JP2017198779A - Projection type display device and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projection type display device capable of changing a color of a comment etc. superimposed in a normally black non-image area in a projection area to be easily recognized.SOLUTION: Projection images picked up by an optical system are projected on a screen. A projection area on a screen includes an image area and a non-image area. An imaging unit 194 picks up an image of the projection area on the screen. A CPU 110 detects whether there are any writing of a comment etc. superimposed on the projection area or a non-image area thereof from the pickup image. When any comment etc. is detected, the CPU 110 changes a fill color in the non-image area to a brightness in which the comment etc. may be easily recognized.SELECTED DRAWING: Figure 1

Description

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

  In recent years, a meeting or the like may be progressed while projecting an image of a document for explanation from a projector or the like on a whiteboard or the like while writing a comment or the like with a pen or the like around the projected video on the whiteboard. . In order to improve the visibility of the projected image, the document projection is usually performed in a dark environment with the illumination turned off.

  A projector normally projects an image in a state including a non-image area around a projected image due to a difference in aspect ratio or keystone correction. That is, the projection area on the screen projected by the projector is composed of a projected video area such as a document video and a surrounding non-video area.

  When writing a comment or the like in the projection area with a pen or the like, it is necessary to improve the visibility of the written comment or the like. Patent Document 1 describes that the brightness of an area in which a comment or the like is written is changed so that the comment or the projected video can be easily viewed.

JP 2011-64777 A

  When the aspect ratio of the image to be projected is different from the aspect ratio of the projection area, the projected video is arranged so as to enter the projection area, and so-called margins are generated on the left and right or the top and bottom. Note that a margin is generated around the projected video even when the video is not arranged in the whole projection area but is arranged slightly smaller. Existing projectors usually project such margins in black.

  In the prior art disclosed in Patent Document 1, for example, when a comment or the like is written in the projection area, the brightness of the portion including the comment or the like in the projection area is increased. This can make it difficult to interpret the material. Even if it is desired to write a comment or the like outside a document image, for example, in a blank area, it is difficult for a participant to read the comment or the like unless the illumination is brightened as long as the projection is black. Eventually, the lighting is temporarily brightened and the participants read it, and then it is darkened again.

  It is an object of the present invention to provide a projection display apparatus and a control method therefor that eliminate such inconveniences.

  In order to achieve such an object, the projection display apparatus according to the present invention displays a projected image in a projection area on the screen including a video area and a non-video area by projecting an image on the screen. Projection means; detection means for detecting presence / absence of drawing overlapping the projection area on the screen; and control means for controlling a fill color of a non-video area of the projection area, wherein the drawing is detected in the projection area And a control unit that changes the fill color to a color that allows the drawing to be visually recognized.

  According to the present invention, it is possible to provide a projection display device capable of improving the visibility of comments or the like written in a non-video area by controlling only the fill color of the non-video area.

It is a schematic block diagram of one Example of this invention. It is explanatory drawing of the use condition of a present Example. It is an operation | movement flowchart of a present Example. It is a flowchart of the fill color control of the non-video area of the present embodiment. It is explanatory drawing of the control shown in FIG. It is a 2nd flowchart of the fill color control of the non-video area | region of a present Example. It is explanatory drawing of the control shown in FIG. It is a 3rd flowchart of the fill color control of the non-video area | region of a present Example. It is a 4th flowchart of the filling color control of the non-video area | region of a present Example.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the examples described below.

  FIG. 1 shows a schematic block diagram of a liquid crystal projector 100 which is an embodiment of a projection display device according to the present invention. Here, although an embodiment applied to a three-plate type liquid crystal projector will be described, a single-plate type may be used. The liquid crystal projector 100 displays the image by controlling the light transmittance of the liquid crystal element according to the image to be displayed and projecting the illumination light whose intensity is modulated by the liquid crystal element on the screen. The screen itself is not limited to a whiteboard.

  FIG. 2 shows the relationship between the liquid crystal projector 100 shown in FIG. 1 and the external device 200 and whiteboard 210 that are video sources. The external device 200 is a video signal source, and transmits a video signal to the liquid crystal projector 100 via a video cable. The liquid crystal projector 100 receives the video signal transmitted from the external device 200 and sequentially projects each frame image of the received video signal on the whiteboard 210. Here, the area (projection area) projected from the liquid crystal projector 100 onto the whiteboard 210 is configured such that the non-video areas 212 and 216 are located on both sides of the video area 214 due to the aspect ratio. The relationship between the video area 214 and the non-video areas 212 and 216 in the projection area is an explanatory example, and other arrangements are possible.

  The configuration and basic operation of the liquid crystal projector 100 will be described with reference to FIG. The liquid crystal projector 100 includes a CPU 110, a ROM 111, a RAM 112, an operation unit 113, an image input unit 130, and an image processing unit 140. The liquid crystal projector 100 further includes a liquid crystal control unit 150, liquid crystal elements 151R, 151G, and 151B, a light source control unit 160, a light source 161, a color separation unit 162, a color composition unit 163, an optical system control unit 170, and a projection optical system 171. . Further, the liquid crystal projector 100 includes a recording / reproducing unit 191, a recording medium 192, a communication unit 193, an imaging unit 194, a display control unit 195, a display unit 196, and an optical sensor unit 197.

  CPU 110 controls each part of liquid crystal projector 100. The ROM 111 stores a control program executed by the CPU 110. The RAM 112 temporarily stores a control program and data as a work memory of the CPU 110. Further, the CPU 110 temporarily stores still image data and moving image data reproduced from the recording medium 192 by the recording / reproducing unit 191 in the RAM 112, and reproduces each image and video using the program stored in the ROM 111. it can. The CPU 110 temporarily stores still image data and moving image data received from the communication unit 193 in the RAM 112, and can reproduce each image and video using a program stored in the ROM 111. In addition, the CPU 110 temporarily stores an image or video obtained by the imaging unit 194 in the RAM 112, converts it into still image data or moving image data using a program stored in the ROM 111, and records the image or video on the recording medium 192. You can also.

  The operation unit 113 receives an instruction from a user (presenter, presenter, or assistant) and transmits an instruction signal corresponding to the operation to the CPU 110. The operation unit 113 includes, for example, a switch, a dial, and a touch panel provided on the display unit 196. The operation unit 113 includes a signal receiving unit (such as an infrared receiving unit) that receives a radio signal from the remote controller and transmits a predetermined instruction signal to the CPU 110 based on the received signal. CPU 110 controls each unit of projector 100 in accordance with control signals input from operation unit 113 and communication unit 193.

  The image input unit 130 is a means for inputting a video signal from an external device, for example, a composite terminal, an S video terminal, a D terminal, a component terminal, an analog RGB terminal, a DVI-I terminal, a DVI-D terminal, or HDMI (registered) Trademark) terminal. The image input unit 130 has conversion means for converting an analog video signal into a digital video signal. The image input unit 130 transmits the input video signal to the image processing unit 140. The image input unit 130 may receive a video signal from an external device via a communication cable, or may receive a video signal from the external device by wireless communication. The external device may be a personal computer, a camera, a mobile phone, a smartphone, a hard disk recorder, a game machine, or the like as long as it can output a video signal.

  The image processing unit 140 performs a changing process such as the number of frames, the number of pixels, and the image shape on the video signal input by the image input unit 130 and supplies the changed signal to the liquid crystal control unit 150. The image processing unit 140 does not have to be a dedicated microprocessor. For example, the CPU 110 may execute the same processing as the image processing unit 140 by a program stored in the ROM 111. The image processing unit 140 can execute processing such as frame thinning processing, frame interpolation processing, resolution conversion processing, and distortion correction processing (keystone correction processing). In addition to the video signal received from the image input unit 130, the image processing unit 140 can also perform the above-described change processing on the image and video reproduced by the CPU 110.

  The liquid crystal control unit 150 controls the transmissivity in units of pixels of the liquid crystal elements (display means) 151R, 151G, and 151B in accordance with one frame of video signal supplied from the image processing unit 140. The liquid crystal control unit 150 includes a control microprocessor. Further, the liquid crystal control unit 150 does not need to be a dedicated microprocessor. For example, the CPU 110 may execute the same processing as the liquid crystal control unit 150 by a program stored in the ROM 111.

  The liquid crystal control unit 150 drives the liquid crystal element 151R according to the R (red) signal of the video signal processed by the image processing unit 140, drives the liquid crystal element 151G according to the G (green) signal, and B (blue). ) The liquid crystal element 151B is driven in accordance with the signal. The color separation unit 162 separates white illumination light from the light source 161 into red light, green light, and blue light, and supplies the separated illumination light to the liquid crystal elements 151R, 151G, and 151B. Thereby, the liquid crystal element 151R displays a red image of the RGB image to be displayed, the liquid crystal element 151G displays a green image of the RGB image to be displayed, and the liquid crystal element 151B is an RGB image to be displayed. The blue image of is displayed. The liquid crystal elements 151R, 151G, and 151B are light modulation units that generate optical images of the respective colors by spatially modulating the illumination light separated by the color separation unit 162.

  The liquid crystal elements (liquid crystal display panels) 151R, 151G, and 151B are display units each having a displayable area larger than an image display area for displaying an image to be projected. The displayable area is an area where each liquid crystal element can display an image, and the image display area is an area where each liquid crystal element displays an image. The image display area is included in the displayable area, and the size of the image display area is equal to or smaller than the size of the displayable area. The liquid crystal control unit 150 has a function as display position control means for controlling the position of the image display area within the displayable area of each of the liquid crystal elements 151R, 151G, and 151B.

  Specific control operations of the liquid crystal elements 151R, 151G, and 151B by the liquid crystal controller 150 and the configurations of the liquid crystal elements 151R, 151G, and 151B will be described later.

  The light source control unit 160 includes a control microprocessor, and controls the light source 161 to be turned on or off, and controls the amount of light when the light source 161 is on. The CPU 110 may execute the same processing as that of the light source control unit 160 by a program stored in the ROM 111. The light source 161 generates illumination light for the liquid crystal elements 151R, 151G, and 151B. The light source 161 includes, for example, a halogen lamp, a xenon lamp, or a high-pressure mercury lamp. Output light from the light source 161 is supplied to the color separation unit 162. The output light of the light source 161 is separated or divided into red, green, and blue colors by the color separation unit 162, and each separated light enters the liquid crystal elements 151R, 151G, and 151B. The color separation unit 162 is an element that separates the output light of the light source 161 into red (R), green (G), and blue (B), and includes, for example, a dichroic mirror and a prism. In addition, when using LED etc. which output the light corresponding to each color as the light source 161, the color separation part 162 becomes unnecessary.

  The color synthesis unit 163 optically synthesizes the light transmitted through the liquid crystal elements 151R, 151G, and 151B. As a result, an optical image indicating the original color of the image to be displayed is generated. The color synthesizing unit 163 is an element that spatially synthesizes red (R), green (G), and blue (B) optical images transmitted through the liquid crystal elements 151R, 151G, and 151B, and includes, for example, a dichroic mirror and a prism. including. The optical image synthesized by the color synthesis unit 163 is a full-color image, and is projected onto the whiteboard 210 as a screen by the projection optical system 171. As a result, the image processed by the image processing unit 140 is projected onto the whiteboard 210.

  The projection optical system 171 projects the optical composite image output from the color composition unit 163 onto the whiteboard. The projection optical system 171 includes a plurality of lenses and a lens driving actuator. The projection optical system 171 performs enlargement, reduction, focus adjustment, and the like of a projection image projected on the screen by driving the lenses. The optical system control unit 170 includes a control microprocessor and controls the magnification and focus of the projection optical system 171. The CPU 110 may execute the same processing as that of the optical system control unit 170 by a program stored in the ROM 111.

The recording / playback unit 191 plays back still image data and moving image data from the recording medium 192, receives still image data and moving image data of images and videos obtained by the imaging unit 194 from the CPU 110, and records them on the recording medium 192. The recording / playback unit 191 also records still image data and moving image data received by the communication unit 193 on the recording medium 192.
The recording / playback unit 191 includes, for example, an interface electrically connected to the recording medium 192 and a microprocessor for communicating with the recording medium 192. The CPU 110 may execute the same processing as the recording / playback unit 191 by a program stored in the ROM 111 instead of a dedicated microprocessor. The recording medium 192 can record still image data, moving image data, control data for controlling the projector 100, and the like. The recording medium 192 may be any type of recording medium such as a magnetic disk, an optical disk, or a semiconductor memory, and may be a detachable recording medium or a built-in recording medium.

  The communication unit 193 is means for communicating with an external device and receiving control signals, still image data, moving image data, and the like from the external device. For example, the communication unit 193 can use a wireless LAN, a wired LAN, USB, or Bluetooth (registered trademark), and the communication method is not limited to a specific one. When the terminal of the image input unit 130 is, for example, an HDMI (registered trademark) terminal, the communication unit 193 may perform CEC communication via the terminal. The external device is, for example, a personal computer, a camera, a mobile phone, a smartphone, a hard disk recorder, a game machine, or a remote control.

  The imaging unit 194 captures a range including an image projected on the screen (here, on the whiteboard 210) by the projection optical system 171. The imaging unit 194 transmits the captured image data to the CPU 110. The CPU 110 temporarily stores the image data from the imaging unit 194 in the RAM 112 and converts the image data into still image data or moving image data based on a program stored in the ROM 111. The imaging unit 194 includes an imaging element that converts an optical image into an image signal, a lens that enters an optical image of a subject into the imaging element, an actuator that drives the lens, a microprocessor that controls the actuator, and an output image signal from the imaging element as a digital signal Including an AD conversion unit for converting into Note that the imaging unit 194 may capture, for example, a viewer side in a direction opposite to a screen (not shown).

  The display control unit 195 includes a dedicated microprocessor that causes the display unit 196 to display an image such as an operation screen for operating the liquid crystal projector 100 and a switch icon. Instead of the dedicated microprocessor, the CPU 110 may execute the same processing as that of the display control unit 195 by a program stored in the ROM 111. The display unit 196 displays an operation screen and a switch icon for operating the liquid crystal projector 100. The display unit 196 may be, for example, a liquid crystal display, a CRT display, an organic EL display, or an LED display. In addition, the display unit 196 may be configured to emit an LED or the like corresponding to each button in order to post a specific button so that the user can recognize it.

  The optical sensor unit 197 receives projection reflected light, illumination light, and other external light of the projection image, and outputs information on ambient light in the installation environment of the liquid crystal projector 100 as a sensor value.

  The functions of the image processing unit 140, the liquid crystal control unit 150, the light source control unit 160, the optical system control unit 170, the recording / playback unit 191 and the display control unit 195 may be realized by a single or a plurality of microprocessors. Some or all of these functions may be executed by the CPU 110 by a program stored in the ROM 111.

  FIG. 3 shows an operation flowchart of this embodiment. The basic operation of the liquid crystal projector 100 will be described with reference to FIG. The CPU 110 implements the control operation in the flowchart shown in FIG. 3 by reading and executing the control program stored in the ROM 111. When the user gives an instruction to turn on the liquid crystal projector 100 using the operation unit 113 or a remote controller (not shown), the CPU 110 controls the power supply unit so as to supply power to each unit of the liquid crystal projector 100 and starts the process shown in FIG. .

  In S301, CPU 110 determines the display mode selected by the operation of operation unit 113 or a remote controller (not shown) by the user. The display modes of the liquid crystal projector 100 include an input image display mode, a file playback display mode, and a file reception display mode. The input image display mode is a mode for displaying video input from the image input unit 130. The file playback display mode is a mode for displaying an image or video of still image data or moving image data read from the recording medium 192 by the recording / playback unit 191. The file reception display mode is a mode in which an image or video of still image data or moving image data received from the outside by the communication unit 193 is displayed. Here, as an illustrative example, the display mode is selected by the user. However, the display mode when the power is turned on may be the display mode when the power is turned off the last time, or one of the display modes may be the default. When no user operation is required in this way, S301 can be omitted.

  FIG. 3 shows a control procedure when the input image display mode is selected in S301. When the file playback display mode or the file reception display mode is selected, only the video source is different from the input image display mode, and the basic control is the same.

  In step S <b> 302, the CPU 110 determines whether a video signal is input from the image input unit 130. When the video signal is not input (No in S302), the CPU 110 waits until the video signal input is detected. When the video signal is input (Yes in S302), the CPU 110 executes a projection process in S303.

  In the projection process (S303), the CPU 110 transmits the video signal input from the image input unit 130 to the image processing unit 140, and causes the image processing unit 140 to perform modification of the number of pixels, the frame rate, and the shape of the video signal. . The image processing unit 140 supplies the image data for one screen after processing to the liquid crystal control unit 150. The CPU 110 causes the liquid crystal control unit 150 to have a transmittance corresponding to the gradation level of each color component of red (R), green (G), and blue (B) of the image data for one screen from the image processing unit 140. As described above, the transmittances of the liquid crystal elements 151R, 151G, and 151B are controlled. At the same time, the CPU 110 causes the light source controller 160 to control the output power of the output light from the light source 161.

  The color separation unit 162 separates white illumination light output from the light source 161 into red (R), green (G), and blue (B), and supplies each color component light to the liquid crystal elements 151R, 151G, and 151B. The amount of transmitted light of each color light supplied to the liquid crystal elements 151R, 151G, and 151B is limited for each pixel of the liquid crystal elements 151R, 151G, and 151B. That is, each of the liquid crystal elements 151R, 151G, and 151B spatially modulates the intensity of incident light with a color image to be displayed. The color component images of red (R), green (G), and blue (B) transmitted through the liquid crystal elements 151R, 151G, and 151B are supplied to the color composition unit 163 and spatially synthesized. The light synthesized by the color synthesis unit 163 is projected onto the whiteboard 210 by the projection optical system 171.

  The CPU 110 sequentially executes this projection processing for each image of one frame while projecting the image.

  When a user inputs an instruction to operate the projection optical system 171 to the CPU 110 through the operation unit 113 during projection, the CPU 110 controls the projection optical system 171 in a state corresponding to the operation content by the optical system control unit 170. That is, the optical system control unit 170 controls the actuator of the projection optical system 171 so as to change the focus of the projection image, the magnification ratio of the optical system, and the like.

  In step S <b> 304, the CPU 110 determines whether the user has input a display mode switching instruction from the operation unit 113 during the projection display. When the user has input a display mode switching instruction using the operation unit 113 (Yes in S304), the CPU 110 returns to S301 and determines the display mode. At this time, the CPU 110 transmits the display mode selection menu screen to the image processing unit 140 as an OSD image, and controls the image processing unit 140 to superimpose the OSD screen on the image being projected. The user selects a display mode while viewing the projected OSD screen. When the display mode switching instruction is not input from the operation unit 113 (No in S304), the CPU 110 proceeds to S305.

  In step S <b> 305, the CPU 110 determines whether a projection end instruction is input from the operation unit 113 by the user. When an instruction to end projection is input from the operation unit 113 by the user (Yes in S305), the CPU 110 stops power supply to each block of the liquid crystal projector 100 and ends image projection. When the user does not input a projection end instruction from the operation unit 113 (No in S305), the CPU 110 returns to S302, and thereafter, the processes from S302 to S305 are performed until the projection end instruction is input from the operation unit 113 by the user. repeat.

  The liquid crystal projector 100 projects an image on the whiteboard 210 in the above procedure.

  The playback operation in the file playback display mode will be briefly described. The CPU 110 causes the recording / playback unit 191 to read out a file list of still image data and moving image data and thumbnail data of each file from the recording medium 192. The recording / playback unit 191 temporarily stores the read file list and thumbnail data in the RAM 112. Based on the program stored in the ROM 111, the CPU 110 generates a character image based on the file list temporarily stored in the RAM 112 and an image based on the thumbnail data of each file, and transmits the image to the image processing unit 140. Then, the CPU 110 controls the image processing unit 140, the liquid crystal control unit 150, the light source control unit 160, and the optical system control unit 170 in the same manner as the projection processing (S303).

  The user refers to the projected file list and thumbnail, and selects which of the still image data and the moving image data recorded on the recording medium 192 is to be reproduced by the operation unit 113. The CPU 110 controls the recording / reproducing unit 191 so as to read the selected still image data or moving image data from the recording medium 192. The recording / playback unit 191 temporarily stores the read still image data or moving image data in the RAM 112. Similar to the projection process (S303), the CPU 110 projects the image data or video data temporarily stored in the RAM 112 onto the whiteboard 210, as with the image processing unit 140, the liquid crystal control unit 150, the light source control unit 160, and the optical system. The controller 170 is controlled. In the case of a still image, the same image is projected at a fixed period, and in the case of a moving image, readout and projection are repeated for each frame. In this way, the liquid crystal projector 100 projects the still image or moving image designated by the user onto the whiteboard 210.

  The operation in the file reception display mode will be briefly described. The CPU 110 temporarily stores still image data or moving image data received from the outside by the communication unit 193 in the RAM 112, and reproduces the still image data or moving image data based on a program stored in the ROM 111. Similar to the projection processing (S303), the CPU 110 projects the still image or moving image data temporarily stored in the RAM 112 onto the whiteboard 210, and the image processing unit 140, the liquid crystal control unit 150, the light source control unit 160, and the like. The optical system control unit 170 is controlled. In the case of a still image, the same image is projected at a fixed period, and in the case of a moving image, readout and projection are repeated for each frame. In this way, the liquid crystal projector 100 projects the still image or moving image designated by the user onto the whiteboard 210.

  FIG. 4 shows an operation flowchart for controlling the brightness of the non-image area of the projection area in this embodiment. The CPU 110 implements the control operation in the flowchart shown in FIG. 4 by reading and executing the control program stored in the ROM 111. CPU110 starts the process sequence shown in FIG. 4 at the time of execution of a projection process (S303).

  FIG. 5 shows an example of changing the brightness of the non-video area in six cases. In FIG. 5, reference numerals 500, 502, 503, 505, 506, 508, 509, 511, 512, 514, 515, and 517 indicate non-image areas before control by comment detection. Reference numerals 550, 552, 553, 555, 556, 558, 559, 561, 562, 564, 565, and 567 indicate non-image areas after control. Reference numerals 501, 504, 507, 510, 513, and 516 indicate video areas before control by comment detection. Reference numerals 551, 554, 557, 560, 563 and 566 indicate video areas after control.

  In step S <b> 401, the CPU 110 captures an image of a projection area (an area including a non-video area 212, a non-video area 216, and a video area 214) projected on the whiteboard 210 via the imaging unit 194. In order to improve the imaging accuracy of comments or the like, imaging may be performed while changing the exposure amount by adjusting the aperture or shutter speed. The imaging unit 194 supplies image (captured image) data obtained by imaging to the image processing unit 140.

  In S402, the CPU 110 instructs the image processing unit 140 to detect whether or not a comment or the like exists in the projection area in the captured image. The image processing unit 140 executes a comment detection process in accordance with this instruction from the CPU 110 and transmits the detection result to the CPU 110. For example, the image processing unit 140 detects a handwritten drawing image such as a comment from the difference between the projected image and the captured image. Of course, other detection methods may be employed. Examples of comments include characters, figures, diagrams, and tables. When a comment or the like is detected, the CPU 110 proceeds to S403, and when no comment or the like is detected, the CPU 110 returns to S401.

  In Case 1 of the example shown in FIG. 5, since a comment or the like is detected in the non-video area 500, the CPU 110 proceeds to S403. In Case 2, since a comment or the like is detected in the video area 503, the CPU 110 proceeds to S403. In Case 3, since a comment or the like is detected in the video area 507, the CPU 110 proceeds to S403. In Case 4, since a comment or the like is detected in the video area 510, the CPU 110 proceeds to S403. In Case 5, since a comment or the like is detected in the video area 513, the CPU 110 proceeds to S403. In Case 6, since no comment or the like is detected in the projection area, the CPU 110 returns to S401.

  In step S403, the CPU 110 instructs the image processing unit 140 to change the fill color of the non-video area. For example, the image processing unit 140 changes the pixel value of the non-video area corresponding to the difference area between the video area subjected to resolution conversion (including equal magnification) and the projection area from 0 to 128. This is equivalent to changing the fill color from black to gray. Note that the change in the fill color is not limited to the change from black to gray, and any change that improves the visibility of comments and the like may be used. For example, the color may be changed to a color complementary to the color of a comment or the like. Further, which non-video area fill color is to be changed may be stored in advance in the ROM 111 as a program and designated by the user through the operation unit 113.

  In Case 1 shown in FIG. 5, the fill color of the non-video areas 500 and 502 is changed from black to gray (non-video areas 550 and 552). In Case 2, the fill color of the non-video area 503 is changed from black to gray (non-video area 553), but the fill color of the non-video area 505 is not changed, and the fill color of the non-video area 505 and the non-video area 555 is changed. Will remain the same. In Case 3, the fill color of the non-video areas 506 and 508 is changed from black to gray (non-video areas 556 and 558). In Case 4, the fill color of the non-video area 509 is changed from black to gray (non-video area 559), but the fill color of the non-video area 511 is not changed, and the fill color of the non-video area 511 and the non-video area 561 is changed. Will remain the same.

  In Case 5, the fill color of the non-video area 514 is changed from black to gray (non-video area 564), but the fill color of the non-video area 512 is not changed, and the fill color of the non-video area 512 and the non-video area 562 is changed. Will remain the same. In Case 6, the fill colors of the non-video areas 515 and 517 are not changed, and the fill colors of the non-video areas 515 and 517 and the fill colors of the non-video areas 565 and 567 remain the same.

  As described above, when a comment or the like written over the non-video area is detected, the fill color of the non-video area is changed to a brighter direction, so that the visibility of the comment or the like is improved.

  When a comment or the like is written on the non-video area, the fill color of the non-video area may be changed. FIG. 6 shows a flowchart of the control operation thus changed. The CPU 110 implements the control operation in the flowchart shown in FIG. 6 by reading and executing the control program stored in the ROM 111. CPU110 starts the process sequence shown in FIG. 6 at the time of execution of a projection process (S303).

  FIG. 7 shows an example of changing the brightness of the non-video area in the control shown in FIG. In FIG. 7, reference numerals 700, 702, 703, 705, 706, 708, 709, and 711 denote non-video areas before control by comment detection. Reference numerals 751, 752, 753, 6755, 756, 758, 759, and 760 indicate non-video areas after control. Reference numerals 701, 704, 707, and 710 indicate video areas before control by comment detection. Reference numerals 752, 754, 757, and 760 denote video areas after control.

  Since S601 is the same process as S301, description thereof is omitted.

  In step S602, the CPU 110 instructs the image processing unit 140 to detect whether or not a comment or the like is present in the non-video area in the captured image. The image processing unit 140 executes a comment detection process in accordance with this instruction from the CPU 110 and transmits the detection result to the CPU 110. For example, the image processing unit 140 detects a handwritten drawing image such as a comment from the difference between the projected image and the captured image. Of course, other detection methods may be employed. When a comment or the like is detected, the CPU 110 proceeds to S603, and when no comment or the like is detected, the CPU 110 returns to S601.

  In Case 1 shown in FIG. 7, since a comment or the like is detected in the non-video area 700, the CPU 110 proceeds to S <b> 603. In Case 2, since a comment or the like is detected in the video area 703, the CPU 110 advances to S603. In Case 3, since no comment or the like is detected in the non-video areas 706 and 708, the CPU 110 returns to S601. In Case 4, since no comment or the like is detected in the non-video areas 709 and 711, the CPU 110 returns to S601.

  Since S603 is the same as S303, the description thereof is omitted.

  In the control operation shown in FIG. 6, when a comment or the like is written over the non-video area, the fill color of the written non-video area is controlled to be brighter, so that the appearance of the video area is changed. The visibility of comments and the like can be improved.

  A control operation in consideration of ambient brightness will be described. FIG. 8 shows a flowchart of a control operation in which the fill color of the non-video area is changed when a comment or the like is written on the projection area when the ambient light has a certain brightness or higher. The CPU 110 implements the control operation in the flowchart shown in FIG. 8 by reading and executing the control program stored in the ROM 111. The CPU 110 starts the processing procedure shown in FIG. 8 when the projection processing (S303) is executed.

  In step S <b> 801, the CPU 110 measures the intensity of ambient light using the optical sensor unit 197 and temporarily stores the measurement value in the RAM 112. In step S <b> 802, the CPU 110 reads the ambient light measurement value from the RAM 112 and compares it with the specified value. The specified value is stored in the ROM 111, for example. If the measured value is equal to or less than the specified value, the CPU 110 proceeds to S803, and if the measured value is greater than the specified value, the CPU 110 returns to S801. The specified value may be input to the CPU 110 by the operation unit 113 when necessary by the user.

  Since S803, S804, and S805 are the same as S401, S402, and S403, respectively, description thereof is omitted.

  The control shown in FIG. 8 controls the fill color of the non-video area when the surroundings are so dark that comments and the like cannot be read as they are, so that the change of the fill color of the non-video area can be limited when necessary.

  Another control operation in consideration of ambient brightness will be described. FIG. 9 shows a flowchart of a control operation in which the fill color of the non-video area is changed when a comment or the like is written over the non-video area when the ambient light has a certain brightness or higher. The CPU 110 implements the control operation in the flowchart shown in FIG. 9 by reading and executing the control program stored in the ROM 111. The CPU 110 starts the processing procedure shown in FIG. 9 when executing the projection processing (S303).

  In step S <b> 901, the CPU 110 measures the intensity of ambient light using the optical sensor unit 197 and temporarily stores the measurement value in the RAM 112. In step S902, the CPU 110 reads the measured value of the ambient light from the RAM 112 and compares it with the specified value. The specified value is stored in the ROM 111, for example. If the measured value is equal to or less than the specified value, the CPU 110 proceeds to S903. If the measured value is greater than the specified value, the CPU 110 returns to S901. The specified value may be input to the CPU 110 by the operation unit 113 when necessary by the user.

  Since S903, S904, and S905 are the same as S601, S602, and S603, respectively, description thereof is omitted.

  In the control shown in FIG. 9, when the surroundings are so dark that the comments cannot be read as they are, and the comments are written on the non-video area, the control of the fill color of the non-video area is enabled. To do. As a result, the change in the fill color of the non-video area can be minimized.

  The presence / absence of writing by the presenter or the presenter and the writing position are determined by imaging by the imaging unit 194 and image recognition, but methods other than imaging can also be used. For example, a presenter or an assistant thereof may instruct the liquid crystal projector 100 to execute writing (and a writing position) with a predetermined operation member, and the CPU 110 may control the projection brightness at the writing position in accordance with this instruction. Good. Further, the presenter may detect the writing operation by means for detecting the operation of the presenter to control the brightness of the projection area or the non-video area.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist thereof.

Claims (10)

Projecting means for displaying a projected image in the projected area on the screen including a video area and a non-video area by projecting an image on the screen;
Detecting means for detecting the presence or absence of drawing overlapping the projection area on the screen;
Control means for controlling the fill color of the non-video area of the projection area, and when the drawing is detected in the projection area, the control means changes the fill color to a color that allows the drawing to be visually recognized. A projection display device characterized by that.   The projection display apparatus according to claim 1, wherein the control unit changes the fill color to a color that allows the drawing to be visually recognized when the drawing overlaps the non-video area.   The projection display device according to claim 1, wherein the control unit changes the fill color of the non-video area where the drawing overlaps to a color that allows the drawing to be visually recognized.   The projection type according to any one of claims 1 to 3, wherein the control unit changes the fill color to a color that allows the drawing to be visually recognized and corresponds to the color of the drawing. Display device. Furthermore, it has an optical sensor unit that measures ambient brightness,
The control means controls the drawing with the fill color when the ambient brightness measured by the optical sensor unit is equal to or less than a predetermined value and the drawing overlaps the video area. The projection display device according to any one of claims 1 to 4. Furthermore, it has an optical sensor unit that measures ambient brightness,
The control means controls the drawing with the fill color when the ambient brightness measured by the optical sensor unit is a predetermined value or less and the drawing overlaps the non-video area. The projection display device according to any one of claims 1 to 4. The detection means is
Imaging means for imaging the projection area on the screen;
7. The projection display device according to claim 1, further comprising a unit that detects the presence or absence of drawing from a captured image of the imaging unit.   The projection display device according to claim 1, wherein the drawing includes a comment written on the image.   The projection display device according to claim 1, wherein the screen is a whiteboard. A method of controlling a projection display device that displays a projected image in a projection area on the screen including a video area and a non-video area by projecting an image on a screen,
A detection step of detecting the presence or absence of drawing overlapping the projection area on the screen;
And a control step of changing the fill color of the non-video area to a color in which the drawing can be visually recognized when the drawing is detected in the projection area by the detecting step. .

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