Display device

Abstract

To provide a technology for achieving face-to-face communication using augmented reality when using a transparent display in a face-to-face manner.SOLUTION: A display device comprises: a first camera that captures a first viewer in a first normal direction of a display face of a transparent display; a second camera that captures a second viewer in a second normal direction which is opposite from the first normal direction of the display face of the transparent display; a microphone; and a control circuit including a user coordinate calculation circuit, a gesture detection circuit, a transcription circuit, and a drawing information generation circuit. The user coordinate calculation circuit specifies the positions of the first viewer and the second viewer based on images from the first camera and the second camera. When the gesture detection circuit determines that the first viewer has spoken, the transcription circuit generates characters based on speech information from the microphone, and the generated characters are displayed on the transparent display by the drawing information generation circuit for the second viewer.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to displays, and is particularly applicable to displays having a transparent display. [Background technology]

[0002] When two users use a transparent display facing each other, for example, the first user can view the necessary information through the screen of the transparent display while looking at the background (e.g., the second user) located behind the transparent display.

[0003] A proposal regarding a transparent display device and a display method thereof is given in JP-T-2015-518580. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2015-518580 Summary of the Invention [Problem to be solved by the invention]

[0005] The present inventors have developed the present disclosure by examining technology for achieving face-to-face communication using augmented reality in face-to-face use of a transparent display.

[0006] An object of the present disclosure is to provide a technology that realizes face-to-face communication using augmented reality when using a transparent display face-to-face.

[0007] Other objects and novel features will become apparent from the description of this specification and the accompanying drawings. [Means for solving the problem]

[0008] A brief outline of the representative aspects of the present invention is as follows.

[0009] That is, The display device is A transparent display and a first camera for capturing an image of a first viewer in a first normal direction of a display surface of the transparent display; a second camera that captures an image of a second viewer in a second normal direction opposite to the first normal direction of the display surface of the transparent display; With a microphone a control circuit having a user coordinate calculation circuit, a gesture detection circuit, a character generation circuit, and a drawing information generation circuit; the user coordinate calculation circuit determines the positions of the first viewer and the second viewer based on the images from the first camera and the second camera; the gesture detection circuit determines whether the first viewer or the second viewer is making a sound; When the gesture detection circuit determines that the first viewer has made a sound, the transcription circuit generates characters based on the voice information from the microphone, and the generated characters are displayed on the transparent display by the drawing information generation circuit toward the second viewer. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating an example of the overall configuration of a display device according to an embodiment. [Diagram 2] FIG. 2 is a diagram for explaining a display example on a transparent display used in the display device of FIG. [Diagram 3] FIG. 3 is a diagram illustrating a display example of a transparent display in face-to-face communication using augmented reality according to the embodiment. [Figure 4] FIG. 4 is an overall block diagram of a display device according to an embodiment. [Diagram 5] FIG. 5 is a diagram illustrating an operation flow of the display device according to the embodiment. [Figure 6]FIG. 6 is a diagram illustrating an example of the overall configuration of a display device according to an embodiment. [Figure 7] FIG. 7 is an overall block diagram of a display device according to an embodiment. [Figure 8] FIG. 8 is a diagram illustrating an operation flow of the display device according to the embodiment. [Figure 9] FIG. 9 is a diagram showing the main components of a transparent display. [Figure 10] FIG. 10 is a diagram illustrating a liquid crystal layer in a transparent state. [Figure 11] FIG. 11 is a diagram illustrating a liquid crystal layer in a scattering state. [Figure 12] FIG. 12 is a cross-sectional view showing a display panel when the liquid crystal layer is in a transparent state. [Figure 13] FIG. 13 is a cross-sectional view showing a display panel when the liquid crystal layer is in a scattering state. [Figure 14] FIG. 14 is a schematic diagram showing an example of the configuration of eye tracking. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0012] The disclosure is merely an example, and those who are skilled in the art can easily come up with appropriate modifications that maintain the gist of the invention, and naturally, these modifications are included in the scope of the present invention. In addition, in order to make the explanation clearer, the width, thickness, shape, etc. of each part may be shown diagrammatically compared to the actual embodiment, but these are merely examples and do not limit the interpretation of the present invention.

[0013] In addition, in this specification and each figure, elements similar to those described above with respect to the previous figures are given the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0014] (Embodiment) Hereinafter, an embodiment (example) according to the present disclosure will be described with reference to the drawings. FIG. 1 is a diagram for explaining an example of the overall configuration of a display device according to an example. FIG. 2 is a diagram for explaining an example of display on a transparent display used in the display device of FIG. 1. FIG. 3 is a diagram for explaining an example of display on a transparent display in face-to-face communication using augmented reality according to an example. FIG. 4 is an overall block diagram of a display device according to an example. FIG. 5 is a diagram for explaining an operation flow of the display device according to an example.

[0015] As shown in FIG. 1, the display device 100 includes a transparent display DSP, a first camera CAMA, a second camera CAMB, a first microphone MICA, and a control circuit CON.

[0016] The transparent display DSP can be configured, for example, by a display panel using polymer dispersed liquid crystal (hereinafter sometimes referred to as "PDLC").

[0017] The first camera CAMA photographs the second user (corresponding person: second observer) USR2 in a first normal direction of the display surface of the transparent display DSP. The second camera CAMB photographs the first user (user: first observer) USR1 in a second normal direction opposite to the first normal direction of the display surface of the transparent display DSP. The first microphone MICA detects the voice of the second user USR2.

[0018] The control circuit CON is electrically connected to the transparent display DSP, the first camera CAMA, the second camera CAMB, and the first microphone MICA. The control circuit CON can detect the position coordinates of the face of the second user USR2 and the line of sight of the second user USR2 based on the image of the second user USR2 captured by the first camera CAMA. The control circuit CON can also detect the position coordinates of the face of the first user USR1 and the line of sight of the first user USR1 based on the image of the first user USR1 captured by the second camera CAMB.

[0019] In the following description, it is assumed that the first camera CAMA captures the second user USR2 (correspondent: second observer) and the second camera CAMB captures the first user USR1 (user: first observer). However, it is also possible to define the user captured by the first camera CAMA as the first user USR1 (correspondent: first observer) and the user captured by the second camera CAMB as the second user USR2 (user: second observer).

[0020] Figure 2 shows an example of the display of the transparent display DSP when the first user USR1 looks at the second user USR2 through the transparent display DSP. As shown in Figure 2, the words spoken by the second user USR2 are transcribed and a speech bubble is displayed at the position of the mouth of the second user USR2 when viewed from the first user USR1, with text displayed in the speech bubble. In this example, the text information "Welcome" is displayed in the speech bubble.

[0021] The display position of the speech bubble is configured to be displayed outside the position coordinates of the second user USR2 as viewed from the first user USR1. That is, the control circuit CON has a character generation circuit (corresponding to CGEA in FIG. 4 described later) that generates characters based on voice information from the first microphone MICA, and displays the generated characters on the transparent display DSP toward the first user USR1. It is preferable that the display position of the characters, that is, the display position of the speech bubble in which the characters are displayed (drawn), is displayed outside the position coordinates indicating the area in which the face of the second user USR2 of the transparent display DSP is projected transparently as viewed from the first user USR1. This makes it easier for the first user USR1 to recognize the characters displayed in the speech bubble. Therefore, in the face-to-face use of the transparent display DSP, face-to-face communication using augmented reality can be realized.

[0022] FIG. 3 shows four other display examples (A, B, C, D) of the transparent display DSP when a first user USR1 sees a second user USR2 through the transparent display DSP.

[0023] Display examples A and B in Fig. 3 are display examples in which the control circuit CON recognizes keywords and contexts based on characters and sentences transcribed from the words spoken by the second user USR2, and displays an arbitrary effect on the face of the second user USR2 projected through the transparent display. Display example A in Fig. 3 is a display example in which text information "happy" is displayed in a speech bubble, and an effect is displayed in which the eyes of the second user USR2 appear as heart marks based on this text information. Display example B in Fig. 3 is a display example in which text information "sad" is displayed in a speech bubble, and an effect is displayed in which tears appear to flow from the eyes of the second user USR2 based on this text information. In other words, the control circuit CON has a keyword detection circuit (corresponding to KWDA in Fig. 4 described later) that can recognize and detect keywords and contexts.

[0024] In the display examples C and D of Fig. 3, the control circuit CON analyzes the image captured by the first camera CAMA, detects the gestures and facial expressions of the second user USR2, and displays an arbitrary effect on the face of the second user USR2 projected through the transparent display. The display example C of Fig. 3 is a display example that displays an effect that makes the second user USR2 look angry by image analysis of a captured image of the angry face of the second user USR2. The display example D of Fig. 3 is a display example that displays an effect that makes the second user USR2 look questioning by image analysis of a captured image of the questioning face of the second user USR2. In other words, the control circuit CON has a gesture detection circuit (corresponding to GEDA in Fig. 4 described later) that can detect gestures and facial expressions.

[0025] A block diagram of the control circuit CON is shown in Fig. 4. The control circuit CON has a first user coordinate calculation circuit COCA, a first gesture detection circuit GEDA, a second user coordinate calculation circuit COCB, a first character generation circuit CGEA, a first keyword detection circuit KWDA, and a drawing information generation circuit DIG.

[0026] The first user coordinate calculation circuit COCA is electrically connected to the first camera CAMA and can detect the position coordinates of the face of the second user USR2 and the line of sight of the second user USR2 based on the image of the second user USR2 captured by the first camera CAMA. In other words, the first user coordinate calculation circuit COCA can identify the position of the second user USR2.

[0027] The first gesture detection circuit GEDA is electrically connected to the first camera CAMA, and can detect gestures and facial expressions of the second user USR2 based on an image of the second user USR2 captured by the first camera CAMA. The first gesture detection circuit GEDA can also identify whether the second user USR2 is making a sound. The first gesture detection circuit GEDA can be configured to have a machine learning function (AI). This allows the first gesture detection circuit GEDA to learn many gestures and facial expressions and accurately determine emotions from the gestures and facial expressions of the second user USR2. This allows the display example described in FIG. 3 to be displayed on the transparent display DSP.

[0028] The second user coordinate calculation circuit COCB is electrically connected to the second camera CAMB and can detect the position coordinates of the face of the first user USR1 and the line of sight of the second user USR2 based on the image of the first user USR1 captured by the second camera CAMB. In other words, the second user coordinate calculation circuit COCB can identify the position of the first user USR1.

[0029] The first character generation circuit CGEA is electrically connected to the first microphone MICA and is capable of generating characters (character information) based on the audio information of words uttered by the second user USR2 detected by the first microphone MICA.

[0030] The first keyword detection circuit KWDA is capable of recognizing and detecting keywords and contexts in the characters generated by the first character generation circuit CGEA.

[0031] The drawing information generating circuit DIG is electrically connected to the first user coordinate calculation circuit COCA, the first gesture detection circuit GEDA, the second user coordinate calculation circuit COCB, the first character creation circuit CGEA, and the first keyword detection circuit KWDA. The drawing information generating circuit DIG receives the detection result of the first user coordinate calculation circuit COCA, the detection result of the first gesture detection circuit GEDA, the detection result of the second user coordinate calculation circuit COCB, the characters generated by the first character creation circuit CGEA, and the detection result of the first keyword detection circuit KWDA. The drawing information generating circuit DIG generates drawing information to be drawn on the transparent display DSP based on these input detection results and characters, and transmits the generated drawing information to the transparent display DSP. As a result, the transparent display DSP can display on the transparent display toward the first user USR1, for example, as described in FIG. 2. In other words, the drawing information generation circuit DIG generates drawing information such that, when viewed from the first user USR1, a speech bubble is displayed at the position of the mouth of the second user USR2 and the characters generated by the first character generation circuit CGEA are displayed in the speech bubble, and supplies the information to the transparent display DSP.

[0032] For example, when the first gesture detection circuit GEDA determines that the second user USR2 has made a sound, the first character generation circuit CGEA generates characters based on the voice information from the first microphone MICA, and the generated characters are displayed on the transparent display DSP toward the first user USR1 by the drawing information generation circuit DIG, thereby operating the display device 100.

[0033] Next, the operation flow of the display device 100 will be described with reference to FIG. 5 based on steps S10 to S16.

[0034] S10: The gaze position of the first user USR1 is detected by the second user coordinate calculation circuit COCB based on the image captured by the second camera CAMB.

[0035] S11: The face coordinate position of the second user USR2 is detected by the first user coordinate calculation circuit COCA based on the image captured by the first camera CAMA.

[0036] S12: The gestures and facial expressions of the second user USR2 are detected by the first gesture detection circuit GEDA based on the image captured by the first camera CAMA.

[0037] S13: If it is determined in S12 that the second user USR2 is speaking, the first transcription circuit CGEA generates characters based on the audio information of the words spoken by the second user USR2 detected by the first microphone MICA.

[0038] S14: If characters are generated in S13, the first keyword detection circuit KWDA recognizes and detects keywords and contexts in the characters generated by the first character generation circuit CGEA.

[0039] S15: The drawing information generating circuit DIG generates drawing information to be displayed on the transparent display DSP based on S10-S14.

[0040] S16: The drawing information generating circuit DIG outputs the generated drawing information to the transparent display DSP. As a result, the transparent display DSP can perform a display such as that shown in Figures 2 and 3. After S16 ends, the process returns to S10 again to perform the operation for the next display.

[0041] Next, another embodiment (example) of the present disclosure will be described with reference to Figures 6, 7, and 8. Figure 6 is a diagram for explaining an example of the overall configuration of a display device according to the example. Figure 7 is an overall block diagram of a display device according to the example. Figure 8 is a diagram for explaining an operation flow of the display device according to the example.

[0042] The display device 100S shown in FIG. 6 differs from the display device 100 shown in FIG. 1 in that a second microphone MICB for detecting the voice of the first user USR1 is added. The control circuit CON can detect the position coordinates of the face of the second user USR2 and the line of sight of the second user USR2 based on the image of the second user USR2 captured by the first camera CAMA. The control circuit CON can also detect the position coordinates of the face of the first user USR1 and the line of sight of the first user USR1 based on the image of the first user USR1 captured by the second camera CAMB. The control circuit CON also has a second character generation circuit (corresponding to CGEB in FIG. 7 described later) that generates characters based on the voice information from the second microphone MICB, and displays the generated characters on the transparent display DSP toward the second user USR2.

[0043] The control circuit CON shown in Fig. 7 differs from the control circuit CON shown in Fig. 4 in that a second gesture detection circuit GEDB electrically connected to the second camera CAMB is provided, and a second character generation circuit CGEB and a second keyword detection circuit KWDB electrically connected to the second microphone MICB are provided. Other configurations and effects of the control circuit CON shown in Fig. 7 are the same as those of the control circuit CON shown in Fig. 4, so that duplicated explanations will be omitted.

[0044] The second gesture detection circuit GEDB can detect gestures and facial expressions of the first user USR1 based on the image of the first user USR1 captured by the second camera CAMB. The second gesture detection circuit GEDB can also identify whether the first user USR1 is making a sound. The second gesture detection circuit GEDB can be configured to have a machine learning function (AI).

[0045] The second transcription circuit CGEB is electrically connected to the second microphone MICB and can generate characters (character information) based on the voice information of the words uttered by the first user USR1 detected by the second microphone MICB. The second keyword detection circuit KWDB can recognize and detect keywords and contexts from the characters generated by the second transcription circuit CGEB.

[0046] The drawing information generating circuit DIG is further electrically connected to the second gesture detection circuit GEDB, the second character generation circuit CGEB, and the second keyword detection circuit KWDB. The drawing information generating circuit DIG further receives the detection result of the second gesture detection circuit GEDB, the characters generated by the second character generation circuit CGEB, and the detection result of the second keyword detection circuit KWDB, and generates drawing information to be drawn on the transparent display DSP based on the input detection results and characters, and transmits the generated drawing information to the transparent display DSP. As a result, the transparent display DSP can display characters for the first user USR1 and characters for the second user USR2, for example, as described in Figures 2 and 3.

[0047] Therefore, a technology can be provided that realizes face-to-face communication using augmented reality when the transparent display DSP of the display device 100S is used face-to-face. That is, the side from which the first user USR1 or the second user USR2 is speaking is detected by the microphone (MICA or MICB), and display information such as text and emotions can be displayed using augmented reality at an appropriate position on the transparent display DSP for the speaking user as seen by the non-speaking user.

[0048] Next, the operation flow of the display device 100S will be described with reference to Fig. 8. Note that S10-S14 are the same as those in Fig. 5, so the overlapping explanations will be omitted. Regarding S15-S16, only the parts that are different from those in Fig. 5 will be explained. Below, steps S20-S26 will be explained.

[0049] S20: The control circuit CON judges whether the second user USR2 is speaking. This judgment can be made, for example, by detecting the gestures and facial expressions of the second user USR2 by the first gesture detection circuit GEDA based on the image captured by the first camera CAMA, or by detecting the gestures and facial expressions of the first user USR1 by the second gesture detection circuit GEDB based on the image captured by the second camera CAMB. If it is judged that the second user USR2 is speaking, the operation of the control circuit CON proceeds to S10. If it is judged that the first user USR1 is speaking, the operation of the control circuit CON proceeds to S22.

[0050] When the process moves to S10, as described with reference to FIG. 5, S10 to S16 are executed, and after S16 is executed, the operation of the control circuit CON moves to S20 again.

[0051] The operation of the control circuit CON when the process proceeds to S22 will be described below.

[0052] S22: The gaze position of the second user USR2 is detected by the first user coordinate calculation circuit COCA based on the image captured by the first camera CAMA.

[0053] S23: The face coordinate position of the first user USR1 is detected by the second user coordinate calculation circuit COCB based on the image captured by the second camera CAMB.

[0054] S24: The gestures and facial expressions of the first user USR1 are detected by the second gesture detection circuit GEDB based on the image captured by the second camera CAMB.

[0055] S25: If it is determined in S24 that the first user USR1 is speaking, the second transcription circuit CGEB generates characters based on the audio information of the words spoken by the first user USR1 detected by the second microphone MICB.

[0056] S26: If characters are generated in S25, the second keyword detection circuit KWDB recognizes and detects keywords and contexts in the characters generated by the second character generation circuit CGEB.

[0057] S15: The drawing information generating circuit DIG generates drawing information for the second user USR2 to be displayed on the transparent display DSP based on S22-S26.

[0058] S16: The drawing information generating circuit DIG outputs the generated drawing information to the transparent display DSP. This allows the transparent display DSP to perform display for the second user USR2, for example, as shown in Figures 2 and 3. After S16 ends, the process returns to S20 again to perform the operation for the next display.

[0059] This makes it possible to realize face-to-face communication using augmented reality when using the transparent display DSP face-to-face.

[0060] Next, a configuration example of a transparent display DSP will be described with reference to Figs. 9 to 13. Fig. 9 is a diagram showing main components of a transparent display. Fig. 10 is a diagram showing a liquid crystal layer in a transparent state. Fig. 11 is a diagram showing a liquid crystal layer in a scattering state. Fig. 12 is a cross-sectional view showing a display panel when the liquid crystal layer is in a transparent state. Fig. 13 is a cross-sectional view showing a display panel when the liquid crystal layer is in a scattering state.

[0061] 9, the transparent display DSP includes a controller CNT indicated by a dashed line in the figure. The controller CNT includes a timing controller TC, gate drivers GD1 and GD2, a source driver SD, a Vcom circuit VC, a light source driver LSD, and the like.

[0062] The timing controller TC generates various signals based on image data and synchronization signals input from the outside. In one example, the timing controller TC performs predetermined signal processing based on the image data to generate a video signal and outputs it to the source driver SD. The timing controller TC also outputs control signals generated based on the synchronization signal to the gate drivers GD1 and GD2, the source driver SD, the Vcom circuit VC, and the light source driver LSD. The timing controller TC will be described in detail later.

[0063] The display area DA indicated by the two-dot chain line in the figure includes a plurality of pixels PX. Each pixel PX includes a switching element SW and a pixel electrode 11. The switching element SW is formed of, for example, a thin film transistor. The switching element SW is electrically connected to a scanning line G and a signal line S. A plurality of pixel electrodes 11 are located in the display area DA and are arranged in a matrix. Therefore, for example, a plurality of pixel electrodes 11 are arranged in a plurality of rows. The pixel electrodes 11 are connected to the signal line S via the switching element SW. A common electrode 21 is located in the display area DA. The common electrode 21 faces the plurality of pixel electrodes 11. Unlike the present embodiment, the common electrode 21 may be divided into at least one pixel PX, each connected to a common line, and a common common voltage may be applied to the common electrode 21. A scanning signal is supplied to each of the scanning lines G from the gate driver GD1 or GD2. A video signal (image signal) is supplied to each of the signal lines S from the source driver SD. A common voltage Vcom is supplied to the common electrode 21 from the Vcom circuit VC. The video signal supplied to the signal line S is applied to the pixel electrode 11 connected to the switching element SW during a period in which the switching element SW is in a conductive state based on the scanning signal supplied to the scanning line G. In the following description, applying a video signal to the pixel electrode 11 to form a potential difference between the pixel electrode 11 and the common electrode 21 may be described as writing a video signal to the pixel PX that includes the pixel electrode 11 (or applying a voltage).

[0064] The light source unit LU is configured to irradiate the liquid crystal layer 30 with light of a color other than achromatic colors, which will be described later. The light source unit LU includes light-emitting elements LS of multiple colors. For example, the light source unit LU includes a light-emitting element (first light-emitting element) LSR that irradiates the liquid crystal layer 30 with light of a first color, a light-emitting element (second light-emitting element) LSG that irradiates the liquid crystal layer 30 with light of a second color, and a light-emitting element (third light-emitting element) LSB that irradiates the liquid crystal layer 30 with light of a third color. It goes without saying that the above-mentioned first color, second color, and third color are different from each other. In this embodiment, the first color is red, the second color is green, and the third color is blue. The light source driver LSD controls the lighting periods of these light-emitting elements LSR, LSG, and LSB. As will be described in detail later, in a driving method in which one frame period has multiple subframe periods, at least one of the three light-emitting elements LSR, LSG, and LSB is lit in each subframe, and the color of the illumination light is switched for each subframe.

[0065] An example of the configuration of a transparent display DSP having a liquid crystal layer 30 that is a polymer dispersed liquid crystal layer will be described below. The liquid crystal layer 30 uses reverse mode polymer dispersed liquid crystal (R-PDLC). Figure 10 is a diagram showing the liquid crystal layer 30 in a transparent state.

[0066] As shown in FIG. 10, the liquid crystal layer 30 includes a liquid crystal polymer 31 and liquid crystal molecules 32. The liquid crystal polymer 31 is obtained, for example, by polymerizing a liquid crystal monomer in a state where the liquid crystal monomer is aligned in a predetermined direction by the alignment regulating force of the alignment films 12 and 22. The liquid crystal molecules 32 are dispersed in the liquid crystal monomer, and are aligned in a predetermined direction depending on the alignment direction of the liquid crystal monomer when the liquid crystal monomer is polymerized. The alignment films 12 and 2 may be horizontal alignment films that align the liquid crystal monomer and the liquid crystal molecules 32 along the XY plane defined by the first direction X and the second direction Y, or may be vertical alignment films that align the liquid crystal monomer and the liquid crystal molecules 32 along the third direction Z.

[0067] The liquid crystal molecules 32 may be positive type having positive dielectric anisotropy or negative type having negative dielectric anisotropy. The liquid crystal polymer 31 and the liquid crystal molecules 32 have the same optical anisotropy. Alternatively, the liquid crystal polymer 31 and the liquid crystal molecules 32 have approximately the same refractive index anisotropy. That is, the liquid crystal polymer 31 and the liquid crystal molecules 32 have approximately the same ordinary refractive index and extraordinary refractive index. Note that the ordinary refractive index and extraordinary refractive index of the liquid crystal polymer 31 and the liquid crystal molecules 32 do not have to be completely the same, and deviations due to manufacturing errors and the like are allowed. In addition, the responsiveness of the liquid crystal polymer 31 and the liquid crystal molecules 32 to an electric field is different. That is, the responsiveness of the liquid crystal polymer 31 to an electric field is lower than the responsiveness of the liquid crystal molecules 32 to an electric field.

[0068] The example shown in Figure 10 corresponds to, for example, a state in which no voltage is applied to the liquid crystal layer 30 (a state in which the potential difference between the pixel electrode 11 and the common electrode 21 is zero), or a state in which a second transparent voltage described later is applied to the liquid crystal layer 30.

[0069] 10, the optical axis Ax1 of the liquid crystalline polymer 31 and the optical axis Ax2 of the liquid crystalline molecule 32 are parallel to each other. In the illustrated example, both the optical axis Ax1 and the optical axis Ax2 are parallel to the third direction Z. The optical axis here corresponds to a line parallel to the traveling direction of a light ray such that the refractive index has one value regardless of the polarization direction.

[0070] As described above, the liquid crystal polymer 31 and the liquid crystal molecules 32 have substantially the same refractive index anisotropy, and the optical axes Ax1 and Ax2 are parallel to each other, so that there is almost no difference in refractive index between the liquid crystal polymer 31 and the liquid crystal molecules 32 in all directions including the first direction X, the second direction Y, and the third direction Z. Therefore, the light L1 incident on the liquid crystal layer 30 in the third direction Z is transmitted through the liquid crystal layer 30 without being substantially scattered. The liquid crystal layer 30 can maintain the parallelism of the light L1. Similarly, the light L2 and L3 incident in an oblique direction inclined to the third direction Z are hardly scattered in the liquid crystal layer 30. Therefore, high transparency is obtained. The state shown in FIG. 10 is called a "transparent state".

[0071] FIG. 11 is a diagram showing the liquid crystal layer 30 in a scattering state. As shown in FIG. 11, as described above, the responsiveness of the liquid crystal polymer 31 to an electric field is lower than that of the liquid crystal molecules 32 to an electric field. Therefore, in a state where a voltage (scattering voltage described later) higher than each of the second transparent voltage and the first transparent voltage described later is applied to the liquid crystal layer 30, the alignment direction of the liquid crystal polymer 31 hardly changes, whereas the alignment direction of the liquid crystal molecules 32 changes according to the electric field. That is, as shown in the figure, the optical axis Ax1 is almost parallel to the third direction Z, whereas the optical axis Ax2 is inclined with respect to the third direction Z. Therefore, the optical axes Ax1 and Ax2 intersect each other. Therefore, a large refractive index difference occurs between the liquid crystal polymer 31 and the liquid crystal molecules 32 in all directions including the first direction X, the second direction Y, and the third direction Z. As a result, the light L1 to L3 incident on the liquid crystal layer 30 is scattered in the liquid crystal layer 30. The state shown in FIG. 11 is called the "scattering state."

[0072] The control unit switches the liquid crystal layer 30 to at least one of a transparent state and a scattering state.

[0073] Fig. 12 is a cross-sectional view showing the display panel PNL when the liquid crystal layer 30 is in a transparent state. As shown in Fig. 12, illumination light L11 emitted from the light-emitting element LS enters the display panel PNL from the end E5, and propagates through the transparent substrate 20, the liquid crystal layer 30, the transparent substrate 10, etc. When the liquid crystal layer 30 is in a transparent state, the illumination light L11 is hardly scattered by the liquid crystal layer 30, and therefore hardly leaks out from the lower surface 10B of the transparent substrate 10 and the upper surface 20T of the transparent substrate 20.

[0074] External light L12 incident on the display panel PNL is transmitted through the liquid crystal layer 30 without being scattered much. That is, external light incident on the display panel PNL from the lower surface 10B is transmitted to the upper surface 20T, and external light incident from the upper surface 20T is transmitted to the lower surface 10B. Therefore, when the display panel PNL is observed from the upper surface 20T side, the user can see the background on the lower surface 10B side through the display panel PNL. Similarly, when the display panel PNL is observed from the lower surface 10B side, the user can see the background on the upper surface 20T side through the display panel PNL.

[0075] 13 is a cross-sectional view showing the display panel PNL when the liquid crystal layer 30 is in a scattering state. As shown in FIG. 13, the illumination light L21 emitted from the light emitting element LS enters the display panel PNL from the end E5 and propagates through the transparent substrate 20, the liquid crystal layer 30, the transparent substrate 10, and the like. In the illustrated example, the liquid crystal layer 30 between the pixel electrode 11α and the common electrode 21 (the liquid crystal layer to which the voltage applied between the pixel electrode 11α and the common electrode 21 is applied) is in a transparent state, so the illumination light L21 is hardly scattered in the region of the liquid crystal layer 30 facing the pixel electrode 11α. On the other hand, the liquid crystal layer 30 between the pixel electrode 11β and the common electrode 21 (the liquid crystal layer to which the voltage applied between the pixel electrode 11β and the common electrode 21 is applied) is in a scattering state, so the illumination light L21 is scattered in the region of the liquid crystal layer 30 facing the pixel electrode 11β. Of the illumination light L21, a portion of the scattered light L211 is emitted to the outside from the upper surface 20T, and a portion of the scattered light L212 is emitted to the outside from the lower surface 10B.

[0076] At the position overlapping with the pixel electrode 11α, the external light L22 incident on the display panel PNL is transmitted through without being scattered by the liquid crystal layer 30, similar to the external light L12 shown in Fig. 12. At the position overlapping with the pixel electrode 11β, the external light L23 incident from the lower surface 10B is partially transmitted through the upper surface 20T after being scattered by the liquid crystal layer 30, at a portion L231. Moreover, the external light L24 incident from the upper surface 20T is partially transmitted through the lower surface 10B after being scattered by the liquid crystal layer 30, at a portion L241.

[0077] Therefore, when the display panel PNL is observed from the upper surface 20T side, the color of the illumination light L21 can be seen at the position overlapping with the pixel electrode 11β. In addition, since a part of the external light L231 passes through the display panel PNL, the background on the lower surface 10B side can also be seen through the display panel PNL. Similarly, when the display panel PNL is observed from the lower surface 10B side, the color of the illumination light L21 can be seen at the position overlapping with the pixel electrode 11β. In addition, since a part of the external light L241 passes through the display panel PNL, the background on the upper surface 20T side can also be seen through the display panel PNL. Note that, since the liquid crystal layer 30 is in a transparent state at the position overlapping with the pixel electrode 11α, the color of the illumination light L21 is hardly seen, and the background can be seen through the display panel PNL.

[0078] Next, an example of the configuration of eye tracking will be described with reference to Fig. 14. Fig. 14 is a schematic diagram showing an example of the configuration of eye tracking.

[0079] In FIG. 14, the camera CAMA (CAMB) measures the eye position of the second user USR2 (first user USR1), and transfers the data to the first user coordinate calculation circuit COCA (second user coordinate calculation circuit COCB) as a position detector. The first user coordinate calculation circuit COCA (second user coordinate calculation circuit COCB) creates position coordinate data indicating the eye position, and transfers the data to the drawing information generation circuit DIG. The drawing information generation circuit DIG calculates the approximate mouth position coordinate of the second user USR2 (first user USR1) based on the position coordinate data indicating the eye position. The drawing information generation circuit DIG generates drawing information by positioning a speech bubble in which characters are displayed based on the calculated mouth position coordinate, and transmits the generated drawing information to the transparent display DSP. As a result, for example, the drawing position of the speech bubble on the transparent display DSP can be drawn at the mouth position of the second user USR2 (first user USR1). Furthermore, when the position of the mouth of the second user USR2 (first user USR1) moves on the transparent display DSP, the drawing position of the speech bubble can be moved to follow the moving position of the mouth of the second user USR2 (first user USR1). This makes it possible to realize the display examples described in Figures 2 and 3 on the transparent display DSP. Therefore, in face-to-face use of a transparent display, face-to-face communication using augmented reality can be realized.

[0080] All display devices that can be implemented by a person skilled in the art through appropriate design modifications based on the display devices described above as the embodiments of the present invention are within the scope of the present invention as long as they include the gist of the present invention.

[0081] Within the scope of the concept of the present invention, a person skilled in the art may conceive of various modifications and alterations, and it is understood that such modifications and alterations also fall within the scope of the present invention. For example, those in which a person skilled in the art appropriately adds or deletes components or modifies the design of each of the above-mentioned embodiments, or adds or omits steps or modifies conditions, are also included in the scope of the present invention as long as they include the gist of the present invention.

[0082] Furthermore, other effects and advantages brought about by the aspects described in this embodiment that are obvious from the description in this specification or that can be appropriately thought of by a person skilled in the art are naturally understood to be brought about by the present invention.

[0083] Various inventions can be formed by appropriately combining the multiple components disclosed in the above embodiments. For example, some components may be deleted from all the components shown in the embodiments. Furthermore, components across different embodiments may be appropriately combined. [Explanation of symbols]

[0084] 100:Display device DSP: Transparent Display CAMA, CAMB: Camera MICA,MICB: Microphone COCA, COCB: User coordinate calculation circuit GEDA, GEDB: Gesture detection circuit CGEA, CGEB: Character generation circuit KWDA, KWDB: Keyword detection circuit DIG: Drawing information generation circuit CON: Control circuit

Claims

1. A transparent display and a first camera for capturing an image of a first viewer in a first normal direction of a display surface of the transparent display; a second camera for photographing a second viewer in a second normal direction opposite to the first normal direction of the display surface of the transparent display; With a microphone a control circuit having a user coordinate calculation circuit, a gesture detection circuit, a character generation circuit, and a drawing information generation circuit; the user coordinate calculation circuit determines the positions of the first viewer and the second viewer based on the images from the first camera and the second camera; the gesture detection circuit determines whether the first viewer or the second viewer is making a sound; When the gesture detection circuit determines that the first viewer has made a sound, the transcription circuit generates characters based on the sound information from the microphone, and the generated characters are displayed on the transparent display by the drawing information generation circuit toward the second viewer. Display device.

2. 2. The display device according to claim 1, A display device in which the generated character is displayed at a position outside the position coordinates of the first viewer when viewed from the second viewer.

3. 2. The display device according to claim 1, The gesture detection circuit determines emotions of the first viewer and the second viewer from their facial expressions, and displays content corresponding to the determined emotion of one of the viewers on the transparent display toward the other viewer.

4. 2. The display device according to claim 1, The display device, wherein the transparent display is a display panel using a polymer dispersed liquid crystal.

5. 2. The display device according to claim 1, The gesture detection circuit has a machine learning function.

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