JP7052538B2 - Display device and display method - Google Patents

Description

The present invention relates to a display device and a display method for displaying an image.

In recent years, a technique for displaying an image on transparent glass such as a windshield of an automobile or a window glass of a building has been developed.

In relation to this, Patent Document 1 below includes a screen in which the optical state changes between a transmission state and a scattering state by applying a voltage, and a projector that projects image light onto the screen to display an image. Display devices have been proposed. According to the display device of Patent Document 1, a normally transparent screen can be temporarily made non-transparent and an image can be displayed on the screen.

Japanese Patent No. 5856284

However, in the display device of Patent Document 1, when displaying an image on a screen, it is necessary to continue to control the voltage applied to the control electrodes arranged inside the screen. Therefore, the display device of Patent Document 1 has a problem that the control of the voltage applied to the screen is complicated and the power consumption is large when displaying the image on the screen.

The present invention solves the above-mentioned problems. Therefore, an object of the present invention is to simplify the voltage control of an image display body whose optical state changes between a transparent state and a non-transparent state when the optical state is changed, and to display an image. It is to provide a display device which can reduce power consumption.

The above object of the present invention is achieved by the following means.

The display device of the present invention has a display function layer whose light scattering property is increased by receiving ultraviolet light and whose light scattering property is reduced by receiving first visible light or applying a voltage, and a voltage on the display function layer. An image display body having a transparent conductive layer for applying light, an ultraviolet light projecting unit that projects ultraviolet light to the image display body, and a first visible light that projects first visible light to the image display body. A light projecting unit, a second visible light projecting unit that projects a second visible light onto an image display body to display an image on the image display body, and an ultraviolet light projecting unit when displaying an image on the image display unit. It also has a control unit for operating the first visible light projection unit and applying a voltage to the transparent conductive layer when the second visible light projection unit is operated and the image is not displayed on the image display body.

In the display method of the present invention, ultraviolet light is projected onto an image display body whose light scattering property is increased by receiving ultraviolet light and whose light scattering property is decreased by receiving first visible light or applying a voltage. The first step, the second step of projecting a second visible light onto an image display body that has increased light scatterability and made it non-transparent, and displaying the image on the image display body, and displaying the image on the image display body. It includes a third step of stopping the light, and a fourth step of projecting a first visible light onto the image display and applying a voltage to reduce the light scattering property of the image display and make it transparent.

According to the present invention, the voltage control of the image display body whose optical state changes between the transparent state and the non-transparent state at the time of changing the optical state is simplified, and the power consumption when displaying the image is simplified. Can be reduced.

It is a perspective view which shows the schematic structure of the display device which concerns on Embodiment 1. FIG. It is sectional drawing which shows the schematic structure of the image display body which concerns on Embodiment 1. FIG. It is sectional drawing which shows the schematic structure of the display function layer in a transparent state. It is sectional drawing which shows the schematic structure of the display function layer in a non-transparent state. It is a figure which shows the optical response characteristic of the display function layer when the 1st visible light is projected in the non-transparent state. It is a figure which shows the optical response characteristic of a display function layer when a voltage is applied in a non-transparent state. It is a figure which shows the operation of the display device when the image display body is made non-transparent. It is a figure which shows the operation of the display device at the time of displaying an image on an image display body. It is a figure which shows the operation of the display device when the image display body is made transparent. It is a figure which shows the state of the projection of the 1st visible light, and the application of voltage when the image display body is made transparent in the display device which concerns on Embodiment 1. FIG. It is a figure which shows the procedure of the display method which concerns on Embodiment 1. FIG. It is sectional drawing which shows the schematic structure of the image display body which concerns on Embodiment 2. It is a figure which shows the state of the projection of the 1st visible light, and the application of voltage when the image display body is made transparent in the display device which concerns on Embodiment 3. FIG. It is a figure which shows the state of the projection of the 1st visible light, and the application of voltage when the image display body is made transparent in the display device which concerns on Embodiment 4. FIG. It is a figure which shows the state when the 1st visible light is projected from the end portion of the image display body in the display device which concerns on Embodiment 5.

Hereinafter, embodiments of the present invention will be described separately from [Embodiment 1] to [Embodiment 5] with reference to the drawings. In the figure, the same reference numerals are used for the same members. In addition, the dimensional ratios in the drawings may be exaggerated for convenience of explanation and may differ from the actual ratios.

[Embodiment 1]
FIG. 1 is a perspective view showing a schematic configuration of the display device 10 according to the first embodiment. The display device 10 of the present embodiment includes an image display body 100, a first projector 200, a second projector 300, a third projector 400, and a control unit 600.

The image display body 100 is a thin plate-shaped member whose optical state changes between a transparent state and a non-transparent state, and is a front surface 100a facing the first projector 200 to the third projector 400 and a side opposite to the front surface 100a. It has a back surface 100b. The image display body 100 changes from a transparent state to a non-transparent state by receiving ultraviolet light, and changes from a non-transparent state to a transparent state by receiving a first visible light or by applying a voltage. .. The image display body 100 is attached to, for example, the windshield of an automobile. A detailed description of the image display body 100 will be described later.

The first projector 200 is a projector that emits ultraviolet light, and is arranged so as to face the front surface 100a of the image display body 100. The first projector 200 projects, for example, ultraviolet light having an intermediate wavelength of about 365 nm as an ultraviolet light projecting unit. The first projector 200 projects ultraviolet light onto the front surface 100a of the image display body 100 to change the light projection region 100c of the ultraviolet light on the image display body 100 from a transparent state to a non-transparent state.

The second projector 300 is a projector that projects visible light having a specific wavelength, and is arranged so as to face the front surface 100a of the image display body 100. The second projector 300 emits first visible light having an intermediate wavelength of, for example, about 450 nm as the first visible light projecting unit. The second projector 300 projects the first visible light onto the front surface 100a of the image display body 100 in the non-transparent state, and changes the ultraviolet light projection region 100c on the image display body 100 from the non-transparent state to the transparent state. Change.

The third projector 400 is a color projector and is arranged so as to face the front surface 100a of the image display body 100. The third projector 400 has one of three colors, blue (intermediate wavelength around 450 nm), green (intermediate wavelength around 532 nm), and red (intermediate wavelength around 640 nm) as the second visible light projector. The second visible light, which is a combination of two or more colors of light, is projected. The third projector 400 projects the second visible light onto the front surface 100a of the non-transparent image display body 100 to display the image 700 on the image display body 100.

The control unit 600 controls the operation of the first projector 200 to the third projector 400 and the on / off of the voltage applied to the image display body 100. The control unit 600 switches between flooded light and non-flooded light of the first projector 200 while communicating with a higher-level control device (not shown). Further, the control unit 600 switches the projection / non-projection of the second projector 300 and switches the voltage applied to the image display body 100 on / off while communicating with the upper control device. Further, the control unit 600 sends image information to the third projector 400 while communicating with a higher-level control device.

The first projector 200 and the third projector 400 are provided so that the image 700 displayed on the image display body 100 by the second visible light is included inside the projection region 100c of ultraviolet light on the image display body 100. Projects ultraviolet light and second visible light. Further, the second projector 300 projects the first visible light so that the projection region 100c of the ultraviolet light is included in the projection region of the first visible light on the image display body 100.

Next, the image display body 100 of the display device 10 will be described in detail with reference to FIG.

FIG. 2 is a cross-sectional view showing a schematic configuration of the image display body 100 according to the first embodiment. The image display body 100 of the present embodiment includes a display function layer 120 and transparent conductive layers 130a and 130b. The image display body 100 is arranged so that the transparent conductive layers 130a and 130b sandwich the display function layer 120. The transparent conductive layer 130a is arranged on the front surface 100a side of the image display body 100, and the transparent conductive layer 130b is arranged on the back surface 100b side of the image display body 100.

The display functional layer 120 is a film member whose optical state changes between a transparent state and a non-transparent state. The display function layer 120 receives ultraviolet light to increase its light scattering property and becomes cloudy, and receives first visible light or applies a voltage to reduce its light scattering property and return to a transparent state. Has characteristics. The display functional layer 120 of this embodiment is a liquid crystal film containing a host liquid crystal molecule 121 and an azobenzene molecule 122. The voltage applied to the display function layer 120 in the present embodiment is, for example, an AC voltage having a frequency of 50 Hz and a voltage value of 50 V.

The transparent conductive layers 130a and 130b are formed by laminating a transparent conductive film that is transparent in the visible light region and has conductivity on a transparent base material such as glass or a transparent resin. For the transparent conductive film, an oxide semiconductor such as indium oxide, tin oxide, or zinc oxide is used.

Next, the display functional layer 120 of the image display body 100 will be described in detail with reference to FIGS. 3A and 3B. FIG. 3A is a cross-sectional view showing a schematic configuration of a transparent display function layer 120, and FIG. 3B is a cross-sectional view showing a schematic configuration of a non-transparent display function layer 120.

As described above, the display functional layer 120 of the present embodiment is a liquid crystal film containing a host liquid crystal molecule (hereinafter, liquid crystal molecule 121) and an azobenzene molecule 122. The structure of the azobenzene molecule 122 changes from a trans body to a cis body when it receives ultraviolet light, and changes from a cis body to a trans body when it receives first visible light. When the azobenzene molecule 122 changes to the cis form, it bends and disturbs the arrangement of the liquid crystal molecule 121. Therefore, ultraviolet light is projected onto the display function layer 120 in which the liquid crystal molecules 121 are arranged substantially perpendicular to the thickness direction of the display function layer (see FIG. 3A) and the liquid crystal phase is the nematic phase. For example, the liquid crystal molecule 121 changes to the focal conic state, and at the same time, the arrangement is disturbed and the liquid crystal molecule 121 changes to the scattered state (see FIG. 3B), and the light scattering property increases. On the other hand, if the liquid crystal molecules 121 are in a scattered state (see FIG. 3B) and the first visible light is projected onto the display function layer 120 in the focal conic state, the liquid crystal molecules 121 are substantially perpendicular to the thickness direction of the display function layer. The light scattering property is reduced by changing to the arrangement state (see FIG. 3A) arranged in. In the following, the arrangement state in which the liquid crystal molecules 121 described above are arranged substantially perpendicular to the thickness direction of the display functional layer (the state shown in FIG. 3A) is simply referred to as an arrangement state, and the arrangement of the liquid crystal molecules 121 is disturbed. The scattered state (state shown in FIG. 3B) is referred to as a scattered state.

As shown in FIG. 3A, the display function layer 120 in which the liquid crystal molecules 121 are arranged is in a transparent state due to a decrease in light scattering property. Therefore, if the second visible light VL is projected onto the display function layer 120, the second visible light VL passes through the display function layer 120. On the other hand, as shown in FIG. 3B, the display functional layer 120 in which the liquid crystal molecules 121 are in a scattered state has an increased light scattering property and is in a non-transparent state. Therefore, if the second visible light VL is projected onto the display function layer 120, the second visible light VL is diffusely reflected on the display function layer 120.

In the display functional layer 120, the structure of the azobenzene molecule 122 changes and the arrangement of the liquid crystal molecules 121 changes when the ultraviolet light is projected and when the first visible light is projected. Therefore, even if the projection of ultraviolet rays and the first visible light is stopped, the arrangement of the liquid crystal molecules 121 after the change is maintained. Therefore, the display functional layer 120 maintains a non-transparent state after the ultraviolet light is projected, and maintains a transparent state after the first visible light is projected, while the liquid crystal molecule 121 maintains the transparent conductive layer 130a. When a voltage is applied between 130b, the liquid crystal molecules 121 scattered and present as shown in FIG. 3B are forced to follow the direction of the generated electric field even if the azobenzene molecule 122 remains in the cis form. It is arranged regularly and becomes an array state. When the voltage is no longer applied, if the azobenzene molecule 122 is a cis form, the regularly arranged liquid crystal molecules 121 return to the scattered state as shown in FIG. 3B.

When the voltage is applied, the display function layer 120 is in a transparent state because the liquid crystal molecules 121 are regularly arranged. The molecule 121 is scattered and returns to the existing scattered state, so that it becomes a non-transparent state. Therefore, the display function layer 120 becomes transparent only when a voltage is applied.

Next, with reference to FIGS. 4A and 4B, the optical response characteristics when the display functional layer 120 of the image display body 100 changes from the non-transparent state to the transparent state will be described. FIG. 4A is a diagram showing the optical response characteristics of the display functional layer 120 when the first visible light is projected in a non-transparent state. FIG. 4B is a diagram showing the optical response characteristics of the display function layer 120 when a voltage is applied in a non-transparent state.

When the first visible light is projected for 2 seconds on the display function layer 120 of the image display body 100 in which ultraviolet light is projected and becomes cloudy and opaque, the display function layer 120 is as shown in FIG. 4A. After starting (turning on) the projection of the first visible light, it gradually becomes transparent and becomes transparent (transparency of 80% or more) in about 7 seconds. The display function layer 120 has an optical characteristic that if the first visible light is projected for 2 seconds or longer, the transparent state is maintained even when the projection of the first visible light is terminated (off). As described above, the display function layer 120 has an optical response characteristic that when it is made transparent only by the first visible light, it takes a long time of about 7 seconds to become transparent, but the transparent state can be maintained.

On the other hand, when a voltage is applied to the display function layer 120 of the image display body 100 which is in a non-transparent state, as shown in FIG. 4B, the display function layer 120 starts (on) applying the voltage, and then 0. It becomes transparent (transmittance of 80% or more) in about 3 seconds, and remains transparent while a voltage is applied. Then, the display function layer 120 becomes non-transparent 0.3 seconds after the application of the voltage is finished (off). In this way, the display function layer 120 can be made transparent in a short time of 0.3 seconds when it is made transparent only by the voltage, but the transparent state cannot be maintained when the application of the voltage is finished (off). Response characteristics.

The display device 10 of the present embodiment effectively utilizes the optical response characteristics of the display function layer 120 of the image display body 100 as described above, thereby changing the optical state of the display function layer 120. The control of the image 700 is simplified and the power consumption when displaying the image 700 is reduced. In addition, the response speed when the display function layer 120 is made transparent is also improved.

Next, the operation of the display device 10 for displaying the image 700 on the image display body 100 will be described with reference to FIGS. 5 to 8.

FIG. 5 is a diagram showing the operation of the display device 10 when the image display body 100 is made non-transparent, and FIG. 6 shows the operation of the display device 10 when the image 700 is displayed on the image display body 100. It is a figure. Further, FIG. 7 is a diagram showing the operation of the display device 10 when the image display body 100 is transparent, and FIG. 8 is a diagram when the image display body 100 is transparent in the display device 10 according to the first embodiment. It is a figure which shows the state of the projection of the 1st visible light and the application of a voltage.

As shown in FIG. 5, when displaying the image 700 on the image display body 100, first, the first projector 200 projects ultraviolet light onto the front surface 100a of the image display body 100. When the ultraviolet light is projected, the display function layer 120 becomes cloudy, and the projected region 100c of the ultraviolet light on the image display body 100 changes from a transparent state to a non-transparent state.

Next, as shown in FIG. 6, the third projector 400 projects the second visible light onto the light projecting region 100c on the non-transparent image display body 100, and the image 700 is projected onto the image display body 100. Is displayed.

In addition, in order to prevent the image display body 100 from returning from the non-transparent state to the transparent state by receiving the second visible light while the image 700 is displayed on the image display body 100, the first projector 200 May project ultraviolet light onto the image display body 100. Specifically, the first projector 200 projects ultraviolet light with an output such that the action of maintaining the cloudy state by the ultraviolet light becomes larger than the action of trying to return to the transparent state by the second visible light. do.

On the other hand, as shown in FIG. 7, when the image 700 is not displayed on the image display body 100 (when the image 700 is erased), first, the first projector 200 and the third projector 400 emit ultraviolet light and second visible light. Stop each of the floodlights.

Next, the second projector 300 projects the first visible light onto the front surface 100a of the image display body 100, and at the same time, the control unit 600 applies a voltage to the image display body 100 to obtain ultraviolet light on the image display body 100. The flooded area 100c of No. 1 is returned from the non-transparent state to the transparent state.

Specifically, as shown in FIG. 8, the control unit 600 starts the projection of the first visible light by the second projector 300 (turns on the first visible light), and at the same time, applies a voltage to the image display body 100. Start (turn on the voltage). Next, the control unit 600 ends the application of the voltage (turns off the voltage) when the voltage is applied for 0.5 seconds, and ends the projection of the first visible light when the first visible light is projected for 0.5 seconds (the projection of the first visible light is terminated). Turn off the first visible light).

In this way, when the projection of the first visible light and the application of the voltage are started at the same time, the image display body 100 tries to change from non-transparent to transparent by both the first visible light and the voltage. 100 changes to a transparent state in 0.3 seconds after starting the projection of the first visible light and the application of the voltage. As described above, it took 7 seconds for the image display body 100 to become transparent only by projecting the first visible light (see FIG. 4A). Therefore, the first visible light is projected at the same time as the voltage is applied. By illuminating, the response speed until the image display body 100 becomes transparent can be increased. Further, the image display body 100 could not maintain the transparent state unless the first visible light was projected for 2 seconds or longer (see FIG. 4A), but the projection of the first visible light and the application of the voltage were started at the same time. Occasionally, the transparent state can be maintained only by projecting the first visible light for 0.5 seconds. Therefore, by simultaneously projecting the first visible light and applying the voltage, the time until the image display body 100 becomes transparent can be shortened, and the image display body 100 can be maintained in the transparent state. The projection time of the first visible light required for the above can also be shortened.

As described above, in the present embodiment, since the projection of the first visible light and the application of the voltage are started at the same time, the time until the image display body 100 is transparently changed is shortened (from 7 seconds to 0.3). Seconds) and the projection time of the first visible light required to maintain transparency can be shortened (from 2 seconds to 0.5 seconds). Therefore, when the image 700 displayed by the second visible light disappears, the image display body 100 can be instantly made transparent, and when the display device 10 of the present embodiment is used for the windshield of an automobile, the front can be visually recognized. The image 700 can be displayed on the windshield without disturbing the sex.

Next, the display method of the present embodiment will be described with reference to FIG. FIG. 9 is a diagram showing a procedure of a display method according to the present embodiment. This procedure is consistent with the operation of the display device 10 described with reference to FIGS. 5-8.

First, ultraviolet light is projected onto the image display body 100 to make the image display body 100 non-transparent (first step). The display function layer 120 of the image display body 100 has an optical feature that the light scattering property is increased by receiving ultraviolet light.

Next, the second visible light is projected onto the image display body 100 to display the image 700 on the image display body 100 (second stage). When the second visible light is projected onto the image display body 100 that has increased light scattering and becomes non-transparent, the image 700 can be displayed on the image display body 100.

Stop displaying the image 700 on the image display body 100 (third stage). When the projection of the second visible light is stopped, the image 700 disappears from the image display body 100.

The first visible light is projected onto the image display body 100 and a voltage is applied to make the image display body 100 transparent (fourth step). When the projection of the first visible light and the application of the voltage are started at the same time, the image display body 100 can be changed from the non-transparent state to the transparent state by both the first visible light and the voltage.

As described above, according to the display device 10 and the display method of the present embodiment, the normally transparent image display body 100 can be temporarily made non-transparent and the image 700 can be displayed on the image display body 100.

As described above, the present embodiment described has the following effects.

(A) The image display body 100 can be made non-transparent by projecting ultraviolet light, and the image display body 100 can be instantly non-transparent by simultaneously starting the projection of the first visible light and the application of voltage. You can change from a transparent state to a transparent state. Therefore, the first visible light is not reflected on the image display body 100, and the visibility in front of the image display body 100 is improved.

(B) Since the image 700 displayed on the image display body 100 by the second visible light projects ultraviolet light so as to be included in the ultraviolet light projection region 100c on the image display body 100, the image display body The image 700 is displayed in the non-transparent area of 100. Therefore, the image 700 is not displayed in the transparent area of the image display body 100, and the visibility of the image 700 is improved.

[Embodiment 2]
The second embodiment will be described with reference to FIG. The second embodiment is an embodiment in which the dimming layer 140 is provided on the image display body 100 of the first embodiment.

FIG. 10 is a cross-sectional view showing a schematic configuration of the image display body 100 according to the second embodiment. The image display body 100 of the present embodiment includes a transparent conductive layer 130a, a display function layer 120, a dimming layer 140, and a transparent conductive layer 130b.

The transparent conductive layer 130a is arranged on the front surface 100a side of the image display body 100, and the transparent conductive layer 130b is arranged on the back surface 100b side of the image display body 100. The display function layer 120 and the dimming layer 140 are arranged between the transparent conductive layer 130a and the transparent conductive layer 130b.

The dimming layer 140 is arranged on the surface side of the display function layer 120 opposite to the surface side on which the ultraviolet light is projected, that is, on the back surface 100b side of the display function layer 120. The dimming layer 140 has an optical property that the light absorption property is increased by receiving ultraviolet light, while the light absorption property is decreased by receiving the first visible light or applying a voltage.

The dimming layer 140 is a transparent film member containing, for example, a photochromic material or an electrochromic material. For example, flugide, diarylethene, etc. are used as the photochromic material. Tungsten oxide or the like is used as the electrochromic material. The dimming layer 140 has an optical property that the light absorption is increased by receiving the ultraviolet light, the color is changed from colorless to gray (or black), and the external light is attenuated. The dimming layer 140 has an optical property that the discoloration disappears by not receiving ultraviolet light, receiving first visible light, or applying a voltage.

The dimming layer 140 may be included in the display function layer 120.

As described above, the present embodiment described above has the following effects in addition to the effects of the first embodiment.

(C) Since the dimming layer 140 is provided on the back surface 100b side of the display function layer 120, the function of absorbing light only in the portion that has received ultraviolet light is exhibited. Therefore, it is possible to absorb the sunlight and the light of the headlight incident from the back surface 100b of the display function layer 120. That is, the contrast is maintained even in a bright environment, and the visibility of the image 700 is improved.

(D) Since the function of absorbing the light of the dimming layer 140 can be controlled by the voltage, the time until the discoloration of the dimming layer 140 disappears (transparency) can be shortened.

[Embodiment 3]
The third embodiment will be described with reference to FIG. The third embodiment is an embodiment in which the timings of the projection of the first visible light and the application of the voltage of the first visible light are staggered.

FIG. 11 is a diagram showing a state of projection of first visible light and application of voltage when the image display body 100 is made transparent in the display device 10 according to the third embodiment.

In the present embodiment, the control unit 600 operates the second projector 300 while applying the voltage to the image display body 100, and the image display body 100 controls the application of the voltage and the second projector 300. After becoming transparent (after 0.5 seconds or more have passed from the projection of the first visible light), the lights are stopped at the same time.

First, when the control unit 600 applies a voltage to the image display body 100, the image display body 100 tries to change from a non-transparent state to a transparent state. Then, while the control unit 600 is about to change from the non-transparent state to the transparent state (within 0.3 seconds from the application of the voltage), the control unit 600 operates the second projector 300 to display the first visible light on the image display body 100. Throw light.

When the first visible light is projected after applying a voltage, the first visible light is projected when the image display body 100 is about to become transparent, so that the first visible light is reflected on the image display body 100. It is possible to prevent the image display body 100 from appearing to be colored for a moment.

As described above, the present embodiment described above has the following effects in addition to the effects of the first embodiment.

(E) Since the first visible light is projected onto the image display body 100 having increased transparency, it is possible to prevent the first visible light from being scattered by the image display body 100. For example, when the image display body 100 is attached to the windshield of an automobile, it is possible to suppress the reflection of the first visible light on the image display body 100, and the visibility in front of the windshield is improved.

[Embodiment 4]
The fourth embodiment will be described with reference to FIG. The fourth embodiment is an embodiment in which the timing of the projection of the first visible light and the application of the voltage of the first visible light of the first embodiment is further shifted from that of the third embodiment.

FIG. 12 is a diagram showing a state of projection of first visible light and application of voltage when the image display body 100 is made transparent in the display device 10 according to the fourth embodiment.

In the present embodiment, the control unit 600 operates the second projector 300 after the image display body 100 becomes transparent due to the voltage applied to the image display body 100, and the voltage application and the second projector 300 are combined with each other. After the image display body 100 becomes transparent (after 0.5 seconds or more have elapsed from the projection of the first visible light), the image display body 100 is stopped at the same time.

First, when the control unit 600 applies a voltage to the image display body 100, the image display body 100 changes from a non-transparent state to a transparent state. Then, the control unit 600 operates the second projector 300 after the image display body 100 changes to the transparent state (after 0.3 seconds or more have elapsed from the application of the voltage), and the first image display body 100 is subjected to the first operation. Project visible light.

When the first visible light is projected after the image display body 100 becomes transparent, the first visible light is projected onto the transparent image display body 100, so that the first visible light is the image display body. It can be prevented from being reflected in 100.

As described above, the present embodiment described above has the following effects in addition to the effects of the first embodiment.

(F) Since the first visible light is projected onto the transparent image display body 100, it is possible to prevent unintended coloring of the image display body 100. For example, when the image display body 100 is attached to the windshield of an automobile, the first visible light is not reflected on the image display body 100, and the visibility in front of the windshield is improved.

[Embodiment 5]
The fifth embodiment will be described with reference to FIG. The fifth embodiment is an embodiment in which the first visible light of the first embodiment is projected from the end portion of the image display body 100.

FIG. 13 is a diagram showing a state in which the first visible light is projected from the end portion of the image display body 100 in the display device 10 according to the fifth embodiment.

The image display body 100 of the present embodiment is the same as the image display body 100 of the first embodiment. In the present embodiment, as shown in FIG. 13, the second projector 300 displays an image from a direction intersecting the direction in which the third projector 400 (see FIG. 1) emits the second visible light (front surface 100a side). The first visible light is projected on the end of the body 100.

In this way, when the first visible light is projected from the end of the image display body 100, the first visible light leaks out of the display function layer 120 because the first visible light guides the inside of the display function layer 120. This does not mean that the image display body 100 can be prevented from being unintentionally colored. Therefore, the transparency of the image display body 100 can be ensured.

If the first visible light is projected from the end of the image display body 100 instead of from the front surface 100a side of the image display body 100, the irradiation distance of the first visible light is extended. Therefore, there is a slight time lag for the first visible light to reach every corner of the image display body 100. However, since the image display body 100 becomes transparent by applying a voltage and then the first visible light is projected, there is no loss due to scattering of the display function layer 120, and the first visible light is projected. 2 It is not necessary to increase the output of the projector 300.

As described above, the present embodiment described above has the following effects in addition to the effects of the first embodiment.

(G) Since the first visible light is projected from the end of the transparent image display body 100, it is possible to prevent unintended coloring of the image display body 100. For example, when the image display body 100 is attached to the windshield of an automobile, the first visible light is not reflected on the image display body 100, and the visibility in front of the windshield is improved.

(H) Since the second projector 300 that emits the first visible light does not need to be provided together with the first projector 200 and the third projector 400, the installation space can be saved.

As described above, the display device 10 of the present invention has been described in the described embodiments 1 to 5. However, the present invention can be appropriately added, modified, and omitted by those skilled in the art within the scope of the technical idea.

For example, the timing and time of the first visible light projection and the application of the voltage are not limited to the timing and time illustrated in FIGS. 8, 11, and 12, and various patterns can be applied.

10 Display device,
100 image display body,
100a front,
100b back,
100c floodlight area,
120 display function layer,
121 Host LCD molecule,
122 Azobenzene molecule,
130a, 130b transparent conductive layer,
140 dimming layer,
200 1st projector (ultraviolet light projector),
300 2nd projector (1st visible light projector),
400 3rd projector (2nd visible light floodlight),
600 control unit,
700 images,
VL second visible light.

Claims (12)

A display function layer in which light scattering is increased by receiving ultraviolet light , light scattering is reduced by receiving first visible light, and light scattering is reduced by applying a voltage, and the display function. An image display body having a transparent conductive layer for applying the voltage to the layer, and
An ultraviolet light projecting unit that projects the ultraviolet light onto the image display body,
A first visible light projecting unit that projects the first visible light onto the image display body,
A second visible light projecting unit that projects a second visible light onto the image display body to display an image on the image display body, and a second visible light projecting unit.
When displaying the image on the image display body, the ultraviolet light projection unit and the second visible light projection unit and the second visible light projection unit are not activated and the voltage is not applied to the transparent conductive layer . When the visible light projection unit is operated and the image is not displayed on the image display body, the first visible light projection unit is not operated without operating the ultraviolet light projection unit and the second visible light projection unit. And a control unit that applies the voltage to the transparent conductive layer,
Has a display device. The image display body is
The display device according to claim 1, wherein the transparent conductive layer is arranged so as to sandwich the display function layer. The image display body is
Light absorption is increased by receiving the ultraviolet light on the surface side of the display function layer opposite to the surface side on which the ultraviolet light is projected, while receiving the first visible light or the above. The display device according to claim 1 or 2, further comprising a dimming layer whose light absorption is reduced by applying a voltage. The control unit
The display device according to any one of claims 1 to 3, wherein after applying the voltage to the image display body, the first visible light projection unit is operated while the voltage is applied. The control unit
The display device according to claim 4, wherein the first visible light projection unit is operated after the image display body becomes transparent due to the application of the voltage. The control unit
The display device according to any one of claims 1 to 5, wherein the operation of the first visible light projection unit and the application of the voltage are stopped after the image display body becomes transparent. The first visible light projecting unit projects the first visible light onto the end portion of the image display from a direction intersecting the direction in which the second visible light is projected, claims 1 to 6. The display device described in any of. The display device according to any one of claims 1 to 7, wherein the voltage applied to the display function layer is an AC voltage. The light scattering property is increased by receiving ultraviolet light, the light scattering property is reduced by receiving the first visible light, and the light scattering property is reduced by applying a voltage . 1 The first step of projecting the ultraviolet light without projecting visible light and without applying the voltage .
The second step of projecting the ultraviolet light and the second visible light onto the image display body whose light scattering property is increased and made non-transparent to display the image on the image display body.
A third step of stopping the display of the image by stopping the projection of the ultraviolet light and the second visible light on the image display body.
Instead of projecting the ultraviolet light and the second visible light onto the image display body, the first visible light is projected and the voltage is applied to reduce the light scattering property of the image display body and make it transparent. The 4th stage of becoming
Display method including. In the fourth stage,
The display method according to claim 9, wherein the first visible light is applied to the image display body and then is projected onto the image display body while the voltage is applied. In the fourth stage,
The display method according to claim 9, wherein the first visible light is made transparent by applying the voltage and then is projected onto the image display while the voltage is applied. In the fourth stage,
The display method according to any one of claims 9 to 11, wherein the first visible light and the voltage are stopped after the image display body becomes transparent.

Images