JP2005195617A - Projector, projector control method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector which acquires a write-in image compensated for an influence of external light. <P>SOLUTION: The projector for projecting a color projection image on a screen by compositing a plurality of color images comprises a camera for imaging the screen; an initial image imaging means for imaging at least a partial region of the screen by the camera as an initial image, without projecting any one of a plurality of colors on at least a partial region of the screen; a color image imaging means for imaging at least the partial region by the camera, when projecting each color by successively projecting the plurality of the colors on at least the partial region of the screen; and a write image acquiring means for acquiring the color write image written on the screen. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a projector device and a writing acquisition method.

2. Description of the Related Art Conventionally, a projector that projects a projected image on a screen is known that projects an image input from an external device to the projector by adding the projected image to the projected image (for example, Patent Document 1).
JP 2001-356405 A (FIG. 9)

  However, the user of the projector may directly write on the screen with respect to the projection image projected on the screen. In this case, the projector cannot directly capture the writing.

  In order to solve the above-described problem, in the first embodiment of the present invention, a projector that projects a color projection image on a screen by combining a plurality of color images, the camera for imaging the screen, and the screen Initial image capturing means for capturing at least a part of the screen by a camera without projecting any of the plurality of colors on at least a part of the screen, and a plurality of colors in order of at least a part of the screen The image is projected onto the area and at least a part of the area is projected by the camera when each color is projected, and the image captured by the initial image capturing means and the color image capturing means is used on the screen. Writing image acquisition means for acquiring a written image of a written color. As a result, when the projection image projected on the screen is directly written on the screen, this writing can be captured. Furthermore, in the present invention, since the influence of external light is compensated, a written image can be acquired with a correct color that is not affected by external light.

  The color image imaging unit may acquire a color writing image of the entire screen by causing at least a part of the region to be captured by the camera while moving on the screen. Thereby, even if it is a case where a projection image is projected, a writing image can be acquired, without conspicuous with respect to the person who is looking at a projection image.

  The plurality of colors are red, green, and blue, and the color image capturing unit acquires an image written on the screen when each color of red, green, and blue is projected, and the written image acquiring unit By subtracting the value of each pixel of the initial image from the value of each pixel of each image obtained by imaging the screen when each color of red, green, and blue is projected, Images of red, green, and blue components may be acquired. Normally, writing to the screen is sufficiently slow compared to the speed at which the camera images the screen. Therefore, in the present invention, three types of images necessary for creating a full-color image are captured by sequentially projecting red, blue, and green light. In this case, even when a single monochrome CCD camera is used, three types of images necessary for creating a full-color image can be captured. Therefore, the projector of the present invention can obtain a full-color written image at a low cost.

  The above color imaging means has means for projecting red, green, and blue light respectively on three different areas on the screen, and the initial image imaging means has three different areas on the screen. When projecting red, green, and blue light respectively, the other part of the area has means for projecting none of red, green, and blue light, and the color image capturing means has 3 You may have a means to image one area | region and another one part area | region simultaneously. Thereby, the time required to acquire the written image can be shortened, and a full-color written image can be acquired.

  Each of the three areas and another part of the area may be captured on the screen while being moved on the screen to obtain a color written image of the entire screen. Thereby, even when a projected image is projected, a full-color written image can be acquired without conspicuous to a person who is looking at the projected image.

  According to a second aspect of the present invention, a projector having a projection unit that projects a color projection image on a screen by combining a plurality of color images and a camera that captures the screen has a color written on the screen. A projector control method for reading an image, comprising: an initial image capturing step for capturing at least a part of the screen by a camera without projecting any of a plurality of colors onto at least a part of the screen; A color image capturing step of sequentially projecting the colors on at least a part of the area of the screen and capturing at least a part of the area by the camera when each color is projected, an initial image capturing unit, and a color image capturing Using the image captured by the means, obtain the color written image written on the screen That includes a write image acquisition step.

  In the projector control method described above, the plurality of colors are red, green, and blue, and the color image capturing step acquires an image written on the screen when each of the colors red, green, and blue is projected. The writing image acquisition step subtracts the value of each pixel of the initial image from the value of each pixel of each image obtained by imaging the screen when each color of red, green, and blue is projected. Thus, images of red, green, and blue components in the written image may be acquired.

  According to a third aspect of the present invention, a projector having a projection unit that projects a color projection image on a screen by combining a plurality of color images and a camera that captures the screen is written on the screen. A projector control program for reading a color image, and an initial image imaging unit for imaging at least a part of the screen by a camera without projecting any of a plurality of colors onto at least a part of the screen. A color image capturing unit that sequentially projects a plurality of colors onto at least a partial area of the screen, and causes each camera to capture at least a partial area when the respective colors are projected; an initial image capturing unit and a color; A color writing image written on the screen using the image captured by the image capturing means. And a writing image acquiring means for acquiring a.

  In the above program, the plurality of colors are red, green, and blue, and the color image capturing unit obtains an image written on the screen when projecting each color of red, green, and blue, and writes the image. The embedded image acquisition means subtracts the value of each pixel of the initial image from the value of each pixel of each image obtained by imaging the screen when each color of red, green, and blue is projected, Images of red, green and blue components in the written image may be acquired.

  The above summary of the invention does not enumerate all the necessary features of the present invention, and sub-combinations of these feature groups can also be the invention.

  Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the invention according to the scope of claims, and all combinations of features described in the embodiments are included. It is not necessarily essential for the solution of the invention.

  FIG. 1 shows a usage pattern of a projector 10 according to an embodiment of the present invention. The projector 10 projects a color projection image on the screen 40 by synthesizing a plurality of color images. Here, the projector 10 is connected to a PC (personal computer) 20 that outputs a projection image, and displays a projection image created by presentation software such as PowerPoint (registered trademark) on the screen 40. The user 300 makes a presentation using the projected image and writes directly on the screen 40 using the writing tool 302.

  The projector 10 according to the embodiment of the present invention acquires a written image on the screen 40 by imaging the screen 40. In addition, the projector 10 records the projection image and the voice of the user 300. Then, the projector 10 reproduces and displays the recorded writing image, projection image, and recorded sound on the screen 40 at the same timing as when recording. When the projector 10 is projecting a projected image, the screen 40 may be exposed not only to light from the projector 10 but also to outside light such as room light or the sun. If the written image on the screen is acquired in such a state, the written image may not be reproduced and displayed in the correct color because it is affected by external light. Therefore, the projector 10 according to the present invention aims to obtain a written image that compensates for the influence of external light on the screen 40.

  FIG. 2 is a diagram for explaining an example of use of the projector 10. In this example, it is assumed that the user 300 projects a presentation material created using, for example, a power point on the screen 40 using the projector 10. The material created at PowerPoint has multiple slides. One slide is composed of a plurality of objects such as characters and drawings, and the user 300 displays a slide image while adding these objects as needed.

  In this example, the projector 10 sequentially projects an image obtained by adding the character object 402 and the character object 404 to the slide image onto the screen 40. In this example, for the sake of simplicity, a state in which characters are described by squares is shown. In this case, the user 300 writes the writings 450, 452, 454, and 456 on the screen while explaining the slide image using a microphone or the like. The figure shown at the end of the figure shows a state where all writing is performed on a slide screen in which all objects to be added are displayed on one slide.

  When the presentation of one slide is finished in this way, the projector 10 projects the next new slide image onto the screen 40. The projector 10 according to the present invention records the projected image, writing, and sound projected on the screen 40 at the time of presentation. Then, at the recorded timing, the projected image, writing and sound are reproduced and displayed. When the projector 10 records the character objects 402 and 404 and the writing 450 to 456 in the order shown in the figure, the character objects 402 and 404 and the writing 450 to 456 are reproduced in the same order, Project onto the screen 40.

  FIG. 3 shows an example of a block diagram of the projector 10. The projector 10 includes a projection unit 100, a camera 142, an imaging unit 140, a storage device 150, a projection image recording unit 160, a captured image recording unit 165, a uniform image determination unit 170, a reading unit 180, a synthesis unit 190, a voice recording unit 200, An audio reproduction unit 210, a microphone 220, a speaker 230, a timing generator 240, a comparison unit 250, a deletion unit 260, and a measurement unit 270 are provided.

  The projection unit 100 includes an R light source 112, a G light source 114, a B light source 116, an R liquid crystal shutter 122, a G liquid crystal shutter 124, a B liquid crystal shutter 126, a projection light generation unit 120, a coupling prism 128, and an optical system 130. Each of the R light source 112, the G light source 114, and the B light source 116 is a white light source that generates light to be transmitted through each of the R liquid crystal shutter 122, the G liquid crystal shutter 124, and the B liquid crystal shutter 126.

  Each of the R liquid crystal shutter 122, the G liquid crystal shutter 124, and the B liquid crystal shutter 126 is a liquid crystal panel divided into a plurality of pixels, and the red component and the green component of the projection image are in accordance with instructions from the projection light generation unit 120. And a red image, a green image, and a blue image, which are blue components, are displayed. As a result, the R liquid crystal shutter 122, the G liquid crystal shutter 124, and the B liquid crystal shutter 126 display a projected image. A red filter, a green filter, and a blue filter are attached to the R liquid crystal shutter 122, the G liquid crystal shutter 124, and the B liquid crystal shutter 126, respectively. The light from the R light source 112 and the light from the G light source 114 are attached. , A red image projection light, a green image projection light, and a green image projection light are generated in accordance with the light from the B light source 116, respectively.

  The projection light generation unit 120 receives electronic data such as a color video signal from the PC 20, and opens and closes the R liquid crystal shutter 122, the G liquid crystal shutter 124, and the B liquid crystal shutter 126 for each pixel based on the received electronic data. As a result, the projection light generation unit 120 causes the R liquid crystal shutter 122, the G liquid crystal shutter 124, and the B liquid crystal shutter 126 to display a red image, a green image, and a blue image. The combining prism 128 combines the projection light of the red image, the green image, and the blue image received from the R liquid crystal shutter 122, the G liquid crystal shutter 124, and the B liquid crystal shutter 126 to generate color projection light, and supplies the optical system 130 with the color projection light. Supply.

  The optical system 130 is an optical system for projecting a projection image onto the screen 40, and includes a projection lens 134 and a half mirror 132. The projection lens 134 receives the color projection light generated by the coupling prism 128 via the half mirror 132 and forms an image on the screen 40. Thereby, the optical system 130 irradiates the screen 40 with the light transmitted through the R liquid crystal shutter 122, the G liquid crystal shutter 124, and the B liquid crystal shutter 126. Then, the optical system 130 projects the projected images displayed on the R liquid crystal shutter 122, the G liquid crystal shutter 124, and the B liquid crystal shutter 126 onto the screen 40. The half mirror 132 transmits the light received from the coupling prism 128 toward the projection lens 134. The half mirror 132 reflects light incident from the screen 40 via the projection lens 134 toward the imaging unit 140.

  The camera 142 captures an image of the screen 40 reflected by the half mirror 132 through the projection lens 134 of the optical system 130. The camera 142 in this example has a CCD image sensor, and this CCD image sensor is a monochrome CCD image sensor. In another example, the camera 142 may have a color CCD image sensor.

  The timing generator 240 counts the time and generates a timing at a predetermined time interval, and the generated time and timing are indicated by the imaging means 140, the projected image recording means 160, the captured image recording means 165, and the audio recording means 200. Give to.

  The imaging unit 140 includes an initial image imaging unit 144 and a color image imaging unit 146. The initial image capturing unit 144 controls the camera 142 without controlling the projection light generation unit 120 to project any light of red, green, and blue colors onto at least a part of the screen 40. At least a part of the screen 40 is imaged. Accordingly, the initial image capturing unit 144 acquires an image captured when only the external light hits the screen 40 as an initial captured image.

  The color image imaging unit 146 controls the projection light generation unit 120 to sequentially project red, green, and blue colors onto at least a partial area of the screen 40, and at least one of the colors is projected. The area of the image is captured by the camera 142. As a result, the color image capturing unit 146 converts the red, green, and blue images that are captured when the external light and the red, green, or blue light irradiated by the projection unit 100 strike the screen 40. Acquired as three color acquisition images corresponding to the respective colors.

  The initial image capturing unit 144 and the color image capturing unit 146 cause at least a part of the region to be captured by the camera 142 while being moved on the screen 40, whereby the initial captured image on the entire screen 40 and the three colors are displayed. Each of the written images is acquired. The initial image capturing unit 144 and the color image capturing unit 146 output the acquired initial captured image and the three-color color captured image to the written image acquiring unit 148, respectively. The partial area may be the entire area of the screen 40. In this case, the initial image capturing unit 144 causes the camera 142 to image the screen 40 without causing the projection light generating unit 120 to project any light of red, green, and blue colors on the entire area of the screen 40. The color image imaging unit 146 causes the projection light generation unit 120 to sequentially project red, green, and blue colors onto the entire area of the screen 40 and project the respective colors. Let's take an image.

  The captured image recording unit 165 includes a written image acquisition unit 148. The writing image acquisition unit 148 acquires a color writing image written on the screen 40 using the images captured by the initial image capturing unit 144 and the color image capturing unit 146. In this example, the written image acquisition means 148 subtracts the value of each pixel of the received initial captured image from the value of each pixel of the received color written image of the three colors, thereby red, green in the written image. , And blue component images are acquired. Thus, the written image acquisition unit 148 acquires a full-color written image that compensates for the influence of external light. The written image acquisition unit 148 records each of the three color written images subjected to compensation in the storage device 150 together with the timing received from the timing generator 240. In this example, the writing image acquisition unit 148 records the writing image together with the time when the writing image is captured with reference to the time when the first projection image is projected.

  The projection image recording means 160 receives a projection image from the PC 20 as electronic data such as a color video signal. Here, the projection image recording means 160 sequentially stores the received projection images in the storage device 150 together with the timing received from the timing generator 240. Here, the projection image recording means 160 compares the newly received projection image with the previously received projection image, and sums up the differences between the newly received projection image and the previously received projection image. When the total value is smaller than a predetermined reference value, the projection image recording unit 160 deletes the newly received projection image and the corresponding time. When the total value is larger than the reference value, the projection image recording means 160 records the time when the projection image was received immediately before the newly received projection image as the end time, and the newly received projection image and its time And record. Thereby, the projection image recording means 160 records the corresponding projection image for each identical projection image in association with the start time and the end time. The projection image recording unit 160 outputs the acquired projection image to the uniform image determination unit 170. Thereby, the timing and order of the projected image projected and the timing and order written on the screen can be accurately recorded.

  The voice recording means 200 receives the voice acquired by the microphone 220 and records it in the storage device in association with the timing at which the voice is acquired. In this example, the audio recording unit 200 associates the time received from the timing generator 240 with the time when the audio reception is started and the time when the audio reception is completed with the received audio data file. To record.

  When the projected image is a presentation material such as PowerPoint, when the slide progresses to the next slide, the written content corresponding to the previous slide is deleted, so when the slide changes, the writing can be acquired. preferable. At the turning point of the slide, a generally uniform projection image is normally output from the PC 20. Therefore, the uniform image determination unit 170 determines whether or not the projection image received from the projection image recording unit 160 is a uniform image. The uniform image judging means 170 in this example calculates and sums the difference in pixel value for each adjacent pixel in the frame of the projection image. When the total value is smaller than a predetermined reference value, the uniform image determining unit 170 determines that the projected image is uniform. The uniform image determining unit 170 causes the image capturing unit 140 to capture the screen 40 to acquire a written image, and associates the obtained written image with the projected image immediately before the projected image determined to be uniform. Store. The uniform image determination unit 170 may determine whether the projection image is uniform by examining the distribution of frequency components of the projection image. When the imaging unit 140 reads the writing, since the light projected on the screen is uniform, the imaging unit 140 can acquire the written image uniformly. When it is determined that the projected image is uniform, the uniform image determining unit 170 may cause the projecting unit 100 to generate more uniform light with the same color tone and project it onto the screen 40. As a result, a monochrome written image can be acquired without conspicuous to the person viewing the projected image.

  When the image newly captured by the imaging unit 140 is recorded in the storage device 150, the comparison unit 250 refers to the storage device 150, the newly captured image, and the image previously captured by the imaging unit 140 Compare. When the difference between the newly captured image and the previously captured image is smaller than a predetermined reference value, the deletion unit 260 deletes the newly captured image. In this example, the comparison unit 250 obtains and sums the difference between pixel values for each pixel in the newly captured image and the previously captured image. When the total value is smaller than a predetermined reference value, the deletion unit 260 deletes a newly captured image. As described above, the projector 10 deletes the written image having the same content, so that it is possible to save the capacity of the memory and the recording apparatus necessary for storing the captured written image. Further, the projector 10 deletes the written image having the same content that is obtained continuously, and even if the written image has a different content, the written image that has not passed the predetermined time is deleted. By appropriately determining the time, the image in the middle of the writing operation can be deleted, and only the written image in the state where the writing has been completed can be recorded.

  The measuring means 270 captures a second new image that is different from the reference value again after the first new image that is different from the reference value is acquired. Measure the time taken. The deleting unit 260 deletes the first new image when the time measured by the measuring unit is shorter than a predetermined reference time. As described above, the captured image recording unit 165 sequentially stores the timing at which the screen 40 is captured in the storage device in association with the captured image.

  The storage device 150 stores the timing at which the projection image is recorded in association with the projection image. In addition, the storage device 150 stores the timing at which the written image is recorded in association with the written image, and stores the timing at which the audio is recorded in association with the audio. The reading unit 180 reads the projection image, the timing when the projection image is projected, the captured image, and the timing when the captured image is captured from the storage device 150.

  The synthesizing unit 190 sequentially synthesizes the projected image and the captured image to project the projected image at the timing when the image is projected and to project the captured image at the timing when the captured image is captured. In this case, the synthesizing unit 190 compares the pixel values of the corresponding pixels in the projected image and the written image corresponding to each of the three colors of red, green, and blue, and selects the darker pixel value. By doing so, the projected image and the written image are synthesized. The projecting unit 100 projects the synthesized image synthesized by the synthesizing unit. Further, the reading unit 180 further reads out the voice and the timing when the voice is acquired from the storage device 150. The audio reproduction unit 210 reproduces the audio at the timing when the audio is acquired. As a result, the presentation can be accurately reproduced in the order in which the projection was performed, the order in which the writing was performed, and the order in which the recording was performed.

  FIG. 4 shows an example of data stored in the storage device 150. The storage device 150 in this example stores a start time at which projection of the projection image is started and an end time at which projection of the projection image is ended in association with the frame number of the projection image. In addition, the storage device 150 stores the time when the writing image was captured in association with the frame number of the writing image. Further, the storage device 150 stores the disclosure time when the audio recording is started and the end time when the audio recording is ended in association with the audio file name.

  In this example, when the projection image with the frame number X0 is projected, the storage device 150 stores the writing image with the frame number A0. When the frame number X1 is captured, the storage device 150 does not store a written image. When the uniform image determining unit 170 determines that the projection image with the frame number Y0 is uniform, the captured image recording unit 165 associates the frame number A0 with the frame number A0 in association with the written image with the frame number A2. The projection image of X2 is recorded in the storage device 150. Further, the storage device 150 stores the voice as one file from the start to the end of the presentation.

  FIG. 5 is a flowchart illustrating an example of a recording operation performed by the projector 10. When a presentation is started by the user 300, the projection light generation unit 120 receives a projection image from the PC 20. The projection light generation unit 120 projects the received projection image onto the screen 40 (S100).

  In this case, the projection image recording unit 160 receives a projection image from the PC 20. Here, the projection image recording means 160 records the received projection image in the storage device 150 together with the time (S105). Here, the projection image recording means 160 compares the newly received projection image with the previously received projection image, and sums up the differences between the newly received projection image and the previously received projection image. When the total value is smaller than a predetermined reference value, the projection image recording unit 160 deletes the newly received captured image and the corresponding time. When the total value is larger than the reference value, the projection image recording unit 160 records the time immediately before newly received as the end time, and further records the newly received projection image and the time. Thereby, the projection image recording means 160 records the projection image corresponding to the slide whose image does not change in association with the start time and end time of the slide.

  The voice recording unit 200 receives the voice acquired by the microphone 220. Here, the voice recording means 200 further receives the timing and time generated by the timing generator 240, and records the received voice in the storage device 150 together with the time (S110).

  Here, the imaging unit 140 images the writing on the screen 40 projected by the projection unit 100, and the captured image recording unit 165 records the acquired written image in the storage device 150 together with the time (S115). In addition, when acquiring the writing image, the imaging unit 140 in this example acquires the writing image in which the influence of the color due to the external light is compensated.

  When an image newly captured by the imaging unit 140 is recorded in the storage device 150 by the captured image recording unit 165, the comparison unit 250 refers to the storage device 150, and the newly captured image and the imaging unit 140 The image is compared with the previously captured image (S120). In this example, the comparison unit 250 obtains and sums up pixel value differences for each pixel. When the total value is smaller than a predetermined reference value (S125 YES), the deletion unit 260 deletes a newly captured image (S130). Then, the process of this flowchart returns to S115.

  When the total value of the pixel value differences is larger than the reference value (NO in S125), the process of this flowchart proceeds to S135. Here, the measurement unit 270 captures a second new image that is different from the reference value again after the first new image that is different from the reference value is acquired. The time elapsed until is measured. When the elapsed time is shorter than the predetermined reference time (YES in S135), the deletion unit 260 deletes the first new image from the storage device 150 (S140). Then, the process of this flowchart returns to S115. When the elapsed time is longer than the predetermined reference time (NO in S135), the measuring unit 270 resets the elapsed time that has been measured, and the image recorded as the second new image is changed to the next first time. Measurement of the elapsed time up to a second new image different from the next reference value by a new image is started. Here, when the presentation by the user 300 is finished (S145 YES), the processing of this flowchart is finished. If the presentation by the user 300 has not ended (NO in S145), the process of this flowchart returns to S115. Thereby, the projector 10 can appropriately record the written image in a state where the writing has been completed, and at the same time, it is possible to save the memory necessary for recording.

  In this example, the comparison unit 250 compares the previously captured image with the newly captured image every time an image is captured and recorded, and the measurement unit 270 is a first different from the reference value. The time from when a new image is recorded until a second new image different from the reference value is recorded is measured, and the deletion means 260 deletes the image based on the comparison result and the elapsed time. Although performed, in other examples, these operations may be performed after all the written images corresponding to the presentation have been recorded. In this example, the deletion unit 260 deletes a newly captured image when the total difference of pixel values is smaller than the reference value, but may delete the previously captured image.

  FIG. 6 is a flowchart illustrating an example of the operation of the uniform image determination unit 170. The uniform image determination unit 170 receives the projection image from the projection image recording unit 160. The uniform image determination unit 170 obtains and sums the difference in pixel value for each adjacent pixel in the frame of the projection image. If the total difference value of the pixel values is smaller than a predetermined reference value (YES at S170), the uniform image determining unit 170 determines that the projected image is uniform. In this case, the uniform image determination unit 170 causes the imaging unit 140 to image the screen 40. Thereby, the imaging unit 140 images the screen and records the acquired written image in the storage device 150 together with the time (S175). Here, the uniform image determination unit 170 notifies the captured image recording unit 165 that it is determined that the projection image is uniform. As a result, the captured image recording unit 165 records the recorded image acquired by the imaging unit 140 in association with the projected image immediately before the projected image in the storage device 150 (S180).

  If the total pixel value difference is larger than a predetermined reference value (NO in S170), the uniform image determination unit 170 determines that the captured image output from the projection image recording unit 160 is not uniform, and this flowchart. This process ends. In this way, the uniform image determination unit 170 can know the transition of the slide of the presentation by determining whether the projection image output from the PC 20 is a substantially uniform projection image. Then, at the turning point of the slide, the uniform image determining unit 170 obtains a writing image in association with the projection image projected on the screen before the uniform projection image, so that the writing with the most writing on the slide is performed. The embedded image can be recorded in association with the written slide image.

  FIG. 7 is a flowchart illustrating an example of a reproduction operation performed by the projector 10. When the user 300 instructs reproduction, the projector 10 operates an internal timer (S200). In this example, the storage device 150 records a start time and an end time in association with the projection image. The reading unit 180 reads the projection image corresponding to the time recorded in the storage device 150 according to the timer (S205), and outputs the read projection image to the synthesizing unit 190.

  In addition, the storage device 150 records the time when the writing image was captured in association with the writing image. The reading unit 180 reads a written image corresponding to the recorded timing according to the timer (S210), and outputs the read written image to the synthesizing unit 190.

  The combining unit 190 combines the projection image and the writing image read by the reading unit 180 and outputs the combined image to the projection light generation unit 120. In this case, the synthesizing unit 190 compares the pixel values of the corresponding pixels in the projected image and the written images of red, green, and blue, and selects the darker pixel value, thereby The written image is synthesized (S215). The synthesizing unit 190 outputs the synthesized image to the projection light generating unit 120. The projection light generation unit 120 displays an image obtained by combining the captured image and the written image on the screen 40 at the recording timing (S220).

The storage device 150 records a start time at which voice recording is started and an end time at which voice recording is ended in association with the voice. The reading unit 180 reads the sound corresponding to the recorded timing according to the timer (S225), and outputs the read sound to the microphone 220. Thereby, the speaker 230 reproduces the sound at the recording timing (S230). This is the end of the process of this flowchart.

  FIG. 8 is a diagram for explaining an example of the operation of the imaging unit 140 in S115 and S175. FIG. 8A is a diagram for explaining a plurality of regions on the screen 40. FIG. 8B is a flowchart illustrating an example of the operation of the imaging unit 140.

  In this example, at least a part of the regions that the camera 142 causes the initial image capturing unit 144 and the color image capturing unit 146 to capture are, for example, the regions 600, 700, and 800 in FIG. The areas 600, 700, 800, etc. are areas having the same width and the same length, and constitute the entire area of the screen 40. And as shown in FIG.8 (b), the area | region 600 has several small area | regions 602, 604, 606,608.

  FIG. 8B is a flowchart illustrating an example of the operation of the imaging unit 140. In S300, the color image capturing unit 146 causes the projection light generation unit 120 to project red, green, and blue light on three different areas on the screen. In S300, the three areas are the small areas 604, 606, and 608. Here, the color image capturing unit 146 controls the projection light generation unit 120 to project red light onto a plurality of small regions 604 in the region 600. Similarly, the color image capturing unit 146 projects green light on the plurality of small regions 606 in the region 600 and projects blue light on the plurality of small regions 608. At this time, the initial image capturing unit 144 controls the projection light generation unit 120 so that light of any color of red, green, and blue is not projected onto the plurality of small regions 602 in the region 600. In this case, the initial image capturing unit 144 and the color image capturing unit 146 cause the projection light generation unit 120 to project a normal projection image in an area other than the area 600. Then, the color image capturing unit 146 causes the camera 142 to acquire the pixel values in the small regions 604, 606, and 608, respectively, when the red, green, and blue colors are projected. In this case, the color image imaging unit 146 causes the camera 142 to simultaneously image three areas and another part of the area. Similarly, the initial image capturing unit 144 causes the camera 142 to acquire the pixel value in the small area 602 without projecting any of red, green, and blue colors. In this figure, R, G, and B indicate that red, green, and blue light are projected, and “None” means any color of red, green, and blue. Indicates a state that is not projected. In any state of none, R, G, and B, the screen 40 is irradiated with external light such as an indoor lamp or the sun.

  In step S <b> 305, the color image capturing unit 146 controls the projection light generation unit 120 to project red light onto the plurality of small regions 602 in the region 600. Similarly, the color image capturing unit 146 projects green light on the plurality of small regions 604 in the region 600 and projects blue light on the plurality of small regions 606. At this time, the initial image capturing unit 144 controls the projection light generation unit 120 to project no red light, green light, or blue light onto the plurality of small regions 608 in the region 600. Then, the color image capturing unit 146 causes the camera 142 to acquire pixel values in the small regions 602, 604, and 606, when red, green, and blue colors are projected. In addition, the initial image capturing unit 144 causes the camera 142 to acquire the pixel value in the small region 608 in a state where none of red, green, and blue is projected.

  Similarly, in S310 and S315, the color image capturing unit 146 acquires pixel values when the red, green, and blue colors of the respective small regions are projected, and the initial image capturing unit 144 acquires the respective small regions. The pixel value when no color is projected on is acquired.

  In S320, each of the color image capturing means 146 acquires pixel values of all states in which red, green, and blue light are projected in all of the plurality of small regions 602, 604, 606, and 608 in the region 600, When the initial image capturing unit 144 acquires pixel values in a state where red, green, and blue light are not projected in all of the plurality of small regions 602, 604, 606, and 608 in the region 600, the written image acquisition unit 148 By subtracting the value of each pixel of the received initial captured image from the value of each pixel of the color writing image of three colors, an image of red, green, and blue components in each small region is acquired. Thereby, the written image acquisition unit 148 acquires an image in which the influence of external light is compensated in each small area.

  In this way, the initial image capturing unit 144 and the color image capturing unit 146 perform the same processing described in S300 to S320 on the region 700 and the region 800. If the initial image capturing unit 144 and the color image capturing unit 146 have not finished scanning all the regions (NO in S325), the flowchart returns to S300. Then, when all the regions have been scanned (YES in S325), the written image acquisition unit 148 acquires the written image written on the screen 40 (S330). As described above, the initial image capturing unit 144 and the color image capturing unit 146 capture the image of the entire screen by causing the camera to capture images while moving each of the three regions and another part of the region on the screen 40. Get the writing image. This is the end of the process of this flowchart.

  Thus, since the projector 10 according to the present invention compensates for the influence of external light, it is possible to acquire a written image with a correct hue that is not affected by external light. In general, writing on the screen is sufficiently slower than the speed at which the camera captures the screen. In the present invention, before the written image changes, red, blue, and green light are sequentially projected to capture the three types of images necessary to create a full-color image. Even if it is used, three types of images necessary for creating a full-color image can be taken. Therefore, the projector 10 of the present invention can obtain a full-color written image at a low cost. Further, when acquiring the written image, small areas are sequentially captured as in this example, so that even if the projection image is projected onto the projector 10 and the screen 40, the person who is viewing the projection image Write images can be acquired without making them stand out.

  In this example, the imaging means 140 divides the screen 40 into rows, images small areas where red, green, and blue light should be projected and small areas where none of the light is projected. By scanning the area over the entire screen, a written image corresponding to the screen 40 was acquired. In another example, the imaging unit 140 uniformly distributes these small areas over the entire screen, A written image may be acquired by imaging the area. In this case, the imaging unit 140 projects red, green, and blue sequentially on different small areas while maintaining the uniformity of the distribution of the distributed small areas, and also distributes the small areas. The image is taken without projecting any light while maintaining the uniformity of the distribution. Then, by repeatedly capturing these areas, writing is performed by acquiring an image in which red, green, and blue light is projected and an image in which neither red, green, or blue light is projected over the entire screen. An image may be acquired.

  FIG. 9 shows an example of a hardware configuration in the PC 20. The PC 20 includes a CPU peripheral unit having a CPU 1000, a RAM 1020, a graphic controller 1075, and a display device 1080 connected to each other by a host controller 1082, a communication I / F 1030 connected to the host controller 1082 by an I / O controller 1084, and a hard disk An input / output unit having a drive 1040 and a CD-ROM drive 1060, and a legacy input / output unit having a ROM 1010, an FD (flexible disk) drive 1050, and an I / O chip 1070 connected to the I / O controller 1084. .

  The host controller 1082 connects the RAM 1020 to the CPU 1000 and the graphic controller 1075 that access the RAM 1020 at a high transfer rate. The CPU 1000 operates based on programs stored in the ROM 1010 and the RAM 1020, and controls each unit. The graphic controller 1075 acquires image data generated by the CPU 1000 or the like on a frame buffer provided in the RAM 1020 and displays it on the display device 1080. Alternatively, the graphic controller 1075 may include a frame buffer that stores image data generated by the CPU 1000 or the like.

  The I / O controller 1084 connects the host controller 1082 to the communication I / F 1030, the hard disk drive 1040, and the CD-ROM drive 1060, which are relatively high-speed input / output devices. The communication I / F 1030 communicates with an external device via a network such as a fiber channel. The hard disk drive 1040 stores programs and data used by the PC 20. The CD-ROM drive 1060 reads a program or data from the CD-ROM 1095 and provides it to the I / O chip 1070 via the RAM 1020.

  The I / O controller 1084 is connected to the ROM 1010 and relatively low-speed input / output devices such as the FD drive 1050 and the I / O chip 1070. The ROM 1010 stores a boot program executed by the CPU 1000 when the PC 20 is started up, a program depending on the hardware of the PC 20, and the like. The FD drive 1050 reads a program or data from the flexible disk 1090 and provides it to the I / O chip 1070 via the RAM 1020. The I / O chip 1070 connects various input / output devices via a flexible disk 1090 and, for example, a parallel port, a serial port, a keyboard port, a mouse port, and the like.

  The program provided to the PC 20 is stored in a recording medium such as the flexible disk 1090, the CD-ROM 1095, or an IC card and provided by the user. The program is read from the recording medium via the I / O chip 1070 and / or the I / O controller 1084, installed in the PC 20, and executed.

  The programs installed and executed on the PC 20 include an imaging unit, a captured image recording unit, a comparison unit, a deletion unit, a measurement unit, a projection image recording unit, a uniform image determination unit, a synthesis unit, a reading unit, a voice recording unit, and a voice. Reproducing means is provided. The imaging means has an initial image imaging means and a color image imaging means. The captured image recording unit has a written image acquisition unit. The operation that each means causes the projector 10 to perform when it operates on the PC 20 is the same as the operation of the corresponding member in the projector 10 described with reference to FIGS.

  The program or module shown above may be stored in an external storage medium. As the storage medium, in addition to the flexible disk 1090 and the CD-ROM 1095, an optical recording medium such as a DVD or PD, a magneto-optical recording medium such as an MD, a tape medium, a semiconductor memory such as an IC card, or the like can be used. Further, a storage device such as a hard disk or RAM provided in a server system connected to a dedicated communication network or the Internet may be used as a recording medium, and the program may be provided to the PC 20 via the network.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

It is a figure which shows the utilization form of the projector 10 which concerns on embodiment of this invention. It is a figure explaining the usage example of the projector. 2 is a diagram illustrating an example of a block diagram of a projector 10. FIG. 3 is a diagram illustrating an example of data stored in a storage device 150. FIG. 6 is a flowchart illustrating an example of a recording operation performed by the projector. 5 is a flowchart showing an example of the operation of a uniform image determination unit 170. 6 is a flowchart illustrating an example of a reproduction operation performed by the projector. It is a figure explaining an example of operation | movement of the imaging means 140 in S115 and S175. It is a figure which shows an example of the hardware constitutions in PC20.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Projector, 20 ... PC, 40 ... Screen, 302 ... Writing instrument, 300 ... User, 100 ... Projection means, 112 ... R light source, 114 ... G Light source, 116... B light source, 120... Projection light generation means, 122... R liquid crystal shutter, 124... G liquid crystal shutter, 126. ... Optical system, 132 ... Half mirror, 134 ... Projection lens, 140 ... Imaging means, 142 ... CCD imaging device, 144 ... Initial image imaging means, 146 ... Color image Image pickup means, 148... Written image acquisition means, 150... Storage device, 160... Projection image recording means, 165.・ Reading means 190 ... synthesizing means, 200 ... sound recording means, 210 ... sound reproduction means, 220 ... microphone, 230 ... speaker, 240 ... timing generator, 250 ... comparison means, 260 ... deletion means, 270 ... measurement means, 450, 452, 454, 456 ... write, 402, 404 ... character object, 600, 700, 800 ... area, 602, 604, 606 608 ... small area, 1000 ... CPU, 1010 ... ROM, 1020 ... RAM, 1030 ... communication I / F, 1040 ... hard disk drive, 1050 ... FD drive, 1060 ... CD-ROM drive, 1070 ... I / O chip, 1075 ... graphic controller, 1080 ... display device, 10 2 ... host controller, 1084 ... I / O controllers, 1090 ... flexible disk, 1095 ... CD-ROM

Claims (9)

A projector that projects a color projection image on a screen by combining a plurality of color images,
A camera for imaging the screen;
Initial image imaging means for imaging at least a partial area of the screen as an initial image by the camera without projecting any of the plurality of colors on at least a partial area of the screen;
Color image imaging means for sequentially projecting the plurality of colors onto the at least part of the area of the screen, and causing the camera to image the at least part of the area when each color is projected;
A projector comprising: a writing image acquisition unit configured to acquire a color writing image written on the screen using an image captured by the initial image capturing unit and the color image capturing unit.   2. The projector according to claim 1, wherein the color image imaging unit acquires a color writing image of the entire screen by causing the camera to capture an image while moving the at least a part of the area on the screen. . The multiple colors are red, green, and blue,
The color image capturing means obtains an image written on the screen when the red, green, and blue colors are projected;
The written image acquisition means determines the value of each pixel of the initial image from the value of each pixel of the image obtained by imaging the screen when the red, green, and blue colors are projected. The projector according to claim 1, wherein an image of red, green, and blue components in the written image is acquired by subtracting. The color imaging means has means for projecting red, green, and blue light to three different areas on the screen,
The initial image capturing unit is configured such that when the color image capturing unit projects red, green, and blue light on the three different regions on the screen, red is applied to other regions. 4. The projector according to claim 3, further comprising: means for projecting neither green light nor blue light, wherein the color image capturing means includes means for simultaneously capturing the three regions and the other partial region.   5. The color written image of the entire screen is acquired by causing each of the three regions and the other part of the region to be imaged by the camera while moving on the screen. projector. Projector control method for causing a projector having a projection means for projecting a color projection image on a screen by combining a plurality of color images and a camera for imaging the screen to read the color image written on the screen Because
An initial image imaging step of imaging the at least a part of the screen by the camera without projecting any of the plurality of colors on the at least a part of the screen;
A color image imaging step of sequentially projecting the plurality of colors onto the at least part of the area of the screen, and causing the camera to capture the at least part of the area when each color is projected;
A projector control method comprising: a writing image acquisition step of acquiring a color writing image written on the screen using images picked up by the initial image pickup means and the color image pickup means. The multiple colors are red, green, and blue,
The color image capturing step obtains an image written on the screen when the red, green, and blue colors are projected,
In the writing image acquisition step, the value of each pixel of the initial image is obtained from the value of each pixel of the image obtained by imaging the screen when the red, green, and blue colors are projected. The projector control method according to claim 6, wherein an image of red, green, and blue components in the written image is acquired by subtracting. A program that causes a projector having a projection unit that projects a color projection image on a screen by combining a plurality of color images and a camera that captures the screen to read the color image written on the screen. In the projector,
Initial image imaging means for imaging the at least a partial area of the screen by the camera without projecting any of the plurality of colors on the at least a partial area of the screen;
Color image imaging means for sequentially projecting the plurality of colors onto the at least part of the area of the screen, and causing the camera to image the at least part of the area when each color is projected;
A program that realizes a writing image acquisition unit that acquires a color writing image written on the screen by using an image captured by the initial image capturing unit and the color image capturing unit. The multiple colors are red, green, and blue,
The color image capturing means obtains an image written on the screen when the red, green, and blue colors are projected;
The written image acquisition means determines the value of each pixel of the initial image from the value of each pixel of the image obtained by imaging the screen when the red, green, and blue colors are projected. The program according to claim 8, wherein an image of red, green, and blue components in the written image is acquired by subtracting.

Images