JP6511725B2 - Interactive display method and interactive display apparatus - Google Patents

Description

  The present invention relates to an interactive display method and an interactive display device.

  2. Description of the Related Art There is known an interactive display device which combines and displays an image based on an image signal input from an external device and an image obtained by drawing an object such as characters or drawings corresponding to an operation on a screen. Here, an image based on an image signal input from an external device is referred to as an external image, and an object corresponding to an operation on a screen is referred to as an operation input object.

  Patent Document 1 describes a drawing mode for drawing an operation input object according to an operation on a screen and a mode for transmitting an operation signal such as a click to an external device according to an operation on the screen (external device operation mode. And bidirectional projectors are described.

JP, 2013-152739, A

  Since the image signal input from the external device to the bidirectional projector is a signal for displaying an image drawn by the external device, the external image changes when an operation is performed on the screen in the external device operation mode. On the other hand, the operation input object is an image drawn by the interactive projector and an image which the external device does not participate in any processing.

  Therefore, in the bidirectional projector described in Patent Document 1, the operation input object does not change even if the external image is changed by performing the operation on the screen in the external device operation mode. For this reason, for example, when the external image representing a specific slide of the application program for presentation and the operation input object representing the comment corresponding to the slide are combined and displayed, from the drawing mode In the external device operation mode, when the next slide is selected by the operation on the screen, the next page is displayed with the comment unrelated to the next slide. Then, in order to delete the operation input object unrelated to the slide, there is a problem that an operation for deleting the operation input object is required in addition to the operation of selecting the next slide.

  The present invention is created to solve such a problem, and an object of the present invention is to eliminate the need for an operation of editing an operation input object which is no longer corresponding to an external image.

  (1) The bidirectional display method for achieving the above object comprises an image signal input step of inputting an image signal from an external device, a display step of displaying an image on a screen based on the display signal, and an operation on the screen An image operation detection step for detecting as an image operation, a drawing step for drawing an operation input object corresponding to the image operation, and a composite image obtained by combining an external image based on the image signal and the operation input object When the output step of outputting the display signal, the interlocked operation detection step of detecting the interlocked operation, and the interlocked operation are detected, the device operation signal corresponding to the interlocked operation is output to the external device and the device operation signal is output. An interlocked editing step of editing the operation input object so as to correspond to a change in the external image according to the correspondence; Including.

  According to the present invention, the operation of editing the operation input object which is no longer corresponding to the external image is unnecessary.

(2) In the interlocked editing step of the interactive display method for achieving the above object, the operation input object may be deleted.
By adopting this configuration, the operation of deleting the operation input object which is no longer compatible with the external image becomes unnecessary.

(3) In the interlocked editing step of the interactive display method for achieving the above object, the operation input object may be enlarged or reduced.
By adopting this configuration, an operation of enlarging or reducing the operation input object so as to correspond to the size of the object represented by the changed external image becomes unnecessary.

(4) In the interlocked editing step of the interactive display method to achieve the above object, the operation input object may be moved.
By adopting this configuration, the operation of moving the operation input object to correspond to the position of the object represented by the changed external image becomes unnecessary.

(5) The bidirectional display method for achieving the above object further includes a mode setting step of setting a drawing mode or an external device operation mode, and in the drawing mode, the operation on the screen is performed in the image operation detection step. An image operation may be detected, and in the external device operation mode, a predetermined operation on the screen may be detected as the interlocked operation in the interlocked operation detection step.
By adopting this configuration, since the same operation performed by the user can be detected as either an image operation or a linked operation according to the mode, the type of operation can be reduced. Therefore, an interactive display device with a simple user interface and easy operation can be realized.

  The present invention is also applicable to a bidirectional display device. The functions of each means described in the claims are realized by hardware resources whose functions are specified by the configuration itself, hardware resources whose functions are specified by a program, or a combination thereof. Also, the functions of these means are not limited to those realized by hardware resources that are physically independent of each other.

The screen block diagram concerning the embodiment of the present invention. FIG. 2 is a block diagram according to an embodiment of the present invention. The screen block diagram concerning the embodiment of the present invention. 3 is a flowchart according to an embodiment of the present invention. The screen block diagram concerning the embodiment of the present invention. The screen block diagram concerning the embodiment of the present invention. 3 is a flowchart according to an embodiment of the present invention. The screen block diagram concerning the embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. The same reference numerals are given to corresponding components in the respective drawings, and the overlapping description will be omitted.

1. Overview A projector 1 as an embodiment of the bidirectional display device of the present invention is a device that projects and displays an image on a projection surface such as a wall, a desk, or a dedicated screen as a screen. As shown in FIG. 1A, the projector 1 has a window as a composite image obtained by combining an external image A22a based on an image signal input from an external device such as a PC or a smartphone and an operation input object A21g corresponding to an operation on a projection surface. Project image A2.

  The projector 1 operates in the drawing mode or the external device operation mode when combining and projecting the external image A 22 a and the operation input object A 21 g. In the drawing mode, the projector 1 detects an operation on the screen as an operation (image operation) for editing the operation input object A21g. When an image operation is detected, the projector 1 draws the operation input object A21g according to the detected image operation. In the external device operation mode, the projector 1 detects an operation on the screen as an operation (external device operation) on an external device such as a PC, and outputs an operation signal corresponding to the external device operation to the external device. Further, in the external device operation mode, the projector 1 detects a specific external device operation as a linked operation, outputs a corresponding operation signal to the external device, and erases all the operation input objects A21g as shown in FIG. 1B. The window image A2 is updated.

2. Configuration of Projector As shown in FIG. 2, the projector 1 includes a light source drive unit 16, a projection light source 17, a liquid crystal light valve 10, and a liquid crystal drive unit 11 in the first housing 1 a as a display unit. , A control unit 15, an external storage 151, an operation unit 18, a power supply unit 19 and the like. The projector 1 further includes a receiving unit 21 functioning as an image operation detecting unit and an interlocking operation detecting unit and a position detecting unit 22 in the second case 1 b connected to the first case 1 a. The projector 1 further includes an electronic pen 23.

  The projection light source 17 is constituted by a high pressure mercury lamp, an LED (Light Emitting Diode), a laser or the like, and is driven by the light source drive unit 16. The input / output interface 14 as an external device interface includes a plurality of types of input / output terminals such as a USB terminal, an Ethernet (registered trademark) terminal, an HDMI terminal, and an RS232c terminal, and communicates with the external device. While inputting an image signal, an apparatus operation signal is output to an external apparatus. The control unit 15 controls each unit of the projector 1 by executing a control program stored in the external storage 151. The control unit 15, which functions as a drawing unit, an output unit, and an interlocked editing unit, includes an image signal processing unit 13 and an OSD processing unit 12, and operates the image signal input from an external device and the operation input from the position detection unit 22. A drawing process is performed based on the position signal, and a projection signal as a display signal is output. The image signal processing unit 13 generates image data of the external image layer and image data of the operation input layer as a result of drawing processing based on the image signal input from the external device and the operation position signal input from the position detection unit 22. Is output to the OSD processing unit 12. The OSD processing unit 12 combines the image data of each layer and outputs a projection signal corresponding to the liquid crystal light valve 10. The liquid crystal drive unit 11 converts the projection signal output from the OSD processing unit 12 into an analog signal for driving each pixel of the liquid crystal light valve 10. The liquid crystal light valve 10 has three liquid crystal panels 10a, 10b and 10c each of which controls the transmittance of light of wavelengths of red, green and blue emitted from the projection light source 17 and separated by a dichroic mirror (not shown). Prepare. The operation unit 18 supplies power from the external power supply to the power supply unit 19 with a menu key 181 for inputting an instruction to project the OSD menu, a selection key 182 for selecting an item in the OSD menu, and the determination key 183. A power switch 184 is provided to turn on and off. The power supply unit 19 supplies power to each unit of the projector 1.

  The electronic pen 23 includes a contact sensor 231, a light emitting unit 232, a power switch 233, and a side switch 234 in a pen-shaped housing. The contact sensor 231 is provided at the tip of the electronic pen 23 and detects the contact state with the object and the non-contact state. The light emitting unit 232 is provided near the tip of the electronic pen 23 and emits light of an infrared wavelength while the contact sensor 231 is detecting a contact state with the object. The power switch 233 is a switch for controlling power supply from the battery (not shown) to the contact sensor 231 and the light emitting unit 232. The side switch 234 functioning as a mode setting unit is a switch for switching from the drawing mode to the external device operation mode. During a period in which the contact sensor 231 detects the contact state with the object in a state where the side switch 234 is pressed, the electronic pen 23 is used to detect an operation on the projection surface as an external device operation. 23 works. Specifically, when the contact sensor 231 detects a contact state with an object in a state where the side switch 234 is pressed, the wavelength of light emitted from the light emitting unit 232 is not pressed by the side switch 234. Change it to the state. In this case, the light emitting unit 232 needs two or more light sources having different wavelengths. For example, when the side switch 234 is pressed, the number of light sources of the light emitting unit 232 to be lit is increased, and the image of the light emitting unit 232 captured by the receiving unit 21 changes from the state where the side switch 234 is not pressed. You may do so. In this case, the light emitting unit 232 needs two or more light sources having the same wavelength or different wavelengths.

  The receiving unit 21 is an infrared video camera for imaging the entire projection area A1 of the projection plane, and receives light of infrared wavelength, and during the period when the tip of the electronic pen 23 is in contact with the projection plane in the projection area A1. And image data corresponding to the light of the infrared wavelength emitted from the electronic pen 23. The position detection unit 22 analyzes the image data output from the reception unit 21 to detect the light emission position of the light of the infrared wavelength, that is, the position of the electronic pen 23, and operates the operation position signal indicating the position of the electronic pen 23. Output. The operation position signal is converted by the control unit 15 into the coordinates of the window image A2. The position detection unit 22 analyzes the image data output from the reception unit 21 to determine whether the side switch 234 of the electronic pen 23 is pressed, and outputs a mode signal according to the determination result. . When the side switch 234 is not pressed, a mode signal indicating the drawing mode is output, and when the side switch 234 is pressed, a mode signal indicating the external device operation mode is output. Therefore, the operation of bringing the tip of the electronic pen 23 into contact with the projection surface in the drawing mode is detected as an image operation, and the operation of bringing the tip of the electronic pen 23 into contact with the projection surface in the external device operation mode is detected as an external device operation. .

3. Two-way projection method 3-1. Drawing Layer and Drawing Area Next, a layer and an area (drawing area) in which the control unit 15 draws an external image and an operation input object will be described with reference to FIG.

  The external image layer A20 shown in FIG. 3A and the operation input layer A21 shown in FIG. 3B are combined with the drawing area A2s in the projection area A1 shown in FIG. 3C. Here, an image of the drawing area A2s obtained by combining the external image layer A20 and the operation input layer A21 is referred to as a window image. The resolution (real resolution) of the effective area of the liquid crystal light valve 10 and the trapezoidal distortion correction value determine the drawing area A2s of the window image for the projection area A1, which is the maximum area that can be projected by the projector 1. When trapezoidal distortion correction is performed, the drawing area A2s of the window image becomes a non-rectangle smaller than the projection area A1 which is the maximum area that can be projected by the projector 1 as shown by a broken line in FIG. 3C. The trapezoidal distortion correction value may be automatically set based on the result of detection of the projection state, or may be set by the user using the OSD menu. The image signal processing unit 13 of the control unit 15 separately draws the external image layer A 20 and the operation input layer A 21 shown in FIG. 3A, and the OSD processing unit 12 superposes and combines two layers in the area A 2 s The projection signal for projecting the image A2 is output.

  In the external image layer A20, an external image is drawn based on an image signal input from the input / output interface 14, that is, based on an image signal output from an external device. When the aspect ratio of the external image and the aspect ratio of the window image A2 are different, the control unit 15 does not cause the external image to protrude from the drawing area of the window image A2, and the two sides of the external image overlap the two sides of the window image A2. Thus, the drawing area A22s of the external image is set. If the resolution of the external image represented by the input image signal does not match the resolution of the set drawing area, the external image is enlarged or reduced.

  The operation input layer A21 is drawn in front of the external image layer A20 in the area A2s. In the operation input layer A21, the image signal processing unit 13 draws icons A21a, A21b, A21c, A21d, A21e, A21p and an operation input object A21g corresponding to the operation position signal input from the position detection unit 22. Icons A21a, A21b, A21c, A21d, and A21e indicate areas for causing the user to select what graphic the operation using the electronic pen 23 on the operation area on the projection plane should be drawn on the operation input layer A21. There is.

3-2. Drawing Mode When the control position signal indicating the area where the icons A21a, A21b, A21c, A21d, and A21e are drawn and the mode signal indicating the drawing mode are input from the position detection unit 22, the control unit 15 corresponds to the respective areas. Prepare for the drawing process.

  When the tip of the electronic pen 23 contacts the area where the icon A21a is projected, the image signal processing unit 13 draws the contact locus of the tip of the electronic pen 23 with the projection plane thereafter as the operation input object A21g on the operation input layer A21. . When the tip of the electronic pen 23 contacts the area where the icon A21b is projected, the image signal processing unit 13 changes the thickness of the line drawn on the operation input layer A21. When the tip of the electronic pen 23 contacts the area where the icon A21c is projected, the image signal processing unit 13 manipulates a rectangle whose start and end points of the contact locus of the tip of the electronic pen 23 with the projection plane thereafter Draw on the input layer A21. When the tip of the electronic pen 23 contacts the area where the icon A21 d is projected, the image signal processing unit 13 determines that the ellipse inscribed in the rectangle whose diagonals have the start point and the end point of the contact locus of the tip of the electronic pen 23 Is drawn on the operation input layer A21. When the tip of the electronic pen 23 contacts the area where the icon A21e is projected, the image signal processing unit 13 projects the image using the electronic pen 23 before that on the contact locus of the tip of the electronic pen 23 with respect to the projection plane thereafter. The operation input object A21g corresponding to the operation on the surface is deleted. Further, while the drawing process corresponding to the icons A21a, A21b, A21c, A21d, A21e is being prepared or executed, the image signal processing unit 13 emphasizes the corresponding icons A21a, A21b, A21c, A21d, A21e. To draw for. The icon A21 p indicates an area where the tip of the electronic pen 23 should be in contact with the projection surface in order to input a print instruction.

3-3. External Device Operation Mode Next, the linked editing process of the projector 1 in the external device operation mode will be described with reference to FIG. When the operation position signal and the mode signal are input from the position detection unit 22, the control unit 15 determines the mode based on the mode signal (S1), and when it is determined as the external device operation mode, the external device operation mode Transition to That is, it is determined whether to detect the device operation or the image operation from the operation signal according to the mode signal.

  When transitioning to the external device operation mode, the control unit 15 determines whether the detected device operation is a linked operation based on the operation position signal (S2). The interlocking operation is an operation on an external device such as a PC and an operation on an operation input object A21g. In this embodiment, the left click on the PC is taken as the linked operation. The OS (Operating System) of the PC brings the tip of the electronic pen 23 into contact with the projection surface while pressing the side switch 234 of the electronic pen 23 and releases the tip of the electronic pen 23 from the projection surface without moving it on the projection surface When the operation position signal corresponding to the operation is input, the left click is recognized. That is, when the operation position signal and the mode signal corresponding to such a left click are input, the control unit 15 determines that the interlock operation is performed.

  If it is determined that the operation is a linked operation, the control unit 15 deletes all operation input objects (S4). That is, the control unit 15 erases all the operation input objects A21g drawn before the interlocked operation as shown in FIGS. 5A and 5B. As a result, the window image A2 displayed on the projection plane by the projector 1 changes as shown in FIGS. 1A to 1B, and the operation input object A21g disappears from the screen.

  Here, as a method of deleting only the operation input object from the operation input layer, an identifier indicating the operation input object or icon is attached to each pixel of the operation input layer, and all the identifiers indicating the operation input object are attached. Reset the pixels of to their initial values. Here, the initial value mentioned here is a pixel to which the pixels of the external image layer on the back are weighted at 100% and added when the layers are superimposed and synthesized, and the pixels of the operation input layer are weighted at 0% and added It will be a value. Also, the operation input layer is divided into a layer for drawing the operation input object and a layer for drawing the icons A21a, A21b, A21c, A21d, A21e, A21p, or the operation input object and the icons are all different. A method of drawing on a layer and resetting the entire layer for drawing an operation input object to an initial value may be adopted.

  Next, the control unit 15 outputs the operation position signal to the external device as a device operation signal (S5). Therefore, in the external device operation mode, the external device recognizes the device operation such as left click, right click, double click, drag, or drop based on the operation position signal, and performs processing according to the recognized device operation.

  Here, an application program for presentation is executed on a PC as an external device, and the application program recognizes a situation in which a left click is recognized as an operation of slide feed (processing of switching a currently displayed slide to the next slide). The effects of the present embodiment will be specifically described on an assumption. As described above, in the present embodiment, the operation recognized as a left click on the PC is detected by the projector 1 as a linked operation. Since the operation position signal corresponding to the interlocked operation is output to the PC, when the projector 1 detects the interlocked operation, the OS of the PC recognizes the left click and the application program recognizes the slide feed operation. When the application program of the PC recognizes the slide feed operation, it draws the data of the next slide as an image to display the next slide. As a result, since the image signal corresponding to the image on which the next slide is drawn is input to the projector 1, the external input image displayed on the projection plane is to represent the next slide. If the operation input object is displayed as a comment on the previous slide represented by the external input image, the comment does not correspond to the next slide. According to the present embodiment, when the operation to change the external input image so as to represent the next slide from the previous slide is performed, all the operation input objects corresponding to the previous slide are erased, so that it corresponds to the next slide. There is no need to perform another operation to delete an operation input object that has been lost. That is, according to the present embodiment, the operation of editing the operation input object which is no longer corresponding to the external image is unnecessary.

  Furthermore, according to the present embodiment, the tip of the electronic pen 23 is brought into contact with the projection surface while pressing the side switch 234 of the electronic pen 23, and the tip of the electronic pen 23 is released from the projection surface without being moved on the projection surface. A series of operations is detected as an image operation for drawing a point in the drawing mode, and is detected as a linked operation by the projector 1 in the device operation mode and is detected as a left click by the PC. Therefore, the type of operation can be reduced. Therefore, the projector 1 with a simple user interface and easy operation can be realized.

4. Other Embodiments The technical scope of the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the scope of the present invention.

  For example, a state in which the side switch 234 is not pressed is set to the external device operation mode, a state in which the side switch 234 is pressed is set to the drawing mode, and predetermined device operations such as left click detected in the external device operation mode You may detect as interlocking device operation.

  Further, for example, a switching operation between the drawing mode and the external device operation mode may be detected using the operation unit 18, or an operation that is not an operation on the screen may be detected as a device operation. Specifically, the operation of pressing the selection key 182 or the determination key 183 of the operation unit 18 may be detected as a device operation and a linked operation. In addition, an operation of pressing a switch of an apparatus (for example, an apparatus such as a laser pointer) having a function of wirelessly transmitting an apparatus operation signal to a projector may be detected as an apparatus operation and a linked operation.

  Further, for example, the window image may be updated by enlarging or reducing the operation input object in accordance with an operation of enlarging or reducing a part of the screen. For example, as shown in FIG. 6A, a pinch is performed in a state where a window image obtained by combining an external image with the operation input layer A21 on which the operation input object A21g is drawn is projected, and the projector that detects the pinch is an apparatus corresponding to the pinch Suppose that the operation signal is output to the PC. In this case, when the PC performs drawing processing for enlarging or reducing a part of the image representing the screen, the object represented by the image signal input from the PC to the projector is enlarged or reduced, and the external image changes. In this case, if the operation input object does not change, the operation input object does not correspond to the external image. Therefore, the projector detects a pinch as a linked operation, and redraws the operation input object A21g enlarged as shown in FIG. 6B on the operation input layer A21 according to the detected pinch, and the operation input object A21g reduced in size It is sufficient to redraw on A21. In addition, in order to detect the pinch which pinches a projection surface with two fingers and it narrows it as apparatus operation and interlocking operation, the infrared laser curtain etc. which detect the contact state of a finger and the projection surface are needed. . By detecting light of an infrared wavelength emitted from the laser curtain and reflected by the finger, it is possible to detect the contact state and the non-contact state of the finger on the projection surface.

  Further, for example, the window image may be updated so that the operation input object moves in accordance with the operation of scrolling the screen. An apparatus operation signal corresponding to a rotation angle of a wheel of an apparatus (for example, an apparatus such as a laser pointer) having a function of wirelessly transmitting an apparatus operation signal to the projector is output from the projector to the PC. In this case, when the PC performs drawing processing for moving an object in the screen, the object represented by the image signal input from the PC to the projector moves, and the external image changes. In this case, if the operation input object does not move, the operation input object does not correspond to the external image. Therefore, in the projector, an operation of turning the wheel may be detected as a linked operation, and the operation input object A21g moved as shown in FIG. 6A to FIG. 6C may be redrawn on the operation input layer A21 according to the detected rotation angle of the wheel. .

  Also, for example, the window image may be updated without editing the operation input layer. For example, the operation input layer A21a for drawing the operation input object A21g shown in FIG. 8A corresponding to the first slide A drawn by the PC, and the operation shown in FIG. 8B corresponding to the second slide B drawn by the PC Storage areas of the operation input layer A21b for drawing the input object A21h are prepared separately. A device operation for switching slides is detected as a linked operation, and each time a linked operation is detected, the operation input layer to be combined with the external image is switched. Thereby, the operation input object corresponding to the slide is displayed according to the switch of the slide. As described above, by enabling the projector to store two or more operation input layers, it is possible to display the operation input object according to the change of the external image without editing the operation input layer.

  For example, in order to project an image, light may be modulated using one liquid crystal panel, light may be modulated using a reflective liquid crystal panel, or DMD (Digital Mirror Device) is used. It may be used to modulate light. Further, for example, a convex mirror may be used to magnify and project a projection image, or a mirror may not be used. Further, for example, the present invention may be applied to a display device such as a touch panel display.

DESCRIPTION OF SYMBOLS 1 ... Projector, 1a ... 1st housing | casing, 1b ... 2nd housing | casing, 10 ... Liquid crystal light valve, 10a, 10b, 10c ... Liquid crystal panel, 11 ... Liquid crystal drive part, 12 ... OSD processing part, 13 ... Image signal processing 14 14 input / output interface 15 control unit 16 light source drive unit 17 projection light source 18 operation unit 19 power supply unit 21 reception unit 22 position detection unit 23 electronic pen 151 ... external memory, 181 ... menu key, 182 ... selection key, 183 ... determination key, 184 ... power switch, 231 ... contact sensor, 232 ... light emitting unit, 233 ... power switch, 234 ... side switch, A1 ... projection area, A2 ... Window image, A20 ... External image layer, A21 ... Operation input layer, A21 g ... Operation input object, A21 h ... Operation input object, A2 p ... icon, A22a ... external image, A22s ... drawing area, A2s ... drawing area

Claims (5)

A bidirectional display method using a bidirectional display device, comprising:
An image signal input step of inputting an image signal from an external device to the bidirectional display device;
A display step of displaying an image on a screen based on a display signal by the interactive display device;
An image operation detection step in which the interactive display device detects an operation on the screen as an image operation;
A drawing step in which the interactive display device draws an operation input object corresponding to the image operation;
Outputting the display signal for displaying a composite image obtained by combining an external image based on the image signal and the operation input object;
Interlocked operation detection step in which the interactive display device detects interlocked operation;
Upon detection of the synchronous operation, and outputs the device operation signals the interactive display device corresponding to the synchronous operation to the external device, the operation so as to correspond to changes in the external image according to the device operation signal Linked editing step to delete input object,
Interactive display method including. Expanding or reducing the operation input object in the linked editing step;
The bidirectional display method according to claim 1. Moving the operation input object in the linked editing step;
The bidirectional display method according to any one of claims 1 to 2. Further including a mode setting step of setting a drawing mode or an external device operation mode;
In the drawing mode, an operation on the screen is detected as the image operation in the image operation detection step;
In the external device operation mode, a predetermined operation on the screen is detected as the interlocked operation in the interlocked operation detection step.
The bidirectional display method according to any one of claims 1 to 3. An image signal input unit for inputting an image signal from an external device;
A display unit for displaying an image on a screen based on a display signal;
An image operation detection unit that detects an operation on the screen as an image operation;
A drawing unit drawing an operation input object corresponding to the image operation;
An output unit that outputs the display signal for displaying a composite image obtained by combining an external image based on the image signal and the operation input object;
An interlocking operation detection unit that detects interlocking operation;
Upon detection of the synchronous operation, and outputs the device operation signal corresponding to the synchronous operation to the external device, interlock to erase the operation input object so as to correspond to the change of the external image according to the device operation signal Editorial department,
Interactive display device.

Images