Display and electronic unit

There are provided a display and an electronic unit capable of enhancing visibility. The display includes: a plurality of pixels each including a light-emission device, and having a light-transmission region in at least a part thereof; and one or more transmittance control devices capable of controlling a transmittance of incident light.

CROSS REFERENCES TO RELATED APPLICATIONS

The present application claims priority to Japanese Priority Patent Application JP 2011-136929 filed in the Japan Patent Office on Jun. 21, 2011, the entire content of which is hereby incorporated by reference.

BACKGROUND

The disclosure relates to a display having a light-emission device, and an electronic unit provided with such a display.

In recent years, AR (Augmented Reality) technology has been studied actively. The AR technology is characterized by presenting a synthesized virtual object as additional information (electronic information) for (a part of) a real environment. The AR technology is a contrast to virtual reality. In the AR technology, explanation or related information about a specific object in a real environment is included and presented in proximity to the actual object targeted for the explanation or related information. Therefore, a technique of acquiring information on a real environment such as a position where a user observes an object, which is a technique used to realize AR, is considered to be important as a basic technique.

Meanwhile, in recent years, electronic units with relatively large displays, which are called a smartphone or a tablet, have been commercialized. After being taken by an image pickup device (a camera) mounted on such an electronic unit, an image of a real environment is displayed on the display, and a virtual object is superimposed and displayed on a screen of the display. AR is thus readily realized with these electronic units.

One of examples of a technique that enhances reality (presence) in AR is a display (with pixels each having a light-transmission region) whose back-surface side is visually recognizable (a so-called transparent display). In this transparent display, it is possible to recognize an actual real environment visually through the display, instead of an image taken by an image pickup device like the one described above. For this reason, it is possible to realize AR with higher presence, by displaying electronic information about the real environment on the display.

One of examples of such a transparent display is an organic electroluminescence (EL) display using the following transparent materials (light transmissive materials) as a semiconductor material and a wiring material (see, for example, “Al and Sn-doped Zinc Indium Oxide Thin film Transistors for AMOLED Back-Plane”, SID2009 proceedings, p. 280-283, by Doo-Hee Cho et al.). In this organic EL display, for instance, an oxide semiconductor (for example, Zn (zinc)-In (indium)-O (oxygen) to which aluminum (Al) and tin (Sn)) are added) is used as the semiconductor material, in a thin-film transistor (TFT). As the wiring material, ITO (Indium Tin Oxide) is used.

SUMMARY

Here, when such a transparent display is used as the display for AR as described above, improvement of visibility is desired so as to enhance the presence further.

It is desirable to provide a display and an electronic unit capable of enhancing visibility.

According to an embodiment of the disclosure, there is provided a display including: a plurality of pixels each including a light-emission device, and having a light-transmission region in at least a part thereof; and one or more transmittance control devices capable of controlling a transmittance of incident light.

According to an embodiment of the disclosure, there is provided an electronic unit including a display, the display including: a plurality of pixels each including a light-emission device, and having a light-transmission region in at least a part thereof; and one or more transmittance control devices capable of controlling a transmittance of incident light.

In the display and the electronic unit according to the above-described embodiments of the disclosure, the transmittance control device capable of controlling the transmittance of the incident light is provided. Therefore, there is realized control of the light transmittance to be appropriate to a light emission state (at the time of light emission or at the time of non-light emission) in the light-emission device in the pixel having the light-transmission region.

According to the display and the electronic unit in the above-described embodiments of the disclosure, the transmittance control device capable of controlling the transmittance of the incident light is provided. Therefore, controlling the light-transmittance to be appropriate to the light emission state in the light-emission device in the pixel having the light-transmission region is realized. Hence, visibility in the display with the pixels each having the light-transmission region is enhanced.

DETAILED DESCRIPTION

Embodiments of the disclosure will be described below in detail with reference to the drawings. It is to be noted that the description will be provided in the following order.1. First embodiment (an example using an electrochromic device that performs transmission and absorption of light)2. Second embodiment (an example using an electrochromic device that performs transmission and reflection of light)3. Third embodiment (an example using an electrowetting device)4. Modifications common to the first to third embodimentsModification 1 (an example in which a transmittance control device is disposed for every horizontal line)Modification 2 (an example in which a transmittance control device is disposed for every subpixel (pixel))Modifications 3 and 4 (examples in each of which a transmittance control device is disposed side by side with each subpixel)5. Module and application examples6. Other modifications

First Embodiment

FIG. 1is a block diagram illustrating a schematic configuration of a display (a display1) according to a first embodiment of the disclosure. This display1includes a display panel10(a display section) and a drive circuit20(a drive section). In the display1, at least a part of a pixel is a light-transmission region (a transparent region), thereby allowing visual recognition of a back-surface side (the display functions as a so-called transparent display), as will be described later.

The display panel10includes a pixel array section13with a plurality of pixels11arranged in a matrix, and displays an image by performing active matrix driving based on an image signal20A and a synchronization signal20B inputted from outside. Each of the pixels11is configured to include a plurality of subpixels corresponding to a plurality of (here, three) colors (i.e., subpixels for the respective colors), as will be described later.

The pixel array section13includes a plurality of scanning lines WSL arranged in rows, a plurality of signal lines DTL arranged in columns, and a plurality of power lines DSL arranged in rows along the scanning lines WSL. One end of each of the scanning line WSL, the signal line DTL, and the power line DSL is connected to the drive circuit20which will be described later. Further, each of the pixels11arranged in rows and columns (arranged in the matrix) is disposed corresponding to an intersection of each of the scanning lines WSL and each of the signal lines DTL. It is to be noted that, inFIG. 1, a plurality of signal lines DTLr, DTLg, and DTLb corresponding to a plurality of colors (i.e., signal lines for the respective colors) which will be described below are simplified and illustrated as each one of the signal lines DTL.

Further, on almost the entire surface of the pixel array section13, a transmittance control device15capable of controlling a transmittance of incident light (a light transmittance) is disposed. In other words, the only one transmittance control device15common to all the pixels11within the pixel array section13is provided here. To be more specific, the resolution of the transmittance control device15is lower than the resolution of the pixels11(i.e. the transmittance control device15is disposed for every plurality of the pixels11(here, for all the pixels11)). Furthermore, in the present embodiment, the transmittance control device15is disposed (arranged like a layer) to face each of the pixels11(each of organic EL devices12which will be described later). Here, the transmittance control device15is capable of switching operation between incident-light transmission operation and incident-light absorption operation. Specifically, the transmittance control device15is allowed to switch the operation between the transmission operation and the absorption operation, at the time of each of light emission and non-light emission (extinction) of the organic EL device12which will be described later. Here, the transmittance control device15is an electrochromic (EC) device which will be described later.

FIG. 2schematically illustrates an example of an internal configuration (a subpixel configuration) of each of the pixels11, in a plan view.

Each of the pixels11is configured to include trichromatic subpixels11R,11G, and11B of red (R), green (G), and blue (B). In other words, each of the pixels11has a subpixel configuration including the three subpixels11R,11G, and11B corresponding to three colors of R, G, and B. Here, the three subpixels11R,11G, and11B are arranged in a line along a horizontal-line direction (an H-line direction) in each of the pixels11. However, the arrangement configuration of the subpixels11R,11G, and11B in each of the pixels11is not limited to this example, and may be other arrangement configuration.

It is to be noted that although not illustrated inFIG. 2, the signal line DTLr, the scanning line WSL, and the power line DSL are connected to the subpixel11R. Similarly, the signal line DTLb, the scanning line WSL, and the power line DSL are connected to the subpixel11B. Also, the signal line DTLg, the scanning line WSL, and the power line DSL are connected to the subpixel11G. In other words, the signal lines DTLr, DTLg, and DTLb corresponding to the respective colors are connected to the subpixels11R,11G, and11B, respectively, whereas each of the scanning line WSL and the power line DSL is connected to the subpixels11R,11G, and11B as a common line.

FIG. 3illustrates an example of an internal configuration (a circuit configuration) of each of the subpixels11R,11G, and11B. In each of the subpixels11R,11G, and11B, the organic EL device12(a light-emission device) and a pixel circuit14are provided.

The pixel circuit14is configured using a write transistor Tr1(for sampling), a drive transistor Tr2, and a retention capacitive element Cs. In other words, this pixel circuit14has a circuit configuration of a so-called “2Tr1C”. Here, each of the write transistor Tr1and the drive transistor Tr2is formed of, for example, a TFT (Thin Film Transistor) of an n-channel MOS (Metal Oxide Semiconductor) type. It is to be noted that the type of the TFT is not limited in particular, and may be, for example, an inverted staggered structure (a so-called bottom gate type), or a staggered structure (a so-called top gate type).

Of the write transistor Tr1in the pixel circuit14, a gate is connected to the scanning line WSL, a drain is connected to the signal line DTL (DTLr, DTLg, and DTLb), and a source is connected to a gate of the drive transistor Tr2and a first end of the retention capacitive element Cs. Of the drive transistor Tr2, a drain is connected to the power line DSL, and a source is connected to a second end of the retention capacitive element Cs and an anode of the organic EL device12. A cathode of the organic EL device12is set to, for example, a fixed potential VSS (e.g., a ground potential) on a wire extending along a horizontal-line direction.

Here, in each of the subpixels11R,11G, and11B of the present embodiment, at least a part thereof is the light-transmission region (a region indicated with a broken line inFIG. 4B), as illustrated in, for example,FIGS. 4A and 4B. Specifically, as will be described later in detail, in the pixel circuit14within each of the subpixels11R,11G, and11B, at least a part of each of a semiconductor layer and an electrode layer as well as a wiring layer of a drive device (the write transistor Tr1, the drive transistor Tr2, and the retention capacitive element Cs) is configured using a light transmissive material (a transparent material). This allows the subpixels11R,11G, and11B to exhibit a high aperture ratio of about 77%, for example. In contrast, each of subpixels101R,101G, and101B according to a comparative example 1 illustrated inFIG. 4C(an example of related art, in which silicon (Si) which is a non-transparent material is used for a semiconductor layer, and non-transparence metal is used for an electrode layer and a wiring layer, of a drive device like the one described above) has a low aperture ratio of about 36%, for example. In other words, in the subpixels11R,11G, and11B configured using the transparent material in at least the part thereof, the higher aperture ratio is realized, and visual recognition of the back-surface side is allowed, as compared with the subpixels101R,101G, and101B configured using only the non-transparent materials.

FIG. 5schematically illustrates a cross-sectional configuration example of the display panel10. The display panel10includes a TFT substrate4, a inter-pixel insulating film51, an organic layer52, an electrode layer53, a flattening film54, and the transmittance control device15, in this order from a front-face (surface) side to a rear-face (back-surface) side of the display1.

The TFT substrate4includes a substrate41, an electrode layer421and a gate electrode422as well as a wiring layer423A, a metal layer423B, a gate insulator43, an oxide semiconductor layer44, a protective layer46, an electrode layer451as well as a wiring layer452, an electrode layer471as well as a metal layer472, and a protective layer48, in this order from the front-face side to the rear-face side from of the display1. The TFT substrate4is configured by forming elements including the drive device (the write transistor Tr1, the drive transistor Tr2, and the retention capacitive element Cs) described above.

The substrate41has optical transparency, and is made of, for example, a glass material or a resin material. It is to be noted that on this substrate41, a buffer layer made of, for example, silicon oxide (SiO2) or silicon nitride (SiN) may be provided beforehand to prevent entrance of contaminants from the substrate41to the drive device.

The electrode layer421is a first electrode of the retention capacitive element Cs. The gate electrode422is, here, a gate electrode of the write transistor Tr1. The wiring layer423A forms wiring and the like in the pixel circuit14. Each of the electrode layer421, the gate electrode422, and the wiring layer423A is formed on the substrate41, and made of, for example, a light transmissive material such as transparent oxide semiconductors including ITO, IZO (Indium Zinc Oxide), and AZO (Aluminum Zinc Oxide), and transparent carbon. The electrode layer421, the gate electrode422, and the wiring layer423A each made of such a material is formed by sputtering, for example.

The metal layer423B is formed to be electrically connected on the wiring layer423A, and is provided to lower resistance (wiring resistance) of the entire wiring including the signal lines DTL, for example. For the metal layer423B, there may be used a layered structure including a metal layer (molybdenum (Mo), titanium (Ti), manganese (Mn) etc.) on the wiring layer423A side and a metal layer (aluminum (Al), copper (Cu) etc.) thereon, for example.

The gate insulator43is provided to cover the electrode layer421, the gate electrode422, the wiring layer423A, and the metal layer423B, and made of, for example, SiO2formed by PECVD (Plasma Enhanced Chemical Vapor Deposition). However, as a substitute therefor, for instance, any of Si3N4, aluminum oxide (Al2O3), and a laminated film made thereof may be used.

The oxide semiconductor layer44is made of, for example, a complex oxide of elements such as In, Ga (gallium), Zn, and Sn, and formed using DC sputtering, RF sputtering, or the like, for example. In particular, it is desirable to use the DC sputtering, in view of sedimentation rate.

The protective layer46is provided on a channel region including the write transistor Tr1and the like in the oxide semiconductor layer44, and functions as a channel protective film. This protective layer46is made of SiO or the like formed by PECVD, for example.

The electrode layer451form electrodes including a second electrode in the retention capacitive element Cs, a source/drain electrode in the write transistor Tr1, and an anode electrode (a pixel electrode) in the organic EL device12. The wiring layer452forms wiring and the like in the pixel circuit14. The electrode layer451and the wiring layer452are also made of, for example, a light transmissive material such as the transparent oxide semiconductors and the transparent carbon described above.

The electrode layer471is provided on a source/drain region in the write transistor Tr1of the electrode layer451, and the metal layer472is provided on the wiring layer452. Each of the electrode layer471and the metal layer472is provided to lower electrical resistance of the source/drain electrode and the wiring, and made of, for example, Al or Cu.

The protective layer48is provided to cover the retention capacitive element Cs, the write transistor Tr1, the wiring, and the like, and functions as a so-called passivation film. The protective layer48is made of, for example, a material with a high gas barrier property, such as Al2O3formed by sputtering or ALD (Atomic Layer Deposition), SiO2and Si3N4formed by sputtering or PECVD, and a laminated film made thereof.

The inter-pixel insulating film51is provided to isolate the organic EL devices12of the subpixels11R,11G, and11B from each other, and made of an organic insulating material such as polyimide and acrylic. The inter-pixel insulating film51may be formed using a spin coating method, a slit coating method, a die coating method, or the like.

The organic layer52has a configuration in which, for example, a luminous layer, a hole injection layer, a hole transport layer, an electron injection layer, and an electron transport layer (none of them illustrated) are laminated.

The electrode layer53forms a cathode electrode (a common electrode) in the organic EL device12, and is provided to cover the organic layer52and the inter-pixel insulating film51from above. This electrode layer53is also made of, for example, a light transmissive material such as the transparent oxide semiconductors and the transparent carbon described above, or a light transmissive material made of a thin metallic layer. It is to be noted that this electrode layer53, the organic layer52, and the electrode layer451form the organic EL device12.

The flattening film54is provided to cover the electrode layer53from above, and made of, for example, a material (an organic insulating material such as polyimide and acrylic) similar to that of the inter-pixel insulating film51.

The transmittance control device15includes a transparent electrode151C, an EC material layer152C, a dielectric film153, an EC material layer152A, and a transparent electrode151A, in this order from the front-face side to the rear-face side of the display1. The transmittance control device15configured of an electrochromic (EC) device is formed by having such a layered structure.

Each of the transparent electrodes151C and151A functions as an electrode (a cathode electrode and an anode electrode) of driving the electrochromic device, and is made of, for example, a light transmissive material such as the transparent oxide semiconductors and the transparent carbon described above. It is to be noted that the transparent electrodes151C and151A are each formed like a comb orthogonal to each other, for example.

The EC material layer152C is made of a cathodic electrochromic material (an EC material) such as a tungsten oxide (WO3), a vanadium oxide (V2O5), and a molybdenum oxide (MoO3), and may be formed using an electron-beam evaporation technique, sputtering, or the like.

The EC material layer152A is made of an anodic EC material such as a nickel oxide (NiO), an iridium oxide (IrO), and a cobalt oxide (CoO), and may be formed using an electron-beam evaporation technique, sputtering, or the like.

The dielectric film153is made of a material such as dielectric bodies including a tantalum oxide (Ta2O5) which is a metal oxide, and porous polymers, for example.

The drive circuit20illustrated inFIG. 1drives the pixel array section13(the display panel10) (i.e. performs display driving). Specifically, the drive circuit20performs display driving for the plurality of pixels11, by sequentially selecting the plurality of pixels11in the pixel array section13, and writing an image signal voltage in each of the subpixels11R,11G, and11B within the selected pixel11, based on the image signal20A. In other words, the drive circuit20performs the display driving for each of the subpixels11R,11G, and11B, based on the image signal20A. The drive circuit20also has a function of driving the transmittance control device15. The drive circuit20includes an image-signal processing circuit21, a timing generation circuit22, a scanning-line drive circuit23, a signal-line drive circuit24, a power-line drive circuit25, and a control-device drive circuit26.

The image-signal processing circuit21performs predetermined image-signal processing on the image signal20A in digital form inputted from outside, and outputs an image signal21A after such image-signal processing to the signal-line drive circuit24. Examples of this predetermined image-signal processing include gamma correction processing, and overdrive processing.

The timing generation circuit22generates and outputs a control signal22A based on the synchronization signal20B inputted from outside, thereby controlling the scanning-line drive circuit23, the signal-line drive circuit24, the power-line drive circuit25, and the control-device drive circuit26to operate together.

The scanning-line drive circuit23sequentially selects the plurality of pixels11, by sequentially applying a selection pulse to the plurality of scanning lines WSL according to (in synchronization with) the control signal22A. Specifically, the scanning-line drive circuit23generates the selection pulse by selectively outputting a voltage Von to be applied to set the write transistor Tr1in an ON state, or a voltage Voff to be applied to set the write transistor Tr1in an OFF state. Here, the voltage Von is a value (a constant value) equal to or higher than an ON voltage of the write transistor Tr1, and the voltage Voff is a value (a constant value) lower than the ON voltage of the write transistor Tr1.

The signal-line drive circuit24generates an analog image signal corresponding to the image signal21A inputted from the image-signal processing circuit21, according to (in synchronization with) the control signal22A, and applies the generated signal to each of the signal lines DTL (DTLr, DTLg, and DTLb). Specifically, the signal-line drive circuit24applies the analog image signal voltage for each color based on this image signal21A to each of the signal lines DTLr, DTLg, and DTLb individually. In this way, image-signal writing is performed for each of the subpixels11R,11G, and11B within the pixel11selected by the scanning-line drive circuit23. It is to be noted that the image-signal writing indicates programming of the image signal voltage for the retention capacitive element Cs, and application of a predetermined voltage between the gate and the source of the drive transistor Tr2.

The power-line drive circuit25sequentially applies a control pulse to the plurality of power lines DSL according to (in synchronization with) the control signal22A, thereby controlling light-emission (lighting) operation and non-light-emission (extinction) operation of the organic EL device12in each of the subpixels11R,11G, and11B in each of the pixels11. To be more specific, the power-line drive circuit25adjusts the width (pulse width) of the control pulse, and thereby controls the length of each of a light-emission period and a non-light-emission period (an extinction period) in each of the subpixels11R,11G, and11B in each of the pixels11(i.e. performs PWM (Pulse Width Modulation) control).

The control-device drive circuit26performs driving operation of applying a drive voltage (a drive voltage Vd1or the like) which will be described later, between the transparent electrodes151A and151C in the transmittance control device15, thereby controlling the operation of the transmittance control device15(i.e. performs switching control between the incident-light transmission operation and the incident-light absorption operation).

[Functions and Effects of Display1]

In this display1, the drive circuit20performs the display driving based on the image signal20A and the synchronization signal20B, on each of the pixels11(each of the subpixels11R,11G, and11B) in the display panel10(the pixel array section13), as illustrated inFIG. 1toFIG. 3. As a result, a drive current is fed into the organic EL device12in each of the subpixels11R,11G, and11B, and hole-electron recombination takes place in the luminous layer in the organic layer52, thereby causing light emission, as illustrated inFIG. 5. Then, in each of the subpixels11R,11G, and11B, emission light Lout1from this organic layer52(the luminous layer) is outputted as display light towards the front-face side (the substrate41side), and emission light Lout2is outputted towards the rear-face side (the transmittance control device15side). In this way, image display based on the image signal20A is performed on the display panel10.

Here, operation of writing the image signal in each of the subpixels11R,11G, and11B is performed, as illustrated inFIG. 3. First, the scanning-line drive circuit23raises the voltage of the scanning line WSL from the voltage Voff to the voltage Von, during a period in which the voltage of the signal line DTL is the image signal voltage and the voltage of the power line DSL is a voltage VH (in a “H (high)” state). This causes the write transistor Tr1to enter the ON state, and thus, a gate potential Vg of the drive transistor Tr2increases to the image signal voltage corresponding to the voltage at this moment of the signal line DTL. As a result, the image signal voltage is written into the retention capacitive element Cs and retained.

Here, at this stage, an anode voltage of the organic EL device12is still smaller than a voltage value (Ve1+Vca) which is the sum of a threshold voltage Ve1and a cathode voltage Vca (=VSS) in the organic EL device12, and the organic EL device12is in a cut-off state. In other words, at this stage, the current is yet to flow between the anode and the cathode of the organic EL device12(i.e. the organic EL device12does not emit light). Therefore, a current Id supplied from the drive transistor Tr2flows to a device capacitance (not illustrated) present in parallel between the anode and the cathode of the organic EL device12, and this device capacitance is charged.

Next, the scanning-line drive circuit23lowers the voltage of the scanning line WSL from the voltage Von to the voltage Voff, during a period in which the voltage of the signal line DTL and the voltage of the power line DSL are maintained at the image signal voltage and the voltage VH (in the “H” state), respectively. This causes the write transistor Tr1to enter the OFF state, and thus, the gate of the drive transistor Tr2enters a floating state. Then, in the state in which a voltage Vgs between the gate and the source of the drive transistor Tr2is kept constant, the current Id flows between the drain and the source of the drive transistor Tr2. As a result, a source potential Vs of the drive transistor Tr2rises, and the gate potential Vg of the drive transistor Tr2also rises by capacitive coupling through the retention capacitive element Cs. This causes the anode voltage of the organic EL device12to become greater than the voltage value (Ve1+Vca) which is the sum of the threshold voltage Ve1and the cathode voltage Vca in the organic EL device12. Consequently, the current Id, which corresponds to the image signal voltage retained by the retention capacitive element Cs, namely, the voltage Vgs between the gate and the source in the drive transistor Tr2, flows between the anode and the cathode of the organic EL device12, and thereby the organic EL device12emits light at desired intensity.

Next, the drive circuit20terminates the light-emission period of the organic EL device12, after a lapse of a predetermined period. Specifically, the power-line drive circuit25lowers the voltage of the power line DSL from the voltage VH to a voltage VL (i.e. shifts the voltage from the “H” state to the “L (low)” state). Then, the source potential Vs of the drive transistor Tr2drops. This causes the anode voltage of the organic EL device12to become smaller than the voltage value (Ve1+Vca) which is the sum of the threshold voltage Ve1and the cathode voltage Vca in the organic EL device12, and the current Id stops flowing between the anode and the cathode. As a result, the organic EL device12extinguishes afterwards (shifts to the extinction period). In this way, the length of the light emission period in each of the subpixels11R,11G, and11B in each of the pixels11is controlled, according to the width of the control pulse applied to the power line DSL (here, the length of the period of the “H” state).

It is to be noted that afterwards, the drive circuit20performs the display driving to repeat the light emission operation and the extinction operation periodically, for every frame period (one vertical period, or one V period). At the same time, the drive circuit20performs scanning in a row direction, with each of the control pulse applied to the power line DSL and the selection pulse applied to the scanning line WSL, for every horizontal period (a 1H period), for example. The display operation (the display driving by the drive circuit20) is thus performed in the display1.

(2. Function of Transmittance Control Device15)

Next, function of the transmittance control device15which is one of characteristic parts in the display1of the present embodiment will be described in detail, while making a comparison with a comparative example (a comparative example 2).

Comparative Example 2

First, unlike the present embodiment, the transmittance control device15is not provided in a display panel (a display panel200) according to the comparative example 2 illustrated inFIG. 6. Specifically, in place of the transmittance control device15, a sealing substrate202(a cover glass) is provided on a flattening film54in the display panel200.

Therefore, in this comparative example 2, at the time of light emission (FIG. 7A) and at the time of non-light emission (FIG. 7B) in each of subpixels11R,11G, and11B (an organic EL device12) in a pixel201, visual-recognition states become those illustrated inFIGS. 7A and 7B, respectively, for example. In other words, first, at the time of the light emission illustrated inFIG. 7A, emission light (emission light Lout1and Lout2) is outputted from each of the subpixels11R,11G, and11B to both of a surface side (a user side) and a back-surface side. On the other hand, at the time of the non-light emission illustrated inFIG. 7B, no emission light is outputted from each of the subpixels11R,11G, and11B and thus, for example, each of the subpixels11R,11G, and11B is in an external-light-transmitted state.

Here, this comparative example 2 is disadvantageous in that visibility decreases because each of the subpixels11R,11G, and11B is usually in the light-transmitted state. Specifically, in an application for normal display, for example, improvement of visibility is prevented even at the time of the non-light emission illustrated inFIG. 7B, because a black display state is not available due to existence of the external light (transmitted light coming from the back-surface side). Moreover, in an application for AR, for instance, the visibility also greatly decreases at the time of the light emission illustrated inFIG. 7A, in an outdoor use with a large quantity of light (external light).

Function of Present Embodiment

In contrast, as illustrated inFIG. 1andFIG. 5, the transmittance control device15capable of controlling the transmittance of the incident light is provided in the display panel10of the present embodiment. This realizes controlling of the light-transmittance to be appropriate to a light emission state (at the time of the light emission or the non-light emission) in the organic EL device12in the pixel11having the light-transmission region, as will be described below in detail.

First, in this transmittance control device15, each of the EC material layers152A and152C exhibits optical transparency when the drive voltage Vd1is not applied between the transparent electrodes151A and151C, as illustrated inFIG. 8A. For this reason, the transmittance control device15as a whole exhibits the optical transparency, and light including the emission light Lout2outputted from the organic EL device12to the rear-face side and external light is allowed to pass therethrough (in a transparent (light transmission) state).

On the other hand, when the drive voltage Vd1is applied between the transparent electrodes151A and151C, each of the EC material layers152A and152C is colored and does not exhibit optical transparency, as illustrated inFIG. 8B. For this reason, the transmittance control device15as a whole does not exhibit the optical transparency, and the light including the emission light Lout2and the external light is not allowed to pass therethrough (in a colored (light absorption) state).

In this way, the transmittance control device15is allowed to switch the operation between the incident-light (the light including the emission light Lout2and the external light) transmission operation and the incident-light absorption operation, depending on the presence or absence of the application of the drive voltage Vd1. Thus, in the present embodiment, the switching control between the transmission operation and the absorption operation as described above is performed at the time of each of the light emission and the non-light emission of the organic EL device12.

In the present embodiment therefore, at the time of each of the light emission and the non-light emission in each of the subpixels11R,11G, and11B (the organic EL device12) in the pixel11, the respective visual recognition states become those illustrated inFIGS. 9A to 9D, for example, depending on the combination of the light transmission state and the light absorption state in the transmittance control device15.

Specifically, first, as illustrated inFIG. 9A, the visual recognition state is similar to that inFIG. 7Ain the comparative example 2, when the transmittance control device15is in the light transmission state at the time of the light emission of the organic EL device12. In other words, the emission light (the emission light Lout1and Lout2) from each of the subpixels11R,11G, and11B is outputted to both of the surface side and the back-surface side of the display1.

Further, as illustrated inFIG. 9B, when the transmittance control device15is in the light transmission state at the time of the non-light emission of the organic EL device12, the visual recognition state is similar to that inFIG. 7Bin the comparative example 2. In other words, for example, an external-light-transmitted state is realized, because no emission light is outputted from each of the subpixels11R,11G, and11B.

On the other hand, as illustrated inFIG. 9C, when the transmittance control device15is in the light absorption state at the time of the non-light emission of the organic EL device12, the visual recognition state becomes as follows. That is, although the emission light is not outputted from each of the subpixels11R,11G, and11B as in the state ofFIG. 9B, the light including the external light is not allowed to pass therethrough because the transmittance control device15is in the light absorption state. Therefore, a black display state is realized as illustrated inFIG. 9C, and the visibility improves in an application for normal display, for example, as compared with the state in each ofFIG. 7BandFIG. 9B.

Furthermore, as illustrated inFIG. 9D, when the transmittance control device15is in the light absorption state at the time of the light emission of the organic EL device12, the visual recognition state becomes as follows. That is, although the emission light from each of the subpixels11R,11G, and11B is outputted to both of the surface side and the back-surface side as in the state ofFIG. 9A, the light including the emission light Lout2and the external light is not allowed to pass therethrough (the rear-face side becomes black), because the transmittance control device15is in the light absorption state. Therefore, as illustrated inFIG. 9D, the visibility improves even in a case where the external light is intense in an application for AR, for example, as compared with the state in each ofFIG. 7AandFIG. 9A.

In the present embodiment, the transmittance control device15capable of controlling the transmittance of the incident light is provided as described above. Thus, the light transmittance is controlled to be appropriate to the light emission state in the organic EL device12in the pixel11having the light-transmission region. Therefore, the visibility in the display1with the pixels11each having the light-transmission region is enhanced (for example, the visibility in displaying information is enhanced, while securing the visibility on the back-surface side). Hence, when this display1is used as a display for AR, for example, the presence is improved.

In addition, since the transmittance control device15is provided as only one device common to all the pixels11in the pixel array section13, configurations of the display panel10and the control-device drive circuit26(wiring and the like used in the driving) are simplified.

Next, other embodiments (a second embodiment and a third embodiment) of the disclosure will be described. It is to be noted that the same elements as those of the first embodiment will be provided with the same characters as those of the first embodiment, and the description will be omitted as appropriate.

Second Embodiment

[Configuration of Display Panel10A]

FIG. 10schematically illustrates a cross-sectional configuration example of a display panel (a display panel10A) according to a second embodiment. The display panel10A of the present embodiment is configured by providing a transmittance control device15A in place of the transmittance control device15in the display panel10of the first embodiment, and is otherwise similar in configuration to the first embodiment.

The transmittance control device15A includes a transparent electrode151C, an EC material layer152C, a dielectric film153, a buffer layer154, a catalytic layer155, and a dimming mirror layer156, in this order from a front-face side to a rear-face side of a display1. In other words, this transmittance control device15A has a configuration in which the buffer layer154, the catalytic layer155, and the dimming mirror layer156are provided in place of the EC material layer152A and the transparent electrode151A in the transmittance control device15.

By having such a configuration, the transmittance control device15A of the present embodiment serves as an electrochromic device capable of switching operation between incidence-light transmission operation and incident-light reflection operation, unlike the transmittance control device15, as will be described later. In other words, this transmittance control device15A is capable of switching the operation between the transmission operation and the reflection operation, at the time of each of light emission and non-light emission of an organic EL device12.

Here, the buffer layer154is made of Al, for example. The catalytic layer155is made of palladium (Pd), for example. The dimming mirror layer156is made of magnesium-nickel (Mg—Ni) alloy, for instance, and functions as a counter electrode (a cathode electrode) for the transparent electrode151C. Therefore, the dimming mirror layer156and the transparent electrode151C are each formed like a comb orthogonal to each other, for example.

[Functions and Effects of Display Panel10A]

In this transmittance control device15A, when a drive voltage Vd2is applied between the transparent electrode151C and the dimming mirror layer156by a control-device drive circuit26, the dimming mirror layer156exhibits optical transparency, as illustrated inFIG. 11A. For this reason, the transmittance control device15A as a whole exhibits optical transparency, and light including emission light Lout2outputted from the organic EL device12towards the rear-face side and external light is allowed to pass therethrough (a transparent (light transmission) state).

On the other hand, when the drive voltage Vd2is not applied between the transparent electrode151C and the dimming mirror layer156, the dimming mirror layer156exhibits light reflectivity (does not exhibit the optical transparency) as illustrated inFIG. 11B. For this reason, the transmittance control device15A as a whole exhibits light reflectivity (does not exhibit the optical transparency), and the light including the emission light Lout2and the external light is reflected to the front-face side of the display1and thus prevented from passing therethrough towards the back-surface side (a mirror (light reflection) state).

In this way, the transmittance control device15A is allowed to switch the operation between the incident-light (the light including the emission light Lout2and the external light) transmission operation and the incident-light reflection operation, depending on the presence or absence of the application of the drive voltage Vd2. In the present embodiment therefore, the switching control between the transmission operation and the reflection operation is performed at the time of each of the light emission and the non-light emission of the organic EL device12.

In the present embodiment, at the time of the light emission and at the time of the non-light emission in each of subpixels11R,11G, and11B (the organic EL device12) in a pixel11A, the respective visual recognition states become, for example, those illustrated inFIGS. 12A to 12D, depending on the combination of a light transmission state and a light reflection state in the transmittance control device15A described above.

Specifically, first, as illustrated inFIG. 12A, when the transmittance control device15A is in the light transmission state at the time of the light emission of the organic EL device12, the visual recognition state is similar to the state inFIG. 9Ain the first embodiment. In other words, the emission light (emission light Lout1and Lout2) from each of the subpixels11R,11G, and11B is outputted to both of the surface side and the back-surface side of the display1.

Further, as illustrated inFIG. 12B, when the transmittance control device15A is in the light transmission state at the time of the non-light emission of the organic EL device12, the visual recognition state is similar to the state inFIG. 9B. In other words, for example, an external-light-transmitted state is realized, because no emission light is outputted from each of the subpixels11R,11G, and11B.

On the other hand, as illustrated inFIG. 12C, when the transmittance control device15A is in the light reflection state at the time of the non-light emission of the organic EL device12, the visual recognition state becomes as follows. That is, although the emission light is not outputted from each of the subpixels11R,11G, and11B as in the state ofFIG. 12B, the light including the external light is not allowed to pass therethrough because the transmittance control device15A is in the light reflection state. Meanwhile, the incident light (external light) from the front-face side is reflected to the front-face side, because the transmittance control device15A is in the light reflection state.

Furthermore, as illustrated inFIG. 12D, when the transmittance control device15A is in the light reflection state at the time of the light emission of the organic EL device12, the visual recognition state becomes as follows. That is, although the emission light from each of the subpixels11R,11G, and11B is outputted to both of the surface side and the back-surface side as in the state ofFIG. 12A, the emission light Lout2towards the back-surface side is reflected to the front-face side resulting in an increase in emission intensity, because the transmittance control device15A is in the light reflection state. Meanwhile, although the external light from the front-face side is reflected, visibility improves because the emission intensity is increased. Therefore, as illustrated inFIG. 12D, the visibility improves even in a case where the external light is intense in an application for AR, for example, as compared with the case in each ofFIG. 7AandFIG. 12A.

In the present embodiment, since the transmittance control device15A is provided, the visibility in the display1with the pixels11each having a light-transmission region is enhanced (for example, the light reflection state is established in a dark environment and thereby, the light including the emission light Lout heading for the back-surface side is extracted on the front-face side, which improves the visibility), as in the first embodiment. Therefore, when this display1is used as a display for AR, for example, the presence is improved.

Third Embodiment

[Configuration of Display Panel10B]

FIG. 13schematically illustrates a cross-sectional configuration example of a display panel (a display panel10B) according to a third embodiment. The display panel10B of the present embodiment is configured by providing a sealing substrate55and a transmittance control device16in place of the transmittance control device15in the display panel10of the first embodiment, and is otherwise similar in configuration to the first embodiment.

The transmittance control device16includes a transparent electrode161A, a hydrophobic insulating film162as well as a partition165, a nonpolar liquid163, a polar liquid164, and a transparent electrode161B, in this order from a front-face side to a rear-face side of a display1.

By having such a configuration, the transmittance control device16of the present embodiment serves as an electrowetting device capable of switching operation between incident-light transmission operation and incident-light absorption operation as will be described later, unlike the transmittance control devices15and15A. In other words, this transmittance control device16is capable of switching the operation between the transmission operation and the absorption operation, at the time of each of light emission and non-light emission of an organic EL device12.

The transparent electrodes161A and161B each function as a driving electrode of the electrowetting device, and is made of, for example, a light transmissive material such as the transparent oxide semiconductors and the transparence carbon described above. It is to be noted that the transparent electrodes161A and161B are each formed like a comb orthogonal to each other, for example.

The partition165is a wall section provided to separate the hydrophobic insulating film162, the nonpolar liquid163, and the polar liquid164in each of subpixels11R,11G, and11B. The partition165is made of, for example, an organic insulating material such as polyimide and acrylic.

The hydrophobic insulating film162is made of a material exhibiting hydrophobicity (water repellency) with respect to the polar liquid164(in the strict sense, exhibiting affinity for the nonpolar liquid163under no electric field), and also having a property excellent in terms of electrical insulation. Specific examples of the material include polyvinylidene fluoride (PVdF) as well as polytetrafluoroethylene (PTFE) which are fluorine-based polymers, and silicone.

The nonpolar liquid163is a liquid material having almost no polarity and exhibiting electrical insulation, and exhibits non-transparency (does not exhibit optical transparency). Examples suitable for the nonpolar liquid163include colored oil (silicon oil and the like), in addition to hydrocarbon-based materials such as decane, dodecane, hexadecane, and undecane.

The polar liquid164is a liquid material having polarity, and exhibits transparency (optical transparency). Examples suitable for the polar liquid164include water, and a solution in which an electrolyte such as potassium chloride and sodium chloride is dissolved. Here, when a voltage is applied to this polar liquid164, wettability (a contact angle between the polar liquid164and the inner surface) for the hydrophobic insulating film162(an inner surface of the partition165) changes greatly as compared with the nonpolar liquid163.

The sealing substrate55is a substrate (a cover glass or the like) provided to seal the entire display panel10B, and is made of a transparent substrate.

[Functions and Effects of Display Panel10B]

In this transmittance control device16, when a drive voltage Vd3is not applied between the transparent electrodes161A and161B, an interface between the nonpolar liquid163and the polar liquid164is flat, as illustrated inFIG. 14. For this reason, the nonpolar liquid163exhibiting the non-transparency is provided over the whole of each of the subpixels11R,11G, and11B. As a result, the transmittance control device16as a whole does not exhibit optical transparency, and light including emission light Lout2and external light is not allowed to pass therethrough (a colored (light absorption) state).

On the other hand, as illustrated inFIG. 15, when the drive voltage Vd3is applied between the transparent electrodes161A and161B, the wettability of the polar liquid164changes greatly as compared with the nonpolar liquid163as described above, and the interface between the nonpolar liquid163and the polar liquid164takes a shape protruding towards the rear-face side. For this reason, the nonpolar liquid163exhibiting the non-transparency is disposed only at a part of each of the subpixels11R,11G, and11B (see an arrow indicated by a broken line inFIG. 15). As a result, the transmittance control device16as a whole exhibits the optical transparency, and the light including the emission light Lout2and the external light is allowed to pass therethrough (a transparent (light transmission) state).

In this way, the transmittance control device16is allowed to switch the operation between the incident-light (the light including the emission light Lout2and the external light) transmission operation and the incident-light absorption operation, depending on the presence or absence of the application of the drive voltage Vd3. In the present embodiment therefore, the switching control between the transmission operation and the absorption operation is performed, at the time of each of the light emission and the non-light emission of the organic EL device12.

Thus, in the present embodiment, at the time of the light emission and at the time of the non-light emission in each of the subpixels11R,11G, and11B (the organic EL device12) in a pixel11, the respective visual recognition states become, for example, similar to those illustrated inFIGS. 9A to 9Din the first embodiment, depending on the combination of a light transmission state and a light absorption state in the transmittance control device16described above.

As a result, similar effects by similar function to those of the first embodiment are obtained in the present embodiment as well. In other words, visibility in the display1with the pixels each having a light-transmission region is enhanced (for example, visibility in displaying information is also enhanced while securing visibility on the back-surface side). Therefore, when this display1is used as a display for AR, for example, the presence is improved.

In addition, in the present embodiment, the transmittance control device16is configured using the electrowetting device and thus, a response speed is made relatively high.

It is to be noted that the present embodiment has been described for the case where the electrowetting device capable of switching the operation between the incident-light transmission operation and the incident-light absorption operation is used as the transmittance control device16, although it is not limited thereto. Alternatively, for example, an electrowetting device capable of switching the operation between incident-light transmission operation and incident-light reflection operation may be used as the transmittance control device.

Next, modifications (modifications 1 to 4) common to the first to third embodiments will be described. It is to be noted that the same elements as those of each of the embodiments will be provided with the same characters as those of each of the embodiments, and the description will be omitted as appropriate.

FIG. 16Aillustrates an internal configuration example (a circuit configuration example) of each of the subpixels (the subpixels11R,11G, and11B) according to a modification 1, together with the transmittance control device15(or the transmittance control device15A or16). In the present modification, unlike each of the embodiments, the transmittance control device15is disposed as one for every plurality of pixels11. Here, in particular, the transmittance control device15is disposed for every horizontal line.

Specifically, here, between the transmittance control device15and the organic EL device12, at least one electrode (here, the fixed potential line VSS forming the cathode electrode) is made common thereto. However, the electrode between the transmittance control device15and the organic EL device12may not be provided as a common electrode, when the transmittance control device15is disposed for every horizontal line. It is to be noted that DL in the figure indicates a drive wire of the transmittance control device15.

In the present modification, such a configuration allows a transparent region (a light-transmission region)10-1and a non-transparent region (a non-light-transmission region)10-2for every horizontal line to be formed in the display panel10,10A, or10B, depending on the application in the AR use, as illustrated inFIG. 17A, for example. In addition, using a cathode wire as the electrode of the transmittance control device15reduces the number of wires, thereby simplifying the drive circuit. It is to be noted that, for instance, the transmittance control device15may be disposed for every vertical line, instead of every horizontal line.

FIG. 16Billustrates an internal configuration example (a circuit configuration example) of each of the subpixels (the subpixels11R,11G, and11B) according to a modification 2, together with the transmittance control device15. In the present modification, the transmittance control device15is provided for every subpixel (pixel), unlike each of the embodiments and the modification 1.

Specifically, here, between the transmittance control device15and the organic EL device12, at least one electrode (here, the fixed potential line VSS forming the cathode electrode) is made common thereto. However, the electrode between the transmittance control device15and the organic EL device12may not be provided as a common electrode, when the transmittance control device15is disposed for every subpixel. In addition, here, a transistor (a selection transistor) Tr3and a scanning line WSL2are provided to drive the transmittance control device15selectively for each of the subpixels11R,11G, and11B. Also, a retention capacitive element Cs2is provided to retain an electric potential between both ends of the transmittance control device15. It is to be noted each of VSS1and VSS2inFIG. 16Bis a fixed potential line.

Therefore, in the present modification, the transparent region10-1and the non-transparent region10-2are realized by the subpixel (pixel) in the display panel10,10A, or10B, depending on the application in the AR use, for instance, as illustrated inFIG. 17B, for example. Specifically, for example, displaying an emphasized outline region of a letter is possible. In addition, the number of wires is reduced by using the cathode wire as the electrode shared with the transmittance control device15, and thereby the drive circuit is simplified.

FIGS. 18A and 18Bare plan views each schematically illustrating an internal configuration (a subpixel configuration) example of each pixel (pixels11-1and11-2), according to modifications 3 and 4, respectively. In each of the respective pixels11-1and11-2of the modifications 3 and 4, the transmittance control device15is disposed side by side with the subpixels11R,11G, and11B, unlike the pixels11and11A of the embodiments.

Specifically, in the pixel11-1of the modification 3 illustrated inFIG. 18A, the three subpixels11R,11G, and11B and the one transmittance control device15are disposed in a matrix (2×2 in columns and rows) in each of the pixels11-1.

In the pixel11-2of the modification 4 illustrated inFIG. 18B, the three subpixels11R,11G, and11B and the one transmittance control device15are aligned along a horizontal-line direction in each of the pixels11-2.

It is to be noted that the subpixels11R,11G, and11B and the transmittance control device15are allowed to share a part of the electrodes, and be formed using ink jet printing, flexographic printing, or the like.

In these modifications 3 and 4, the above-described configurations allow the visual recognition state at the time of each of the light emission and the non-light emission in the pixels11-1and11-2to be obtained, as represented by the modification 3 illustrated inFIGS. 19A to 19D, for example. In other words, at the time of each of the light emission and the non-light emission in each of the subpixels11R,11G, and11B (the organic EL device12) in the pixel11-1, the visual recognition states similar to those of the embodiments are achieved, depending on the combination of the light transmission state and the light absorption state (or the light reflection state) in the transmittance control device15.

Therefore, similar effects by similar function to those of the embodiments are obtained in the modifications 3 and 4 as well. In other words, the visibility in the display1with the pixels each having the light-transmission region is enhanced. Therefore, when this display1is used as a display for AR, for instance, the presence is improved.

Module and Application Examples

With reference toFIG. 20toFIG. 25G, application examples of the display1in each of the embodiments and the modifications will be described below. The display1in each of the embodiments and the modifications may be applied to electronic units in all fields, which display externally-input image signals or internally-generated image signals as still or moving images. The electronic units include television receivers, digital cameras, laptop computers, portable terminals such as portable telephones, video cameras, and the like.

For instance, the display1is incorporated into any of various kinds of electronic units such as application examples 1 to 5 which will be described later, as a module illustrated inFIG. 20. This module is formed, for example, by providing a region210exposed at one side of a substrate31from a sealing substrate32. In this exposed region210, an external connection terminal (not illustrated) is formed by extending wires of the drive circuit20. This external connection terminal may be provided with a flexible printed circuit (FPC)220for input and output of signals.

Application Example 1

FIG. 21illustrates an external view of a television receiver to which the display1is applied. This television receiver has, for example, an image-display screen section300that includes a front panel310and a filter glass320. The image-display screen section300is configured using the display1.

Application Example 2

FIGS. 22A and 22Beach illustrate an external view of a digital camera to which the display1is applied. This digital camera includes, for example, a flash emitting section410, a display section420, a menu switch430, and a shutter release440. The display section420is configured using the display1.

Application Example 3

FIG. 23illustrates an external view of a laptop computer to which the display1is applied. This laptop computer includes, for example, a main section510, a keyboard520for entering characters and the like, and a display section530displaying an image. The display section530is configured using the display1.

Application Example 4

FIG. 24illustrates an external view of a video camera to which the display1is applied. This video camera includes, for example, a main section610, a lens620disposed on a front face of this main section610to shoot an image of a subject, a start/stop switch630in shooting, and a display section640. The display section640is configured using the display1.

Application Example 5

FIGS. 25A to 25Gillustrate external views of a portable telephone to which the display1is applied. This portable telephone is, for example, a unit in which an upper housing710and a lower housing720are connected by a coupling section (a hinge section)730, and includes a display740, a sub-display750, a picture light760, and a camera770. The display740or the sub-display750is configured using the display1.

The technology of the present disclosure has been described with reference to the embodiments, the modifications, and the application examples, but is not limited to these embodiments, modifications, and application examples, and may be variously modified.

For example, in the embodiments, the modifications, and the application examples, the description has been provided with reference to the case where the electrochromic device or the electrowetting device is used as an example of the transmittance control device, although it is not limited thereto. The transmittance control device may be configured using other types of device. In addition, in the embodiments, the modifications, and the application examples, the organic EL device is used an example of the light-emission device, but a light-emission device other than the organic EL device (e.g., an inorganic EL device, LED (Light Emitting Diode), and the like) may be used.

Further, in the embodiments, the modifications, and the application examples, the description has been provided by taking the display panel of the so-called bottom emission type as an example, although it is not limited thereto. The display panel may be of a so-called top emission type.

Furthermore, in the embodiments, the modifications, and the application examples, the description has been provided with reference to the case where the light transmittance is controlled in (switched between) two stages (transmission or non-transmission) in the transmittance control device, although it is not limited thereto. The light transmittance may be controlled in (switched between) multiple stages.

In addition, in the embodiments, the modifications, and the application examples, the description has been provided with reference to the case where the display1is of the active matrix type. However, the configuration of the pixel circuit14provided for the active matrix driving is not limited to those described for the embodiments, the modifications, and the application examples. In other words, the configuration of the pixel circuit14is not limited to the “2Tr1C” circuit configuration described for the embodiments, the modifications, and the application examples. For instance, a capacitive element, a transistor, and the like may be added to the pixel circuit14or provided as a substitution, as necessary. In that case, a necessary drive circuit other than the scanning-line drive circuit23, the signal-line drive circuit24, and the power-line drive circuit25may be added according to a change of the pixel circuit14.

Further, in the embodiments, the modifications, and the application examples, the description has been provided with reference to the case where the timing generation circuit22controls the drive operation in the scanning-line drive circuit23, the signal-line drive circuit24, the power-line drive circuit25, and the control-device drive circuit26. However, the drive operation of these circuits may controlled by other circuit. Furthermore, control of the scanning-line drive circuit23, the signal-line drive circuit24, the power-line drive circuit25, and the control-device drive circuit26may be performed by hardware (a circuit) or software (a program).

Moreover, in the embodiments, the modifications, and the application examples, the description has been provided with reference to the case where each of the write transistor Tr1, the drive transistor Tr2, and the like is formed of the n-channel transistor (e.g., the TFT of the n-channel MOS type), although it is not limited thereto. In other words, each of the write transistor Tr1, the drive transistor Tr2, and the like may be formed of a p-channel transistor (e.g., a TFT of a p-channel MOS type).

The present technology may be configured as follows.(1) A display including:a plurality of pixels each including a light-emission device, and having a light-transmission region in at least a part thereof; andone or more transmittance control devices capable of controlling a transmittance of incident light.(2) The display according to (1), wherein the transmittance control device is capable of switching operation between incident-light transmission operation and incident-light absorption operation or reflection operation.(3) The display according to (2), wherein the transmittance control device is capable of switching the operation between the transmission operation and the absorption operation or the reflection operation, at a time of each of light emission and non-light emission of the light-emission device.(4) The display according to any one of (1) to (3), wherein the one or more transmittance control devices are disposed to face the light-emission devices.(5) The display according to any one of (1) to (3), wherein the one or more transmittance control devices are disposed side by side with the light-emission devices.(6) The display according to any one of (1) to (5), wherein the transmittance control device is disposed for every plurality of the pixels.(7) The display according to (6), wherein the transmittance control device is provided as being common to all the pixels.(8) The display according to (6), wherein the transmittance control device is disposed for every horizontal line or every vertical line.(9) The display according to any one of (1) to (5), wherein the transmittance control device is disposed for each of the pixels.(10) The display according to any one of (1) to (9), wherein one or more electrodes are made common between the transmittance control device and the light-emission device.(11) The display according to any one of (1) to (10), wherein the transmittance control device is an electrochromic device or an electrowetting device.(12) The display according to any one of (1) to (11), whereinthe pixels each include a pixel circuit, the pixel circuit including the light-emission device and a drive device, andat least a part of a semiconductor layer and an electrode layer of the drive device as well as a wiring layer is configured using a light transmissive material, in the pixel circuit.(13) The display according to any one of (1) to (12), wherein the light-emission device is an organic EL device.(14) An electronic unit including a display, the display including:a plurality of pixels each including a light-emission device, and having a light-transmission region in at least a part thereof; andone or more transmittance control devices capable of controlling a transmittance of incident light.