be hard to see display based on the light from the light emitting layer.

An object of the present disclosure is to improve visibility of a display device.

SUMMARY

A display device according to the present disclosure includes a first substrate, a plurality of light emitting pixels, a first internal layer, a second substrate, a liquid crystal layer, and first to fourth electrodes. The first substrate includes a first surface and a second surface on an opposite side of the first surface, the first substrate transmitting visible light in a direction perpendicular to the first surface and the second surface. The plurality of light emitting pixels are configured to be capable of emitting light independently of one another. The first internal layer is disposed on the first surface, the first internal layer including a first circuit configuration that is a circuit configuration electrically connected to each of the plurality of light emitting pixels. The second substrate transmits visible light. The liquid crystal layer is located between the first substrate and the second substrate in a first cross section that is a cross section in a direction perpendicular to the first surface. The first electrode is located between at least one of the plurality of light emitting pixels and the liquid crystal layer in the first cross section, the first electrode reflecting visible light. The second electrode is located between the liquid crystal layer and the first substrate in the first cross section without overlapping with the first electrode in plan view, the second electrode transmitting visible light. The third electrode is located between the liquid crystal layer and the second substrate in the first cross section while overlapping the first electrode in plan view, the third electrode transmitting visible light. The fourth electrode is located between the liquid crystal layer and the second substrate in the first cross section while overlapping the second electrode in plan view, the fourth electrode transmitting visible light.

DETAILED DESCRIPTION

Embodiments of a display device according to the present disclosure will be explained below with reference to the accompanying drawings. Note that configurations of the display devices according to the embodiments of the present disclosure are examples and are not limited to the following description content.

Note that, in the explanation of the present disclosure, components having the same or substantially the same functions as functions described in other drawings are denoted by the same reference numerals, and the explanation the components is sometimes omitted as appropriate. Even if the same or substantially the same portions are represented, dimensions and ratios of the portions are sometimes represented differently depending on the drawings. For example, from the viewpoint of ensuring visibility of the drawings, in explanation of the drawings, only main components are denoted by reference numerals and signs and, even components having the same or substantially the same functions as the functions described in other drawings may are sometimes not denoted by the reference numerals and signs.

Note that, in the explanation of the present disclosure, alphanumeric characters or the like may be added to the ends of reference numerals and signs to distinguish components having the same or similar functions. In the explanation of the present embodiments, a plurality of components having the same or similar functions are sometimes collectively referred to by omitting alphanumeric characters or the like at the ends of reference numerals and signs.

Note that, in the explanation of the present disclosure, for simplification of explanation, it is assumed that the front surface and the rear surface of a display device are respectively surfaces parallel to an x-y plane. It is assumed that a direction from the front surface to the rear surface of the display device is a z+ direction. That is, in the explanation of the present disclosure, the front surface side means a z− side. Similarly, the rear surface side means a z+ side.

Note that, in the explanation of the present disclosure, “transparent” includes a concept of “having transparency or translucency”. That is, “transparent” includes not only transmitted light being not absorbed but also a degree of the transmitted light being absorbed being small. In addition, “opaque” includes a concept of “opaque or translucency being small”. That is, “opaque” is not limited to light being not transmitted, that is, being blocked but also a degree of transmitted light being absorbed being large. In the explanation of the present disclosure, “transmittance” indicates a ratio of brightness or a light amount of visible light passing through a panel to brightness or a light amount of visible light made incident on the panel. In other words, “transmittance” is a transmittance with respect to visible light.

Note that, in the explanation of the present disclosure, “external light” is ambient light such as illumination light or natural light made incident on the front or rear surface of the display device from the outside of the display device, that is, the surrounding environment.

A display device according to the present disclosure is a double-sided display type transparent display that is capable of displaying an image and character information on both surfaces based on light from at least one of a light emitting section, a reflecting section, and a transmitting section and can transmit external light from one display surface side to the other display surface side.

Note that the display device according to the present disclosure can be used as, for example, a transparent display of a video reproduction device or a navigation device mounted on an automobile. As an example, the display device according to the present disclosure is provided at a boundary between an environment having a large influence of external light such as the outside of a vehicle or the outdoors and an environment having a small influence of external light such as the inside of a vehicle or the interior of a room, for example, a part or all of a window or an outer plate surface of an automobile or a part or all of a window or a wall surface of a building. Here, the “environment having a large influence of external light” means that a light amount of external light is larger compared with a light amount of light from the light emitting section of the display device.

For example, the display device according to the present disclosure can be disposed such that one display surface faces an “environment having a large influence of external light” and the other display surface faces an “environment having a small influence of external light”. As an example, when the display device according to the present disclosure is used as a part or all of a window or an outer plate surface of an automobile, the front surface side of the display device faces the inner side of a vehicle interior and can be visually recognized from the inside of the vehicle. Similarly, the rear surface side of the display device faces the outer side and can be visually recognized from the outside of the vehicle.

First Embodiment

FIG.1is a cross-sectional view schematically illustrating an example of a configuration of a display device1according to a first embodiment.FIG.1illustrates a first cross section in a direction perpendicular to a surface on a front surface side of a glass substrate3b.

As illustrated inFIG.1, the display device1according to the present embodiment includes an organic EL display (OLED)1aand a reflective display (RD)1c.

The OLED1ais configured as a top emission type transparent display. According to the top emission type OLED1a, it is possible to make display brighter than a bottom emission type OLED. The OLED1ais provided on the z− side of the display device1. The display surface of the OLED1ais on the z− side of the display device1.

The RD1cis provided on the rear surface side of the display device1. The RD1cis configured as a reflective transparent display. As the RD1c, for example, a reflective liquid crystal display (LCD) can be used. However, a reflective display formed using a material other than liquid crystal may be used. Note that, in the explanation of the present disclosure, a case in which a reflective LCD is applied as the RD1cis illustrated. A display surface of the RD1cis the back surface side of the display device1.

The display device1according to the present embodiment is formed by bonding the OLED1aand the RD1cvia an adhesive layer2. Specifically, the glass substrate3bon the rear surface side of the OLED1aand a glass substrate3con the z− side of the RD1care bonded by the adhesive layer2. The adhesive layer2is transparent to visible light and is formed of, for example, an OCA (Optically Clear Adhesive).

Configuration of the OLED

As illustrated inFIG.1, the OLED1aincludes a glass substrate3a, a glass substrate3b, a thin film transistor (TFT) substrate5a, a polarizing plate81a, a À/4 phase difference plate83a, and a sealing layer85a.

The glass substrate3aand the glass substrate3bare disposed be separated substantially in parallel. The glass substrate3ais provided on the z− side of the display device1, that is, the display surface side of the OLED1a. The glass substrate3bis provided on the rear surface side of the display device1, that is, on the RD1cside. Here, the glass substrate3baccording to the first embodiment is an example of the first substrate. The surface on the front surface side of the glass substrate3baccording to the first embodiment is an example of the first surface. The surface on the rear surface side of the glass substrate3baccording to the first embodiment is an example of the second surface. The glass substrate3aaccording to the first embodiment is an example of the third substrate.

The TFT substrate5ais provided between the glass substrate3aand the glass substrate3b, for example, on the z− side of the glass substrate3b. On the TFT substrate5a, a plurality of light emitting sections6are provided. The plurality of light emitting sections6are configured to be capable of emitting light independently of one another. As explained below with reference toFIG.12, the plurality of light emitting sections6are arrayed in a matrix on the TFT substrate5a. Each of the plurality of light emitting sections6corresponds to any one of an R light emitting pixel100R_n, a G light emitting pixel100G_n, and a B light emitting pixel100B_n (n is a natural number).

FIG.1illustrates a light emitting section6aand a light emitting section6bamong the plurality of light emitting sections6. The light emitting section6aincludes a gate electrode53a, a source-drain electrode54a, a transparent electrode61a, a reflecting electrode64a, a connecting electrode63a, and a light emitting layer65a. The light emitting section6bincludes a gate electrode53b, a source-drain electrode54b, a transparent electrode61b, a reflecting electrode64b, a connecting electrode63b, and a light emitting layer65b.

Here, the gate electrode53aand the source-drain electrode54aconfigure a TFT102corresponding to the light emitting section6aamong a plurality of TFTs102inFIG.12. The gate electrode53band the source-drain electrode54bconfigure the TFT102corresponding to the light emitting section6bamong the plurality of TFTs102inFIG.12.

In the TFT substrate5a, each of the plurality of TFTs102is covered by an insulating member51a. Each of the transparent electrode61a, the transparent electrode61b, the reflecting electrode64a, the reflecting electrode64b, the light emitting layer65a, and the light emitting layer65bis covered by an insulating member55a. Here, the TFT substrate5aaccording to the first embodiment or the plurality of TFTs102covered by the insulating member51aon the TFT substrate5ais an example of the first internal layer. A circuit configuration including the plurality of TFTs102according to the first embodiment is an example of the first circuit configuration.

The transparent electrode61aand the transparent electrode61bare respectively provided on the z− side of the light emitting section6aand the light emitting section6b.

The reflecting electrode64aand the reflecting electrode64bare respectively provided on the z+ side of the light emitting section6aand the light emitting section6b. The reflecting electrode64ais provided in a position facing the transparent electrode61ato be separated from the transparent electrode61asubstantially parallel. The reflecting electrode64bis provided at a position facing the transparent electrode61bto be separated from the transparent electrode61bsubstantially in parallel. The reflecting electrode64aand the reflecting electrode64bare respectively provided to be separated from the TFTs102corresponding thereto via insulating members51a.

Each of the connecting electrode63aand the connecting electrode63bextends in the z direction on the inside of the insulating member51a. The connecting electrode63aelectrically connects the reflecting electrode64aand the source-drain electrode54a. The connecting electrode63belectrically connects the reflecting electrode64band the source-drain electrode54b.

The light emitting layer65aand the light emitting layer65baccording to the first embodiment are located between layers of the plurality of TFTs102covered by the insulating member51aand the glass substrate3b. That is, in the display device1according to the first embodiment, the light emitting layer65aand the light emitting layer65bare located between the glass substrate3aand the glass substrate3b. The light emitting layer65ais provided between the transparent electrode61aand the reflecting electrode64a. The light emitting layer65aemits light when a voltage exceeding a threshold voltage is applied between the transparent electrode61aand the reflecting electrode64a. The light emitting layer65bis provided between the transparent electrode61band the reflecting electrode64b. The light emitting layer65bemits light when a voltage exceeding the threshold voltage is applied between the transparent electrode61band the reflecting electrode64b. As explained below with reference toFIG.12, the light emitting layer65aand the light emitting layer65bconfigure a light emitting element101provided in a light emitting pixel100_ncorresponding thereto among a plurality of light emitting pixels100_n(n is a natural number). Each of the light emitting layer65aand the light emitting layer65bis a light emitting diode (LED) made of an organic compound.

The polarizing plate81ais provided on the z− side of the glass substrate3a, that is, on the side of the glass substrate3aopposite to the glass substrate3b. That is, the glass substrate3bis located between the polarizing plate81aand a transparent electrode74e. The polarizing plate81apolarizes visible light. Here, the polarizing plate81aaccording to the embodiment is an example of the first polarizing layer.

The λ/4 phase difference plate83ais provided between the glass substrate3aand the polarizing plate81a. That is, the λ/4 phase difference plate83ais located between the polarizing plate81aand the glass substrate3b. The λ/4 phase difference plate83aaccording to the embodiment is an example of the first λ/4 phase difference plate.

The sealing layer85ais provided between the glass substrate3aand the glass substrate3b. Specifically, the sealing layer85aincludes a spacer87. The spacer87forms a sealing layer85aserving as a gap between the glass substrate3aand the TFT substrate5a. That is, in the OLED1a, the glass substrate3aand the TFT substrate5aare separated by the length of the spacer87in the z direction and provided substantially in parallel.

Configuration of the Reflective Display

As illustrated inFIG.1, the RD1cincludes the glass substrate3c, a glass substrate3d, a TFT substrate5c, a dimming layer7, a filter layer8, a polarizing plate81c, a λ/4 phase difference plate83c, and a transparent insulating layer85c.

The glass substrate3cand the glass substrate3dare disposed to be separated in substantially parallel. The glass substrate3cis provided on the z− side of the display device1, that is, the OLED1aside. The glass substrate3dis provided on the z+ side of the display device1, that is, the display surface side of the RD1c. Here, the glass substrate3daccording to the embodiment is an example of the second substrate. The glass substrate3caccording to the first embodiment is an example of the fourth substrate. The surface on the rear surface side of the glass substrate3caccording to the first embodiment is an example of the third surface. The surface on the front surface side of the glass substrate3caccording to the first embodiment is an example of the fourth surface.

A plurality of reflecting sections4and a plurality of transmitting sections9are provided in the RD1c. The plurality of reflecting sections4are respectively configured to be capable of reflecting independently of one another. The plurality of transmitting sections9are respectively configured to be capable of dimming independently of each other. As explained below with reference toFIG.12, the plurality of reflecting sections4and the plurality of transmitting sections9are arrayed in matrixes on the TFT substrate5c. Each of the plurality of reflecting sections4corresponds to any one of an R reflecting pixel160R_n, a G reflecting pixel160G_n, and a B reflecting pixel160B_n (n is a natural number). Each of the plurality of transmitting sections9corresponds to a dimming pixel110_n(n is a natural number).

FIG.1illustrates a reflecting section4aand a reflecting section4bamong the plurality of reflecting sections4and a transmitting section9aamong the plurality of transmitting sections9. The reflecting section4aincludes a gate electrode53c, a source-drain electrode54c, a transparent electrode71, a reflecting electrode74c, a connecting electrode73c, and a color filter45a. The reflecting section4bincludes a gate electrode53d, a source-drain electrode54d, a transparent electrode71, a reflecting electrode74d, a connecting electrode73d, and a color filter45b. The transmitting section9aincludes a gate electrode53e, a source-drain electrode54e, a transparent electrode71, a transparent electrode74e, a connecting electrode73e, and the transparent insulating layer85c.

Here, the gate electrode53cand the source-drain electrode54cconfigure a TFT163corresponding to the reflecting section4aamong a plurality of TFTs163illustrated inFIG.12. The gate electrode53dand the source-drain electrode54dconfigure the TFT163corresponding to the reflecting section4bamong the plurality of TFTs163illustrated inFIG.12. The gate electrode53eand the source-drain electrode54econfigure a TFT113corresponding to the transmitting section9aamong a plurality of TFTs113illustrated inFIG.12.

The TFT substrate5cis provided between the glass substrate3cand the filter layer8, for example, on the z+ side of the glass substrate3c. Here, the TFT substrate5caccording to the first embodiment is an example of the second internal layer.

On the TFT substrate5c, the gate electrode53c, the gate electrode53d, the gate electrode53e, the source-drain electrode54c, the source-drain electrode54d, the source-drain electrode54e, the connecting electrode73c, the connecting electrode73d, and the connecting electrode73eare provided.

Each of the connecting electrode73c, the connecting electrode73d, and the connecting electrode73eextends in the z direction on the inside of an insulating member51c. The connecting electrode73celectrically connects the reflecting electrode74cand the source-drain electrode54c. The connecting electrode73delectrically connects the reflecting electrode74dand the source-drain electrode54d. The connecting electrode73eelectrically connects the transparent electrode74eand the source-drain electrode54e.

In the TFT substrate5c, each of the plurality of TFTs113and the plurality of TFTs163are covered by an insulating member51c. On the z+ side of the TFT substrate5c, an insulating member55cis provided in a position facing each of the reflecting section4aand the reflecting section4b. The length of the insulating member55cin the z direction is ½ times the length of the dimming layer7in the z direction. Here, a layer of the TFT substrate5caccording to the first embodiment or the plurality of TFTs113and the plurality of TFTs163covered by the insulating member51cin the TFT substrate5cis an example of the second internal layer. A circuit configuration including the plurality of TFTs163of the TET substrate5caccording to the first embodiment is an example of the second circuit configuration. A circuit configuration including the plurality of TFTs113of the TFT substrate5caccording to the first embodiment is an example of the third circuit configuration.

The dimming layer7is provided between the glass substrate3band the glass substrate3d. The dimming layer7according to the first embodiment is located between the glass substrate3cand the glass substrate3d. Specifically, the dimming layer7is provided between the filter layer8and the TFT substrate5c. Here, the dimming layer7according to the embodiment is an example of the liquid crystal layer. A spacer77is located in the dimming layer7.

The transparent electrode71is located between the glass substrate3dand the filter layer8. The transparent electrode71is provided on the z− side of the filter layer8.

As an example, the transparent electrode71may overlap the reflecting electrode74cand the reflecting electrode74din plan view. That is, the transparent electrode71may be provided over the at least one reflecting electrode74cand the at least one reflecting electrode74dand may be shared by the at least one reflecting section4and the at least one transmitting section9. In this case, the transparent electrode71according to the embodiment is an example of the third electrode and the fourth electrode that are integrally formed. With this configuration, the number of steps relating to manufacturing can be reduced compared with when the transparent electrode71is formed for each of the reflecting electrode74cand the reflecting electrode74d.

As an example, the transparent electrode71may include an electrode overlapping the reflecting electrode74cin a plan view and an electrode separated from the electrode and overlapping the reflecting electrode74din plan view. That is, the transparent electrode71according to the embodiment may be divided into two or more electrodes. In this case, among two or more electrodes of the transparent electrode71according to the embodiment, an electrode overlapping the reflecting electrode74cin plan view is an example of the third electrode. Among two or more electrodes of the transparent electrode71according to the embodiment, an electrode overlapping the reflecting electrode74din plan view is an example of the fourth electrode.

Each of the reflecting electrode74cand the reflecting electrode74dis located between at least one of the plurality of light emitting pixels100_nand the dimming layer7. Each of the reflecting electrode74cand the reflecting electrode74dis provided on the z+ side of the insulating member55cof the TFT substrate5c, that is, at the boundary between the insulating member55cand a dimming member75. The reflecting electrode74cand the reflecting electrode74dare respectively provided on the z− side of the transparent electrode71. The reflecting electrode74cand the reflecting electrode74dare respectively provided to be separated by a distance d1substantially in parallel to the transparent electrode71. Note that each of the reflecting electrode74cand the reflecting electrode74dmay not be provided in positions corresponding to all the light emitting pixels100_n. Here, the reflecting electrode74cand the reflecting electrode74daccording to the embodiment are respectively examples of a first electrode. In addition, a region of a dimming member75alocated between “the reflecting electrode74cand the reflecting electrode74d” and the transparent electrode71according to the embodiment is an example of the first portion. The distance d1according to the embodiment is an example of the thickness of the first portion.

The transparent electrode74eis located between the glass substrate3band the dimming layer7. The transparent electrode74edoes not overlap each of the reflecting electrode74cand the reflecting electrode74din plan view. The transparent electrode74eis provided on the z+ side of the insulating member51cof the TFT substrate5c, that is, at the boundary between the insulating member51cand the dimming member75. The transparent electrode74eis provided on the z− side of the transparent electrode71. The transparent electrode74eis provided to be separated from the transparent electrode71by a distance d2substantially parallel to the transparent electrode71. The distance d2is twice or approximately twice the distance d1. With this configuration, optical path lengths in the dimming layer7of light reflected by each of the reflecting electrode74cand the reflecting electrode74dand light transmitted through the transparent electrode74ecan be equalized. Here, the transparent electrode74eaccording to the embodiment is an example of the second electrode. A region of a dimming member75blocated between the transparent electrode74eand the transparent electrode71according to the embodiment is an example of the second portion. The distance d2according to the embodiment is an example of the thickness of the second portion.

The spacer77is a member for forming gaps, in which the dimming member75is filled, between the reflecting electrode74c, the reflecting electrode74d, and the transparent electrode74eand the transparent electrode71. The transparent electrode71is provided on the z− side of the insulating member55cvia the spacer77. In other words, the transparent electrode71is provided to be separated from each of the reflecting electrode74cand the reflecting electrode74dby the length of the spacer77in the z direction.

Dimming member75is filled between the reflecting electrode74c, the reflecting electrode74d, and the transparent electrode74eand transparent electrode71. Between the reflecting electrode74cand the transparent electrode71, between the reflecting electrode74dand the transparent electrode71, and between the transparent electrode74eand the transparent electrode71, a state of the dimming member75changes in a state in which a voltage is applied and a state in which a voltage is not applied.

As the dimming member75, a normally white material and a normally black material can be used as appropriate. Examples of the normally white material include TN (Twisted Nematic) liquid crystal and ECB (Electrically Controlled Birefringence) liquid crystal. Examples of the normally black material include VA (Vertical Alignment) liquid crystal, guest-host liquid crystal, PNLC (polymer network liquid crystal), SPD (suspended particles), and an electrochromic material. Note that the dimming member75only has to be selected as appropriate according to, for example, characteristics of an operating voltage and response speed.

For example, between the reflecting electrode74cand the transparent electrode71, between the reflecting electrode74dand the transparent electrode71, and between the transparent electrode74eand the transparent electrode71, the dimming member75transitions between a transmission mode for transmitting visible light and a dimming mode for blocking visible light according to a voltage applied by the TFT113and the TFT163. In other words, in the dimming layer7, transmittance with respect to visible light changes according to the voltage applied by the TFT113and the TET163. Therefore, it is preferable that the dimming member75has an operation voltage required for the mode transition low enough for the dimming member75to be driven by the TFT substrate5c.

Details of the transition is explained using the dimming member75located between the reflecting electrode74cand the transparent electrode71as an example. For example, when the dimming member75is a normally white material, in a state in which no voltage is applied between the reflecting electrode74cand the transparent electrode71, the dimming layer7is transparent to visible light when being sandwiched by the polarizing plate81aand the polarizing plate81c. On the other hand, in a state where a voltage exceeding the threshold voltage is applied between the reflecting electrode74cand the transparent electrode71, the dimming layer7becomes opaque to visible light when being sandwiched by the polarizing plate81aand the polarizing plate81c. The dimming layer7sandwiched by the polarizing plate81aand the polarizing plate81cbecoming transparent or opaque is sometimes simply described that the dimming layer7becomes transparent or opaque. Depending on a material used as the normally white material, the dimming layer7itself sometimes becomes transparent or opaque. In that case, the polarizing plate81aand the polarizing plate81cmay not be used.

For example, when the dimming member75is TN liquid crystal, in a state in which no voltage is applied between the reflecting electrode74cand the transparent electrode71, the dimming member75is arrayed horizontally with respect to the reflecting electrode74cand the transparent electrode71. At this time, when being sandwiched by the polarizing plate81aand the polarizing plate81c, the dimming layer7is transparent to visible light. On the other hand, in a state in which a voltage exceeding the threshold voltage is applied between the reflecting electrode74cand the transparent electrode71, the dimming member75is arrayed perpendicularly to the reflecting electrode74cand the transparent electrode71. Consequently, when being sandwiched by the polarizing plate81aand the polarizing plate81c, the dimming layer7becomes opaque to visible light.

On the other hand, for example, when the dimming member75is a normally black material, in a state in which no voltage is applied between the reflecting electrode74cand the transparent electrode71, the dimming layer7is opaque to visible light when being sandwiched by the polarizing plate81aand the polarizing plate81c. On the other hand, in a state in which a voltage exceeding the threshold voltage is applied between the reflecting electrode74cand the transparent electrode71, the dimming layer7becomes transparent to visible light when being sandwiched by the polarizing plate81aand the polarizing plate81c. Depending on a material used as the normally black material, the dimming layer7itself sometimes becomes transparent or opaque. For example, the dimming layer7becomes transparent or opaque when any one of guest-host liquid crystal, PNLC, SPD, and an electrochromic material is used as the normally black material. In that case, the polarizing plate81aand the polarizing plate81cmay not be used.

The filter layer8is provided between the transparent electrode71and the glass substrate3d, for example, on the z-side of the glass substrate3d. The color filter45a, the color filter45b, and the transparent insulating layer85care provided in the filter layer8.

The color filter45ais located between the glass substrate3dand the reflecting electrode74c. Specifically, the color filter45ais provided in a position facing the reflecting electrode74cin the reflecting section4a. The color filter45bis located between the glass substrate3dand the reflecting electrode74d. Specifically, the color filter45ais provided in a position facing the reflecting electrode74din the reflecting section4b. Here, the color filter45aaccording to the embodiment is an example of the first color filter. The color filter45baccording to the embodiment is an example of the second color filter.

The transparent insulating layer85cis provided in a position facing the transparent electrode74ein the transmitting section9a. The transparent insulating layer85cis transparent to visible light. The transparent insulating layer85cis configured by, for example, an insulator. As the insulator forming the transparent insulating layer85c, for example, an inorganic or organic insulating film can be used. As an example, the transparent insulating layer85ccan be formed by stacking inorganic or organic insulating films. The transparent insulating layer85cis provided to align height with the height of the color filter45aand the color filter45b. The transparent electrode71can be formed flat when the heights of the color filter45a, the color filter45b, and the transparent insulating layer85c, that is, the height of the filter layer8is aligned.

Note that a color filter may be provided between the glass substrate3dand the transparent electrode74e, that is, in a position facing the transparent electrode74ein the transmitting section9a. The transparent insulating layer85cis not an essential component and may not be provided in the display device1. That is, a color filter may be provided instead of the transparent insulating layer85cor in addition to the transparent insulating layer85c.

Note that the filter layer8may be formed as one color filter in which a plurality of wavelength selection regions having selectivity of two or more wavelengths corresponding to the color filters45aand45band a region having no wavelength selectivity such as the transparent insulating layer85care arrayed in a matrix. Alternatively, in the filter layer8formed as one color filter, a region having no wavelength selectivity may not be provided.

The polarizing plate81cis provided on the z− side of the glass substrate3d, that is, the side of the glass substrate3dopposite to the glass substrate3c. That is, the glass substrate3dis located between the polarizing plate81cand the transparent electrode71. The polarizing plate81cpolarizes visible light. Here, the polarizing plate81caccording to the embodiment is an example of the second polarizing layer.

The λ/4 phase difference plate83cis provided between the glass substrate3dand the polarizing plate81c. The λ/4 phase difference plate83caccording to the embodiment is an example of the second λ/4 phase difference plate.

Note that each of the glass substrate3a, the glass substrate3b, the glass substrate3c, and the glass substrate3dis a plate-like member transparent to visible light. Each of the glass substrate3a, the glass substrate3b, the glass substrate3c, and the glass substrate3dtransmits visible light in a direction perpendicular or substantially perpendicular to the surface on the front surface side and the rear surface side. Each of the glass substrate3a, the glass substrate3b, the glass substrate3c, and the glass substrate3dhas, for example, a rectangular flat plate-like shape. The glass substrate3a, the glass substrate3b, the glass substrate3c, and the glass substrate3dhave, for example, the same shape.

Each of TFT the substrate5aand the TFT substrate5cmay be formed of a material transparent to visible light. As each of the TFT substrate5aand the TET substrate5c, a-Si, LTPS (Low Temperature PolySilicon), IGZO, or the like can be used as appropriate. Each of the TFT substrate5aand the TFT substrate5cis formed of, for example, a plate-like member but may be formed of a film-like member.

Each of the insulating member51a, the insulating member55a, the insulating member51c, and the insulating member55cmay be formed of a material that is transparent to visible light and has electrical insulation. As each of the insulating member51a, the insulating member55a, the insulating member51c, and the insulating member55c, for example, silicon nitride (SiN) and silicon oxide (SiO) can be used.

Each of the transparent electrode61a, the transparent electrode61b, the transparent electrode71, the connecting electrode73e, and the transparent electrode74eis transparent to visible light.

Each of the connecting electrode63a, the connecting electrode63b, the reflecting electrode64a, the reflecting electrode64b, the connecting electrode73c, the connecting electrode73d, the reflecting electrode74c, and the reflecting electrode74dis opaque to visible light and reflects the visible light. As each of the connecting electrode63a, the connecting electrode63b, the reflecting electrode64a, the reflecting electrode64b, the connecting electrode73c, the connecting electrode73d, the reflecting electrode74c, and the reflecting electrode74d, metal, glass and resin having metal layers provided on the surfaces thereof, and the like can be used as appropriate.

Note that each of the transparent electrode61a, the transparent electrode61b, the reflecting electrode64a, the reflecting electrode64b, the transparent electrode71, the reflecting electrode74c, the reflecting electrode74d, and the transparent electrode74ehas, for example, a rectangular flat plate shape. The transparent electrode61aand the transparent electrode61bhave, for example, the same shape. The reflecting electrode64a, the reflecting electrode64b, and the transparent electrode74ehave, for example, the same shape.

Note that each of the polarizing plate81aand the polarizing plate81cmay be formed of a plate-like member or may be formed of a film-like member.

Note that each of the λ/4 phase difference plate83aand the λ/4 phase difference plate83cmay be formed of a plate-like member or may be formed of a film-like member.

Note that the polarizing plate81a, the polarizing plate81c, the λ/4 phase difference plate83a, and the λ/4 phase difference plate83care not essential components and may not be provided depending on the material of the dimming member75. For example, when IN liquid crystal, VA liquid crystal, or ECB liquid crystal is applied as the dimming member75, the display device1can be configured to include the polarizing plate81a, the polarizing plate81c, the λ/4 phase difference plate83a, and the λ/4 phase difference plate83c. On the other hand, for example, when guest-host liquid crystal, PNLC, SPD, or an electrochromic material is applied as the dimming member75, the display device1can be configured not to include the polarizing plate81a, the polarizing plate81c, the λ/4 phase difference plate83a, and the λ/4 phase difference plate83c.

Note that, for example, when the polarizing plate81aand the polarizing plate81care unnecessary in the display device1according to the material of the dimming member75, the distance d2can be set equal to the distance d1. In this case, the transparent electrode74ecan be provided in the same position as the position of each of the reflecting electrode74cand the reflecting electrode74din the z direction. As an example, the insulating member55cmay be provided on the front surface side of the transparent electrode74e, that is, between the transparent electrode74eand the insulating member51cas in each of the reflecting electrode74cand the reflecting electrode74d. As an example, the insulating member55cmay not be provided on the front surface side of each of the reflecting electrode74cand the reflecting electrode74d, that is, between each of the reflecting electrode74cand the reflecting electrode74dand the insulating member51cas in the transparent electrode74e.

Note that the sealing layer85ais transparent to visible light. The sealing layer85ais provided to reduce deterioration of the OLED1a. For example, an inert gas is filled in the sealing layer85a. As the inert gas, for example, nitrogen gas can be used.

Note that the sealing layer85ais not limited to an aspect in which the inert gas is filled. For example, the inside of the sealing layer85amay be vacuum. Here, in the present disclosure, vacuum means, for example, a state in which the concentration of at least a part of gases contributing to degradation of the OLED1asuch as oxygen gas and hydrogen gas is lower than gas concentration in the surrounding environment, gas molecules may be present, and the vacuum includes a decompressed state. For example, a hygroscopic material may be encapsulated on the inside of the sealing layer85a. For example, the sealing layer85amay be formed by stacking inorganic or organic insulating films.

Note that the sealing layer85ais not an essential component and may not be provided in the display device1.

FIG.2andFIG.3are plan views schematically illustrating examples of a configuration of the display device1according to the first embodiment.FIG.2illustrates a configuration of the display device1viewed from the display surface side of the OLED1a.FIG.3illustrates a configuration of display device1viewed from the display surface side of the RD1c.

As illustrated inFIG.2, a display surface of the OLED1a, that is, a display surface on the front surface side of the display device1includes a light emitting region R11and a transparent region R2. The light emitting region R11and the transparent region R2are regions different from each other in plan view, that is, on the x-y plane.

As illustrated inFIG.3, a display surface of the RD1c, that is, a display surface on the rear surface side of the display device1includes a reflection region R13and a dimming region R3. The reflection region R13and the dimming region R3are regions different from each other in plan view.

On the other hand, the light emitting region R11and the reflection region R13are regions overlapping each other in plan view. The transparent region R2and the dimming region R3are regions overlapping each other in plan view.

The light emitting region R11is a region where each of the plurality of light emitting sections6is arrayed. That is, the light emitting region R11is a region R1where light for display is emitted from the plurality of light emitting sections6.FIG.2illustrates a case in which an R light emitting pixel, a G light emitting pixel, and a B light emitting pixel are provided in the light emitting regions R11.

The reflection region R13is a region where each of the plurality of reflecting sections4is arrayed. That is, the reflection region R13is the region R1from which light for display is emitted by the plurality of reflecting sections4.FIG.3illustrates a case in which an R reflecting pixel, a G reflecting pixel, and a B reflecting pixel are provided in the light emitting regions R11.

The transparent region R2is a region between the plurality of light emitting sections6.

The dimming region R3is a region between the plurality of reflecting sections4, that is, a region between the transparent electrode71and the transparent electrode74eand is a region where each of the plurality of transmitting sections9is arrayed.

Next, action of the display device1according to the embodiment is explained.

Note that, in the following explanation, a mode in which light for display is emitted from each of the plurality of light emitting sections6is referred to as “light emission” mode. A mode in which light for display is emitted from each of the plurality of reflecting sections4is referred to as “reflection” mode. A mode in which external light is emitted from each of the plurality of transmitting sections9is referred to as “transmission” mode. A mode in which light for display is transmitted by controlling the transmittance of each of the plurality of transmitting sections9is referred to as “dimming” mode. As an example, a mode in which light for display is emitted from each of the plurality of light emitting sections6and light for display is emitted from each of the plurality of reflecting sections4is referred to as “light emission/reflection” mode.

In the following explanation, it is assumed that the dimming member75is TN liquid crystal.

FIG.4is a diagram for explaining a “light emission/reflection/transmission” mode of the display device1according to the first embodiment.

In the “light emission/reflection/transmission” mode, the TFT substrate5afeeds an electric current corresponding to a video to be output to between the transparent electrode61aand the reflecting electrode64aprovided in positions corresponding to the video to be output and between the transparent electrode61band the reflecting electrode64bprovided in positions corresponding to the video to be output. Consequently, light from each of the plurality of light emitting sections6is emitted from the display surface of the OLED1aas indicated by an arrow Ag1and an arrow Ar1inFIG.4. That is, the OLED1ais capable of outputting a video for the interior.

In the “light emission/reflection/transmission” mode, the TFT substrate5cdoes not apply a voltage exceeding the threshold voltage between each of the reflecting electrode74cand the reflecting electrode74dprovided in positions corresponding to the video to be output and the transparent electrode71. That is, the dimming layer7becomes transparent to visible light. Consequently, as indicated by an arrow Ac, light is made incident on each of the reflecting electrode74cand the reflecting electrode74dvia the polarizing plate81c, the λ/4 phase difference plate83c, the glass substrate3d, the color filter45a, the transparent electrode71, and the dimming layer7. Reflected light by each of the reflecting electrode74cand the reflecting electrode74dis emitted from the display surface of the RD1cas indicated by an arrow Ag2and an arrow Ar2. That is, the RD1cis capable of outputting a video for the exterior.

In the “light emission/reflection/transmission” mode, the TFT substrate5cdoes not apply a voltage exceeding the threshold voltage between all of the transparent electrodes74eand the transparent electrode71. Consequently, the transmitted light by each of the plurality of transmitting sections9is emitted from each of the display surface of the OLED1aand the display surface of the RD1cas indicated by an arrow Ac and an arrow Ad. That is, the display device1transmits an outdoor scene and an interior scene.

Therefore, in the “light emission/reflection/transmission” mode, the display device1can display, with the OLED1a, a video for the interior on the outdoor scene. The display device1can display, with the RD1c, the video for the exterior to be superimposed on the interior scene. With a configuration in which the video display for the doors is performed by the reflective RD1c, the visibility can be improved using reflected light of external light without increasing display luminance even in an environment in which the external light is strong.

FIG.5is a diagram for explaining a “reflection/transmission” mode of the display device1according to the first embodiment.

In the “reflection/transmission” mode, the TFT substrate5adoes not feed an electric current between all of the transparent electrodes61aand the reflecting electrodes64aand between all of the transparent electrodes61band the reflecting electrodes64b. Consequently, a video for the interior is not output from the OLED1a.

In the “reflection/transmission” mode, the TFT substrate5cdoes not apply a voltage exceeding the threshold voltage between each of the reflecting electrode74cand the reflecting electrode74dprovided in positions corresponding to a video to be output and the transparent electrode71. Consequently, the RD1cis capable of outputting a video for the exterior.

In the “reflection/transmission” mode, the TET substrate5cdoes not apply a voltage exceeding the threshold voltage between all of the transparent electrodes74eand the transparent electrode71. Consequently, the display device1transmits an outdoor scene and an interior scene.

Therefore, in the “reflection/transmission” mode, the display device1can transmit the outdoor scene and the interior scene. That is, the user can view the outdoor scenery from the interior using the display device1as a window. The display device1can also display, with the RD1c, a video for the exterior to be superimposed on the interior scene.

FIG.6andFIG.7are respectively diagrams for explaining a “light emission/reflection” mode and a “light emission/reflection/dimming” mode of the display device1according to the first embodiment.

FIG.6illustrates a case in which the dimming member75requiring a concurrent use of the polarizing plate81aand the polarizing plate81csuch as TN liquid crystal is used. UnlikeFIG.6,FIG.7illustrates a case in which the dimming member75not requiring a concurrent use of the polarizing plate81aand the polarizing plate81csuch as guest-host liquid crystal is used. In this case, as illustrated inFIG.7, the transparent electrode74eand each of the reflecting electrode74cand the reflecting electrode74dare provided in the same or substantially the same position in the z direction. Therefore, whereas the distance d2is twice or approximately twice the distance d1in the example illustrated inFIG.6, the distance d2is equal or substantially equal to the distance d1in the example illustrated inFIG.7.

In the “light emission/reflection” mode and the “light emission/reflection/dimming” mode, the TFT substrate5afeeds an electric current corresponding to a video to be output to between the transparent electrode61aand the reflecting electrode64aprovided in positions corresponding to the video to be output and between the transparent electrode61band the reflecting electrode64bprovided in positions corresponding to the video to be output. Consequently, as illustrated inFIG.6andFIG.7, the OLED1acan output a video for the interior.

In the “light emission/reflection” mode and the “light emission/reflection/dimming” mode, the TFT substrate5cdoes not apply a voltage exceeding the threshold voltage between each of the reflecting electrode74cand the reflecting electrode74dprovided in positions corresponding to a video to be output and the transparent electrode71. Consequently, as illustrated inFIG.6andFIG.7, the RD1cis capable of outputting a video for the exterior.

In the “light emission/reflection” mode, the TFT substrate5capplies a voltage exceeding the threshold voltage between all of the transparent electrodes74eand the transparent electrode71. Consequently, when the dimming member75requiring a concurrent use of the polarizing plate81aand the polarizing plate81cis used, the dimming layer7sandwiched by the polarizing plate81aand the polarizing plate81cbecomes opaque to visible light. Specifically, as indicated by the arrow Ad inFIG.6, light made incident via the polarizing plate81cand the dimming layer7is blocked by the polarizing plate81a. As indicated by the arrow Ac inFIG.6, light made incident via the polarizing plate81aand the dimming layer7is blocked by the polarizing plate81c. On the other hand, when the dimming member75not requiring a concurrent use of the polarizing plate81aand the polarizing plate81cis used, the dimming layer7becomes opaque to visible light. Specifically, as indicated by the arrow Ad and the arrow Ac inFIG.7, light made incident via each of the glass substrate3aand the glass substrate3cis blocked by the dimming layer7. Consequently, as illustrated inFIG.6andFIG.7, the display device1does not transmit an outdoor scene and an interior scene.

Therefore, in the “light emission/reflection” mode, the display device1can block external light from the exterior or the interior and display only a video for the interior and a video for the exterior. That is, with the display device1in the “light emission/reflection” mode, even if strong external light is made incident on the RD1cside from the exterior, for example, in a bright environment in the daytime, a video can be displayed on the OLED1ain the interior without being affected by the external light.

Note that, in the “light emission/reflection/dimming” mode, the TFT substrate5ccan apply a voltage corresponding to a video to be output between the transparent electrode74eand the transparent electrode71provided in positions corresponding to the video to be output. Consequently, each of the plurality of transmitting sections9can be set to any transmittance state from a transmission state to a light blocking state can be set according to a video to be output. The video can be output by the plurality of transmitting sections9.

For example, in an environment such as daytime when the exterior is brighter than the interior, the display device1in the “light emission/reflection/dimming” mode further displays a video for the interior, which is the same as videos of the plurality of light emitting sections6, by using external light transmitted through the plurality of transmitting sections9from the exterior side to the interior side. Consequently, it is possible to improve the visibility of a video for the interior on the display surface of the OLED1awhen strong external light is made incident.

For example, in an environment such as a nighttime environment when the interior is brighter than the exterior, the display device1in the “light emission/reflection/dimming” mode further displays a video for the exterior, which is the same as videos of the plurality of reflecting sections4, using external light transmitted through the plurality of transmitting sections9from the interior side to the exterior side. Consequently, it is possible to improve the visibility of a video for the exterior on the display surface of the RD1c.

FIG.8andFIG.9are respectively diagrams for explaining a “light emission/transmission” mode of the display device1according to the first embodiment.

FIG.8illustrates a case in which the dimming member75requiring a concurrent use of the polarizing plate81aand the polarizing plate81csuch as TN liquid crystal is used. UnlikeFIG.8,FIG.9illustrates a case in which the dimming member75not requiring a concurrent use of the polarizing plate81aand the polarizing plate81csuch as guest-host liquid crystal is used. In this case, as illustrated inFIG.9, the transparent electrode74eand each of the reflecting electrode74cand the reflecting electrode74dare provided in the same or substantially the same position in the z direction. Therefore, whereas the distance d2is twice or approximately twice the distance d1in the example illustrated inFIG.8, the distance d2is equal or substantially equal to the distance d1in the example illustrated inFIG.9.

In the “light emission/transmission” mode, the TFT substrate5afeeds an electric current corresponding to a video to be output to between the transparent electrode61aand the reflecting electrode64aprovided in positions corresponding to the video to be output and between the transparent electrode61band the reflecting electrode64bprovided in positions corresponding to the video to be output. Consequently, the OLED1acan output a video for the interior.

In the “light emission/transmission” mode, the TFT substrate5capplies a voltage exceeding the threshold voltage between each of all of the reflecting electrodes74cand74dand the transparent electrode71. Consequently, when the dimming member75requiring a concurrent use of the polarizing plate81aand the polarizing plate81cis used, light indicated by the arrow Ac inFIG.8made incident via the polarizing plate81cand the dimming layer7is reflected by the reflecting electrode74cand thereafter blocked by the polarizing plate81c. On the other hand, when the dimming member75not requiring a concurrent use of the polarizing plate81aand the polarizing plate81cis used, light indicated by the arrow Ac inFIG.9made incident via the glass substrate3cis blocked by the dimming layer7. Consequently, as illustrated inFIG.8andFIG.9, a video for the exterior is not output from the RD1c.

In the “light emission/transmission” mode, the TFT substrate5cdoes not apply a voltage exceeding the threshold voltage between all of the transparent electrodes74eand the transparent electrode71. Consequently, the display device1transmits an outdoor scene and an interior scene.

Therefore, in the “light emission/transmission” mode, the display device1can transmit the outdoor scene and the interior scene. That is, an outdoor user can view the interior scene using the display device1as a window. The display device1can also display, with the OLED1a, a video for the interior to be superimposed on the outdoor scene.

Note that, as explained with reference toFIG.6, when a video is output using external light transmitted through the plurality of transmitting sections9, at least one of video display by the plurality of reflecting sections4and video display by the plurality of light emitting sections6may not be performed. That is, the display device1can implement not only the “light emission/reflection/dimming” mode but also the “dimming” mode, the “light emission/dimming” mode, or the “reflection/dimming” mode.

Note that, although an example in which the TN liquid crystal is used as the dimming member75has been mainly explained, a method of applying the voltage for causing the dimming member to transition between the transmission mode and the dimming mode differs depending on a type of the dimming member75. For example, a case in which the dimming member75is a normally white material is the same as the case in which the dimming member75is the TN liquid crystal. On the other hand, when the dimming member75is a normally black material, the dimming member can be set to the transmission mode by applying a voltage exceeding the threshold voltage and the dimming member can be set to the dimming mode by not applying a voltage exceeding the threshold voltage.

Note that a color filter45may be provided in each of the plurality of transmitting sections9. For example, the plurality of transmitting sections9may include an R transmission pixel in which the same color filter45as the color filter45of the R reflecting pixel is provided, a G transmission pixel in which the same color filter45as the color filter45of the G reflecting pixel is provided, and a B transmission pixel in which the same color filter45as the color filter45of the B reflecting pixel is provided. With this configuration, since a color video can be output by the plurality of transmitting sections9, the visibility of a video can be further improved.

Note that, for example, in an environment such as a nighttime environment when the interior is brighter than the exterior, when a video for the exterior is displayed by the plurality of reflecting sections4, each of the plurality of reflecting sections4may be irradiated with illumination light. That is, the display device1may further include an illumination device configured to be capable of irradiating each of the plurality of reflecting sections4with illumination light.

As explained above, the display device1according to the present embodiment is a double-sided transparent display integrally formed by bonding the OLED1aand the reflective and transmissive RD1c. In the display device1, the plurality of transmitting sections9are configured to be capable of controlling the transmittance of external light based on dimming data independently of video display by the plurality of reflecting sections4based on reflection data and the video display by the plurality of light emitting sections6based on video data.

With this configuration, it is possible to perform display with high definition by using the OLED1ain the interior and with increased display luminance by using the reflective RD1cin the exterior. That is, with the display device1according to the embodiment, it is possible to improve the visibility of the display device1.

Since the liquid crystal for video display of the RD1cis also used for dimming, it is unnecessary to separately provide a dimming element. It is possible to realize a reduction in thickness and weight of the device.

Second Embodiment

First, a configuration of the display device1according to the present embodiment is explained. Here, differences from the display device1according to the first embodiment are mainly explained and redundant explanation is omitted as appropriate.FIG.10is a cross-sectional view schematically illustrating an example of a configuration of the display device1according to a second embodiment.FIG.2illustrates a first cross section in a direction perpendicular to the surface on the rear surface side of the glass substrate3a.

The display device1according to the present embodiment has a configuration in which an OLED configured as a bottom emission type transparent display and an RD configured as a reflective type transparent display are combined. Specifically, as illustrated inFIG.10, the display device1according to the present embodiment has a configuration in which the components of the OLED1aare incorporated in the RD1cillustrated inFIG.1.

As illustrated inFIG.10, the display device1includes the glass substrate3a, the glass substrate3d, the TFT substrate5, the dimming layer7, the filter layer8, the polarizing plate81a, the polarizing plate81c, the λ/4 phase difference plate83a, and the λ/4 phase difference plate83c.

The glass substrate3aand the glass substrate3dare disposed to be separated substantially in parallel. The glass substrate3ais provided on the z− side, that is, the front surface side of the display device1. The polarizing plate81aand the λ/4 phase difference plate83aare provided on the front surface side of the glass substrate3aas in the display device1illustrated inFIG.1. That is, the glass substrate3a, the polarizing plate81a, and the λ/4 phase difference plate83aaccording to the present exemplary embodiment are provided in the position of the glass substrate3cof the RD1cillustrated inFIG.1. The glass substrate3dis provided on the z+ side of the display device1, that is, on the rear surface side. The polarizing plate81cand the λ/4 phase difference plate83care provided on the rear surface side of the glass substrate3das in the display device1illustrated inFIG.1.

In the display device1, the plurality of reflecting sections4, the plurality of light emitting sections6, and the plurality of transmitting sections9are provided.FIG.10illustrates the reflecting section4aand the reflecting section4bamong the plurality of reflecting sections4, the light emitting section6aand the light emitting section6bamong the plurality of light emitting sections6, and the transmitting section9aamong the plurality of transmitting sections9.

The TFT substrate5is provided between the glass substrate3aand the filter layer8, for example, on the z+ side of the glass substrate3a. Here, the glass substrate3aaccording to the second embodiment is an example of the first substrate. The surface on the back surface side of the glass substrate3aaccording to the second embodiment is an example of the first surface. The surface on the front surface side of the glass substrate3aaccording to the second embodiment is an example of the second surface.

On the TFT substrate5, the gate electrode53a, the gate electrode53b, the gate electrode53c, the gate electrode53d, the gate electrode53e, the source-drain electrode54a, the source-drain electrode54b, the source-drain electrode54c, the source-drain electrode54d, the source-drain electrode54e, the connecting electrode63a, the connecting electrode63b, the connecting electrode73c, the connecting electrode73d, and the connecting electrode73eare provided. In the TFT substrate5, each of the plurality of TFTs102, the plurality of TFTs113, and the plurality of TFTs163are covered by an insulating member51as in the display device1illustrated inFIG.1. Each of the transparent electrode61a, the transparent electrode61b, the reflecting electrode64a, the reflecting electrode64b, the light emitting layer65a, and the light emitting layer65bis covered by an insulating member55. That is, the plurality of TFTs113and the plurality of TFTs163according to the second embodiment are located between the light emitting layer65aand the light emitting layer65band the glass substrate3a. The reflecting electrode64aand the reflecting electrode74cand the reflecting electrode64band the reflecting electrode74dare provided to be separated from each other substantially in parallel via the insulating member55.

Here, the insulating member51according to the present embodiment corresponds to the insulating member51aand the insulating member51cof the display device1illustrated inFIG.1. Similarly, the insulating member55according to the present embodiment corresponds to the insulating member55aand the insulating member55cof the display device1illustrated inFIG.1. That is, the display device1according to the present embodiment is equivalent to a configuration in which the plurality of TFTs102provided in the insulating member51ain the configuration of the display device1illustrated inFIG.1are provided in the insulating member51ctogether with the plurality of TFTs113and the plurality of TFTs163. Similarly, the display device1according to the present embodiment is equivalent to a configuration in which each of the transparent electrode61a, the transparent electrode61b, the reflecting electrode64a, the reflecting electrode64b, the light emitting layer65a, and the light emitting layer65bprovided in the insulating member55ain the configuration of the display device1illustrated inFIG.1is provided in the insulating member55cbetween the reflecting electrode74cand the insulating member51c. Therefore, in the display device1according to the second embodiment, the surface on the front surface side of the TFT substrate5corresponds to and is in contact with the glass substrate3a. In the display device1according to the second embodiment, a transparent electrode74eis provided on the surface on the rear surface side of the TFT substrate5.

Here, the TFT substrate5according to the second embodiment or layers of the plurality of TFTs102, the plurality of TETs113, and the plurality of TFTs163covered by the insulating member51in the TFT substrate5are an example of the first internal layer. The surface on the front surface side of the TFT substrate5according to the second embodiment is an example of the fifth surface. The surface on the rear surface side of the TFT substrate5according to the second embodiment is an example of the sixth surface. A circuit configuration including the plurality of TFTs102of the TFT substrate5according to the second embodiment is an example of the first circuit configuration. A circuit configuration including the plurality of TFTs163of the TFT substrate5according to the second embodiment is an example of the second circuit configuration. A circuit configuration including the plurality of TFTs113of the TFT substrate5according to the second embodiment is an example of the third circuit configuration.

Note that, unlike the display device1illustrated inFIG.1, in the display device1according to the present embodiment, the adhesive layer2, the glass substrate3b, the glass substrate3c, and the sealing layer85aare not provided.

Next, action of the display device1according to the embodiment is explained.FIG.11is a diagram for explaining a “light emission/reflection/transmission” mode of the display device1according to the second embodiment.

In the “light emission/reflection/transmission” mode, the TFT substrate5applies a voltage exceeding a threshold voltage between the transparent electrode61aand the reflecting electrode64aprovided in positions corresponding to a video to be output and between the transparent electrode61band the reflecting electrode64bprovided in positions corresponding to the video to be output. Consequently, light from each of the plurality of light emitting sections6is emitted from the display surface on the front surface side as indicated by the arrow Ag1and the arrow Ar1illustrated inFIG.11. That is, the display device1is capable of outputting a video for the interior with the display surface on the front surface side.

In the “light emission/reflection/transmission” mode, the TFT substrate5does not apply a voltage exceeding the threshold voltage between each of the reflecting electrode74cand the reflecting electrode74dprovided in positions corresponding to a video to be output and the transparent electrode71. Consequently, as indicated by arrow Ac inFIG.11, the light is made incident on each of the reflecting electrode74cand the reflecting electrode74dvia the polarizing plate81c, the λ/4 phase difference plate83c, the glass substrate3d, the color filter45a, the transparent electrode71, and the dimming member75. The light reflected by each of the reflecting electrode74cand the reflecting electrode74dis emitted from the display surface on the rear surface side as indicated by the arrow Ag2and the arrow Ar2illustrated inFIG.11. That is, the display device1is capable of outputting a video for the exterior with the display surface on the rear surface side.

In the “light emission/reflection/transmission” mode, the TFT substrate5does not apply a voltage exceeding the threshold voltage between all of the transparent electrodes74eand the transparent electrode71. Consequently, the transmitted light by each of the plurality of transmitting sections9is emitted from each of the display surfaces on both surface sides as indicated by the arrow Ac and the arrow Ad illustrated inFIG.11. That is, the display device1transmits an outdoor scene and an interior scene.

Therefore, as in the display device1illustrated inFIG.1, the display device1according to the present embodiment can display a video for the interior to be superimposed on an exterior scene and display a video for the exterior to be superimposed on an interior scene in the “light emission/reflection/transmission” mode.

Note that, like the display device1illustrated inFIG.1, the display device1according to the present embodiment is capable of implementing not only the “light emission/reflection/transmission” mode and but also the modes of the “light emission” mode, the “reflection” mode, the “transmission” mode, the “dimming” mode, the “light emission/reflection” mode, the “light emission/transmission” mode, the “reflection/transmission” mode, the “light emission/dimming” mode, the “reflection/dimming” mode, and the “light emission/reflection/dimming” mode.

As explained above, the display device1according to the present embodiment is a double-sided transparent display integrally formed by combining the OLED1aand the reflective and transmissive RD1c. In the display device1according to the present embodiment, the plurality of light emitting sections6corresponding to the OLEDs1aare configured as bottom emission type transparent displays. In general, the bottom emission type is easier to manufacture than the top emission type. Therefore, with the configuration according to the present embodiment, it is possible to reduce processes and the number of components relating to manufacturing and realize a further reduction in thickness, weight, and cost of the device compared with when the device is formed by bonding the OLED1aand RD1c.

Display Control in the Display Device

Here, a specific circuit configuration and display control of the display device1according to the embodiments explained above are explained with reference to the drawings. Here, the display device1according to the second embodiment is explained as an example.

Note that, in the explanation of the present disclosure, when the plurality of R light emitting pixels100R_n, the plurality of G light emitting pixels100G_n, and the plurality of B light emitting pixels100B_n (n is a natural number) are not distinguished, the light emitting pixels are described as a plurality of light emitting pixels100_n. Similarly, when the plurality of R reflecting pixels160R_n, the plurality of G reflecting pixels160G_n, and the plurality of B reflecting pixels160B_n are not distinguished, the reflecting pixels are described as a plurality of reflecting pixels160_n.

FIG.12is a diagram schematically illustrating an example of a circuit configuration of the display device1according to the embodiments.

As illustrated inFIG.12, the TFT substrate5includes the plurality of light emitting pixels100_n, the plurality of dimming pixels110_n, and the plurality of reflecting pixels160_n. The plurality of light emitting pixels100_n, the plurality of dimming pixels110_n, and the plurality of reflecting pixels160_nhave a circuit configuration in which the pixels are arrayed in a matrix on the TFT substrate5.

The plurality of light emitting pixels100_nconfigure the plurality of light emitting sections6and are configured to be capable of turning on and off light emission independently of one another. The plurality of dimming pixels110_nconfigure the plurality of transmitting sections9and are configured to be capable of turning on and off transmission for visible light or changing the transmittance thereof independently of one another. The plurality of reflecting pixels160_nconfigure the plurality of reflecting sections4and are configured to be capable of turning on and off reflection independently of one another.

For example, the plurality of R light emitting pixels100R_n are arrayed in positions overlapping the plurality of R reflecting pixels160R_n in plan view. For example, the plurality of G light emitting pixels100G_n are arrayed in positions overlapping the plurality of G reflecting pixels160G_n in plan view. For example, the plurality of B light emitting pixels100B_n are arrayed in positions overlapping the plurality of B reflecting pixels160B_n in plan view. For example, the plurality of dimming pixels110_nare arrayed in positions different from the plurality of reflecting pixels160_nin plan view.

As illustrated inFIG.12, each of the plurality of light emitting pixels100_nincludes the light emitting element101, a TFT102, a TFT105, a holding capacitor106, and a holding capacitor107.

The light emitting element101is a diode that emits light with luminance corresponding to a value of an electric current flowing between an anode and a cathode. The anode of the light emitting element101is electrically connected to the drain of the TFT102. For example, the anode of the light emitting element101corresponding to the light emitting layer65ais electrically connected to a source electrode of the source-drain electrode54avia the transparent electrode61aand the connecting electrode63a. For example, the anode of the light emitting element101corresponding to the light emitting layer65bis electrically connected to a source electrode of the source-drain electrode54bvia the transparent electrode61band the connecting electrode63b. The cathode of the light emitting element101is electrically connected to a power supply wire104on a Vss side. For example, the cathode of the light emitting element101corresponding to the light emitting layer65ais electrically connected to the power supply wire104on the Vss side via the reflecting electrode64a. For example, the cathode of the light emitting element101corresponding to the light emitting layer65bis electrically connected to the power supply wire104on the Vss side via the reflecting electrode64b.

The TFT102is a drive transistor of the light emitting element101. The TFT102is, for example, a P-type TFT. For example, the source and the drain of the TFT102correspond to the source-drain electrode54aand the source-drain electrode54b. The gate of the TFT102corresponds to the gate electrode53aand the gate electrode53b. The source of the TFT102is electrically connected to a power supply wire103on a Vdd side. The gate of the TFT102is electrically connected to the drain of the TFT105. The gate of the TFT102is electrically connected to the power supply wire103on the Vdd side via the holding capacitor106and the holding capacitor107. The TFT102supplies an electric current corresponding to a voltage held in the holding capacitor106and the holding capacitor107to the light emitting element101.

The TFT105is a switch transistor of the light emitting element101. The TFT105is, for example, a P-type TFT. The source of the TET105is electrically connected to a signal line130corresponding thereto. For example, in the R light emitting pixel100R_n, the source of the TET105is electrically connected to a signal line130R_n. For example, in the G light emitting pixel100G_n, the source of the TFT105is electrically connected to a signal line130G_n. For example, in the B light emitting pixel100B_n, the source of the TFT105is electrically connected to a signal line130B n. The gate of the TFT105is electrically connected to a scanning line drive circuit121via a scanning line Gate_n corresponding thereto. The drain of the TFT105is electrically connected to the gate of the TFT102, one end of the holding capacitor106, and one end of the holding capacitor107. The TET105is turned on or off according to a voltage applied by the scanning line drive circuit121.

The holding capacitor106and the holding capacitor107are electrically connected between the power supply wire103on the Vdd side and the power supply wire104on the Vss side. Specifically, the holding capacitor106is electrically connected between the drain of the TFT105and the power supply wire103on the Vdd side. The holding capacitor107is electrically connected between the drain of the TFT105and the power supply wire104on the Vss side. The holding capacitor106and the holding capacitor107hold a potential difference between the potential of the power supply wire103on the Vdd side and the potential of the gate of the TFT102at the time when the TFT105is turned off. That is, the holding capacitor106and the holding capacitor107hold a voltage corresponding to a signal voltage.

As illustrated inFIG.12, each of the plurality of dimming pixels110_nincludes a liquid crystal element111, a TFT113, a holding capacitor114, and a holding capacitor115.

The liquid crystal element111corresponds to the dimming member75in a position corresponding to the transparent electrode74e. One end of the liquid crystal element111is electrically connected to a power supply wire112on a Vcom side via the transparent electrode71. The other end of the liquid crystal element111is electrically connected to the drain of the TFT113, that is, a drain electrode of the source-drain electrode54evia the transparent electrode74e. The transmittance of the liquid crystal element111is controlled from the transmission state to the light blocking state by applying an alternating electric field between the transparent electrode71and the transparent electrode74e.

The TFT113is a switch transistor of the liquid crystal element111. The TFT113is, for example, a P-type TFT. For example, the source and the drain of the TFT113correspond to the source-drain electrode54e. The gate of the TFT113corresponds to the gate electrode53e. The source of the TFT113is electrically connected to a signal line140T_n corresponding thereto. The gate of the TFT113is electrically connected to one end of the holding capacitor114and the scanning line Gate_n corresponding thereto. The drain of the TFT113is electrically connected to one end of the liquid crystal element111, one end of the holding capacitor114, and one end of the holding capacitor115. The TFT113is turned on/off according to the voltage applied by the scanning line drive circuit121.

The holding capacitor114and the holding capacitor115are electrically connected between scanning lines Gate_n and Gate_n+1 corresponding thereto. Specifically, the holding capacitor114is electrically connected between the gate and the drain of the TFT113. The holding capacitor115is electrically connected between the drain of the TFT113and the scanning line Gate_n+1 corresponding thereto. The holding capacitor114and the holding capacitor115hold a voltage corresponding to a scanning signal from the scanning line drive circuit121.

As illustrated inFIG.12, each of the plurality of reflecting pixels160_nincludes a liquid crystal element161, a TFT163, a holding capacitor164, and a holding capacitor165.

The liquid crystal element161corresponds to the dimming member75in a position corresponding to the reflecting electrode74cand the reflecting electrode74d. One end of the liquid crystal element161is electrically connected to a power supply wire162on the Vcom side via the transparent electrode71. The other end of the liquid crystal element161is electrically connected to the drain of the TFT113. For example, in the R reflecting pixel160R_n, the other end of the liquid crystal element161is electrically connected to a drain electrode of the source-drain electrode54dvia the reflecting electrode74d. For example, in the G reflecting pixel160G_n, the other end of the liquid crystal element161is electrically connected to a drain electrode of the source-drain electrode54cvia the reflecting electrode74c. The transmittance of the liquid crystal element161is controlled from the transmission state to the light blocking state by applying an alternating electric field between the transparent electrode71and the reflecting electrode74cand between the transparent electrode71and the reflecting electrode74d.

The TFT163is a switch transistor of the liquid crystal element161. The TFT163is, for example, a P-type TFT. The source and the drain of the TFT163correspond to the source-drain electrode54cand the source-drain electrode54d. The gate of the TFT163corresponds to the gate electrode53cand the gate electrode53d. The source of the TFT163is electrically connected to a signal line140corresponding thereto. For example, in the R reflecting pixel160R_n, the source of the TFT163is electrically connected to a signal line140R_n. For example, in the G reflecting pixel160G_n, the source of the TFT163is electrically connected to a signal line140G_n. For example, in the B reflecting pixel160B_n, the source of the TFT163is electrically connected to a signal line140B_n. A gate of the TFT163is electrically connected to one end of the holding capacitor164and the scanning line Gate_n corresponding thereto. The drain of the TFT163is electrically connected to one end of the liquid crystal element161, one end of the holding capacitor164, and one end of the holding capacitor165. The TFT163is turned on/off according to a voltage applied by the scanning line drive circuit121.

The holding capacitor164and the holding capacitor165are electrically connected between the scanning lines Gate_n and the Gate_n+1 corresponding thereto. Specifically, the holding capacitor164is electrically connected between the gate and the drain of the TFT163. The holding capacitor165is electrically connected between the drain of the TFT163and the scanning line Gate_n+1 corresponding thereto. The holding capacitor164and the holding capacitor165hold a voltage corresponding to a scanning signal from the scanning line drive circuit121.

Note that a holding capacitor provided in the TFT substrate5is formed simultaneously with a TFT using the same material as the TFT. The holding capacitor provided on the TFT substrate5is, for example, a capacitive element having structure in which an electrode, an insulating film, and an electrode are stacked in this order.

As illustrated inFIG.12, the TFT substrate5includes the scanning line Gate_n, the scanning line Gate_n+1 (n is a natural number), the scanning line drive circuit121, a plurality of signal lines130, an OLED drive circuit131, a plurality of signal lines140, an LCD drive circuit141, and a timing control circuit150.

The scanning line drive circuit121is electrically connected to the scanning line Gate_n and the scanning line Gate_n+1. The scanning line Gate_n is electrically connected to the gate of the TFT105of the light emitting pixel100_ncorresponding thereto, the gate of the TFT113of the dimming pixel110_ncorresponding thereto, and the gate of the TFT163of the reflecting pixel160_ncorresponding thereto. The scanning line Gate_n+1 is electrically connected to the drain of each of the TFTs113via the holding capacitor115of the dimming pixel110_ncorresponding thereto.

The scanning line drive circuit121outputs a scanning signal to the scanning line Gate_n and the scanning line Gate_n+1 to scan the plurality of light emitting pixels100_nin order. Specifically, the TFT105of the light emitting pixel100_nis turned on or off in units of rows. Consequently, the scanning line drive circuit121applies a signal voltage output from the OLED drive circuit131to the plurality of light emitting pixels100_nof a selected row by the signal line130corresponding thereto and causes each of the light emitting elements101of the plurality of light emitting pixels100_nto emit light with luminance corresponding to video data.

Similarly, the scanning line drive circuit121outputs a scanning signal to the scanning line Gate_n and the scanning line Gate_n+1 to sequentially scan the plurality of dimming pixels110_nand the plurality of reflecting pixels160_n. Specifically, the TFT113of the dimming pixel110_nand the TFT163of the reflecting pixel160_nare turned on or off in units of rows. Consequently, the scanning line drive circuit121applies the signal voltage output from the LCD drive circuit141to the plurality of dimming pixels110_nand the plurality of reflecting pixels160_nin the selected row via the signal line140corresponding thereto, changes the transmittance of the liquid crystal element111of each of the plurality of dimming pixels110_naccording to diming data, and changes the reflectance of the liquid crystal element161of each of the plurality of reflecting pixels160_naccording to reflection data.

The OLED drive circuit131applies a signal voltage corresponding to the video data to each of the plurality of light emitting pixels100_nvia the plurality of signal lines130. The signal line130R_n is electrically connected to the source of the TFT105of the R light emitting pixel100R_n. The signal line130R_n supplies a video signal Sig_OLED-R_n corresponding to the video data to the R light emitting pixel100R_n. The signal line130G_n is electrically connected to the source of the TFT105of the G light emitting pixel100G_n. The signal line130G_n supplies the video signal Sig_OLED-G_n corresponding to the video data to the G light emitting pixel100G_n. The signal line130B n is electrically connected to the source of the TET105of the B light emitting pixel100B_n. The signal line130B n supplies the video signal Sig_OLED-B_n corresponding to the video data to the B light emitting pixel100B_n. Here, the R light emitting pixel100R_n is a pixel of an OLED that emits red light. The G light emitting pixel100G_n is an OLED pixel that emits green light. The B light emitting pixel100B_n is an OLED pixel that emits blue light.

The LCD drive circuit141applies a signal voltage corresponding to dimming data and reflection data to each of the plurality of dimming pixels110_nand the plurality of reflecting pixels160_nvia the plurality of signal lines140. The signal line140T_n is electrically connected to the source of the TFT113of the dimming pixel110_n. The signal line140T_n supplies a dimming signal Sig_LCD-T n corresponding to the dimming data to the dimming pixel110_n. The signal line140R_n is electrically connected to the source of the TFT163of the R reflecting pixel160R_n. The signal line140R_n supplies a reflection signal Sig_LCD-R_n corresponding to the reflection data to the R reflecting pixel160R_n. The signal line140G_n is electrically connected to the source of the TFT163of the G reflecting pixel160G_n. The signal line140G_n supplies a reflection signal Sig_LCD-G_n corresponding to the reflection data to the G reflecting pixel160G_n. The signal line140B_n is electrically connected to the source of the TET163of the B reflecting pixel160B_n. The signal line140B_n supplies a reflection signal Sig_LCD-B_n corresponding to the reflection data to the B reflecting pixel160B_n. Here, the R reflecting pixel160R_n is a pixel of an LCD in which a color filter that transmits red light is provided. The G reflecting pixel160G_n is a pixel of an LCD in which a color filter that transmits green light is provided. The B reflecting pixel160B_n is a pixel of an LCD in which a color filter that transmits blue light is provided.

The timing control circuit150is electrically connected to each of the scanning line drive circuit121, the OLED drive circuit131, and the LCD drive circuit141. The timing control circuit150controls operation timings of the scanning line drive circuit121, the OLED drive circuit131, and the LCD drive circuit141based on an input image signal. Here, the timing control circuit150according to the embodiment is an example of the control circuit.

FIG.13is a signal waveform chart schematically illustrating an example of dimming control of the display device1according to the embodiments.

As illustrated inFIG.13, the timing control circuit150controls the scanning line drive circuit121to raise a scanning line signal Vgate at timing corresponding to the input image signal. The scanning line drive circuit121generates, for example, a rectangular pulse signal at timing conforming to the control of the timing control circuit150, scans the plurality of light emitting pixels100_nin order, and scans the plurality of dimming pixels110_nand the plurality of reflecting pixels160_nin order. Therefore, the pulse width of the pulse signal corresponds to one scanning period.

Based on the input image signal, the timing control circuit150supplies a signal voltage corresponding to the video data to the OLED drive circuit131and supplies a signal voltage corresponding to the dimming data and the reflection data to the LCD drive circuit141.

Here, as illustrated inFIG.12, the timing control circuit150controls, based on the input image signal, for each frame, the amplitude of the dimming signal applied from the LCD drive circuit141to each of the plurality of dimming pixels110_n.

As explained above, the timing control circuit150controls, based on the input image signal, for each frame, the amplitude of the LCD signal Vsig as a dimming signal applied to each of the plurality of dimming pixels110_n. In other words, the timing control circuit150controls the transmittance of the liquid crystal element111of the dimming pixel110_nfrom transmission to light blocking based on the input image signal.

The timing control circuit150can control light emission of the plurality of light emitting pixels100_n, the transmittance of the plurality of dimming pixels110, and the reflectance of the plurality of reflecting pixels160_nby controlling rising timing of the scanning line signal Vgate based on the input image signal. In other words, the timing control circuit150can control light emission, dimming, and reflection of the pixels in the display device1with one gate pulse signal. With this configuration, dimming in pixel units corresponding to a display image can be easily realized.

As hardware of the timing control circuit150, for example, a processor such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array) can be used as appropriate.

Note that the timing control circuit150includes, for example, a processor such as a CPU (Central Processing Unit) and a memory such as a RAM (Random Access Memory) and may implement the control explained above by the processor executing a control program loaded in the memory. In this case, the control program may be provided by being incorporated in advance in, for example, a ROM (Read Only Memory). The control program may be provided by being recorded in a computer-readable recording medium such as a CD-ROM, a flexible disk (FD), a CD-R, or a DVD (Digital Versatile Disk) as a file in an installable format or an executable format. Further, the control program may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. The control program may be provided or distributed through a network such as the Internet.

According to at least one embodiment explained above, the visibility of the display device can be improved.

According to the present disclosure, it is possible to improve visibility of a display device.

The following technique is disclosed by the description of the embodiments explained above.

(1) A display device comprising:a first substrate including a first surface and a second surface on an opposite side of the first surface, the first substrate transmitting visible light in a direction perpendicular to the first surface and the second surface;a plurality of light emitting pixels configured to be capable of emitting light independently of one another;a first internal layer disposed on the first surface, the first internal layer including a first circuit configuration that is a circuit configuration electrically connected to each of the plurality of light emitting pixels;a second substrate transmitting visible light;a liquid crystal layer located between the first substrate and the second substrate in a first cross section that is a cross section in a direction perpendicular to the first surface;a first electrode located between at least one of the plurality of light emitting pixels and the liquid crystal layer in the first cross section, the first electrode reflecting visible light;a second electrode located between the liquid crystal layer and the first substrate in the first cross section without overlapping with the first electrode in plan view, the second electrode transmitting visible light;a third electrode located between the liquid crystal layer and the second substrate in the first cross section while overlapping the first electrode in plan view, the third electrode transmitting visible light; anda fourth electrode located between the liquid crystal layer and the second substrate in the first cross section while overlapping the second electrode in plan view, the fourth electrode transmitting visible light.

(2) The display device according to (1), further comprising a first color filter located between the third electrode and the second substrate in the first cross section.

(3) The display device according to (2), wherein the first color filter is located between the fourth electrode and the second substrate in the first cross section.

(4) The display device according to any one of (1) to (3), whereinthe liquid crystal layer includes a first portion located between the first electrode and the third electrode and a second portion located between the second electrode and the fourth electrode, andthickness of the second portion is twice thickness of the first portion.

(5) The display device according to any one of (1) to (4), further comprising a first polarizing layer and a second polarizing layer that polarize visible light, whereinthe first substrate is located between the first polarizing layer and the second electrode in the first cross section, andthe second substrate is located between the second polarizing layer and the third electrode in the first cross section.

(6) The display device according to (5), further comprising:a first λ/4 phase difference plate located between the first polarizing layer and the first substrate in the first cross section; anda second λ/4 phase difference plate located between the second polarizing layer and the second substrate in the first cross section.

(7) The display device according to any one of (1) to (6), whereinthe third electrode and the fourth electrode are integrally formed.

(8) The display device according to any one of (1) to (7), whereinthe plurality of light emitting pixels are located between the first internal layer and the first substrate in the first cross section.

(9) The display device according to (8), further comprising a third substrate transmitting visible light, whereinthe plurality of light emitting pixels are located between the first substrate and the third substrate in the first cross section.

(10) The display device according to (9), further comprising:a fourth substrate including a third surface and a fourth surface on an opposite side of the third surface, the fourth substrate transmitting visible light in a direction perpendicular to the third surface and the fourth surface; anda second internal layer disposed on the third surface, the second internal layer including a second circuit configuration that is a circuit configuration electrically connected to the first electrode and a third circuit configuration that is a circuit configuration electrically connected to the second electrode, whereinthe liquid crystal layer is located between the second substrate and the fourth substrate in the first cross section.

(11) The display device according to any one of (1) to (7), whereinthe first internal layer is located between the plurality of light emitting pixels and the first substrate in the first cross section.

(12) The display device according to (11), whereinthe first internal layer includes a fifth surface that faces and is in contact with the first surface and a sixth surface that is located on an opposite side of the fifth surface, and the second electrode is disposed on the sixth surface.

(13) The display device according to (12), whereinthe first internal layer includes a second circuit configuration that is a circuit configuration electrically connected to the first electrode and a third circuit configuration that is a circuit configuration electrically connected to the second electrode.