JP2017173675A - Display device and method for controlling display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To delete drawing not corresponding to an image after change, when the drawing is performed to the displayed image by an indication body and when a displayed image is changed.SOLUTION: A projector 10 includes a display part which displays a supplied drawing image and a display image supplied from an external device on a display surface, a position specification part which specifies the position of the indication body with respect to the display surface, a drawing part which generates the drawing image according to the position specified by the position specification part and supplies the drawing image to the display part, and a drawing image control part which deletes the displayed drawing image, when the display image is switched from a first display image to a second display image.SELECTED DRAWING: Figure 1

Description

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

  Patent Document 1 discloses a technique for performing cursor movement and click operation of a PC by sending a control signal from the display device in response to an operation of a remote controller in a display device that displays an image supplied from a PC (Personal Computer). Has been. According to this technology, for example, when an image of a presentation material is supplied from a PC to a display device, the PC is operated by operating the display device with a remote controller, and the page of the displayed material is advanced. Can be reverted.

JP 2004-53760 A

  Some display devices that display an image supplied from an external device draw an image of a line corresponding to the movement locus of the indicator by moving the indicator on the display surface of the image. In such a display device, when the video to be displayed is changed by operating the PC, a line drawn with respect to the image before the change remains, and the line does not make sense for the video after the change.

  The present invention provides a technique for erasing a drawing that does not correspond to the changed image when the displayed image changes when drawing is performed on the displayed image.

The present invention provides a display unit that displays a supplied drawing image and a display image supplied from an external device on a display surface, a position specifying unit that specifies a position of an indicator with respect to the display surface, and the drawing image as the position. The drawing unit that is generated according to the position specified by the specifying unit and supplies the drawing image to the display unit, and the display image is displayed when the display image is changed from the first display image to the second display image. Provided is a display device including a drawing image control unit that erases the drawing image.
According to the present invention, when drawing is performed on the displayed image by the indicator, when the displayed image changes, the drawing that does not correspond to the changed image can be erased.

In the present invention, there are a plurality of terminals to which the display image is supplied, the display unit displays the display image supplied from the terminal, and the drawing image control unit displays the display image on the display unit. When the terminal for supplying is changed, the drawn image may be erased.
According to this configuration, when the device that supplies the display image is changed and the displayed image changes, the drawing that does not correspond to the changed image can be erased.

In the present invention, the drawing image control unit may delete the drawing image when the display image supplied from the external device is changed.
According to this configuration, when the supplied display image is changed and the displayed image is changed, the drawing that does not correspond to the changed image can be erased.

Further, in the present invention, there may be provided an imaging unit that captures the display surface, and when the display image displayed on the display surface captured by the imaging unit is changed, the drawn image may be erased. Good.
According to this configuration, when the displayed image changes, the drawing that does not correspond to the changed image can be erased.

In the present invention, the drawing image control unit may acquire an instruction from a user and delete the drawing image when the acquired instruction is an instruction to change the display image.
According to this configuration, when the display image is changed in accordance with an instruction to change the display image, it is possible to erase a drawing that does not correspond to the changed image.

In the present invention, the drawing image control unit may acquire a predetermined gesture as the instruction.
According to this configuration, when a display image is changed by a gesture, a drawing that does not correspond to the changed image can be erased.

Moreover, in this invention, it is good also as a structure which has a memory | storage part which memorize | stores the said drawing image displayed on the said display surface when the said display image is displayed on the said display surface.
According to this configuration, it is possible to save a drawing image to be erased.

In the present invention, the storage unit associates the drawing image deleted by the drawing image control unit with information representing the display image displayed when the drawing image is displayed. When the display unit displays the display image again after the display unit finishes displaying the display image, the drawing image control unit is stored in the storage unit in association with information representing the display image. The drawing image may be supplied to the display unit.
According to this configuration, the erased drawn image can be restored according to the displayed image.

In the present invention, the drawing image control unit may be configured to erase the drawing image in a predetermined region in the display surface.
According to this configuration, it is possible to erase only the drawn image in a specific area among the areas displaying the image.

In the present invention, the drawing image control unit may acquire a predetermined gesture as an instruction for determining the region.
According to this configuration, it is possible to designate an area from which the drawn image is erased.

The present invention is also a control method for a display device having a display unit that displays a supplied drawing image and a display image supplied from an external device on a display surface, and specifies a position of an indicator with respect to the display surface. A position specifying step, a drawing step of generating the drawing image according to the position specified in the position specifying step, supplying the drawing image to the display unit, and the display image from the first display image to the second Provided is a display device control method comprising a drawn image control step of erasing the displayed drawn image when the display image is changed.
According to the present invention, when drawing is performed on the displayed image by the indicator, when the displayed image changes, the drawing that does not correspond to the changed image can be erased.

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. The figure which showed an example of the image projected on the screen SC. The figure which showed an example of the image projected on the screen SC. The flowchart which showed an example of the flow of the process which the control part 110 performs. The figure which showed an example of the image projected on the screen SC. The figure which showed an example of the image projected on the screen SC. The figure which showed an example of the image projected on the screen SC. The figure for demonstrating a modification. The figure for demonstrating a modification.

[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, and a light emitting device 30 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 a PC (Personal Computer) 40 that is an example of an external device wirelessly or by wire, and projects an image represented by a video signal supplied from the PC 40 onto a screen SC. The projector 10 also has a drawing function for drawing an image at a position designated by the indicator 20 or the finger, and a PC operation function for using the indicator 20 or the finger as a connected PC pointing device.

  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 serving as an image display surface. However, the image may be projected 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 the wall surface by a metal fitting, but may be installed on the ceiling.

  The pen-type indicator 20 functions as a pointing device when using the drawing function and the PC operation function described above, and is projected when the user operates the GUI (Graphical User Interface) of the PC that the projector 10 projects. This is used when the user draws on the image.

  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. Further, by stacking the light emitting units, a finger at a position away from the screen SC may be irradiated. The light emission from the light emitting device 30 is controlled by 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. 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 a program stored in the ROM, in the projector 10, the control unit 110 controls each unit and projects an image on the screen SC, a function that uses the finger or the indicator 20 as a pointing device, A drawing function, a PC operation function, a gesture function for operating the PC 40 in accordance with a user's gesture, and the like are realized. The storage unit 120 stores setting values related to the image quality of the projected image and information related to various functions. The storage unit 120 also stores an image drawn by the drawing function.

  The video interface 160 has a plurality of connectors (terminals) to which video signals are supplied, such as RCA, D-Sub, HDMI (registered trademark), USB (Universal Serial Bus), and the like. Is supplied to the video processing unit 150. The video interface 160 is an example of a video acquisition unit that acquires a plurality of video signals. The video interface 160 may include a wireless communication interface such as a wireless LAN or Bluetooth (registered trademark), and may acquire a video signal by wireless communication.

  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 the video signal supplied from the video interface 160. In addition, the video processing unit 150 acquires a signal for an on-screen image such as a GUI for operating the projector 10 and an image drawn by a drawing function from the control unit 110. The video processing unit 150 includes a VRAM (Video RAM) 151. The VRAM 151 includes an area for developing a video signal and an area for developing an on-screen image signal, and each signal is developed in each area. The video processing unit 150 has various image processing functions, performs image processing on the video signal developed in the VRAM 151, and adjusts the image quality of the projected image. In addition, when an on-screen image signal is supplied from the control unit 110, the video processing unit 150 outputs a video signal obtained by superimposing the on-screen image signal and the video signal supplied from the video interface 160. To supply.

  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 the video signal supplied from the video processing unit 150. The video signal supplied to the drive circuit 144 includes gradation data representing the gradation of the red component in the image to be projected, gradation data representing the gradation of the green component in the image to be projected, and the blue component in the image to be projected. Gradation data representing the gradations. 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 has 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 an image signal representing the generated image. 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 controls the lighting and extinguishing of the light emitting diodes by the control unit 110, and transmits an infrared light signal for controlling the lighting and extinguishing of the light emitting unit 230. The communication unit 180 has a communication interface for communicating with a PC, and includes, for example, a USB or LAN communication interface.

  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 of each phase of the phase P12, the phase P13, and the phase P14. The time point at which the exposure ends is determined by the set shutter speed and is within the period of each phase. Image signals of images captured by the imaging unit 170A and the imaging unit 170B during the exposure periods of phase P12 to phase P14 are supplied to the position specifying unit 113.

  The position specifying unit 113 uses the image represented by the image signal supplied from the imaging unit 170A and the imaging unit 170B, and the position of the finger or the light emitting unit 230 on the projected image, or the distance from the screen SC to the light emitting unit 230. Is identified. 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 various functions such as a drawing function and a PC operation function are executed.

  The drawing unit 112 draws the projected image according to the position specified by the position specifying unit 113. When the gesture operation is performed, the connector that supplies the video signal to the video processing unit 150 is switched, or the image to be projected is changed, the drawn image control unit 114 draws with the indicator 20 or the finger. The stored drawing image is stored and the display of the drawing image is controlled.

  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)
Next, an operation example of the present embodiment will be described with reference to FIGS. 5, 6, and 8-10 are diagrams illustrating an example of an image projected on the screen SC, and FIG. 7 is a flowchart illustrating an example of a flow of processing performed by the control unit 110.

  The user opens a document file for presentation on the PC 40 connected to the projector 10. When the PC 40 displays one page of the document, a video signal representing the displayed page is supplied from the PC 40 to the projector 10. The video interface 160 acquires the video signal supplied from the PC 40 and supplies the acquired video signal to the video processing unit 150.

  When the drawing function is on, the control unit 110 supplies an on-screen image signal for operating the PC 40 with a gesture to the video processing unit 150. The video processing unit 150 develops the supplied signal in the VRAM 151 and supplies the video signal subjected to image processing in the VRAM 151 to the projection unit 140. Projection unit 140 projects an image represented by the supplied video signal onto screen SC.

  FIG. 5 is a diagram showing an example of an image projected on the screen SC. When the projection unit 140 projects an image onto the screen SC, an image of the page displayed on the PC 40 and an image G10 for gesture operation are projected onto the screen SC. The image G10 includes an image G101, an image G102, and an image G103 arranged in the vertical direction.

  When drawing a projected image, the user positions the indicator 20 on the screen SC. Control unit 110 (position specifying unit 113) specifies the position of indicator 20 when indicator 20 is positioned on screen SC. The control unit 110 analyzes the video signal supplied from the imaging unit 170A and the imaging unit 170B, and specifies the position of the indicator 20 at a predetermined cycle. When the user moves the indicator 20 on the screen SC, the control unit 110 (drawing unit 112) sends a signal of an on-screen image (an example of a drawing image) of a line connecting the positions of the specified indicator 20 to the video processing unit. 150. The video processing unit 150 develops the on-screen image signal in the area of the VRAM 151 where the on-screen image signal is developed, and supplies the projection unit 140 with a video signal in which the on-screen image is superimposed on the screen image of the PC 40. . When the projection unit 140 projects an image of the supplied video signal, for example, an image P20 corresponding to the movement of the indicator 20 is projected as shown in FIG.

  When the drawing function is on, the control unit 110 determines whether a gesture operation has been performed, a connector that supplies a video signal to the video processing unit 150 in the video interface 160 is switched, or an image to be projected is changed. We are monitoring When the gesture operation is performed, the control unit 110 (drawing image control unit 110) changes the connector that supplies the video signal to the video processing unit 150, or the image to be projected changes. The process shown in FIG.

  Specifically, the control unit 110 analyzes video signals supplied from the imaging unit 170A and the imaging unit 170B, and monitors image changes at the positions of the images G101, G102, and G103. For example, when the user moves his / her hand from the position shown in FIG. 8 in the direction of arrow A, the image G101, the image G102, and the image G103 are projected on the user's hand, and thus are supplied from the imaging unit 170A and the imaging unit 170B. In the video signal, the images at these positions change in the order of the position of the image G101, the position of the image G102, and the position of the image G103.

  When the image changes in the order of the position of the image G101, the position of the image G102, and the position of the image G103 in the video signals supplied from the imaging unit 170A and the imaging unit 170B, the control unit 101 performs a gesture for the user to advance the page. (YES in step SA1). When control unit 110 determines that the user has made a gesture to advance the page, control unit 110 controls communication unit 180 as a message corresponding to the gesture and transmits the message to PC 40 (step SA2). When the process of step SA2 is completed, the control unit 110 monitors the contents of the VRAM 151 and determines whether the image to be projected has changed (step SA3). If the image to be projected has not been changed (NO in step SA3), control unit 110 continues to monitor the contents of VRAM 151.

  On the other hand, when the PC 40 having received a message from the projector 10 obtains a message indicating an instruction to advance the page, it advances the page of the open document from the first page to the second page, and outputs the video signal of the second page of the document. Supply to the projector 10. At this time, the image supplied from the PC 40 and displayed by the projector 10 changes from the first page image (first display image) to the second page image (second display image). The video processing unit 150 develops the supplied video signal in the VRAM 151. When a new video signal is developed in the VRAM 151, the image projected by the projection unit 140 is the image of the second page of the document. When the projected image is changed (YES in step SA3), the control unit 110 renders the data of the image drawn using the indicator 20 (data of the image P20 developed in the area where the on-screen image of the VRAM 151 is developed). Is stored in the storage unit 120 (step SA4).

  When the process of step SA4 is completed, the control unit 110 erases the drawing image data developed in the area where the on-screen image of the VRAM 151 is developed (step SA5). When the process of step SA5 is performed, the on-screen image of the drawn image disappears, and thus the projected image P20 is not displayed, and the second page image displayed on the PC 40 as shown in FIG. Is projected on the screen SC.

When the user draws with the indicator 20 while the image of FIG. 9 is being projected, for example, as shown in FIG. 10, an image P21 corresponding to the movement of the indicator 20 is projected.
Here, when the user moves his / her hand from the position shown in FIG. 10 in the direction of arrow B, in the video signals supplied from the imaging unit 170A and the imaging unit 170B, the position of the image G103, the position of the image G102, and the image G101. The images at these positions change in the order of the positions.

  When the image changes in the order of the position of the image G103, the position of the image G102, and the position of the image G101 in the video signals supplied from the imaging unit 170A and the imaging unit 170B, the control unit 101 performs a gesture for returning the page. (YES in step SA1). If control unit 110 determines that the user has made a gesture to return the page, control unit 110 controls communication unit 180 as a message corresponding to the gesture and transmits the message to PC 40 as a message corresponding to the gesture (step SA2). When the process of step SA2 is completed, the control unit 110 monitors the contents of the VRAM 151 and determines whether the projected image has been changed (step SA3).

  On the other hand, when the PC 40 sent a message from the projector 10 obtains a message indicating an instruction to return the page, it returns the page of the open document from the second page to the first page, and outputs the video signal of the first page of the document. Supply to the projector 10. At this time, the image supplied from the PC 40 and displayed by the projector 10 changes from the image on the second page (second display image) to the image on the first page (first display image). The video processing unit 150 develops the supplied video signal in the VRAM 151. When a new video signal is developed in the VRAM 151, the image projected by the projection unit 140 is the image of the first page of the document. When the image to be projected changes (YES in step SA3), the control unit 110 renders the data of the image drawn using the indicator 20 (data of the image P21 developed in the area where the on-screen image of the VRAM 151 is developed). Is stored in the storage unit 120 (step SA4).

  When the process of step SA4 is completed, the control unit 110 erases the drawing image data developed in the area where the on-screen image of the VRAM 151 is developed (step SA5). When the process of step SA5 is performed, the on-screen image of the drawn image disappears, so that the projected image P21 is not displayed, and the first page image displayed on the PC 40 as shown in FIG. Is projected on the screen SC.

  Next, an operation example when the image projected by the projector 10 is changed by operating the PC 40 will be described. For example, as shown in FIG. 6, when the user operates the PC 40 while the image of the first page of the document and the image P20 are displayed, and performs the operation of advancing the page of the open document to the second page, The video signal of the second page of the document is supplied from the PC 40 to the video interface 160. The video processing unit 150 develops the video signal supplied from the video interface 160 in the VRAM 151 and supplies the video signal subjected to image processing in the VRAM 151 to the projection unit 140. Projection unit 140 projects the image of the second page represented by the supplied video signal onto screen SC.

  When the controller 110 monitors the contents of the VRAM 151 and determines that the image to be projected has been changed, the controller 110 executes the processing shown in FIG. When the image to be projected is changed without performing the operation of switching the connector of the video interface 160 for acquiring the video signal (NO in step SA1, NO in step SA6, and YES in step SA7), the control unit 110 displays the indicator 20. The data of the image drawn by using (the data of the image P20 developed in the area where the on-screen image of the VRAM 151 is developed) is stored in the storage unit 120 (step SA4). When the process of step SA4 is completed, the control unit 110 erases the drawing image data developed in the area where the on-screen image of the VRAM 151 is developed (step SA5). When the process of step SA5 is performed, the on-screen image of the drawn image disappears, and thus the projected image P20 is not displayed, and the second page image displayed on the PC 40 as shown in FIG. Is projected on the screen SC. In addition, the control part 110 complete | finishes the process of FIG. 7, when it is judged as NO by step SA7.

  Note that even when the image of the second page is displayed, after drawing with the indicator 20, the user operates the PC 40 to return the page of the open document to the first page. Since a new video signal is developed and projected on the VRAM 151, the control unit 110 determines NO in step SA1, NO in step SA6, and YES in step SA7, and performs the processes in steps SA4 and SA5. .

  Next, an operation example when an operation of switching the connector of the video interface 160 for acquiring the video signal is performed in the projector 10 will be described. For example, the PC 40 is connected to the D-sub connector of the video interface, and from the state where the image of FIG. 6 is displayed, another PC is connected to the HDMI connector of the video interface, and the user acquires the video signal. Is switched from D-sub to HDMI, the control unit 110 executes the processing shown in FIG. When an operation of switching the connector of the video interface 160 for acquiring the video signal is performed (NO in step SA1, YES in step SA6), the control unit 110 monitors the contents of the VRAM 151 and determines whether the projected video has been changed. (Step SA3).

  Here, the video processing unit 150 develops the video signal supplied from the HDMI connector in the VRAM 151. When a new video signal is developed in the VRAM 151, the image projected by the projection unit 140 becomes an image of the video signal supplied from the PC connected to the switched connector, and the projected image is changed. When the image to be projected changes (YES in step SA3), the control unit 110 renders the data of the image drawn using the indicator 20 (data of the image P21 developed in the area where the on-screen image of the VRAM 151 is developed). Is stored in the storage unit 120 (step SA4).

  When the process of step SA4 is completed, the control unit 110 erases the drawing image data developed in the area where the on-screen image of the VRAM 151 is developed (step SA5). When the process of step SA5 is performed, the on-screen image of the drawn image is lost, and thus the projected image P21 is not displayed, and the image of the video signal supplied from the HDMI connector is projected on the screen SC.

  As described above, according to the present embodiment, when the image displayed when drawing with the indicator 20 is changed, the drawn image is deleted. That is, when the displayed image is drawn by the indicator 20, if the displayed image changes, the drawing that does not correspond to the changed 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. In the present embodiment, the drawing image data stored in the storage unit 120 may be transmitted to the PC 40, and the drawing image data may be stored in the PC 40. According to this configuration, it is possible to confirm the drawn image written in the projected image by outputting the stored drawn image data by the printer or displaying the data on the display. In the present embodiment, the drawing image data stored in the storage unit 120 may be deleted when the power of the projector 10 is turned off.

[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, in the image represented by the video signal supplied from the imaging unit 170A and the imaging unit 170B, the monitoring area for monitoring the change of the image to identify the gesture operation is within the projection area where the image is projected. In the region including the positions of the image G101, the image G102, and the image G103, the present invention is not limited to the monitoring region of the embodiment. For example, the monitoring area may be an area outside the area where the projection unit 140 projects an image.

  FIG. 11 is a diagram illustrating an example of a modified example of the monitoring area in the present modified example. In FIG. 11, an area A <b> 20 represents an area captured by the imaging unit 170 </ b> A and the imaging unit 170 </ b> A, and an area A <b> 10 represents an area of an image projected by the projection unit 140. The control unit 110 provides a monitoring area A30 for specifying a gesture operation on the left side of the projection area A10 outside the projection area A10 on which an image is projected by the projection section 140. In the monitoring area A30, the control unit 110 determines that the user has made a gesture to advance the page when the image changes sequentially from above, and when the image changes sequentially from below, It may be determined that the user has made a gesture to return the page.

  In the present invention, the erased drawing image may be restored using the drawing image data stored in the storage unit 120. In this modification, when the control unit 110 stores the drawing image data in the storage unit 120 in step SA4, for example, a checksum of a predetermined area in the image represented by the video signal developed in the VRAM 151 is calculated. The image data is stored in association with the drawing image data. This checksum is an example of information representing an image supplied from an external device. In step SA5, the drawn image is erased. Therefore, in step SA4 of this modification, the drawing image to be erased by the control unit 110 and information representing the image supplied from the external device when the drawn image was displayed. Are stored in association with each other. When the projected image is changed, the control unit 110 deletes the displayed drawn image in step SA5, and then determines a predetermined area in the image represented by the video signal newly supplied from the external device and developed in the VRAM 151. Calculate the checksum of. When the calculated checksum is stored in the storage unit 120, the control unit 110 acquires drawing image data stored in association with the calculated checksum, and develops the acquired drawing image data in the VRAM 151. To do. The area for calculating the checksum may be configured such that the user sets an area including the page number, for example. According to this configuration, for example, an image to be displayed after shifting from the state of FIG. 6 in which the image and the drawing image of the first page of the document are displayed to the state of FIG. 9 in which the image of the second page is displayed. Is returned to the first page image (that is, when the first page image is displayed again after displaying the first page image), it is stored in association with the checksum of the first page image. The image P20 is displayed again, and the erased image can be restored according to the image to be displayed.

  The present invention is not limited to a configuration that erases all drawn images in an area where an image is projected. For example, a drawn image in a specific area designated by a user is erased and designated. The drawn image outside the area may be configured not to erase the drawn image. For example, the control unit 110 divides an image projection area into a plurality of areas as indicated by broken lines in FIG. 12, and when a gesture operation is performed in any of the areas, The drawing image displayed in the area may be erased, and the drawing image displayed in another area may not be erased.

  In the present invention, the video signals supplied from the imaging unit 170A and the imaging unit 170B may be analyzed to determine whether the projected image has changed. In the present modification, the control unit 110 specifies in advance a region in which an image projected by the projection unit 140 appears in the video signals supplied from the imaging unit 170A and the imaging unit 170B. The control unit 110 analyzes the video signal supplied from the imaging unit 170A and the imaging unit 170B, and performs the above-described processing of step SA4 and step SA5 when the image in the specified area is changed. Note that in the image represented by the video signal supplied from the imaging unit 170A and the imaging unit 170B, a drawn image or a user may appear. When the drawing image is displayed, the control unit 110 determines whether or not the projected image has been changed due to a change in an image of a portion other than the displayed drawing image. In addition, the control unit 110 analyzes the video signal supplied from the imaging unit 170A and the imaging unit 170B, and specifies a portion where the user is shown. When there is a part where the user is shown, the control unit 110 determines whether or not the projected image has changed due to a change in the image of the part other than the part where the user is shown.

  In the embodiment described above, the projector 10 projects an image indicated by the video signal supplied from the PC 40, and the projector 10 generates and projects an image to be drawn on the projected image. It is not limited. For example, in a display device including a touch panel, an image is drawn with a finger or a stylus pen on the displayed image. In this configuration, the display device monitors the displayed image as in the above-described embodiment. When the displayed image is changed, the display device stores the drawn image and erases the displayed drawn image. Even in this configuration, when drawing is performed on the displayed image by the indicator, if the displayed image changes, the drawing that does not correspond to the changed image can be erased.

  DESCRIPTION OF SYMBOLS 1 ... Display system, 10 ... Projector, 20 ... Indicator, 30 ... Light-emitting device, 110 ... Control part, 112 ... Drawing part, 113 ... Position specification part, 114 ... Drawing image control part, 120 ... Memory | storage part, 130 ... Operation 140, projection unit, 150, video processing unit, 160 ... video interface, 170A, 170B ... imaging unit, 180 ... communication unit, 210 ... control unit, 211 ... signal acquisition unit, 212 ... light emission control unit, 220 ... communication Part, 230 ... light emitting part, 240 ... operation part, 250 ... power source, SC ... screen.

Claims (11)

A display unit for displaying a supplied drawing image and a display image supplied from an external device 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 the drawing image according to the position specified by the position specifying unit, and supplies the drawing image to the display unit;
A display device comprising: a drawing image control unit that erases the displayed drawing image when the display image is changed from the first display image to the second display image. A plurality of terminals to which the display image is supplied;
The display unit displays the display image supplied from the terminal,
The display device according to claim 1, wherein the drawing image control unit erases the drawing image when a terminal for supplying the display image to the display unit is changed. The display device according to claim 2, wherein the drawing image control unit erases the drawing image when the display image supplied from the external device is changed. An imaging unit that captures the display surface;
The display device according to any one of claims 1 to 3, wherein the drawn image is erased when the display image displayed on the display surface photographed by the imaging unit is changed. The said drawing image control part acquires the instruction | indication from a user, and when the acquired instruction | indication is an instruction | indication which changes the said display image, the said drawing image is erased. Display device. The display device according to claim 5, wherein the drawing image control unit acquires a predetermined gesture as the instruction. The display device according to any one of claims 1 to 6, further comprising a storage unit that stores the drawing image displayed on the display surface when the display image is displayed on the display surface. The storage unit stores the drawing image erased by the drawing image control unit in association with information representing the display image displayed when the drawing image is displayed;
When the display unit displays the display image again after the display unit finishes displaying the display image, the drawing image control unit associates with the information representing the display image and stores the drawing image stored in the storage unit The display device according to claim 7, wherein: is supplied to the display unit. The display device according to claim 1, wherein the drawing image control unit erases the drawing image in a predetermined region in the display surface. The display device according to claim 9, wherein the drawing image control unit acquires a predetermined gesture as an instruction for determining the region. A control method of a display device having a display unit for displaying a supplied drawing image and a display image supplied from an external device on a display surface,
A position specifying step for specifying the position of the indicator with respect to the display surface;
A drawing step of generating the drawing image according to the position specified in the position specifying step, and supplying the drawing image to the display unit;
And a drawing image control step of erasing the displayed drawing image when the display image is changed from the first display image to the second display image.

Images