JP2016065893A - Display device and electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device and an electronic device which are easily visible.SOLUTION: The display device includes a switch liquid crystal unit, a display unit, and a control unit according to an embodiment. The switch liquid crystal unit includes first and second switching elements. The display unit is overlapped on the switch liquid crystal unit. The control unit carries out a first operation in a first period and a second operation in a second period after the first period. The first operation includes an operation of supplying a first signal having a first voltage value to the first switching element, and an operation of supplying a second signal having a second voltage value different from the first voltage value to the second switching element. The second operation includes an operation of supplying a post-switch signal to the first switching element and an operation of supplying a third signal having the first voltage value and a first supply start time in the second period to the second switching element. The post-switch signal has at least one of a second supply start time different from the first supply start time and a third voltage value different from the first voltage value and the second voltage value.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a display device and an electronic device.

  There is a display device that can visually recognize a stereoscopic image with the naked eye. For example, there is a parallax barrier display device using an element such as a liquid crystal element. By employing the head tracking technology, an appropriate image is provided according to the position of the viewer. In a display device, improvement in visibility is required.

JP 2013-24957 A

  Embodiments of the present invention provide an easy-to-see display device and electronic device.

  According to the embodiment of the present invention, the display device includes a switch liquid crystal unit, a display unit, and a control unit. The switch liquid crystal unit includes a first switch element and a second switch element. The display unit is overlaid on the switch liquid crystal unit. The control unit performs a first operation in a first period and performs a second operation in a second period after the first period. The first operation includes an operation of supplying a first signal having a first voltage value to the first switch element, and a second signal having a second voltage value different from the first voltage value to the second switch element. Supplying an operation. The second operation includes an operation of supplying a signal after switching to the first switch element, and a third signal having the first supply start time and the first voltage value during the second period. Supplying to the element. The post-switching signal has at least one of a second supply start time that is different from the first supply start time and a third voltage value that is different from the first voltage value and the second voltage value.

1 is a block diagram illustrating a display device according to a first embodiment. 1 is a schematic cross-sectional view illustrating a part of a display device according to a first embodiment. 1 is a schematic cross-sectional view illustrating a part of a display device according to a first embodiment. 3 is a circuit diagram illustrating a part of the display device according to the first embodiment; FIG. FIG. 5A and FIG. 5B are schematic views illustrating the operation of the display device according to the first embodiment. FIG. 6A to FIG. 6C are schematic views illustrating the operation of the display device according to the first embodiment. FIG. 7A to FIG. 7D are diagrams illustrating the transmittance characteristics of the display device according to the first embodiment. 1 is a schematic view illustrating a part of a display device according to a first embodiment. FIG. 9A to FIG. 9D are diagrams illustrating response characteristics of the display device according to the first embodiment. It is a figure which illustrates the voltage characteristic of the display apparatus which concerns on 1st Embodiment. It is a figure which illustrates the transmittance | permeability characteristic of the display apparatus which concerns on 1st Embodiment. 1 is a schematic view illustrating a part of a display device according to a first embodiment. It is a figure which illustrates switch operation | movement of the display apparatus which concerns on 1st Embodiment. FIG. 14A and FIG. 14B are schematic views illustrating a part of the display device according to the first embodiment. It is a figure which illustrates the brightness | luminance characteristic of the display apparatus which concerns on 1st Embodiment. It is a figure which illustrates switch operation | movement of the display apparatus which concerns on 2nd Embodiment. It is a figure which illustrates the transmittance | permeability characteristic of the display apparatus which concerns on 2nd Embodiment. It is a figure which illustrates the luminance characteristic of the display apparatus which concerns on 2nd Embodiment. It is a schematic diagram which illustrates a part of display apparatus which concerns on 3rd Embodiment. It is a figure which illustrates switch operation | movement of the display apparatus which concerns on 3rd Embodiment. It is a figure which illustrates switch operation | movement of the display apparatus which concerns on 4th Embodiment. It is a schematic diagram which illustrates the electronic device which concerns on 5th Embodiment. It is a schematic diagram which illustrates the other electronic device which concerns on 5th Embodiment. FIG. 10 is a schematic view illustrating still another electronic device according to the fifth embodiment. FIG. 10 is a schematic view illustrating still another electronic device according to the fifth embodiment. FIG. 10 is a schematic view illustrating still another electronic device according to the fifth embodiment. FIG. 10 is a schematic view illustrating still another electronic device according to the fifth embodiment.

Embodiments of the present invention will be described below with reference to the drawings.
It should be noted that the disclosure is merely an example, and those skilled in the art can easily conceive of appropriate modifications while maintaining the gist of the invention are naturally included in the scope of the present invention. In addition, the drawings may be schematically represented with respect to the width, thickness, shape, and the like of each part in comparison with actual aspects for the sake of clarity of explanation, but are merely examples, and the interpretation of the present invention is not limited. It is not limited.
In addition, in the present specification and each drawing, elements similar to those described above with reference to the previous drawings are denoted by the same reference numerals, and detailed description may be omitted as appropriate.

(First embodiment)
FIG. 1 is a block diagram illustrating a display device according to the first embodiment.
In the display device 100, for example, a storage unit 15, a backlight 20, a display unit 30, a switch liquid crystal unit 40, a control unit 50, and an imaging unit 60 are provided. In the display device 100, for example, a parallax barrier type stereoscopic view using a liquid crystal barrier is possible. In the display device 100, stereoscopic viewing can be performed with the naked eye.

  The control unit 50 includes, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), and a ROM (Read Only Memory). The control unit 50 controls the operations of the display unit 30 and the switch liquid crystal unit 40. The control unit 50 supplies a display control signal to the display unit 30. The control unit 50 supplies a switch control signal to the switch liquid crystal unit 40. For example, the display unit 30 and the switch liquid crystal unit 40 operate in synchronization with each other. The control unit 50 may supply a backlight control signal to the backlight 20 based on a video signal supplied from the outside.

  The backlight 20 emits light toward the display unit 30. For example, an LED (Light Emitting Diode) is used as the light source of the backlight 20. A CCFL (Cold Cathode Fluorescent Lamp) may be used as the light source of the backlight 20.

  The switch liquid crystal unit 40 includes a plurality of elements. The element performs a switching operation. In the switch operation, the transmission state and the non-transmission state whose transmittance is lower than that of the transmission state are switched. The switch liquid crystal unit 40 is a liquid crystal barrier using liquid crystal as an element. The switch liquid crystal unit 40 operates according to the position of the viewer. An electrode is provided in the element, and the switching operation of the element is controlled by changing the voltage applied to the electrode. The orientation of the liquid crystal is controlled according to the voltage, and the transmission state and the non-transmission state are switched according to the change in the position of the viewer. Examples of elements will be described later.

  The display unit 30 is overlaid on the switch liquid crystal unit 40. The display unit 30 emits display light including a parallax image. As the display unit 30, for example, a liquid crystal display (LCD) is used. The display unit 30 performs display by modulating the light emitted from the backlight 20 by the liquid crystal display element. As the display unit 30, an organic EL display (OELD: Organic Electroluminescence Luminescence Display) may be used.

The imaging unit 60 includes, for example, an imaging element such as a CCD (Charge Coupled Device). The imaging unit 60 captures a viewer who views the display on the display device 100 and acquires an image of the viewer. The control unit 50 calculates the position (angle) of the viewer based on the image acquired by the imaging unit 60. The display device 100 may have a face recognition function for recognizing the face of the viewer. This facilitates the identification of the viewer in the image.
As the position of the viewer, for example, a relative angle between the viewer and the display device 100 may be used. For example, the angle between the normal of the display screen at the reference point of the display screen of the display device 100 and the viewer may be used as the position of the viewer. As the viewer position, a distance between a point obtained by projecting the viewer's position on a plane including the display screen and a reference point on the display screen may be used.

  As the storage unit 15, for example, a nonvolatile memory such as an EEPROM (Electrically Erasable Programmable Read-Only Memory) is used. The storage unit 15 stores data and programs necessary for controlling the display device 100.

FIG. 2 is a schematic cross-sectional view illustrating a part of the display device according to the first embodiment.
FIG. 2 illustrates the backlight 20, the display unit 30, and the switch liquid crystal unit 40.
In this example, the switch liquid crystal unit 40, the display unit 30, and the backlight 20 are stacked in this order. The light emitted from the backlight 20 reaches the viewer through the display unit 30 and the switch liquid crystal unit 40. The display unit 30, the switch liquid crystal unit 40, and the backlight 20 may be stacked in this order.

FIG. 3 is a schematic cross-sectional view illustrating a part of the display device according to the first embodiment.
FIG. 3 illustrates the backlight 20, the display unit 30, and the switch liquid crystal unit 40.
The display unit 30 and the switch liquid crystal unit 40 are bonded via an adhesive layer 51. For the adhesive layer 51, for example, an optical elastic resin is used. The display unit 30 and the switch liquid crystal unit 40 are bonded so that there is no optical loss. The display unit 30 includes a TFT (Thin Film Transistor) substrate 31a, a pixel electrode 31b, a first liquid crystal layer 32, a first counter electrode 33d, a color filter 33c, a counter substrate 33b, and a first polarizing plate 33a. , A second polarizing plate 34. The first liquid crystal layer 32 is provided between the TFT substrate 31a and the counter substrate 33b. A pixel electrode 31 b is provided between the TFT substrate 31 a and the first liquid crystal layer 32. A first counter electrode 33 d is provided between the counter substrate 33 b and the first liquid crystal layer 32. A color filter 33c is provided between the counter substrate 33b and the first counter electrode 33d. Between the first polarizing plate 33a and the second polarizing plate 34, the TFT substrate 31a, the first liquid crystal layer 32, the first counter electrode 33d, the color filter 33c, and the counter substrate 33b are provided.

  The switch liquid crystal unit 40 includes a third polarizing plate 41, a first substrate 42, a second counter electrode 43, a second liquid crystal layer 44, a transparent electrode 45, a second substrate 46, and a fourth polarizing plate 48. ,including. A first substrate 42 is provided between the third polarizing plate 41 and the fourth polarizing plate 48. A second substrate 46 is provided between the fourth polarizing plate 48 and the first substrate 42. A second liquid crystal layer 44 is provided between the first substrate 42 and the second substrate 46. A transparent second counter electrode 43 is provided between the first substrate 42 and the second liquid crystal layer 44. A transparent electrode 45 is provided between the second substrate 46 and the second liquid crystal layer 44. The second counter electrode 43, the transparent electrode 45, and the liquid crystal layer 44 therebetween correspond to one element 47. Between the third polarizing plate 41 and the fourth polarizing plate 48, the first substrate 42, the second counter electrode 43, the second liquid crystal layer 44, the transparent electrode 45, and the second substrate 46 are provided. In this example, the adhesive layer 51 is provided between the first polarizing plate 33 a and the fourth polarizing plate 48. One of the first polarizing plate 33a and the fourth polarizing plate 48 may be omitted.

FIG. 4 is a circuit diagram illustrating a part of the display device according to the first embodiment.
FIG. 4 illustrates a pixel circuit of the display unit 30.
The pixel 70 includes a TFT element Tr and a liquid crystal element LC. The TFT element Tr is, for example, a MOS-FET (Metal Oxide Semiconductor Field Effect Transistor). The gate of the TFT element Tr is connected to the scanning line GCL. The source of the TFT element Tr is connected to the pixel signal line SGL. One end of the liquid crystal element LC is connected to the drain of the TFT element Tr. The other end of the liquid crystal element LC is connected to the counter electrode 33d.

FIG. 5A and FIG. 5B are schematic views illustrating the operation of the display device according to the first embodiment.
These drawings illustrate the switch operation (head tracking operation) of the switch liquid crystal unit 40.
In the display unit 30, for example, left-eye pixels L that display a left-eye image and right-eye pixels R that display a right-eye image are alternately arranged.
The switch liquid crystal unit 40 includes a non-transmissive element group 40a including a plurality of non-transparent elements 47 and a transmissive element group 40b including a plurality of transmissive elements 47. When “LRLR”, “LR” is one cycle. When “LLRRLLRR”, “LLRR” is one cycle. The number of elements 47 provided in the transmissive element group 40b is preferably three or more. Thereby, a fine movement can be performed and a natural display can be implemented.

  As shown in FIG. 5A, the switch liquid crystal unit 40 includes a non-transmissive element group 40a and a transmissive element group 40b. According to this arrangement, the left eye of the human viewer 80 can see the left eye pixel L of the display unit 30. The switch liquid crystal unit 40 of this example is a variable parallax barrier, and includes a plurality of elements that perform a switching operation for switching between a transmissive state and a non-transmissive state. According to the movement of the viewer 80, the position of the non-transmissive element group 40a and the position of the transmissive element group 40b change. In the example of FIG. 5A, the element 40b1 is included in the transmissive element group 40b. The element 40a1 is included in the non-transmissive element group 40a.

  As shown in FIG. 5B, the left eye of the viewer 80 moves in the direction of the arrow 81 in the figure by the movement of the viewer 80. The switching operation of the plurality of elements 47 included in the switch liquid crystal unit 40 is controlled so that the left eye of the human viewer 80 can visually recognize the left eye pixel L of the display unit 30. In FIG. 5A, the element 40b1 is in the transmissive state, and in FIG. 5B, the element 40b1 is changed to the non-transmissive state. In FIG. 5A, the element 40a1 is in a non-transmissive state, and in FIG. 5B, the element 40a1 is changed to a transmissive state.

  The control unit 50 acquires information on the position of the viewer 80 (image of the viewer 80) by the imaging unit 60, and each of the plurality of elements 47 included in the switch liquid crystal unit 40 based on the acquired information. Execute the switch operation. Thereby, when the position of the viewer 80 moves, the viewer 80 can recognize stereoscopic vision appropriately.

FIG. 6A to FIG. 6C are schematic views illustrating the operation of the display device according to the first embodiment.
These drawings illustrate the manner in which the viewer moves with respect to the display device 100.
An imaging unit 60 is provided at a predetermined position of the display device 100. A distance between the viewer 80 and the display screen 101 of the display device 100 is a distance D. The viewer 80 moves in a horizontal direction (the direction of the arrow 81 in the figure) with the display screen 101 of the display device 100 at a position away from the distance D. As the position of the viewer 80, for example, an angle between the normal of the display screen 101 at the reference point of the display screen 101 of the display device 100 and the viewer 80 may be used. The reference point of the display screen 101 is, for example, the center of the display screen 101 in the horizontal and vertical directions.

  The imaging unit 60 captures an image of the viewer 80. The control unit 50 calculates the viewing angle θ (position) based on the image of the viewer 80 imaged by the imaging unit 60. The control unit 50 causes each of a plurality of elements included in the switch liquid crystal unit 40 to perform a switching operation in accordance with a change in the viewing angle θ (position) of the viewer 80.

FIG. 7A to FIG. 7D are diagrams illustrating the transmittance characteristics of the display device according to the first embodiment.
FIG. 7A shows transmittance characteristics in the switch liquid crystal unit 40.
In the figure, the vertical axis represents transmittance Tr (%), and the horizontal axis represents time t (ms).
FIG. 7B to FIG. 7D show a part of the switch liquid crystal unit 40.
The transmittance characteristic 91 is a transmittance characteristic when the switch liquid crystal unit 40 is in the state of FIG. The transmittance characteristic 92 is a transmittance characteristic when the switch liquid crystal unit 40 is in the state of FIG. The transmittance characteristic 93 is a transmittance characteristic when the switch liquid crystal unit 40 is in the state of FIG.

  7B to 7D, the switch liquid crystal unit 40 includes elements 1 to 8, and a transparent electrode is connected to each of the elements 1 to 8. Each of the elements 1 to 8 is switched between a transmission state (transmission) and a non-transmission state (light shielding) by controlling the voltage applied to the transparent electrode. The application of voltage is simply referred to as voltage ON. Not applying voltage is simply referred to as voltage OFF. The voltage OFF is synonymous with applying a voltage of 0 (V).

  Liquid crystal display methods include normally white and normally black. In normally white, the element of the switch liquid crystal unit 40 is transmitted when the voltage is OFF and shielded when the voltage is ON. In normally white, the transmittance is maximized when no voltage is applied, and the transmittance is minimized when a voltage is applied. In normally black, the element of the switch liquid crystal unit 40 is shielded when the voltage is OFF, and is transmitted when the voltage is ON. In normally black, the transmittance is minimized when no voltage is applied, and the transmittance is maximized when a voltage is applied. This embodiment is a case of normally white.

  In FIG. 7B, element 1, element 7 and element 8 are shielded from light by voltage ON. The elements 2 to 6 are made transparent by the voltage OFF. The viewer 80 moves, for example, from left to right as shown in FIGS. 6 (a) to 6 (c). The switch liquid crystal unit 40 performs a switch operation according to the movement of the viewer 80. Specifically, the element 2 is controlled from voltage OFF to voltage ON and switched from transmission to light shielding. The element 7 is controlled from voltage ON to voltage OFF and switched from light shielding to transmission. Thereby, the liquid crystal opening position of the switch liquid crystal unit 40 is shifted by one element from the left to the right in the figure. Note that the liquid crystal opening means that the liquid crystal of the element is in a transmissive state. The liquid crystal opening position is the position of the transmissive element.

  The response of the liquid crystal generally responds faster when a voltage is applied. In the case of normally white, as described in the process, the response from light transmission to light shielding responds faster than light transmission from light transmission. In the case of normally black, light-to-transmission responds faster than light-to-light. In the normally white of this example, as shown in FIG. 7C, the element 2 (from transmission to light shielding) responds faster than the element 7 (from light shielding to transmission). The element 7 responds later than the element 2 as shown in FIG. Since the response of the element 7 is slow, the transmittance of the switch liquid crystal unit 40 temporarily decreases as indicated by the transmittance characteristic 92 in FIG. For this reason, the screen becomes dark and visibility is reduced.

FIG. 8 is a schematic view illustrating a part of the display device according to the first embodiment.
In the first period T1, elements 1 to 5 are arranged in the switch liquid crystal unit 40 from right to left in the drawing. The elements 1 to 4 are transparent when the voltage is OFF, and the element 5 is light-shielded when the voltage is ON. In the second period T2, in accordance with the movement of the viewer 80, the liquid crystal opening position of the switch liquid crystal unit 40 is shifted by one element from right to left in the drawing. The element 1 is controlled from the voltage OFF to the voltage ON, and switched from transmission to light shielding. The element 5 is controlled from the voltage ON to the voltage OFF, and is switched from light shielding to transmission.

FIG. 9A to FIG. 9D are diagrams illustrating response characteristics of the display device according to the first embodiment.
FIG. 9A shows voltage characteristics applied to the element 5 of FIG.
FIG. 9B shows a voltage characteristic applied to the element 1 of FIG.
In the figure, the horizontal axis represents time t, and the vertical axis represents voltage V.
FIG. 9C shows the transmittance characteristics of the element 1 and the element 5.
In the figure, the horizontal axis represents time t, and the vertical axis represents transmittance Tr. The transmittance characteristic 94 indicates the transmittance characteristic of the element 5, and the transmittance characteristic 95 indicates the transmittance characteristic of the element 1.
FIG. 9D shows the transmittance characteristics of the switch liquid crystal unit 40.
In the figure, the horizontal axis represents time t, and the vertical axis represents transmittance Tr. A transmittance characteristic 96 indicates the transmittance characteristic of the entire switch liquid crystal unit 40.

  In FIG. 9A, the element 5 is controlled from the voltage ON to the voltage OFF at time ta, and is switched from light shielding to transmission. In FIG. 9B, the element 1 is controlled from the voltage OFF to the voltage ON at time ta, and is switched from transmission to light shielding. At this time, the element 1 and the element 5 are not switched simultaneously due to a difference in response time of the liquid crystal. That is, as shown in FIG. 9C, the liquid crystal barrier from transmission to light shielding (corresponding to the switch liquid crystal unit 40) responds quickly (see the transmittance characteristic 95 of the element 1), and the liquid crystal barrier from light shielding to transmission is delayed. (See the transmittance characteristic 94 of the element 5). For this reason, as shown in the transmittance characteristic 96 of FIG. 9D, the transmittance of the entire switch liquid crystal unit 40 is temporarily lowered, and the luminance is lowered.

FIG. 10 is a diagram illustrating voltage characteristics of the display device according to the first embodiment.
In the figure, the response time toff (msec) is the time required for switching from light shielding to transmission when the element 5 in FIG. 8 is at voltage OFF, and the response time ton (msec) is the time from element 1 in FIG. Indicates the time taken for switching.
For example, 5 (V) is applied to the element 1 and the element 5. Here, the same voltage is applied to all elements included in the switch liquid crystal unit 40. When 5 (V) is applied to the element 1 and the element 5, the response time toff of the element 5 is longer than the response time ton of the element 1. From this, it can be seen that the response of the element 5 is delayed from the response of the element 1.

FIG. 11 is a diagram illustrating the transmittance characteristics of the display device according to the first embodiment.
In the figure, the vertical axis represents transmittance Tr (%), and the horizontal axis represents time t (ms). A transmittance characteristic 97 indicates a transmittance characteristic when the applied voltage is 3 (V), and a transmittance characteristic 98 indicates a transmittance characteristic when the applied voltage is 5 (V).

  10 and 11, when the voltage applied to the element 1 and the element 5 is 3 (V), for example, the response time toff (38.8 ms) and the response time ton (37.4 ms) are substantially the same. For this reason, a change in luminance is suppressed by lowering the applied voltage to 3 (V) than when the applied voltage is 5 (V).

  The liquid crystal barrier for head tracking switches the liquid crystal opening position according to the movement of the viewer. At this time, there are simultaneously an element that switches from light shielding to transmission and an element that switches from transmission to light shielding. When the liquid crystal used for the element is normally white, the response from light shielding to transmission is slower than the response from transmission to light shielding. For this reason, according to the study of the present inventor, it has been found that when one of the responses is slow, the numerical aperture of the liquid crystal barrier temporarily changes and is recognized as flickering of brightness by the viewer. For this reason, visibility is reduced.

On the other hand, it is conceivable that the response time from light shielding to transmission is substantially the same as the response time from transmission to light shielding. For example, as described above with reference to FIGS. 10 and 11, there is a method of reducing the applied voltage.
However, in general, when the applied voltage is lowered, the tone becomes halftone and contrast is hardly obtained. In the case of normally white, crosstalk may be deteriorated. In the case of normally black, the brightness of the stereoscopic display may be lowered.

  In general, since the liquid crystal barrier needs only white and black, it only needs to have a binary value of voltage on / off. In order to make the responses uniform, the voltage is set to 3 V (for example, the value varies depending on the characteristics of the liquid crystal, depending on the characteristics). At this time, the contrast may be lowered and the crosstalk may be deteriorated. Therefore, a voltage is set so that the response is the same at the end of the transmissive portion to be switched as described above. Thereby, the fall of contrast can be controlled. For example, the electrode is composed of 14 non-transmissive portions and 4 transmissive portions. According to the embodiment, the number of element portions for adjusting the voltage may be two at both ends. For this reason, since there are only two portions where the optical characteristics are deteriorated, the deterioration is reduced. Further, since the positions are at both ends, the influence of crosstalk can be suppressed. Further, when the relationship between the crosstalk and the number of transmission parts is plotted on a graph, the crosstalk takes an optimum value within a certain range. For example, 2 to 6 transmission parts are optimal. Thus, the influence of crosstalk can be suppressed by setting the number of transmitting portions to 2 to 4.

FIG. 12 is a schematic view illustrating a part of the display device according to the first embodiment.
The switch liquid crystal unit 40 includes a first element 111 and a second element 112. The controller 50 performs the first operation in the first period T1 and the second operation in the second period T2 after the first period T1. The first element 111 corresponds to a first switch element. The second element 112 corresponds to a second switch element.

  In the first operation, in the first period T1, an operation of supplying the first signal having the first voltage to the first element 111 and a second voltage value having a second voltage value different from the first voltage value to the second element 112 are performed. An operation of supplying a signal is performed. In this example, the first signal is S1, the first voltage value is V1, the second signal is S2, and the second voltage value is V2. The first element 111 is supplied with a first signal S1, and the second element 112 is supplied with a second signal S2. The first voltage value V1 is, for example, 0 (V), and the second voltage value V2 is, for example, 5 (V). In the first operation, the first element 111 is in a transmission state by the first signal S1 (voltage 0 (V), voltage OFF), and the second element 112 is in the second signal S2 (voltage 5 (V), voltage ON). Non-transparent state. The switch liquid crystal unit 40 switches the liquid crystal opening position in the direction of the arrow 113.

  In the second operation, in the second period T2, an operation of supplying the switched signal CS to the first element 111, and a third signal S3 having the first supply start time t11 and the first voltage value V1 in the second period T2. Is supplied to the second element 112. In the second operation, the first element 111 is set in a non-transmission state with the switched signal CS, and the second element 112 is set in a transmission state with the third signal S3. In the case of this example, in the second element 112, the first voltage value V1 included in the third signal S3 is, for example, 0 (V). For this reason, the voltage is turned off at the first supply start time t11. The post-switching signal CS is supplied to the first element 111 at the first supply start time t11.

  In the present embodiment, the post-switching signal CS has a first voltage value V1 and a third voltage value V3 that is different from the second voltage value V2. The third voltage value V3 is a value between the first voltage value V1 and the second voltage value V2. The second voltage value V2 is greater than the first voltage value V1, and the third voltage value V3 is greater than the first voltage value V1. For example, the first voltage value V1 = 0 (V), the second voltage value V2 = 5 (V), and the third voltage value V3 = 3 (V). In addition, these voltage values are examples and are not limited to these.

  The first element 111 is transparent when the voltage is OFF in the first operation, and is shielded when the voltage is ON in the second operation. The second element 112 is shielded when the voltage is ON in the first operation, and is transmitted when the voltage is OFF in the second operation. At this time, the response time toff (V2 to V1) of the liquid crystal of the second element 112 is 43.8 (ms) in the example of FIG. The response time ton (V1 to V3) of the liquid crystal of the first element 111 is 37.4 (ms) in the example of FIG.

  In the present embodiment, the response time ton of the first element 111 (transmission to light shielding) having a fast liquid crystal response is lengthened in accordance with the response time toff of the second element 112 (light shielding to transmission) having a slow liquid crystal response. Specifically, the response time ton of the liquid crystal is lengthened by lowering the voltage applied to the first element 111. It is desirable that the response time ton of the liquid crystal of the first element 111 and the response time toff of the liquid crystal of the second element 112 are substantially the same. That is, the response time when switching from transmission to light shielding is substantially the same as the response time when switching from light shielding to transmission. Thereby, a luminance change can be suppressed and visibility can be improved.

  Here, as described above, when the applied voltage is lowered, there is a possibility that the crosstalk deteriorates in the case of normally white. Accordingly, it is desirable that the first element 111 is supplied with the fourth signal S4 having the fourth voltage value V4 higher than the third voltage value V3 in the third period T3 after the second period T2. The fourth voltage value V4 is, for example, the second voltage value V2. Thereby, the deterioration of crosstalk can be prevented.

  The first voltage value V1 = 0 (V), the second voltage value V2 = 3 (V), and the third voltage value V3 = 3 (V) may be used. In this case, the response time toff (V2 to V1) of the liquid crystal of the second element 112 is 38.8 (ms) in the example of FIG. The response time ton (V1 to V3) of the liquid crystal of the first element 111 is 37.4 (ms) in the example of FIG.

FIG. 13 is a diagram illustrating a switch operation of the display device according to the first embodiment.
The first element 111 is supplied with the first signal S1 having the first voltage value V1 in the first period T1, and is in a transmissive state. The first element 111 is supplied with a switching signal CS having a third voltage value V3 (voltage ON) at the first supply start time t11 in the second period T2, and switched from transmission to light shielding.

  The second element 112 is supplied with the second signal S2 having the second voltage value V2 in the first period T1, and is in a light shielding state. The second element 112 is supplied with the third signal S3 having the first voltage value V1 (voltage OFF) at the first supply start time t11 in the second period T2, and switched from light shielding to transmission. In the case of this example, the second element 112 has a slower liquid crystal response than the first element 111. For this reason, even if the voltage is turned off, the second element 112 does not immediately switch from light shielding to transmission.

  As described above with reference to FIG. 12, in this embodiment, the switching from transmission to light shielding in the first element 111 is delayed by lowering the voltage applied to the first element 111. As a result, the response time when the first element 111 switches from transmission to light shielding is made substantially the same as the response time when the second element 112 switches from light shielding to transmission.

  According to the present embodiment, by changing the voltage, the luminance change can be suppressed and the visibility can be improved. 12 and 13 exemplify and describe two elements, three or more elements may be used.

FIG. 14A and FIG. 14B are schematic views illustrating a part of the display device according to the first embodiment.
In FIG. 14A, the switch liquid crystal unit 40 is provided with elements 1 to 7. In the first period T1, the first signal S1 (for example, V1 = 0 (V)) is supplied to the elements 1 to 5, and the second signal S2 (for example, V2 = 5 (V)) is supplied to the elements 6 and 7. Is supplied. Thereby, the elements 1 to 5 are transmitted and the elements 6 and 7 are shielded from light. In the second period T2, the second signal S2 is supplied to the element 1, and the element 1 is switched from transmission to light shielding. The first signal S1 is supplied to the element 6, and the element 6 is switched from light shielding to transmission. Thereby, the elements 1 and 7 are shielded from light, and the elements 2 to 6 are transmitted.

  In the above, due to the response characteristics of the liquid crystal, switching from light blocking to transmitting is delayed from switching from transmitting to light blocking. That is, the element 6 responds later than the element 1. For this reason, the luminance change is recognized.

  On the other hand, the switch operation of FIG. In the first period T1, the first signal S1 (for example, V1 = 0 (V)) is supplied to the elements 1 to 5, and the second signal S2 (for example, V2 = 5 (V)) is supplied to the elements 6 and 7. Is supplied. Thereby, the elements 1 to 5 are transmitted and the elements 6 and 7 are shielded from light. In the second period T2, a post-switching signal CS (for example, V3 = 3 (V)) is supplied to the element 1, and the element 1 is switched from transmission to light shielding. The third signal S3 (for example, V1 = 0 (V)) is supplied to the element 6, and the element 6 is switched from light shielding to transmission. The elements 2 to 5 are supplied with the first signal S1. The element 7 is supplied with the second signal S2.

  In the above, the voltage applied to the element 1 is lowered, so that switching from transmission to light shielding in the element 1 is delayed. Thereby, the response time when switching from transmission to light shielding in the element 1 can be made substantially the same as the response time when switching from light shielding to transmission in the element 6.

FIG. 15 is a diagram illustrating the luminance characteristics of the display device according to the first embodiment.
FIG. 15 shows the luminance characteristics of the switch liquid crystal unit 40 when the switch operation of FIG. 14B is performed.
In the figure, the vertical axis represents relative luminance Br (%), and the horizontal axis represents time t (ms).
Thus, it can be seen that the luminance change can be suppressed by making the response time of the element 1 and the response time of the element 6 substantially the same.

  As described above, according to the present embodiment, even when three or more elements are used, a change in luminance can be suppressed and visibility can be improved.

(Second Embodiment)
FIG. 16 is a diagram illustrating the switch operation of the display device according to the second embodiment.
In the present embodiment, in the second operation (see FIG. 12) performed in the second period T2, the second supply start time t12 for supplying the post-switching signal CS to the first element 111 is delayed. Specifically, the second supply start time t12 is later than the first supply start time t11. In the second operation, it is desirable that the first element 111 is supplied with the post-switching signal CS having the second voltage value V2. The second voltage value V2 is 5 (V), for example. In the present embodiment, switching from transmission to light shielding in the first element 111 is delayed by a change in voltage application timing, not a voltage change.

  As described above, the second element 112 has a slower liquid crystal response than the first element 111. After the voltage is turned off at the first supply start time t11, the second element 112 requires a delay time X1 (ms) before switching from light shielding to transmission. Therefore, the second supply start time t12 at which the post-switching signal CS is supplied to the first element 111 is set to a time point shifted behind the delay time X1 from the first supply start time t11. Thereby, the timing at which the first element 111 switches from transmission to light shielding and the timing at which the second element 112 switches from light shielding to transmission can be made substantially the same.

FIG. 17 is a diagram illustrating the transmittance characteristics of the display device according to the second embodiment.
In the figure, the vertical axis represents transmittance (%), and the horizontal axis represents time (ms). The transmittance characteristic 114 is a transmittance characteristic when the delay time X1 in FIG. 16 is 0 (ms). The transmittance characteristic 115 is a transmittance characteristic when the delay time X1 in FIG. 16 is 10 (ms). The transmittance characteristic 116 is a transmittance characteristic when the delay time X1 in FIG. 16 is 14 (ms). The transmittance characteristic 117 is a transmittance characteristic when the delay time X1 in FIG. 16 is 20 (ms).

FIG. 18 is a diagram illustrating luminance characteristics of the display device according to the second embodiment.
FIG. 18 shows luminance change ratios (%) when the delay time X1 is 0 (ms), 10 (ms), 14 (ms), and 20 (ms). Note that “upper” indicates a portion protruding upward in the transmittance characteristics 114 to 117 in FIG. 17. “Lower” indicates a portion protruding downward in the transmittance characteristics 114 to 117 of FIG.

  According to the present embodiment, by changing the voltage application timing, it is possible to suppress the luminance change and improve the visibility, as in the first embodiment. Furthermore, according to the present embodiment, since the voltage is not changed, it is possible to prevent the deterioration of crosstalk and the like.

  The change in voltage in the first embodiment may be combined with the change in voltage application timing in the second embodiment.

(Third embodiment)
FIG. 19 is a schematic view illustrating a part of the display device according to the third embodiment.
The switch liquid crystal unit 40 includes a first element 121 and a second element 122. The controller 50 performs the first operation in the first period T1 and the second operation in the second period T2 after the first period T1. The first element 121 corresponds to a first switch element. The second element 122 corresponds to a second switch element. This embodiment is a case of normally black.

  In the first operation, in the first period T1, an operation of supplying a first signal having a first voltage value to the first element 121 and a second voltage value different from the first voltage value to the second element 122 are performed. The operation of supplying two signals is performed. In this example, the first signal is S1, the first voltage value is V1, the second signal is S2, and the second voltage value is V2. The first element 121 is supplied with a first signal S1, and the second element 122 is supplied with a second signal S2. The first voltage value V1 is, for example, 0 (V), and the second voltage value V2 is, for example, 5 (V). In the first operation, the first element 121 is made non-transmissive by the first signal S1 (voltage 0 (V), voltage OFF), and the second element 122 is second signal S2 (voltage 5 (V), voltage ON). The transmission state is set. The switch liquid crystal unit 40 switches the liquid crystal opening position in the direction of the arrow 123.

  In the second operation, in the second period T2, an operation of supplying the switched signal CS to the first element 121, and a third signal having the first supply start time t11 and the first voltage value V1 in the second period T2. The operation of supplying S3 to the second element 122 is performed. In the second operation, the first element 121 is set to the transmission state by the post-switching signal CS, and the second element 122 is set to the non-transmission state by the third signal S3. In the second element 122, the first voltage value V1 included in the third signal S3 is, for example, 0 (V). For this reason, the voltage is turned off at the first supply start time t11. The post-switching signal CS is supplied to the first element 121 at the first supply start time t11.

  In the present embodiment, the post-switching signal CS is a third voltage value V3 that is different from the first voltage value V1 and the second voltage value V2. The third voltage value V3 is a value between the first voltage value V1 and the second voltage value V2. The second voltage value V2 is greater than the first voltage value V1, and the third voltage value V3 is greater than the first voltage value V1. For example, the first voltage value V1 = 0 (V), the second voltage value V2 = 5 (V), and the third voltage value V3 = 3 (V). In addition, these voltage values are examples and are not limited to these.

  The first element 121 is shielded when the voltage is OFF in the first operation, and is transmitted when the voltage is ON in the second operation. The second element 122 is transparent when the voltage is ON in the first operation, and is shielded when the voltage is OFF in the second operation.

  In the present embodiment, the response time ton of the first element 121 having a fast liquid crystal response (from light shielding to transmitting) is increased in accordance with the response time toff of the second element 122 having a slow liquid crystal response (from transmitting to light shielding). Specifically, the response time ton of the liquid crystal is lengthened by lowering the voltage applied to the first element 121. It is desirable that the response time ton of the liquid crystal of the first element 121 and the response time toff of the liquid crystal of the second element 122 are substantially the same. That is, the response time when switching from transmission to light shielding is substantially the same as the response time when switching from light shielding to transmission. Thereby, a luminance change can be suppressed and visibility can be improved.

  The first element 121 is desirably supplied with the fourth signal S4 having the fourth voltage value V4 higher than the third voltage value V3 in the third period T3 after the second period T2. The fourth voltage value V4 is, for example, the second voltage value V2.

FIG. 20 is a diagram illustrating the switch operation of the display device according to the third embodiment.
The first element 121 is supplied with the first signal S1 having the first voltage value V1 in the first period T1, and is in a light shielding state. The first element 121 is supplied with the switching signal CS having the third voltage value V3 (voltage ON) at the first supply start time t11 in the second period T2, and is switched from light shielding to transmission.

  The second element 122 is supplied with the second signal S2 having the second voltage value V2 in the first period T1, and is in a transmissive state. The second element 122 is supplied with the third signal S3 having the first voltage value V1 (voltage OFF) at the first supply start time t11 in the second period T2, and switched from transmission to light shielding. In the case of this example, the second element 122 has a slower liquid crystal response than the first element 121. For this reason, even if the voltage is turned off, the second element 122 does not immediately switch from transmission to light shielding.

  As described above with reference to FIG. 19, in this embodiment, the switching from the light shielding to the transmission in the first element 121 is delayed by lowering the voltage applied to the first element 121. Accordingly, the response time when the first element 121 switches from light shielding to transmission is made substantially the same as the response time when the second element 122 switches from transmission to light shielding.

  According to the present embodiment, by changing the voltage, it is possible to suppress the luminance change and improve the visibility, as in the first embodiment. In FIG. 19 and FIG. 20, two elements are illustrated and described, but three or more elements may be used.

(Fourth embodiment)
FIG. 21 is a diagram illustrating the switch operation of the display device according to the fourth embodiment.
In the present embodiment, the second supply start time t12 for supplying the post-switching signal CS to the first element 121 is delayed in the second operation (see FIG. 19) performed in the second period T2. Specifically, the second supply start time t12 is later than the first supply start time t11. In the second operation, it is desirable that the first element 121 is supplied with the post-switching signal CS having the second voltage value V2. The second voltage value V2 is 5 (V), for example. In this embodiment, the change from the light shielding to the transmission in the first element 121 is delayed by the change in the voltage application timing, not the voltage change.

  The second element 122 has a slower liquid crystal response than the first element 121. After the voltage is turned off at the first supply start time t11, the second element 122 requires a delay time X2 (ms) before switching from transmission to light shielding. Accordingly, the second supply start time t12 at which the post-switching signal CS is supplied to the first element 121 is set to a time point shifted behind the delay time X2 from the first supply start time t11. Thereby, the timing when the first element 121 switches from light shielding to transmission can be made substantially the same as the timing when the second element 122 switches from transmission to light shielding.

  According to the present embodiment, by changing the voltage application timing, it is possible to suppress a change in luminance and improve the visibility, as in the third embodiment. Furthermore, according to the present embodiment, since the voltage is not changed, it is possible to prevent a luminance change or the like during stereoscopic display.

  Note that the change in voltage in the third embodiment may be combined with the change in voltage application timing in the fourth embodiment.

(Fifth embodiment)
FIG. 22 is a schematic view illustrating an electronic device according to the fifth embodiment.
The electronic device is provided with the display device in each of the above-described embodiments. The electronic device is exemplified as a liquid crystal display. The liquid crystal display includes a video display screen unit 510, a front panel 511, and a filter glass 512.

FIG. 23 is a schematic view illustrating another electronic device according to the fifth embodiment.
The electronic device is exemplified as a digital camera. The digital camera includes a display unit 522, a menu switch 523, and a shutter button 524.

FIG. 24 is a schematic view illustrating still another electronic device according to the fifth embodiment.
The electronic device is exemplified as a video movie camera. The video movie camera includes a main body portion 531, a lens 532, a start / stop switch 533, and a display portion 534.

FIG. 25 is a schematic view illustrating still another electronic device according to the fifth embodiment.
The electronic device is exemplified as a notebook personal computer (notebook PC). The notebook PC includes a main body 541, a keyboard 542, and a display unit 543.

FIG. 26 is a schematic view illustrating still another electronic device according to the fifth embodiment.
The electronic device is exemplified as a mobile phone. The mobile phone includes an upper housing 551, a lower housing 552, and a display 554.

FIG. 27 is a schematic view illustrating still another electronic device according to the fifth embodiment.
The electronic device is exemplified as a smartphone or a tablet. The smartphone or tablet includes a housing 561 and a display unit 562.

  According to the embodiment, a display device and an electronic device that are easy to see can be provided.

The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. For example, regarding the specific configuration of each element such as a switch liquid crystal unit, a display unit, and a control unit included in the display device, the person skilled in the art appropriately implements the present invention by appropriately selecting from a well-known range, As long as an effect can be obtained, it is included in the scope of the present invention.
Moreover, what combined any two or more elements of each specific example in the technically possible range is also included in the scope of the present invention as long as the gist of the present invention is included.

  Any display device that can be implemented by a person skilled in the art based on the above-described display device as an embodiment of the present invention is also included in the scope of the present invention as long as it includes the gist of the present invention.

In the scope of the idea of the present invention, those skilled in the art can conceive various changes and modifications, and it is understood that these changes and modifications also belong to the scope of the present invention.
For example, those in which the person skilled in the art appropriately added, deleted, or changed the design of the above-described embodiments, or those in which the process was added, omitted, or changed the conditions are also included in the gist of the present invention. As long as it is provided, it is included in the scope of the present invention.

  In addition, other functions and effects brought about by the aspects described in the present embodiment, which are apparent from the description of the present specification, or can be appropriately conceived by those skilled in the art, are naturally understood to be brought about by the present invention. .

 DESCRIPTION OF SYMBOLS 1-8 ... Element, 15 ... Memory | storage part, 20 ... Backlight, 30 ... Display part, 31a ... TFT substrate, 31b ... Pixel electrode, 32 ... 1st liquid crystal layer, 33a ... 1st polarizing plate, 33b ... Opposite substrate, 33c ... Color filter, 33d ... First counter electrode, 34 ... Second polarizing plate, 40 ... Switch liquid crystal unit, 40a ... Non-transmissive element group, 40b ... Transmission element group, 41 ... Third polarizing plate, 42 ... First substrate 43 ... 2nd counter electrode, 44 ... 2nd liquid crystal layer, 45 ... Transparent electrode, 46 ... 2nd board | substrate, 47 ... Element, 48 ... 4th polarizing plate, 50 ... Control part, 51 ... Adhesive layer, 60 ... Imaging Part, 70 ... pixel, 80 ... viewer, 81, 113, 123 ... arrow, 91 to 98 ... transmittance characteristic, 100 ... display device, 101 ... display screen, 111, 121 ... first element, 112, 122 ... 2nd element, 114-117 ... transparent Excess ratio characteristic 510 ... Video display screen part 511 ... Front panel 512 ... Filter glass 522 ... Display part 523 ... Menu switch 524 ... Shutter button 531 ... Main part 532 ... Lens, 533 ... Stop switch, 534: Display unit, 541 ... Main body, 542 ... Keyboard, 543 ... Display unit, 551 ... Upper housing, 552 ... Lower housing, 554 ... Display, 561 ... Housing, 562 ... Display unit

Claims (9)

A switch liquid crystal unit including a first switch element and a second switch element;
A display unit overlaid on the switch liquid crystal unit;
A control unit that performs a first operation in a first period and performs a second operation in a second period after the first period;
With
The first operation includes
Supplying a first signal having a first voltage value to the first switch element;
Supplying a second signal having a second voltage value different from the first voltage value to the second switch element;
Including
The second operation is:
Supplying a signal after switching to the first switch element;
Supplying the second switch element with a third signal having a first supply start time and the first voltage value during the second period;
Including
The post-switch signal is
A second supply start time different from the first supply start time; and
The display device having at least one of a third voltage value different from the first voltage value and the second voltage value.   The third voltage value is between the first voltage value and the second voltage value, the second voltage value is greater than the first voltage value, and the third voltage value is greater than the first voltage value. The display device according to claim 1, which is larger. The first switch element and the second switch element can switch between a transmissive state and a non-transmissive state having a lower transmittance than the transmissive state,
The first switch element is in the transmission state in the first operation, and is in the non-transmission state in the second operation,
The display device according to claim 2, wherein the second switch element is in the non-transmissive state in the first operation and is in the transparent state in the second operation.   4. The first switch element according to claim 1, wherein a fourth signal having a fourth voltage value higher than the third voltage value is supplied to the first switch element in a third period after the second period. The display device described in 1.   The display device according to claim 4, wherein the fourth voltage value is the second voltage value.   The display device according to claim 1, wherein the second supply start time is later than the first supply start time.   The display device according to claim 6, wherein in the second operation, the post-switching signal having the second voltage value is supplied to the first switch element. The first switch element and the second switch element can switch between a transmissive state and a non-transmissive state having a lower transmittance than the transmissive state,
The first switch element is in the non-transmissive state in the first operation, and is in the transmissive state in the second operation,
The display device according to claim 2, wherein the second switch element is in the transmissive state in the first operation and in the non-transmissive state in the second operation.   An electronic device comprising the display device according to claim 1.