DISPLAY DEVICE

A display device includes: a plurality of first colored particles contained in a space between a first substrate and a second substrate; a light-emitting portion having a first light-emitting element provided on the first substrate, and a first-light-emitting-element driving circuit provided on the first substrate and configured to drive the first light-emitting element; a first transparent portion disposed in a direction along a main surface of the first substrate with respect to the light-emitting portion; a first electrode provided in the light-emitting portion; and a second electrode provided in the first transparent portion and being nckudestransparent. The display device is capable of switching between a light-transmitting state of the first transparent portion in which the first electrode attracts the plurality of first colored particles, and a light-blocking state of the first transparent portion in which the second electrode attracts the plurality of first colored particles.

TECHNICAL FIELD

The disclosure relates to a display device.

BACKGROUND ART

See-through display devices have been known in the related art.

CITATION LIST

Patent Literatures

Patent Literature 2: United States Unexamined Patent Application Publication No. 2016/0005353

Patent Literature 3: Korean Unexamined Patent Application Publication No. 10-2014-0098504

SUMMARY

Technical Problem

The known see-through display devices provide dark display. There are three reasons why this problem arises. Firstly, a components within the display device blocks much of light that is about to pass though the display device. Secondly, enhancing the luminance of light that is emitted from a light-emitting portion, by providing a reflective plate and other components in the light-emitting portion is structurally difficult. Thirdly, display visibility degrades due to mixture of light that is emitted by the display device and ambient light around the display device.

Solution to Problem

A display device according to one aspect of the disclosure includes the following: a first substrate and a second substrate facing each other; a plurality of first colored particles contained in a space between the first substrate and the second substrate; a light-emitting portion having a first light-emitting element provided on the first substrate, and a first-light-emitting-element driving circuit provided on the first substrate and configured to drive the first light-emitting element; a first transparent portion disposed in a direction along a main surface of the first substrate with respect to the light-emitting portion; a first electrode provided in the light-emitting portion; and a second electrode provided in the first transparent portion and being transparent, wherein the display device is capable of switching between a light-transmitting state of the first transparent portion in which the first electrode attracts the plurality of first colored particles, and a light-blocking state of the first transparent portion in which the second electrode attracts the plurality of first colored particles.

A display device according to one aspect of the disclosure includes the following: a first substrate and a second substrate facing each other; a plurality of colored particles contained in a space between the first substrate and the second substrate; a polymer-dispersed liquid crystal provided on the first substrate; a driving circuit portion provided on the first substrate, and having a liquid-crystal driving circuit configured to drive the polymer-dispersed liquid crystal; a transparent portion disposed in a direction along a main surface of the first substrate with respect to the driving circuit portion; a first electrode provided in the driving circuit portion; and a second electrode provided in the transparent portion and being transparent, wherein the display device is capable of switching between a light-transmitting state of the transparent portion in which the first electrode attracts the plurality of colored particles, and a light-blocking state of the transparent portion in which the second electrode attracts the plurality of colored particles.

Advantageous Effect of Disclosure

The aspects of the disclosure can achieve a display device with bright display.

DESCRIPTION OF EMBODIMENTS

Embodiments of the disclosure will be described below. It is noted that for convenience in description, components having the same functions as those of previously described components will be denoted by the same signs, and that their description will not be repeated in some cases.

First Embodiment

FIG.1is a schematic sectional view of a configuration of a light-emitting structure101according to a first embodiment of the disclosure. The light-emitting structure101is one of the main constituents of a see-through display device.

The light-emitting structure101includes the following: a first substrate1and a second substrate2facing each other; and a plurality of first colored particles4contained in a space3between the first substrate1and second substrate2. The space3is filled with a transparent insulating liquid for instance.

The light-emitting structure101includes the following: a light-emitting portion7having a first light-emitting element5and a first-light-emitting-element driving circuit6; and a first transparent portion8. The first light-emitting element5is provided on the first substrate1and is preferably, but not limited to, a self-luminous element (e.g., an OLED, a QLED, and a μLED). In other words, a see-through display device provided with the light-emitting structure101is preferably, but not limited to, an OLED display device, a QLED display device, or a μLED display device. The first-light-emitting-element driving circuit6is a circuit provided on the first substrate1, and that drives the first light-emitting element5. The first transparent portion8is disposed in a first direction DI along a main surface of the first substrate1with respect to the light-emitting portion7. The main surface of the first substrate1is a surface of the first substrate1on which various components are mainly mounted, and in the light-emitting structure101, it is a surface of the first substrate1adjacent to the space3. Each of the light-emitting portion7and first transparent portion8includes one end to the other end of the light-emitting structure101in a second direction D2substantially orthogonal to the main surface of the first substrate1. Such a relation where the direction is substantially orthogonal to the main surface of the first substrate1includes a relation where the direction is deemed to be orthogonal to the main surface of the first substrate1, as well as a relation where the direction is exactly orthogonal to the main surface of the first substrate1.

The light-emitting structure101includes a first electrode9provided in the light-emitting portion7, and a second electrode10provided in the first transparent portion8and being transparent. Examples of the material of the first electrode9include an opaque conductive film, such as a chromium film, and a transparent conductive film, such as an indium-tin-oxide (ITO) film. An example of the material of the second electrode10is a transparent conductive film, such as an ITO film. The second electrode10necessarily needs to be transparent, whereas the first electrode9does not necessarily need to be transparent. The first colored particles4have the physical property of being electrically chargeable and can be attracted by each of the driven first electrode9and driven second electrode10.

The light-emitting structure101is capable of switching between a light-transmitting state of the first transparent portion8, and a light-blocking state of the first transparent portion8. The light-transmitting state of the first transparent portion8is a state in which the first electrode9attracts the plurality of first colored particles4. The light-blocking state of the first transparent portion8is a state in which the second electrode10attracts the plurality of first colored particles4.

In the light-transmitting state of the first transparent portion8, the plurality of first colored particles4are not in the first transparent portion8at all or are scarcely in the first transparent portion8; hence, light that is about to pass through the first transparent portion8, which is inherently transparent, is not blocked by the plurality of first colored particles4. That the light-emitting structure101can switch into the light-transmitting state of the first transparent portion8is a basis for the fact that the light-emitting structure101is one of the main constituents of a see-through display device.

In the light-blocking state of the first transparent portion8, the plurality of first colored particles4are all or mostly in the first transparent portion8; hence, light that is about to pass through the first transparent portion8, which is inherently transparent, is blocked by the plurality of first colored particles4and thus does not pass through the first transparent portion8.

The foregoing configuration can minimize components that can block light that is about to pass through the first transparent portion8during the light-transmitting state of the first transparent portion8. Further, the light-emitting portion7does not necessarily need to be transparent in order to bring the first transparent portion8into the light-transmitting state; when the light-emitting portion7does not have to be transparent, the luminance of light emitted by the light-emitting portion7can be enhanced by providing a reflective plate and other components in the light-emitting portion7. Accordingly, a see-through display device capable of bright display can be achieved.

Furthermore, using the plurality of first colored particles4as a material for switching between the light-transmitting state and light-blocking state of the first transparent portion8offers low electric power for moving this material and facilitates displacement control of the material when compared with an instance where a fluid is used as the material, and thus, this usage has the effect of capable of shortening switching time. One reason of why the material's displacement control is easy is that the first colored particles4are easy to move because they are much smaller in size than a fluid, which is a mass.

A pitch P between the first electrode9and second electrode10along the main surface of the first substrate1(i.e., in the first direction D) is preferably 80 μm or smaller and is more desirably 50 μm or smaller. This enables quick switching between the light-transmitting state and light-blocking state of the first transparent portion8, thereby offering convenience in view of display contrast and high-speed responsibility in the light-emitting structure101. It is noted that the pitch P is defined by the distance between a center9cof the first electrode9along the main surface of the first substrate1and a center10cof the second electrode10along the main surface of the first substrate1.

Two of the plurality of first colored particles4move in mutually different directions during the switching between the light-transmitting state of the first transparent portion8and the light-blocking state of the first transparent portion8. This is one of conspicuous differences between the plurality of first colored particles4as being a material for the switching between the light-transmitting state and light-blocking state of the first transparent portion8, and a fluid as being this material.

The light-emitting structure101is produced in the expectation that the light-emitting portion7and the first transparent portion8are to be observed from the first substrate1. In other words, the light-emitting structure101is a bottom-emission type, in which light emitted by the light-emitting portion7is taken out from a side on which the first substrate1is disposed. On the other hand, the light-emitting structure101may be a top-emission type, in which light emitted by the light-emitting portion7is taken out from a side on which the second substrate2is disposed (in other words, this light-emitting structure101is produced in the expectation that the light-emitting portion7and the first transparent portion8are to be observed from the second substrate2).

The light-emitting structure101further includes an insulating layer11covering the first light-emitting element5and first-light-emitting-element driving circuit6, an insulating layer12covering the first electrode9, and an insulating layer13covering the second electrode10and being transparent. Each of the insulating layers11and12may or may not be transparent.

FIG.2illustrates an example circuit configuration in the light-emitting structure101including the first light-emitting element5, the first-light-emitting-element driving circuit6, the first electrode9, and a first-electrode driving circuit14. The first-electrode driving circuit14drives the first electrode9and is provided in the light-emitting structure101.

Herein, the first light-emitting element5is described as being a self-luminous element. The first light-emitting element5has a cathode grounded. The first light-emitting element5has an anode connected to a power supply line, not shown, via a driving transistor15. The driving transistor15has a gate connected to a signal line17via a writing transistor16. The writing transistor16has a gate connected to a gate line18. A capacitor19is connected between the driving transistor15and the writing transistor16. The first-light-emitting-element driving circuit6has the driving transistor15, the writing transistor16, and the capacitor19.

The first electrode9is connected to a signal line21via a transistor20. The transistor20has a gate connected to a gate line22. The first-electrode driving circuit14has the transistor20. In accordance with combination of the ON-OFF control of the transistor20based on the potential of the gate line22, and the potential of the signal line21, the first-electrode driving circuit14can control whether the first electrode9attracts the plurality of first colored particles4. For instance, when the potential of the first electrode9is positive, the first-electrode driving circuit14can control the first electrode9to attract the plurality of first colored particles4.

FIG.3is a plan view of an example configuration of the light-emitting structure101. It is noted that the side-to-side direction in the individual plan views corresponds to the first direction D1(seeFIG.1), a direction perpendicular to their drawing sheets corresponds to the second direction D2(seeFIG.1).FIG.4(a)is a sectional view taken along line A-A inFIG.3. andFIG.4(b)is a sectional view taken along line B-B inFIG.3. The individual plan views illustrating an example configuration of light-emitting structures are views in the second direction D2(seeFIG.1), which is substantially orthogonal to the main surface of the first substrate1.FIG.4(a)andFIG.4(b)illustrate an example configuration of the first substrate1and individual components mounted thereon.

The second electrode10has a rectangular shape. The first electrode9is provided in the form of a stripe on both sides of the second electrode10, two for each side. The first light-emitting element5overlaps the first electrode9. InFIG.3, component No.23denotes a gate bus line, and component No.24denotes a TFT.

As illustrated inFIG.4(a)andFIG.4(b), a base material25, an insulating layer26, the first electrode9and second electrode10, and an insulating layer27are stacked in the stated order. The insulating layers26and27are both transparent. The insulating layer26has a through-hole28, via which the second electrode10and a TFT29are connected together. The first light-emitting element5has an anode5aconnected to a TFT24, an electroluminescence layer5b,and a cathode5c.The electroluminescence layer5boverlaps the anode5aand the TFT24. InFIG.4(a)andFIG.4(b), component No.30denotes a source bus line, and component No.31denotes a source bus line for the second electrode10. The base material25with the TFTs24and29and other components formed thereon corresponds to the first substrate1.

For the pitch P to measure 50 μm or smaller, the driving circuits and a light-emitting circuit need to be long and narrowly formed perpendicularly to the first light-emitting element5. Accordingly, it is desirable to form the first electrode9and first-electrode driving circuit14(seeFIG.2) in a pair for each of RGB pixels. This can enhance transmittance during single-color display.

The TFT29is typically provided on the first substrate1, as illustrated inFIG.4(a)andFIG.4(b). On the other hand, no TFT is preferably formed on the second substrate2. This can reduce the cost for the second substrate2.

FIG.5is a plan view of second electrodes10aand10b,which are modifications of the second electrode10. The plan view inFIG.5is a view in the second direction D2(seeFIG.1), which is substantially orthogonal to the main surface of the first substrate1. Like the second electrodes10aand10b,the second electrode10may be a fishbone electrode. To be specific, the shape of each of the second electrodes10aand10bviewed in the second direction D2includes a trunk32and branches33branched from the trunk32. Each of the second electrodes10aand10bis provided with a plurality of branches33on both sides extending from the center, the trunk32. The branches33of the second electrode10ain the second direction D2are rectangular, and the branches33of the second electrode10bin the second direction D2are triangular. This enables the plurality of first colored particles4to be uniformly dispersed on the basis of the mechanism disclosed in the following document. The second electrode10aor10bcan be used instead of the second electrode10not only in the light-emitting structure101, but also in all light-emitting structures.

Second Embodiment

FIG.6is a schematic sectional view of a configuration of a light-emitting structure102according to a second embodiment of the disclosure. Differences between the light-emitting structure102and the light-emitting structure101will be mainly described.

The light-emitting structure102is structured such that the light-emitting portion7has a protrusion34protruding in the second direction D2, which is substantially orthogonal to the main surface of the first substrate1, in the space3. The protrusion34, which functions as a partition, can prevent the plurality of first colored particles4from moving opposite the first transparent portion8with respect to the light-emitting portion7. This enables the plurality of first colored particles4to be dispersed with a suitable distribution in the space3within the light-emitting structure102.

The protrusion34includes at least a part of the first electrode9. Forming the protrusion34by the use of at least a part of the first electrode9can achieve the light-emitting structure102with a small number of components.

The light-emitting structure102includes the following: a plurality of second colored particles35contained in the space3; a second transparent portion36disposed opposite the first transparent portion8with respect to the light-emitting portion7; and a third electrode37provided in the light-emitting portion7. The second colored particles35, the second transparent portion36, and the third electrode37respectively have a configuration similar to that of the first colored particles4, a configuration similar to that of the first transparent portion8, and a configuration similar to that of the first electrode9. Moreover, the light-emitting structure102is capable of switching into a light-transmitting state of the second transparent portion36in which the third electrode37attracts the plurality of second colored particles35.

An example circuit configuration in the light-emitting structure102including the first light-emitting element5, the first light-emitting-element driving circuit6, the first electrode9, and the first-electrode driving circuit14is the same as that illustrated inFIG.2. The light-emitting structure102is structured such that the first light-emitting element5and the first-light-emitting-element driving circuit6are provided on the first substrate1, and that the first electrode9and the first-electrode driving circuit14are provided on the second substrate2.

FIG.7is a schematic sectional view of a configuration of a light-emitting structure102′ according to the second embodiment of the disclosure. Differences between the light-emitting structure102′ and the light-emitting structure102will be mainly described.

The light-emitting structure102′ is structured, when compared with the light-emitting structure102, such that the second substrate2per se is turned upside down, and that the positional relationship between the first substrate1and second substrate2is inverted.

FIG.8is a plan view of an example configuration of each of the light-emitting structures102and102′.FIG.9(a)is a sectional view taken along line A-A inFIG.8and corresponds to the light-emitting structure102, andFIG.9(b)is a sectional view taken along line B-B inFIG.8and corresponds to the light-emitting structure102.FIG.10(a)is a sectional view taken along line A-A inFIG.8and corresponds to the light-emitting structure102′, andFIG.10(b)is a sectional view taken along line B-B inFIG.8and corresponds to the light-emitting structure102′.FIG.9(a),FIG.9(b),FIG.10(a), andFIG.10(b)each illustrate an example configuration of the first substrate1and second substrate2as well as the individual components mounted thereon.

The first electrode9and third electrode37are provided in the form of a strip on both sides of the second electrode10, one for each side. Like the light-emitting structure101, the light-emitting structures102and102′ are each also structured such that the second electrode10and the TFT29are connected together via the through-hole28. The second electrode10, the through-hole28, and the TFT29are formed on and in a base material39and an insulating layer40. The base material39with the TFT29and other components formed thereon corresponds to the second substrate2.

The light-emitting structures102and102′ are each structured such that a space38between the first electrode9and the third electrode37is formed in the second direction D2, which is substantially orthogonal to the main surface of the first substrate1with respect to the first light-emitting element5. This can prevent light emitted by the first light-emitting element5from passing through the first electrode9and/or the third electrode37and can thus reduce a loss of the light within the light-emitting structure. Resin, such as acrylic, for instance may be provided in the space38.

The first substrate1preferably has a thickness of 20 μm or smaller and more desirably has a thickness of 10 μm or smaller. This can reduce parallax in the light-emitting structure102′ that results from the thickness of the first substrate1. An example method of setting the thickness of the first substrate 1 at 20 μm or smaller is a laser liftoff (LLO) process.

Third Embodiment

FIG.11is a schematic sectional view of a configuration of a light-emitting structure103according to a third embodiment of the disclosure. Differences between the light-emitting structure103and the light-emitting structure102will be mainly described.

The light-emitting structure103is structured such that the first-electrode driving circuit14(seeFIG.2), which drives the first electrode9, is provided on the first substrate1. An example circuit configuration in the light-emitting structure103including the first light-emitting element5, the first-light-emitting-element driving circuit6, the first electrode9, and the first-electrode driving circuit14is the same as that illustrated inFIG.2. The light-emitting structure103is structured such that the first light-emitting element5, the first-light-emitting-element driving circuit6, the first electrode9, and the first-electrode driving circuit14are all provided on the first substrate1. The absence of TFTs on the second substrate2can reduce the cost for the second substrate2.

FIG.12is a plan view of an example configuration of the light-emitting structure103.FIG.13(a)is a sectional view taken along line A-A inFIG.12, andFIG.13(b)is a sectional view taken along line B-B inFIG.12.FIG.13(a)andFIG.13(b)illustrate an example configuration of the first substrate1and the individual components mounted thereon.

Like the light-emitting structure102, the light-emitting structure103is also structured such that the second electrode10and the TFT29are connected together via the through-hole28. The TFT29is formed on the base material25, and the second electrode10and the through-hole28are formed on and in the insulating layer26.

Fourth Embodiment

FIG.14is a schematic sectional view of a configuration of a light-emitting structure104according to a fourth embodiment of the disclosure. Differences between the light-emitting structure104and the light-emitting structure102′ will be mainly described.

The light-emitting structure104is structured such that the light-emitting portion7has an optical member41for enhancing the contrast of light emitted by the first light-emitting element5, in addition to the first light-emitting element5and first-light-emitting-element driving circuit6. Examples of the optical member41include a layer having a function similar to that of a polarizing plate (hereinafter, also referred to as a polarizing layer), a layer having a function similar to that of a λ/4 wavelength plate (hereinafter, also referred to as a λ/4 wavelength layer), and a color filter. This can enhance the contrast of light emitted by the first light-emitting element5.

An example circuit configuration in the light-emitting structure104including the first light-emitting element5, the first-light-emitting-element driving circuit6, the first electrode9, and the first-electrode driving circuit14is the same as that illustrated inFIG.2. The light-emitting structure104is structured such that the first light-emitting element5and the first-light-emitting-element driving circuit6are provided on the first substrate1, and the first electrode9and the first-electrode driving circuit14are provided on the second substrate2.

FIG.15is a plan view of an example configuration of the light-emitting structure104.FIG.16(a)is a sectional view taken along line A-A inFIG.15, andFIG.16(b)is a sectional view taken along line B-B inFIG.15.FIG.16(a)andFIG.16(b)illustrate an example configuration of the first substrate1and second substrate2as well as the individual components mounted thereon.

Like the light-emitting structure102′, the light-emitting structure104is also structured such that the second electrode10and the TFT29are connected together via the through-hole28. The second electrode10, the through-hole28, and the TFT29are formed on and in the base material39and the insulating layer40.

The optical member41inFIG.16(a)andFIG.16(b)has a polarizing layer42and a24wavelength layer43. The optical member41is provided immediately above the first light-emitting element5(to be specific, in the second direction D2, which is substantially orthogonal to the main surface of the first substrate1) on the insulating layer26. The optical member41is structured such that the λ/4 wavelength layer43and the polarizing layer42are stacked in the stated order on the insulating layer26. The optical member41may have a color filter having a property corresponding to the color of light that is emitted by the first light-emitting element5.

The first substrate1preferably has a thickness of 20 μm or smaller and more desirably has a thickness of 10 μm or smaller. This can reduce parallax in the light-emitting structure104that results from the thickness of the first substrate1. An example method of setting the thickness of the first substrate 1 at 20 μm or smaller is a laser liftoff process.

Fifth Embodiment

FIG.17is a schematic sectional view of a configuration of a light-emitting structure105according to a fifth embodiment of the disclosure. Differences between the light-emitting structure105and the light-emitting structure103will be mainly described.

The light-emitting structure105is structured such that the light-emitting portion7has a second light-emitting element44and a second-light-emitting-element driving circuit45provided on the second substrate2. The second-light-emitting-element driving circuit45is a circuit that drives the second light-emitting element44. The second light-emitting element44and the second-light-emitting-element driving circuit45respectively have a configuration similar to that of the first light-emitting element5, and a configuration similar to that of the first-light-emitting-element driving circuit6. A light-blocking layer may be inserted between the first light-emitting element5and the second light-emitting element44. The light-emitting structure105enables display of a display pattern that is different between both sides of a display device. A possible example is right-and-left reverse display on the front and the back.

An example circuit configuration in the light-emitting structure105including the first light-emitting element5, the first-light-emitting-element driving circuit6, the first electrode9, and the first-electrode driving circuit14is the same as that illustrated inFIG.2. The light-emitting structure105is structured such that the first light-emitting element5, the first-light-emitting-element driving circuit6, the first electrode9, and the first-electrode driving circuit14are all provided on the first substrate1.

An example circuit configuration of the second light-emitting element44and second-light-emitting-element driving circuit45in the light-emitting structure105is similar to that of the first light-emitting element5and first-light-emitting-element driving circuit6illustrated inFIG.2. The light-emitting structure105is structured such that the second light-emitting element44and the second-light-emitting-element driving circuit45are provided on the second substrate2.

FIG.18is a plan view of an example configuration of the light-emitting structure105.FIG.19(a)is a sectional view taken along line A-A inFIG.18, andFIG.19(b)is a sectional view taken along line B-B inFIG.18.FIG.19(a)andFIG.19(b)illustrate an example configuration of the first substrate1and second substrate2as well as the individual components mounted thereon.

Like the light-emitting structure103, the light-emitting structure105is also structured such that the second electrode10and the TFT29are connected together via the through-hole28. The TFT29is formed on the base material25, and the second electrode10and the through-hole28are formed on and in the insulating layer26.

InFIG.19(a)andFIG.19(b), a source bus line46, a gate bus line47, and a TFT48are formed on the base material39. The second light-emitting element44has an anode44aconnected to the TFT48, an electroluminescence layer44b,and a cathode44c.The base material39with the TFT48and other components are formed thereon corresponds to the second substrate2.

The first substrate2preferably has a thickness of 20 μm or smaller and more desirably has a thickness of 10 μm or smaller. This can reduce parallax in the light-emitting structure105that results from the thickness of the second substrate2. An example method of setting the thickness of the second substrate 2 at 20 μm or smaller is a laser liftoff process.

Sixth Embodiment

FIG.20is a schematic sectional view of a configuration of a light-emitting structure106according to a sixth embodiment of the disclosure. Differences between the light-emitting structure106and the light-emitting structure103will be mainly described.

The light-emitting structure106includes the following: the first substrate1and the second substrate2facing each other; and the plurality of first colored particles (colored particles)4contained in the space3between the first substrate1and second substrate2. The space3is filled with a transparent insulating liquid for instance.

The light-emitting structure106includes a polymer-dispersed liquid crystal49, a driving circuit portion51having a liquid-crystal driving circuit50, and a transparent portion52. The polymer-dispersed liquid crystal49is provided on the first substrate1. The liquid-crystal driving circuit50is a circuit provided on the first substrate1, and that drives the polymer-dispersed liquid crystal49. The transparent portion52is disposed in the first direction D1, which is along the main surface of the first substrate1with respect to the driving circuit portion51. Each of the driving circuit portion51and transparent portion52includes one end to the other end of the light-emitting structure106in the second direction D2, which is substantially orthogonal to the main surface of the first substrate1.

The light-emitting structure106includes the first electrode9provided in the driving circuit portion51, and the transparent second electrode10provided in the transparent portion52.

The light-emitting structure106is capable of switching between a light-transmitting state of the transparent portion52and a light-blocking state of the transparent portion52. The light-transmitting state of the transparent portion52is a state in which the first electrode9attracts the plurality of first colored particles4and is equivalent to the foregoing light-transmitting state of the first transparent portion8with the first transparent portion8replaced with the transparent portion52. The light-blocking state of the transparent portion52is a state in which the second electrode10attracts the plurality of first colored particles4and is equivalent to the foregoing light-blocking state of the first transparent portion8with the first transparent portion8replaced with the transparent portion52.

The foregoing configuration can minimize components that can block light that is about to pass through the transparent portion52during the light-transmitting state of the transparent portion52. Accordingly, a see-through display device capable of bright display can be achieved.

Furthermore, using the plurality of first colored particles4as a material for switching between the light-transmitting state and light-blocking state of the transparent portion52offers low electric power for moving this material and facilitates displacement control of the material when compared with an instance where a fluid is used as the material, and thus, this usage has the effect of capable of shortening switching time.

The light-emitting structure106emits light by the use of the scattering of the polymer-dispersed liquid crystal49. Light is introduced through light-guiding from an end face, and irradiation from an oblique front face. The polymer-dispersed liquid crystal49does not generate heat; hence, using the light-emitting structure106can achieve a display device with less display non-uniformity. The insulating layer11covers the first-electrode driving circuit14.

FIG.21illustrates an example circuit configuration in the light-emitting structure106including the polymer-dispersed liquid crystal49, the liquid-crystal driving circuit50, the first electrode9, and the first-electrode driving circuit14.

The polymer-dispersed liquid crystal49is connected to a signal line54via a transistor53. The transistor53has a gate connected to a gate line55. The liquid-crystal driving circuit50has the transistor53.

FIG.22is a plan view of an example configuration of the light-emitting structure106.FIG.23(a)is a sectional view taken along line A-A inFIG.22, andFIG.23(b)is a sectional view taken along line B-B inFIG.22.FIG.23(a)andFIG.23(b)illustrate an example configuration of the first substrate1and second substrate2as well as the individual components mounted thereon.

Like the light-emitting structure103, the light-emitting structure106is also structured such that the second electrode10and the TFT29are connected together via the through-hole28. The second electrode10, the through-hole28, and the TFT29are formed on and in the base material39and the insulating layer40.

As illustrated inFIG.23(a), a low-refractive-index layer56, the base material25made of ITO for instance, a common electrode57, the polymer-dispersed liquid crystal49, a driving electrode58, an insulating layer59, a TFT60, a source bus line61, a light-guiding mirror aperture62, and a base material63are stacked in the stated order. The driving electrode58is connected to the TFT60via a through-hole64formed in the insulating layer59.

The base material25preferably has a thickness of 20 μm or smaller and more desirably has a thickness of 10 μm or smaller. This can reduce parallax in the light-emitting structure106that results from the thickness of the base material25. An example method of setting the thickness of the base material25at 20 μm or smaller is a laser liftoff process.

Seventh Embodiment

FIG.24is a schematic plan view of a configuration of a main part107of a light-emitting structure according to a seventh embodiment of the disclosure. InFIG.24, components not directly illustrated inFIG.24will be denoted as appropriate by signs in the other drawings.

In the main part107, the space3is divided into a plurality of (herein, four) regions3a,3b,3c,and3dby at least one (herein, four) partition member65a,65b,65c,or65din a third direction D3. The third direction D3is a direction along the main surface of the first substrate1and is a direction perpendicular to the first direction D1(i.e., a direction in which the light-emitting portion7and the first transparent portion8are arranged, or a direction in which the driving circuit portion51and the transparent portion52are arranged). Moreover, the plurality of first colored particles4are contained dispersedly in the plurality of regions3a,3b,3c,and3d.It is noted that the third direction D3corresponds to the direction of an electric field in the main part107. This can reduce imbalance in the distribution of the plurality of first colored particles4in the third direction D3. When the second electrode10is the second electrode10aor10b(seeFIG.5) including the trunk32and branches33, the interval between two of the partition members65a,65b,65c,and65dadjacent to each other may be an integral multiple of the interval between two branches33adjacent to each other. Further, the height of each of the partition members65a,65b,65c,and65dis desirably as large as the distance between the first substrate1and second substrate2.

The foregoing characteristic features of the main part107may be further applied also to the aforementioned light-emitting structures other than the light-emitting structure101.

Others

The first electrode9, and a plurality of electrodes including the third electrode37when a light-emitting structure is provided with the third electrode37, may be driven collectively or individually. When provided for each of many pixels in a display device, these many first electrodes9may be driven independently of each other in the unit of one or more pixels (e.g., for each pixel) in the display device. This holds true for the third electrode37.

The foregoing light-emitting structures are applicable to a display device.FIG.25illustrates an example of the display device. A display device100includes a red light-emitting portion7r,a green light-emitting portion7g,and a blue light-emitting portion7b.Forming the individual red light-emitting portion7r,green light-emitting portion7g,and blue light-emitting portion7bby the use of a single light-emitting portion7or a single polymer-dispersed liquid crystal49can achieve the display device100. An example of the light-emitting portion7that constitutes any one of the red light-emitting portion7r,green light-emitting portion7g,and blue light-emitting portion7bis a light-emitting portion having a self-luminous element (e.g., an OLED, a QLED, and a μLED) as the first light-emitting element5.

Summary

A display device according to a first aspect of the disclosure includes the following: a first substrate and a second substrate facing each other; a plurality of first colored particles contained in a space between the first substrate and the second substrate; a light-emitting portion having a first light-emitting element provided on the first substrate, and a first-light-emitting-element driving circuit provided on the first substrate and configured to drive the first light-emitting element; a first transparent portion disposed in a direction along a main surface of the first substrate with respect to the light-emitting portion; a first electrode provided in the light-emitting portion; and a second electrode provided in the first transparent portion and being transparent, wherein the display device is capable of switching between a light-transmitting state of the first transparent portion in which the first electrode attracts the plurality of first colored particles, and a light-blocking state of the first transparent portion in which the second electrode attracts the plurality of first colored particles.

The display device according to a second aspect of the disclosure is structured, in the first aspect, such that a pitch between the first electrode and the second electrode along the main surface of the first substrate is 80 μm or smaller.

The display device according to a third aspect of the disclosure is structured, in the first or second aspect, such that two of the plurality of first colored particles move in mutually different directions during the switching between the light-transmitting state of the first transparent portion and the light-blocking state of the first transparent portion.

The display device according to a fourth aspect of the disclosure is structured, in any one of the first to third aspects, such that the light-emitting portion has a protrusion protruding in a direction substantially orthogonal to the main surface of the first substrate in the space.

The display device according to a fifth aspect of the disclosure is structured, in the fourth aspect, such that the protrusion includes at least a part of the first electrode.

The display device according to a sixth aspect of the disclosure includes the following in any one of the first to fifth aspects: a plurality of second colored particles contained in the space; a second transparent portion disposed opposite the first transparent portion with respect to the light-emitting portion; and a third electrode provided in the light-emitting portion, wherein the display device is capable of switching into a light-transmitting state of the second transparent portion in which the third electrode attracts the plurality of second colored particles.

The display device according to a seventh aspect of the disclosure is structured, in the sixth aspect, such that a space between the first electrode and the third electrode is formed in a direction substantially orthogonal to the main surface of the first substrate with respect to the first light-emitting element.

The display device according to an eighth aspect of the disclosure is structured, in any one of the fourth to seventh aspects, such that the first substrate has a thickness of 20 μm or smaller.

The display device according to a ninth aspect of the disclosure is structured, in any one of the first to eighth aspects, such that no TFT is formed on the second substrate.

The display device according to a tenth aspect of the disclosure is structured, in any one of the first to ninth aspects, such that the light-emitting portion has an optical member for enhancing a contrast of light emitted by the first light-emitting element.

The display device according to an eleventh aspect of the disclosure is structured, in any one of the first to tenth aspects, such that the light-emitting portion has a second light-emitting element provided on the second substrate.

The display device according to a twelfth aspect of the disclosure is structured, in any one of the first to eleventh aspects, such that the first light-emitting element is a self-luminous element.

The display device according to a thirteenth aspect of the disclosure is structured, in any one of the first to twelfth aspects, such that a shape of the second electrode viewed in a direction substantially orthogonal to the main surface of the first substrate includes a trunk, and a branch branched from the trunk.

The display device according to a fourteenth aspect of the disclosure is structured, in any one of the first to thirteenth aspects, such that the space is divided into a plurality of regions by at least one partition member in the direction along the main surface of the first substrate, and the plurality of first colored particles are contained dispersedly in the plurality of regions.

A display device according to a fifteenth aspect of the disclosure includes the following: a first substrate and a second substrate facing each other; a plurality of colored particles contained in a space between the first substrate and the second substrate; a polymer-dispersed liquid crystal provided on the first substrate; a driving circuit portion provided on the first substrate, and having a liquid-crystal driving circuit configured to drive the polymer-dispersed liquid crystal; a transparent portion disposed in a direction along a main surface of the first substrate with respect to the driving circuit portion; a first electrode provided in the driving circuit portion; and a second electrode provided in the transparent portion and being transparent, wherein the display device is capable of switching between a light-transmitting state of the transparent portion in which the first electrode attracts the plurality of colored particles, and a light-blocking state of the transparent portion in which the second electrode attracts the plurality of colored particles.

The display device according to a sixteenth aspect of the disclosure is structured, in the fifteenth aspect, such that the space is divided into a plurality of regions by at least one partition member in the direction along the main surface of the first substrate, and the plurality of colored particles are contained dispersedly in the plurality of regions.

The disclosure is not limited to the foregoing embodiment. Various modifications can be devised within the scope of the claims. An embodiment that is obtained in combination as appropriate with the technical means disclosed in the respective embodiments is also included in the technical scope of the disclosure. Furthermore, combining the technical means disclosed in the respective embodiments can form a new technical feature.