JP2017181539A - Display device and method of controlling the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique which, when an image is drawn with a pointer on a displayed image, allows for modifying the drawn image in accordance with changes in the displayed image.SOLUTION: A projector 10 comprises a display unit for displaying an image on a display surface, a position identification unit for identifying a position of a pointer on the display surface, an image drawing unit configured to generate a drawn image based on the positions identified by the position identification unit, an image control unit configured to generate an image comprising the drawn image overlaid on a background image supplied from an external device, and an acquisition unit configured to acquire notification sent from the external device in accordance with changes in the background image. The image control unit processes the drawn image in response to the notification acquired by the acquisition unit.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a display device and a display device control method.

  As an invention that uses an indicator as a pointing device, for example, there is a projector disclosed in Patent Document 1. This projector includes an image sensor, and images the indicator with the image sensor. Then, the projector specifies the coordinates of the indicator in the projection area from the image obtained by shooting, and performs drawing processing based on the specified coordinates.

JP 2013-247486 A

  In the case of the projector disclosed in Patent Document 1, when drawing is performed with an indicator while a PC (Personal Computer) image is being projected, a line drawn according to the movement of the indicator is generated and projected by the projector. Is. Here, when the projected image changes when the PC is operated, the line drawn on the image before the change remains, and the drawing performed using the indicator does not make sense on the image after the change. End up with no drawing.

  The present invention provides a technique for changing a drawn image in accordance with a change in an image to be displayed when drawing is performed on a displayed image by an indicator.

The present invention includes a display unit that displays an image on a display surface, a position specifying unit that specifies a position of an indicator with respect to the display surface, a drawing unit that generates a drawing image based on the position specified by the position specifying unit, An image control unit that generates the image obtained by superimposing the drawing image on a background image supplied from an external device and supplies the image to the display unit, and a notification sent from the external device according to a change in the background image is acquired. An acquisition unit, and the image control unit provides a display device that processes the drawn image in response to the notification acquired by the acquisition unit.
According to the present invention, when drawing is performed on the displayed image by the indicator, the drawn image can be changed according to the change of the displayed image.

In the present invention, the notification may be a notification that instructs to erase the drawn image.
According to this configuration, the drawn image can be processed in response to the notification, and the drawn image that does not correspond to the background image can be erased.

In the present invention, the notification may be a notification indicating a change in the background image, and the image control unit may process the drawing image according to the notification.
According to this configuration, the drawn image can be processed in response to the notification, and the drawn image that does not correspond to the background image can be erased.

In the present invention, the process may be a process of deleting the drawn image.
According to this configuration, the drawn image can be erased in response to the notification, and the drawn image that does not correspond to the background image can be erased.

Further, in the present invention, the background image is an image representing a page, the notification represents a change of the page, and the drawing image displayed on the display unit and the display unit display the display image. A storage unit that associates and stores the page, and the image control unit acquires the drawing image corresponding to the page specified by the notification from the storage unit, and superimposes the acquired drawing image It is good.
According to this configuration, when the background image changes, the drawing image before the change can be erased, and the drawing image corresponding to the background image after the change can be displayed.

The present invention is also a control method for a display device having a display unit for displaying an image on a display surface, the position specifying step for specifying the position of the indicator with respect to the display surface, and the position specified by the position specifying step. A drawing step for generating a drawing image based on the image, an image control step for generating the image obtained by superimposing the drawing image on a background image supplied from an external device and supplying the image to the display unit, and the background image from the external device An acquisition step of acquiring a notification sent in response to the change of the image, and in the image control step, a method of controlling the display device for processing the drawn image in accordance with the notification acquired in the acquisition step is provided.
According to this method, when the displayed image is drawn by the indicator, the drawn image can be changed according to the change of the displayed image.

1 is a diagram showing an apparatus that constitutes a display system 1. FIG. The figure which showed the hardware constitutions of the projector 10 and the indicator 20. The functional block diagram of the control part 110 and the control part 210. FIG. The figure which showed an example of the time chart which detects a pointer.

[Embodiment]
(Configuration of the embodiment)
FIG. 1 is a diagram showing an apparatus constituting a display system 1 according to an embodiment of the present invention. The display system 1 includes a projector 10, an indicator 20, a light emitting device 30, and an information processing device 40 that project an image onto a screen SC serving as an image display surface.

  A projector 10 that is an example of a display device is connected to an information processing device 40 that is an example of an external device by RDP (Remote Desktop Protocol), and projects an image supplied from the information processing device 40 onto a screen SC. In other words, the projector 10 operates as a remote desktop client. The projector 10 also has a drawing function for drawing an image at a position indicated by the indicator 20 or a finger.

  The projector 10 according to the present embodiment is installed obliquely above the screen SC and projects an image toward the screen SC. In the present embodiment, the projector 10 projects an image onto the screen SC, but may project an image onto a wall surface (display surface) instead of the screen SC. Further, in the present embodiment, the projector 10 is configured to be installed on a wall surface by a metal fitting, but may be installed on a ceiling or a desk. When installing on a ceiling, an image may be projected on a desk.

  The pen-type indicator 20 functions as a pointing device when the projector 10 is used, and uses a PC operation function and a drawing function for operating a GUI (Graphical User Interface) of the information processing apparatus 40 projected by the projector 10. Used when.

  The light emitting device 30 includes a light emitting unit that irradiates light (infrared light in the present embodiment) to a finger on the screen SC. The light emitting device 30 is installed above the upper end of the screen SC, and emits light by diffusing light downward in the range of the angle θ. The light emitted from the light emitting device 30 forms a light layer along the screen SC. In the present embodiment, the angle θ reaches approximately 180 degrees, and a light layer is formed on almost the entire screen SC. The surface of the screen SC and the light layer formed by the light emitting device 30 are preferably close to each other. The light layer has a thickness so that a finger located at a position away from the surface of the screen SC can be irradiated. Moreover, you may irradiate the finger in the distant position by laminating | stacking a light emission part. The light emission from the light emitting device 30 is controlled by the projector 10.

  The information processing apparatus 40 is a so-called personal computer, in which presentation software, a word processor, and the like are installed. The information processing apparatus 40 functions as a remote desktop server and supplies a screen of a program executed in response to an access from a client to the projector 10.

  FIG. 2 is a diagram illustrating a hardware configuration of the projector 10 and the indicator 20. The indicator 20 includes a control unit 210, a communication unit 220, a light emitting unit 230, an operation unit 240, and a power source 250. The power source 250 is, for example, a dry battery or a secondary battery, and supplies power to the control unit 210, the communication unit 220, the light emitting unit 230, and the operation unit 240. The operation unit 240 includes a switch (not shown) that controls power supply from the power supply 250 to each unit. When the switch of the operation unit 240 is turned on, power is supplied from the power source 250 to each unit, and when the switch of the operation unit 240 is turned off, supply of power from the power source 250 to each unit is stopped. The light emitting unit 230 includes a light emitting diode that emits infrared light, and is provided at the tip of the indicator 20. Lighting and extinguishing of the light emitting unit 230 is controlled by the control unit 210. The light emitting unit 230 is a point light source, and light emitted from the light emitting unit 230 spreads on the spherical surface from the tip of the indicator 20. The communication unit 220 includes a light receiving element that receives infrared light. The communication unit 220 receives various signals transmitted by infrared light from the projector 10. The communication unit 220 converts various received signals into electric signals and supplies them to the control unit 210. The control unit 210 is connected to the light emitting unit 230 and the communication unit 220. The control unit 210 starts control of the light emitting unit 230 according to a signal supplied from the communication unit 220, and controls lighting and extinguishing of the light emitting diode of the light emitting unit 230.

  The projector 10 includes a control unit 110, a storage unit 120, an operation unit 130, and a projection unit 140. The projector 10 includes a video processing unit 150, a video interface 160, an imaging unit 170 </ b> A, an imaging unit 170 </ b> B, and a communication unit 180. The control unit 110 is a microcomputer including a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). When the CPU executes the program stored in the ROM, in the projector 10, the control unit 110 controls each unit and projects an image on the screen SC, or a PC operation using the finger or the indicator 20 as a pointing device. Functions and drawing functions are realized.

  The video interface 160 has a plurality of connectors such as RCA, D-Sub, HDMI (registered trademark), and USB (Universal Serial Bus), and supplies images supplied from the external device to the connectors to the video processing unit 150. The video interface 160 may have a wireless communication interface such as a wireless LAN or Bluetooth (registered trademark), and may acquire an image by wireless communication.

  The storage unit 120 stores setting values related to the image quality of the projected image and information related to various functions. The operation unit 130 includes a plurality of buttons for operating the projector 10. The control unit 110 controls each unit in accordance with the operated button, thereby adjusting an image projected on the screen SC and setting various functions of the projector 10. The operation unit 130 also includes a light receiving unit (not shown) that receives an infrared light signal from a remote controller (not shown). The operation unit 130 converts a signal transmitted from the remote controller into an electric signal and supplies the electric signal to the control unit 110, and the control unit 110 controls each unit according to the supplied signal.

  The projection unit 140 and the video processing unit 150 cooperate to function as a display unit that displays an image. The video processing unit 150 acquires an image supplied from the video interface 160. In addition, the video processing unit 150 acquires an on-screen image such as a GUI for operating the projector 10 and an image (drawing image) drawn with a drawing function from the control unit 110. The video processing unit 150 includes a VRAM (Video RAM) 151, and includes an area for developing an image supplied from an external device and an area for developing an on-screen image supplied from the control unit 110. Expand the image into each area. The video processing unit 150 has various image processing functions, performs image processing on the image developed in the VRAM 151, and adjusts the image quality of the projected image. Further, when an on-screen image is supplied from the control unit 110, the video processing unit 150 supplies an image obtained by superimposing the on-screen image on the image supplied from the external device to the projection unit 140.

  The projection unit 140 that projects an image includes a light source 141, a light valve 142, a drive circuit 144, and a projection optical system 143. The light source 141 is a lamp that emits light, and the light emitted from the light source 141 is split into red, green, and blue light by a plurality of dichroic mirrors and mirrors (not shown), and each of the split red, green, and blue is split. Is guided to the light valve 142. The light source 141 may be a light emitting diode or a semiconductor laser device that emits laser light instead of a lamp.

  The drive circuit 144 acquires an image supplied from the video processing unit 150. The image supplied to the drive circuit 144 includes gradation data representing the gradation of the red component in the projected image, gradation data representing the gradation of the green component in the projected image, and the blue component in the projected image. It has gradation data representing gradation. The drive circuit 144 extracts gradation data of each color of red, green, and blue, and drives the light valve 142 based on the extracted gradation data of each color.

  The light valve 142 includes the above-described liquid crystal light valve on which red light is incident, the above-described liquid crystal light valve on which green light is incident, and the above-described liquid crystal light valve on which blue light is incident. The liquid crystal light valve is a transmissive liquid crystal panel and includes pixels arranged in a matrix with a plurality of rows and a plurality of columns. A liquid crystal light valve that receives red light is driven based on red gradation data, and a liquid crystal light valve that receives green light is driven based on green gradation data, and a liquid crystal light that receives blue light. The valve is driven based on the blue gradation data. In each liquid crystal light valve, each pixel is controlled by the drive circuit 144, and the transmittance of the pixel changes. By controlling the transmittance of the pixels, the light of each color transmitted through the liquid crystal light valve becomes an image corresponding to each gradation data. Red, green, and blue light images transmitted through the liquid crystal light valve are combined by a dichroic prism (not shown) and are incident on the projection optical system 143. The projection optical system 143 is an optical system that magnifies an incident image, and magnifies the incident image with a lens or a mirror and projects it onto the screen SC. When an image is projected on the screen SC, the image is displayed on the screen SC which is a display surface. Note that a reflective liquid crystal panel may be employed instead of the transmissive liquid crystal panel, or a digital mirror device or the like may be used.

  The projector 10 includes two imaging units 170A and 170B in order to specify the position of the indicator 20, the finger, and the distance to the screen SC by a stereo method. The image capturing unit 170A and the image capturing unit 170B receive an image on an image sensor (such as a CMOS or CCD) that receives infrared light emitted from the light emitting unit 230 or infrared light emitted from the light emitting device 30 and reflected by a finger. An optical system that forms an image, a diaphragm that restricts light incident on the image sensor, and the like are provided. The imaging unit 170A and the imaging unit 170B use the range including the screen SC as an imaging range, generate an image of the captured range, and output the generated image to the control unit 110. In the present embodiment, since the projector 10 is installed obliquely above the screen SC, the imaging unit 170A and the imaging unit 170B image the range including the screen SC from diagonally above. The communication unit 180 includes a light emitting diode that emits infrared light. The communication unit 180 is controlled by the control unit 110 to turn on and off the light emitting diode, and transmits an infrared light signal for controlling the on and off of the light emitting unit 230. The communication unit 180 has a communication interface for communicating with a PC, and includes a communication interface such as a USB, a wireless LAN, and a wired LAN.

  FIG. 3 is a functional block diagram showing a configuration of functions realized by the control unit 110 executing a program and functions realized by the control unit 210. First, functions realized in the control unit 110 of the projector 10 will be described.

  The position specifying unit 113 periodically specifies the position of the light emitting unit 230 of the indicator 20 and the position of the finger that is an example of the indicator in the image projection area, for example, using the time chart shown in FIG. The period for specifying the position of the finger and the position of the light emitting unit 230 has four phases from phase P11 to phase P14 as shown in FIG. When detecting the position of the finger or the position of the light emitting unit 230, the phase P11 to the phase P14 are repeated. Phase P11 is a phase for synchronizing the timing at which the projector 10 performs imaging with the imaging unit 170A and the imaging unit 170B, the timing at which the indicator 20 emits light, and the timing at which the light emitting device 30 emits infrared light. In phase P11, the position specifying unit 113 controls the communication unit 180 so that an infrared light synchronization signal is output in a predetermined period te1.

  In the indicator 20, the control unit 210 emits light so that the light emitting unit 230 is turned on in a preset period te <b> 2 when a predetermined time has elapsed since the communication unit 220 received the synchronization signal and received the synchronization signal. The unit 230 is controlled. In the present embodiment, the light emitting unit 230 is controlled to light up from the start time of the phase P12, the phase P13, and the phase P14. In addition, the position specifying unit 113 controls the light emitting device 30 so that the light emitting device 30 emits infrared light in the period te2 from the start time of the phase P12 and the phase P14.

  In phase P12 to phase P14, the position specifying unit 113 controls the imaging unit 170A and the imaging unit 170B, and images a predetermined range including the screen SC at the set shutter speed. The exposure period in which exposure is performed by the electronic shutter function in the imaging unit 170A and the imaging unit 170B starts from the start time of each phase of the phase P12 to the phase P14, and the time point at which the exposure ends is determined by the set shutter speed. Images captured by the imaging unit 170A and the imaging unit 170B during the exposure periods of the phase P12 to the phase P14 are supplied to the position specifying unit 113.

  The position specifying unit 113 uses the images supplied from the imaging unit 170A and the imaging unit 170B to specify the position of the finger or the light emitting unit 230 on the projected image and the distance from the screen SC to the light emitting unit 230. Specifically, in the phase P12 and the phase P14, when infrared light emitted from the light emitting device 30 is irradiated on the finger, the image obtained by the imaging unit 170A and the imaging unit 170B is emitted from the light emitting device 30. Infrared light reflected by the finger is reflected. Further, in phase P12 and phase P14, when the light emitting unit 230 is within the imaging range of the imaging unit 170A and the imaging unit 170B, infrared light emitted by the light emitting unit 230 on the images obtained by the imaging unit 170A and the imaging unit 170B Also reflected. In the phase P13, since the light emitting device 30 does not emit light, the infrared light emitted from the light emitting unit 230 appears in the images obtained by the imaging unit 170A and the imaging unit 170B.

  In phase P12 to phase P14, the position specifying unit 113 specifies the position of the infrared light reflected in the images obtained by the imaging unit 170A and the imaging unit 170B and the distance to the screen SC by a stereo method. The position specifying unit 113 specifies infrared light at a position close to the position of the infrared light whose position has been specified in phase P13 out of the infrared light whose positions have been specified in phase P12 and phase P14. Is the position of the light emitting unit 230. Further, the position specifying unit 113 sets the position of the infrared light far from the infrared light whose position is specified in phase P13 among the infrared lights whose positions are specified in phase P12 and phase P14 as the finger position. If the infrared light is not within the imaging range in phase P13, the position specifying unit 113 sets the position specified in phase P12 and phase P14 as the finger position. These specified positions are used when a drawing function or a GUI operation is performed.

  The image control unit 112 supplies an on-screen image (drawn image) to the video processing unit 150 according to the position detected by the position specifying unit 113 for the projected image, and the position indicated by the indicator 20 or the finger. Draw on. That is, the image control unit 112 also functions as a drawing unit that generates a drawing image. Further, the image control unit 112 controls storage of an image drawn according to the position of the indicator 20 or the finger and display of the image.

  Next, functions realized in the control unit 210 of the indicator 20 will be described. The signal acquisition unit 211 acquires the synchronization signal received by the communication unit 220. The light emission control unit 212 acquires the synchronization signal from the signal acquisition unit 211, and when a predetermined time has elapsed since the acquisition of the synchronization signal, the light emission unit 230 is turned on in the period te2 in phase P12 to phase P14. 230 is controlled.

(Operation example of embodiment)
An operation example of this embodiment will be described. The user designates the information processing apparatus 40 as a connection destination of the remote desktop, and performs an operation to instruct connection on the projector 10. When an operation to instruct connection to the information processing apparatus 40 is performed, the control unit 110 transmits information such as a user name and a password necessary for connection to the information processing apparatus 40 by controlling the communication unit 180. To do. The information processing apparatus 40 receives an operation for instructing connection with the projector 10, transmits information such as an address, a password, and a user name necessary for connection from the information processing apparatus 40 to the projector 10. The communication unit 180 may receive the information and transmit it to the control unit 110.

  The information processing apparatus 40 permits the connection of the projector 10 according to the information transmitted from the projector 10 and establishes a session. When the information processing apparatus 40 permits the connection of the projector 10, the information processing apparatus 40 supplies a GUI image (an example of a background image) provided by the information processing apparatus 40 to the projector 10. In the projector 10, the communication unit 180 acquires an image supplied from the information processing apparatus 40, and the image acquired by the communication unit 180 is sent to the video processing unit 150. The supplied image is sent from the video processing unit 150 to the projection unit 140, and the GUI image of the information processing apparatus 40 is projected onto the screen SC.

  In addition, the user operates the information processing apparatus 40 to perform an operation for connecting to a session established by the projector 10. When this operation is performed, the information processing apparatus 40 connects to the session established by the projector 10 and displays a GUI screen provided to the projector 10. In this state, it is possible to operate the GUI screen provided to the projector 10 also on the information processing apparatus 40.

  Next, when the user performs an operation for starting the presentation program in the information processing apparatus 40, the information processing apparatus 40 starts the presentation program and displays a GUI image (an example of a background image) of the program in the projector. 10 is supplied. The projector 10 projects the supplied image onto the screen SC.

  Next, when the user performs an operation to open the slide file for presentation in the information processing apparatus 40, the information processing apparatus 40 opens the slide file and supplies the slide image (an example of a background image) to the projector 10. To do. When the projector 10 projects the supplied image onto the screen SC, an image of a slide for presentation is displayed.

  When the user performs drawing on the projected image with the drawing function, the user performs an operation to turn on the drawing function on the projector 10. When the drawing function is turned on in the projector 10, it is possible to draw with the indicator 20 on the projected image. Specifically, the user brings the indicator 20 into contact with the drawing position on the screen SC. When the drawing function is on, the control unit 110 (position specifying unit 113) analyzes the images supplied from the imaging unit 170A and the imaging unit 170B, and specifies the position of the indicator 20. The control unit 110 (image control unit 112) generates an on-screen image according to the detected position of the indicator, and supplies the generated on-screen image to the video processing unit 150. When the on-screen image is supplied to the video processing unit 150, the on-screen image is superimposed on the projected slide image and projected. That is, the control unit 110 and the video processing unit 150 cooperate to function as an image control unit that generates an image in which a drawing image is superimposed on an image supplied from an external apparatus and supplies the image to the projection unit 140. For example, when the user moves the indicator 20 in contact with the screen SC, an on-screen image of a line corresponding to the movement locus of the indicator 20 (hereinafter referred to as a drawn image for convenience of explanation) is projected onto the screen SC. Is done.

  Next, when the user performs an operation to advance or return the slide for presentation, the information processing apparatus 40 changes the slide to be displayed and detects the change of the slide. When detecting the change of the slide, the information processing apparatus 40 sends a notification indicating that the image to be provided has been changed to the projector 10 through a session established with the projector 10. Further, the information processing apparatus 40 provides the changed slide image to the projector 10.

  When the projector 10 projects the image supplied from the information processing device 40 onto the screen SC, the image of the changed slide is projected onto the screen SC. When the communication unit 180, which is an example of the acquisition unit according to the present invention, acquires a notification indicating that the image has been changed, the control unit 110 (image control unit 112) deletes the on-screen image. Thereby, on the screen SC, the projected drawing image is erased, and only the image of the slide after the change is projected.

  As described above, according to the present embodiment, when the displayed image is drawn by the indicator, the drawn image is processed according to the change in the displayed image, and the changed image is handled. Undrawn image can be erased.

  In the above description, an example in which drawing is performed using the indicator 20 has been described. However, in the present invention, even when a user's finger is used as the indicator, drawing is performed according to the position of the finger. be able to.

[Modification]
As mentioned above, although embodiment of this invention was described, this invention is not limited to embodiment mentioned above, It can implement with another various form. For example, the present invention may be implemented by modifying the above-described embodiment as follows. In addition, you may implement each embodiment mentioned above and the following modifications, combining one or more suitably.

  In the embodiment described above, when an operation for changing a slide is performed, the information processing apparatus 40 sends a notification indicating that the image to be provided has been changed to the projector 10, and the projector 10 draws in response to the notification. Although the image is erased, the notification for erasing the drawn image is not limited to this notification. For example, when changing the image to be provided to the projector 10, the information processing apparatus 40 may send a notification instructing deletion of the drawn image to the projector 10, and the projector 10 displays the drawn image in response to this notification. It may be deleted.

  In the embodiment described above, when an operation for changing a slide is performed, a notification indicating that the image to be provided has been changed is sent to the projector 10, and in a modified example, a notification instructing deletion of the drawn image is sent. Sending these notifications is not limited to when a slide changing operation is performed. For example, even when an operation for enlarging or reducing an image of a slide is performed in the information processing apparatus 40, the information processing apparatus 40 transmits the notification of the above-described embodiment or the notification of the modification to the projector 10. Also good. According to this modification, when the displayed image is drawn by the indicator, the drawn image is processed according to the change of the displayed image, and the drawn image does not correspond to the enlarged or reduced image. The image can be erased.

  When an operation for enlarging or reducing the slide image is performed, the drawn image may be enlarged or reduced in accordance with the enlargement or reduction of the slide image instead of deleting the drawn image. In the case of this modification, the information processing apparatus 40 sends, for example, the coordinates of the vertices of the area that is enlarged and displayed on the slide to the projector 10. The control unit 110 of the projector 10 performs enlargement or reduction of the drawn image and change of the display position based on the area specified by the coordinates sent from the information processing apparatus 40.

  In the embodiment described above, the apparatus that displays the image and the drawing image supplied from the information processing apparatus 40 is a projector, but the apparatus that displays the image and the drawing image supplied from the information processing apparatus 40 is a projector. It is not limited. For example, the device that displays the image and the drawn image supplied from the information processing device 40 may be a direct-view display device. In the case of a display device including a direct-view display device, for example, a touch panel that can detect the position of a finger is adopted, and the position of a finger that is an indicator is detected by the touch panel instead of the imaging unit 170A and the imaging unit 170B. In the display device, a drawn image is displayed according to the position of the finger specified by the touch panel, and the drawn image is erased according to a notification sent from the information processing device 40.

In the above-described embodiment, the projector 10 erases the drawn image in response to the notification from the information processing apparatus 40, but the process performed in response to the notification is not limited to erasing the drawn image. For example, when sending the slide image to the projector 10, the information processing apparatus 40 transmits the slide page number to the projector 10, and the projector 10 acquires the page number sent from the information processing apparatus 40. When the projector 10 generates a drawing image, the drawing image data and the display position of the drawing image are stored in the storage unit 120 or the RAM in association with the page number represented by the acquired information.
Next, when an operation for changing the slide is performed by the user, the information processing apparatus 40 sends a notification indicating that the image has been changed, the image of the changed slide, and the page number of the changed slide to the projector 10. The control unit 110 of the projector 10 erases the drawn image in response to the notification. Further, after erasing the drawing image, the control unit 110 acquires the drawing image data stored in association with the page number sent from the projector 10 and the display position of the drawing image, and acquires the acquired display position. The on-screen image is sent to the video processing unit 150 so that the drawn image represented by the data is displayed. According to this configuration, for example, when the slide of the first page is displayed and the drawing is performed by the indicator 20 and the slide is advanced to the second page and then returned to the first page, the first page slide It is possible to restore and display the drawn image drawn when is displayed.

DESCRIPTION OF SYMBOLS 1 ... Display system, 10 ... Projector, 20 ... Indicator, 30 ... Light-emitting device, 40 ... Information processing apparatus, 110 ... Control part, 112 ... Image control part, 113 ... Position specification part, 120 ... Memory | storage part, 130 ... Operation , 140 ... projection unit, 150 ... video processing unit, 151 ... VRAM, 160 ... video interface, 170A, 170B ... imaging unit, 180 ... communication unit, 210 ... control unit, 211 ... signal acquisition unit, 212 ... light emission control unit , 220 ... communication unit, 230 ... light emitting unit, 240 ... operation unit, 250 ... power source, SC ... screen.

Claims (6)

A display unit for displaying an image on a display surface;
A position specifying unit for specifying the position of the indicator with respect to the display surface;
A drawing unit that generates a drawing image based on the position specified by the position specifying unit;
An image control unit that generates the image in which the drawing image is superimposed on a background image supplied from an external device and supplies the generated image to the display unit;
An acquisition unit for acquiring a notification sent from the external device according to a change in the background image,
The said image control part processes the said drawing image according to the notification which the said acquisition part acquired. Display apparatus. The display device according to claim 1, wherein the notification is a notification that instructs to erase the drawn image. The notification is a notification representing a change in the background image,
The display device according to claim 1, wherein the image control unit processes the drawn image according to the notification. The display device according to claim 2, wherein the process is a process of erasing the drawn image. The background image is an image representing a page,
The notification represents a change of the page;
A storage unit that stores the drawing image displayed by the display unit and the page displayed by the display unit in association with each other;
The display device according to claim 3, wherein the image control unit acquires the drawing image corresponding to the page specified by the notification from the storage unit, and superimposes the acquired drawing image. A control method of a display device having a display unit for displaying an image on a display surface,
A position specifying step for specifying the position of the indicator with respect to the display surface;
A drawing step for generating a drawing image based on the position specified in the position specifying step;
An image control step of generating the image obtained by superimposing the drawing image on a background image supplied from an external device and supplying the generated image to the display unit;
Obtaining a notification sent from the external device in response to a change in the background image,
In the image control step, the drawing image is processed according to the notification acquired in the acquisition step.

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