JP2017181536A - 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 erasing a drawn image not corresponding to the displayed image.SOLUTION: A projector 10 comprises a display unit for displaying a drawn image and a background image supplied from an external device on a display surface, a position detection unit for detecting a position of a pointer on the display surface, an image drawing unit configured to generate a drawn image to be displayed on the display surface in accordance with the positions detected by the position detection unit and to feed the drawn image to the display unit, a luminance detection unit configured to detect luminance of the background image, and a drawn image control unit configured to erase a drawn image when luminance detected by the luminance detection unit changes while the image is being drawn.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 erasing a drawing that does not correspond to a displayed image when the displayed image is drawn by an indicator.

The present invention provides a display unit that displays a drawn image and a background image supplied from an external device on a display surface, a position detection unit that detects a position of an indicator relative to the display surface, and the position detection unit that displays the drawn image. A drawing unit that generates the image according to the specified position and supplies the drawing image to the display unit, a luminance detection unit that detects the luminance of the background image, and the luminance detection unit that detects the drawing image during display Provided is a display device including a drawn image control unit that erases the drawn image when the luminance changes.
According to the present invention, when an image changes after the displayed image is drawn by the indicator, the drawing that does not correspond to the displayed image can be erased.

Further, in the present invention, when the drawing image control unit is set to perform the erasing, the drawing image is erased when the luminance detected by the luminance detecting unit is changed, and the erasing is performed. If the brightness is not detected, the drawn image may not be erased even if the brightness detected by the brightness detector changes.
According to this configuration, it is possible to select whether or not to erase the drawn image according to the luminance of the background image.

In the present invention, the drawing image control unit associates the drawing image generated by the drawing unit during display of the background image with the luminance of the background image detected by the luminance detection unit in the storage unit. When the brightness detected by the brightness detection unit changes, the drawing image stored in the storage unit in association with the changed brightness may be supplied to the display unit.
According to this configuration, it is possible to restore the erased drawn image.

Further, in the present invention, when the brightness detected by the brightness detector changes when the setting for restoring the erased image is changed, the drawn image control unit correlates with the changed brightness. If the drawing image stored in the storage unit is supplied to the display unit and the deleted image is not set to be restored, even if the luminance detected by the luminance detection unit is changed, The drawing image stored in the storage unit in association with luminance may not be supplied to the display unit.
According to this configuration, it is possible to select whether to restore the drawn image according to the luminance of the background image.

Further, in the present invention, the image display unit includes an imaging unit that captures the display surface and generates an image of the captured display surface, and the luminance detection unit displays the image displayed by the display unit in the image generated by the imaging unit. It is good also as a structure which detects the brightness | luminance of parts other than the said drawing image among images, and when the said brightness changes, the said drawing image control part erase | eliminates the said drawing image.
According to this configuration, a change in luminance of the background image can be monitored, and a drawn image can be erased according to the change in luminance of the background image.

The present invention is also a method for controlling a display device including a display unit that displays a drawn image and a background image supplied from an external device on a display surface, the position detecting step detecting the position of an indicator with respect to the display surface A drawing step of generating the drawing image according to the position specified in the position detection step, supplying the drawing image to the display unit, a luminance detection step of detecting the luminance of the background image, and the drawing image And a drawing image control step for erasing the drawing image when the luminance detected in the luminance detection step changes during display of the display device.
According to the present invention, when an image changes after the displayed image is drawn by the indicator, the drawing that does not correspond to the displayed 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 flowchart which showed the flow of the process which the control part 110 performs.

[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 40 that is an example of an external device, 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 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 when the user operates a GUI (Graphical User Interface) of the PC projected by the projector 10 or the user performs drawing using a drawing function. 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.

  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 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 is realized.

  The video interface 160 has a plurality of connectors to which video signals are supplied such as RCA, D-Sub, HDMI (registered trademark), USB (Universal Serial Bus), etc., and performs video processing on the video signals supplied from the external device to the connectors. To the unit 150. 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 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 the video signal supplied from the video interface 160. In addition, the video processing unit 150 acquires from the control unit 110 an on-screen image signal such as a GUI for operating the projector 10, a cursor indicating the position indicated by the indicator 20, and an image drawn by the drawing function. The video processing unit 150 includes a VRAM (Video RAM) 151, and includes a region for developing a video signal and a region for developing a signal of an on-screen image, and develops each signal in each region. 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 supplies a video signal on which the on-screen image signal is superimposed 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 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 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 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 detection 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 detection 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 detection 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 detection unit 113 controls the imaging unit 170A and the imaging unit 170B, and images a predetermined range including the screen SC at a 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. 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 detection unit 113.

  The position detection 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 and the light emitting unit 230 on the projected image, and 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 detection 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 detection unit 113 specifies infrared light at a position close to the position of the infrared light whose position is specified in phase P13 among the infrared light whose positions are specified in phase P12 and phase P14, and the specified infrared light Is the position of the light emitting unit 230. Also, the position detection unit 113 sets the position of the infrared light far from the infrared light whose position has been specified in phase P13 among the infrared light whose positions have been specified in phase P12 and phase P14 as the finger position. Note that if the infrared light is not in the imaging range in the phase P13, the position detection unit 113 sets the position specified in the phases P12 and P14 as the finger position. These specified positions are used when a drawing function or a GUI operation is performed.

  The drawing unit 112 supplies an on-screen image signal to the video processing unit 150 according to the position detected by the position detection unit 113 for the projected image, and draws the image at the position indicated by the indicator 20 or the finger. Do. The drawn image control unit 114 controls storage of an image (drawn image) drawn according to the position of the indicator 20 or the finger and display of the image. The luminance detection unit 115 analyzes the image signal supplied from the imaging unit 170A and the imaging unit 170B, specifies an area in which the background image appears in the image represented by the image signal, excluding the drawn image, and determines the luminance value of the background image. Create a histogram. The drawn image control unit 114 controls the video processing unit 150 in accordance with the change in the histogram created by the luminance detection unit 115 to erase or restore the drawn 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)
Next, an operation example of the present embodiment when the drawing function is on will be described. When the video signal is supplied from the PC 40, 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 video signal is supplied to the video processing unit 150, an image represented by the video signal is projected on the screen SC. Since this image is the background of the image projected by the rendering function, hereinafter, for convenience of explanation, the image projected by the video signal supplied from the PC is referred to as a background image. For example, it is assumed that an image displayed on the PC 40 is projected by the projector 10. When the video signal of the first page image of the document displayed on the PC 40 is supplied from the PC 40 to the projector 10, the first page image of the document is projected onto the screen SC.

  When drawing a projected image with a drawing function, the user brings the indicator 20 into contact with the position on the screen SC where the drawing is performed. When the drawing function is on, the control unit 110 analyzes the image signal supplied from the imaging unit 170A and the imaging unit 170B, and detects the position of the indicator 20. The control unit 110 generates an on-screen image according to the detected position of the indicator, and supplies a signal representing the generated on-screen image to the video processing unit 150. When the on-screen image signal is supplied to the video processing unit 150, the on-screen image signal is developed in the VRAM 151, and the on-screen image is superimposed on the first page image of the document and projected. For example, when the user moves the indicator 20 while making contact with the screen SC, a signal of 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 description) is sent to the VRAM 151. The drawn image is projected at the position where the indicator 20 has been unfolded and moved.

  Next, when the indicator 20 moves away from the screen SC, the control unit 110 analyzes the image signal supplied from the imaging unit 170A and the imaging unit 170B, and a background image is reflected in the image represented by the image signal except for the drawing image. A region is specified, and a histogram of luminance values of the background image is created. Note that the histogram of the luminance values of the background image may be created based on the video signal supplied from the external device. Next, the control unit 110 stores the created histogram in the RAM.

  The control unit 110 detects the position of the indicator 20 and executes the process shown in FIG. 5 when the indicator 20 is not in contact with the screen SC. FIG. 5 is a flowchart showing a flow of processing for erasing a drawn image in accordance with a change in luminance of a background image.

  The control unit 110 analyzes the image signals supplied from the imaging unit 170A and the imaging unit 170B, specifies an area in which a background image appears in the image represented by the image signal, excluding a drawn image, and a histogram of luminance values of the background image. Is created (step SA1). Note that the histogram of the luminance values of the background image may be created based on the video signal supplied from the external device. Next, when the process of step SA1 is completed, the control unit 110 determines whether the luminance value histogram of the background image created in step SA1 is the same as the histogram stored in the RAM after projection of the drawn image (step SA2).

  When the histogram created in step SA1 and the histogram stored in the RAM are the same (YES in step SA2), control unit 110 returns the process flow to step SA1. For example, after the drawing by the indicator 20 is finished, the displayed page is not changed from the first page, and the histogram created in step SA1 is the same as the histogram stored in the RAM after the drawing image is projected. If so, the control unit 110 determines YES in step SA2.

  Next, for example, when the page of the document displayed on the PC 40 is changed from the first page to the second page, the video signal of the image on the second page is supplied from the PC 40 to the projector 10. The projector 10 projects the image of the second page according to this video signal. Here, in step SA1, the control unit 110 creates a histogram of luminance values of the second page image. Here, since the histogram stored in the RAM is a histogram of the luminance value of the image of the first page of the document, the histogram stored in the RAM and the histogram created in step SA1 are different.

  When the histogram created in step SA1 and the histogram stored in the RAM are different (NO in step SA2), the control unit 110 associates the histogram stored in the RAM with the displayed drawing image and the position of the drawing image. Is stored in the storage unit 120 (step SA3), and the histogram created in step SA1 is stored in the RAM (step SA4).

  Next, the control unit 110 determines whether the same histogram as that stored in the RAM in step SA4 is stored in the storage unit 120 (step SA5). When the same histogram as the histogram stored in the RAM in step SA4 is not stored in the storage unit 120 (NO in step SA5), the control unit 110 deletes the drawn image developed in the VRAM 151 (step SA6) and performs processing. Is returned to step SA1.

  For example, when the document page displayed on the PC 40 is changed from the first page to the second page, and the second page becomes the background image for the first time, the histogram of the luminance values of the second page image is stored. Since the image is not stored in the unit 120, the control unit 110 deletes the drawn image in step SA6, and only the image of the second page is projected on the screen SC.

  Next, when the user moves the indicator 20 on the screen SC while the second page image is displayed, a drawing image corresponding to the movement of the indicator 20 is superimposed on the second page image. Projected. When the indicator 20 moves away from the screen SC, the control unit 110 analyzes the image signal supplied from the imaging unit 170A and the imaging unit 170B, and determines an area in which the background image appears in the image represented by the image signal, excluding the drawing image. Identify and create a histogram of the luminance values of the background image. Next, the control unit 110 stores the created histogram in the RAM.

  Thereafter, the control unit 110 executes the processing shown in FIG. The control unit 110 analyzes the image signals supplied from the imaging unit 170A and the imaging unit 170B, specifies an area in which a background image appears in the image represented by the image signal, excluding a drawn image, and a histogram of luminance values of the background image. Is created (step SA1). When the process of step SA1 is completed, the control unit 110 determines whether the luminance value histogram of the background image created in step SA1 is the same as the histogram stored in the RAM after the drawing image is projected (step SA2). If the background image does not change after displaying the drawn image, the control unit 110 determines YES in step SA2 because the histogram created in step SA1 is the same as the hysteresis and gram stored in the RAM, and the process is executed. Return the flow to step SA1.

  Next, when the page of the document displayed on the PC 40 returns from the second page to the first page, and the first page becomes a background image, the control unit 110 displays a histogram of luminance values of the second page image. Is created in step SA1. Here, since the histogram of the luminance value of the image of the second page is stored in the RAM as described above, the control unit 110 determines NO in step SA2. If the determination is NO in step SA2, control unit 110 associates the histogram of the brightness value of the image on the second page with the displayed drawn image and the position of the drawn image, and stores them in storage unit 120 (step SA3). The histogram created in step SA1 is stored in the RAM (step SA4).

  Next, the control unit 110 determines whether the same histogram as that stored in the RAM in step SA4 is stored in the storage unit 120 (step SA5). Here, since the histogram of the image of the first page of the displayed document is stored in the storage unit 120 as described above, the control unit 110 determines YES in step SA5. If it is determined YES in step SA5, control unit 110 deletes the drawn image developed in VRAM 151 (step SA7), and then restores the drawn image (step SA8).

  Specifically, the control unit 110 acquires the drawing image and the position of the drawing image that are associated with the same histogram as the histogram stored in the RAM in step SA4. The control unit 110 supplies a drawing image signal to the video processing unit 150 so that the acquired drawing image is displayed at the acquired position.

  For example, the page of the document displayed on the PC 40 is changed from the second page to the first page, and as described above, the histogram of the image on the first page, the drawn image, and the position of the drawn image are stored in the storage unit 120. If so, the control unit 110 acquires the drawing image and the position of the drawing image stored in the storage unit 120 in association with the histogram of the displayed background image (first page image). When the control unit 110 supplies a drawing image signal to the video processing unit 150 so that the acquired drawing image is displayed at the acquired position, the drawing image projected when the first page image is displayed is displayed. It is restored and projected on the background image.

  In the above description, an example of drawing using the indicator 20 has been described. However, in the present invention, even when a user's finger is used as the indicator, drawing or drawing depending on the position of the finger is performed. Images can be erased and restored.

Further, in the present invention, the above-described function for erasing the drawn image is configured to be turned on / off on the menu screen. When the function is set to on, the above operation is performed, and when the function is set to off. The above-described operation may not be performed, and the drawn image may not be deleted until an operation for deleting the drawn image is performed.
Further, in the present invention, when the function for erasing the drawn image is set to ON, the function for restoring the drawn image described above is set to ON as a configuration that can be set to ON / OFF on the menu screen. If it is set to OFF, if it is determined to be NO in step SA3, the flow of processing may be shifted to step SA8 to erase the drawn image.

[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 above-described embodiment, the control unit 110 analyzes the image signal supplied from the imaging unit 170A and the imaging unit 170B, specifies an area in which the background image appears in the image represented by the image signal, excluding the drawn image, Although a histogram of luminance values of the background image is created, a histogram of luminance values of a predetermined region of the background image may be created. For example, the page number portion of the document to be projected may be designated by a user operation, and a luminance value histogram may be created for the image in the designated area.

  In the embodiment described above, the histogram of the luminance value of the background image is created based on the image signal supplied from the imaging unit 170A and the imaging unit 170B, but the configuration for creating the histogram of the luminance value of the background image is as follows. The configuration is not limited to that of the embodiment. For example, a background image developed in the VRAM 151 may be analyzed using a video signal supplied from the PC 40, and a histogram of luminance values of the background image may be created.

  In the embodiment described above, a background image is captured by the imaging unit 170A and the imaging unit 170B, and the drawn image is erased or restored in accordance with a change in the luminance value of the background image. However, the drawn image is erased or restored. The configuration to be performed is not limited to the configuration of the embodiment. For example, the imaging unit 170A and the imaging unit 170B capture the screen SC and the surroundings of the screen SC, and specify the brightness of the room in which the projector 10 is installed from the images obtained by the imaging unit 170A and the imaging unit 170B. The projector 10 may delete or restore the drawn image when the brightness of the specified room changes beyond a predetermined threshold after displaying the drawn image. In the case of this modification, the erased drawn image may be restored when the brightness of the specified room returns to the brightness when the drawn image is generated. Further, the movement of the user near the screen SC may be detected from the images obtained by the imaging unit 170A and the imaging unit 170B, and the drawn image may be erased or restored according to the movement of the user.

  In the embodiment described above, the apparatus that displays the image and the drawing image of the video signal supplied from the external apparatus is a projector, but the apparatus that displays the image and the drawing image of the video signal supplied from the external apparatus is It is not limited to a projector. For example, a device that displays an image and a drawn image of a video signal supplied from an external device 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 the finger that is an indicator is detected by the touch panel. The display device displays a drawn image according to the detected finger position. In the display device, similarly to the above-described modification, a histogram of the luminance value of the background image is created, and the drawn image is erased and restored in the same manner as in the embodiment according to the change of the histogram.

  In the present invention, the projector 10 may be a stationary projector, and a projector installed on a desk may project an image onto the screen SC.

DESCRIPTION OF SYMBOLS 1 ... Display system, 10 ... Projector, 20 ... Indicator, 30 ... Light-emitting device, 40 ... PC, 110 ... Control part, 112 ... Drawing part, 113 ... Position detection part, 114 ... Drawing image control part, 115 ... Luminance detection , 120 ... storage section, 130 ... operation section, 140 ... projection section, 150 ... video processing section, 160 ... video interface, 170A, 170B ... imaging section, 180 ... communication section, 210 ... control section, 211 ... signal acquisition section , 212... Light emission control unit, 220.

Claims (6)

A display unit for displaying a drawn image and a background image supplied from an external device on a display surface;
A position detector for detecting the position of the indicator relative to the display surface;
A drawing unit that generates the drawing image according to the position specified by the position detection unit, and supplies the drawing image to the display unit;
A luminance detection unit for detecting the luminance of the background image;
A display device comprising: a drawing image control unit that erases the drawing image when the luminance detected by the luminance detection unit changes during display of the drawing image. The drawing image control unit erases the drawing image when the luminance detected by the luminance detection unit changes when the setting for performing the erasing is performed, and when the setting for performing the erasing is not performed. The display device according to claim 1, wherein the drawn image is not erased even if the luminance detected by the luminance detection unit changes. The drawing image control unit causes the storage unit to store the drawing image generated by the drawing unit during display of the background image in association with the luminance of the background image detected by the luminance detection unit;
3. The display according to claim 1, wherein when the luminance detected by the luminance detection unit is changed, the drawing image stored in the storage unit is supplied to the display unit in association with the luminance after the change. apparatus. When the brightness detected by the brightness detection unit changes, the drawn image control unit is stored in the storage unit in association with the changed brightness when the brightness detected by the brightness detection unit changes. When the drawing image is supplied to the display unit and the deleted image is not set to be restored, even if the luminance detected by the luminance detection unit is changed, the storage is performed in association with the changed luminance. The display device according to claim 3, wherein the drawn image stored in the unit is not supplied to the display unit. An image capturing unit that captures the display surface and generates an image of the captured display surface;
The luminance detection unit detects the luminance of a portion other than the drawing image in the image displayed by the display unit in the image generated by the imaging unit,
The display device according to claim 1, wherein the drawn image control unit erases the drawn image when the luminance changes. A control method of a display device including a display unit that displays a drawn image and a background image supplied from an external device on a display surface,
A position detecting step for detecting a 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 detection step, and supplying the drawing image to the display unit;
A luminance detection step for detecting the luminance of the background image;
And a drawing image control step of erasing the drawing image when the luminance detected in the luminance detection step changes during display of the drawing image.

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