JP6071208B2 - Projection device - Google Patents

Description

  The present invention relates to a projection apparatus.

  In a projection apparatus typified by a liquid crystal projector, the projection apparatus main body may obstruct the viewer's line of sight, and conversely, the viewer may obstruct projection from the projection apparatus main body. In order to prevent these, the projection apparatus may be installed so as to project an image downward or upward from the installation surface to the projection surface. At this time, the optical axis of the projection light projected from the projection device toward the projection plane has an inclination angle that is not perpendicular to the projection plane. Such tilt projection distorts the image on the projection surface into a trapezoid. This is called keystone distortion.

  As a method for correcting this trapezoidal distortion, there is known a method for predistorting an image before projection into a trapezoid in a reverse direction. This is called keystone correction (keystone distortion correction or keystone correction). As a specific process, a correction image having a trapezoidal shape opposite to the projection image having distortion when trapezoid correction is not performed is generated, and this correction image is displayed on the liquid crystal panel and projected.

  On the other hand, recent projectors have a high demand for larger screens and higher resolutions. In order to meet these demands, the number of pixels in the screen of one frame tends to increase. Since the time for one frame is basically constant, the clock per pixel becomes faster as the number of pixels increases.

  Since trapezoidal correction requires multiplication processing, in a multi-pixel system that requires a high-speed clock, internal operations such as the operation of a multiplier may not be completed in one clock. In addition, the amount of calculation for correction is large, and correction may not be completed in one frame.

  As a technique for preventing a distortion correction operation failure in a multi-pixel system, Patent Document 1 describes that an original image is divided into a plurality of images, and the divided images are synthesized on a projector and projected onto a screen. Specifically, each divided image is cut out from the original image so as not to cause a pixel defect at the division boundary, and a deformation that eliminates distortion at the time of projection is given to each divided image. Then, the divided images thus deformed are combined and projected so as to be one screen.

JP 2008-312099 A

  In the prior art, an original image is input to N image cutout means, and each image cutout means cuts out a divided image portion in charge. N image deformation means deform the divided image from the corresponding image cutout means according to a designated deformation function. With such a configuration, it is possible to easily cope with a change in the deformation function for correcting distortion.

  However, since the original image is input to the N image cutting means, N memories that can store the original image are required, and the required memory capacity becomes enormous.

An object of the present invention is to reduce the necessary memory capacity when an image to be projected is divided and trapezoidal correction is performed for each divided image .

The projection device according to the present invention is a projection device, and uses a part of the input image to generate a first image and a second image, and stores the first image. a first image processing means for performing keystone correction using the first image, storing the second image, the second image processing means for performing keystone correction using the second image, Projection means for projecting an image generated on the basis of the image that has been trapezoidally corrected by the first image processing means and the image that has been trapezoidally corrected by the second image processing means; The first image processing means supplies the second image processing means with an image corresponding to the first area of the first image based on the inclination of the projection device with respect to the screen, and the second image processing means. The image processing means includes an image corresponding to the first area and the image And performing keystone correction using the second image.

According to the present invention, when an image to be projected is divided and trapezoidal correction is performed for each divided image, a necessary memory capacity can be reduced .

1 is a system configuration diagram including an embodiment of a projection apparatus according to the present invention. It is a schematic block diagram of a present Example. It is a schematic block diagram of an image processing unit. It is a schematic block diagram of a trapezoid correction part. It is explanatory drawing of trapezoid correction | amendment operation | movement. It is a time chart explaining trapezoid correction operation. It is an operation | movement flowchart of a present Example. It is a schematic block diagram of another structure of an image process part. It is a schematic block diagram of the trapezoid correction | amendment part in FIG. It is a time chart explaining the trapezoid correction | amendment operation | movement of the trapezoid correction | amendment part shown in FIG. 6 is an operation flowchart of the second embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a use state diagram of a liquid crystal projector which is an embodiment of a projection apparatus according to the present invention. Reference numeral 100 denotes a projection apparatus represented by a liquid crystal projector. Reference numeral 200 denotes an image signal source that outputs an image signal, such as a personal computer (PC), a DVD playback device, or a television tuner. Reference numeral 300 denotes a screen that displays a projection image from the projection apparatus 100.

  FIG. 2 shows a schematic block diagram of the projection apparatus 100. Reference numeral 101 denotes a control unit for controlling each block of the projection apparatus 100. Reference numeral 102 denotes an operation unit that receives an operation from the operator. Reference numeral 103 denotes a power supply unit that controls power supply to each block of the projection apparatus 100.

  A liquid crystal unit 104 includes one or a plurality of liquid crystal panels, and an image to be projected is formed on the liquid crystal panel. Reference numeral 105 denotes a liquid crystal driving unit for forming an image on the liquid crystal panel of the liquid crystal unit 104 based on the input image signal. A light source 106 supplies light to the liquid crystal unit 104. Reference numeral 107 denotes a projection optical system for projecting an optical image obtained by supplying light emitted from the light source 106 to the liquid crystal unit 104 on the screen 300. Reference numeral 108 denotes a light source control unit for controlling the amount of light of the light source 106 and the like.

  An optical system control unit 109 controls operations of a zoom lens, a focus lens, a shift lens, and the like included in the projection optical system 107, and performs zoom magnification, focus adjustment, projection position control, and the like.

  Reference numeral 110 denotes an analog input unit that receives an analog video signal from a PC, a DVD playback device, a TV tuner, or the like, and includes an RGB terminal, an S terminal, a D terminal, and the like. Reference numeral 111 denotes an AD converter that converts a video signal obtained by the analog input unit 110 into a digital signal.

  A digital input unit 112 receives a digital video signal output from a PC, a DVD player, a TV tuner, or the like, and includes a DVI terminal or an HDMI terminal. In the HDMI terminal, a control signal may be transmitted from the outside at the same time, and thereby video control or the like may be performed.

  Reference numeral 113 denotes a USB interface for receiving various information data files such as video data, image data, and video files from the outside, and sending them to the outside. A pointing device, a keyboard, a USB flash memory, or the like can be connected to the USB interface 113.

  A card interface 114 reads and writes various information data files such as video data, image data, and video files with respect to a card-type recording medium.

  Reference numeral 115 denotes a communication unit that transmits and receives various information data files such as video data, image data, and video files and other command signals from the intranet and the Internet. The communication unit 115 is configured by, for example, a wired LAN or a wireless LAN.

  Reference numeral 116 denotes a built-in memory for storing various information data files such as video data, image data, and video files, and includes a semiconductor memory, a hard disk, and the like.

  Reference numerals 117 to 120 denote image processing units that perform predetermined processing including distortion correction on the four divided images divided by the image dividing unit 132 and supply the processed images to the liquid crystal driving unit 105. Each of the image processing units 117 to 120 performs correction suitable for displaying the divided image signal from the image dividing unit 132 on the liquid crystal unit 104. For example, there is a process of converting the number of pixels of the image signal in accordance with the number of pixels of the liquid crystal panel. Further, since the liquid crystal panel is AC driven, the number of frames of the input video signal is doubled and correction suitable for image formation by the liquid crystal panel is performed. The AC drive of a liquid crystal panel is a method in which the direction of the electric field applied to the liquid crystal of the liquid crystal panel is alternately switched to display, and the liquid crystal panel has a reverse direction (negative polarity) even if the direction of the voltage applied to the liquid crystal is the positive direction (positive polarity). The property that can generate an image is also used. At this time, since it is necessary to send the image for the forward direction and the image for the reverse direction one by one to the liquid crystal drive unit 105, the image processing units 117 to 120 perform processing for doubling the number of frames of the video signal. Do. The liquid crystal driving unit 105 forms an image on the liquid crystal panel of the liquid crystal unit 104 based on the image signals from the image processing units 117 to 120.

  Reference numeral 121 denotes an inclination sensor that detects the displacement of the projection apparatus 100 from the direction of gravity. The tilt sensor 121 is used as means for detecting the tilt of the projection optical axis with respect to the screen on the assumption that the angle of the screen with respect to the horizontal is known. A file reproduction unit 122 reproduces a document file input from the AD conversion unit 111, the digital input unit 112, the USB interface 113, the card interface 114, the communication unit 115, and the like. The file reproduction unit 122 generates an image signal to be posted to the user from the document file and outputs the image signal to the image division unit 132.

  A focus detection unit 123 detects the focal length by detecting the distance between the projection apparatus 100 and the screen 300. Reference numeral 124 denotes an imaging unit that images the direction of the screen 300. Reference numeral 125 denotes a screen photometry unit that measures the amount and luminance of light reflected by the screen 300. Reference numeral 126 denotes a light source photometry unit that measures the amount and luminance of light emitted from the light source 106. Reference numeral 127 denotes a display unit that displays the state of the main body of the projection apparatus 100, a warning, and the like. Reference numeral 128 denotes a display control unit that controls the display unit 127.

  Reference numeral 129 denotes a battery for supplying power when the projection apparatus 100 main body is carried and used. Reference numeral 130 denotes a power supply input unit that rectifies an external AC power supply to a predetermined voltage and supplies the rectified power to the power supply unit 103. A timer 131 detects the operation time of the projection apparatus 100 main body and each block.

  An image dividing unit 132 divides the image data input from the devices 111 to 115 into a predetermined number of regions and supplies the divided image data to the image processing units 117 to 120.

  In the present embodiment, four image processing units 117 to 120 are provided, and the image dividing unit 132 divides one screen into four divided images, but the number of divided images, that is, the number of image processing units 117 to 120 is divided. Is not limited to this example. The video signal or the image signal input from the AD conversion unit 111 and the digital input unit 112 may be directly supplied to the image division unit 132.

  A normal operation of the projection apparatus 100 will be described. When power-on is instructed from the operation unit 102, the control unit 101 of the projection apparatus 100 instructs the power supply unit 103 to supply power to each block, and puts each block in a standby state. After the power is turned on, the control unit 101 instructs the light source control unit 108 to start light emission from the light source 106. Next, the control unit 101 instructs the optical system control unit 109 to adjust the projection optical system 107 in accordance with the focus information obtained by the focus detection unit 123. In the optical system control unit 109, the zoom lens, the focus lens, and the shift lens of the projection optical system 107 are operated to control the projection light to form an image on the screen 300. With the above operation, preparation for projection is completed.

  Next, the image dividing unit 132 divides the image signal input to the digital input unit 112, for example, into four divided images, and supplies the divided images to the image processing units 117 to 120. The image processing units 117 to 120 perform image processing according to an instruction from the control unit 101 on each divided image and supply the image to the liquid crystal driving unit 105. Image processing by the image processing units 117 to 120 includes conversion to a resolution suitable for the liquid crystal unit 104, double speed conversion, gamma correction, correction for uneven brightness, trapezoidal correction, and the like.

  The liquid crystal driving unit 105 combines the processed divided images from the image processing units 117 to 120 into one screen again, and converts the obtained combined image into a format suitable for forming an image on the liquid crystal panel of the liquid crystal unit 104. The data is converted and output to the liquid crystal unit 104. The liquid crystal panel of the liquid crystal unit 104 displays an image based on the image data from the liquid crystal driving unit 105. Light emitted from the light source 106 is transmitted through the liquid crystal panel of the liquid crystal unit 104 to undergo spatial intensity modulation, and is projected onto the screen 300 by the projection optical system 107.

  When the power off is instructed from the operation unit 102, the control unit 101 instructs the block to perform the end process. When preparation for termination is completed, the power supply unit 103 sequentially ends power supply to each block.

  Although the case where the image of the video signal input from the digital input unit 112 is projected has been described, the same applies to the case where the video data input from the other devices 110, 113, 114, 115 is displayed.

  FIG. 3 shows a schematic block diagram of the image processing units 117 to 120. The internal configuration of the image processing units 117 to 120 is the same.

  A resolution conversion unit 30 converts the resolution of the image. Reference numeral 31 denotes a trapezoidal correction unit that corrects distortion of the projection image caused by the inclination of the projection apparatus 100 with respect to the screen 300. Reference numeral 32 denotes a double speed processing unit that performs a process of doubling the number of frames of the video signal in order to drive the liquid crystal panel with alternating current. Reference numeral 33 denotes a gamma correction unit for correcting the voltage versus transmittance (or reflectance) characteristics of the liquid crystal panel. Reference numeral 34 denotes an unevenness correction unit that corrects unevenness in luminance and color of the liquid crystal panel.

  A memory 35 stores image data of one frame for resolution conversion, keystone correction, and double speed processing. The resolution conversion unit 30, the keystone correction unit 31, and the double speed processing unit 32 can read / write data from / to the memory 35 via the memory bus 36.

  The resolution conversion unit 30, the keystone correction unit 31, the double speed processing unit 32, the gamma correction unit 33, and the unevenness correction unit 34 are connected to the control unit 101 via the register bus 37 and are controlled by the control unit 101.

  The trapezoid correction unit 31 has a path for exchanging image data with the trapezoid correction unit of another image processing unit.

  The resolution converting unit 30 converts the corresponding divided image from the image dividing unit 132 into a resolution that matches the number of pixels of the liquid crystal panel. The detailed operation of the trapezoid correction unit 31 that performs trapezoid correction that cancels the distortion of the projection image caused by the tilt of the optical system of the projection apparatus 100 with respect to the screen 300 is performed on the output image of the resolution conversion unit 30. It will be described later.

  The double speed processing unit 32 sets the output image data of the trapezoidal correction unit 31 to a double frame rate for AC driving of the liquid crystal panel. The gamma correction unit 33 performs gamma correction for correcting the voltage versus transmittance (or reflectance) characteristics of the liquid crystal panel on the image data that has been doubled by the double speed processing unit 32. The unevenness correction unit 34 performs processing for correcting at least one of luminance unevenness and color unevenness of the liquid crystal panel on the output image of the gamma correction unit 33. The output image data of the unevenness correction unit 34 is supplied to the liquid crystal drive unit 105. In this embodiment, four systems of output image data from the image processing units 117 to 120 are supplied to the liquid crystal driving unit 105.

  FIG. 4 shows a schematic block diagram of the trapezoidal correction unit 31. Reference numeral 40 denotes a communication unit that receives image data from the previous resolution conversion unit 30. A memory interface unit 41 reads / writes data from / to the memory 35. A pixel buffer 42 buffers data from the memory interface unit 41 for a predetermined area. A filter 43 performs a predetermined filter process on image data for a predetermined area received from the pixel buffer 42. Reference numeral 44 denotes a masking unit that adds a mask signal to a non-signal portion generated by image reduction. A memory control unit 45 controls the memory 35 in accordance with an instruction from the control unit 101. A communication unit 46 transmits / receives image data to / from the trapezoid correction unit of another image processing unit.

  The detailed operation of the trapezoid correction unit 31 shown in FIG. 4 will be described. The communication unit 40 takes in the image data from the resolution conversion unit 30 and supplies it to the memory interface unit 41. The memory interface unit 41 converts the image data from the communication unit 40 into an optimal format for writing to the memory 35 in accordance with an instruction from the control unit 101. The memory interface unit 41 also converts the image data read from the memory 35 into a format suitable for subsequent processing in accordance with an instruction from the memory control unit 45.

  The pixel buffer 42 expands the image data output from the memory interface unit 41 by a region having a predetermined size vertically and horizontally. This predetermined size is determined according to an instruction from the control unit 101.

  The filter 43 performs a two-dimensional filter process on the output image data of the pixel buffer 42. Specifically, the filter 43 performs reduction / enlargement processing necessary for trapezoidal correction, edge enhancement, smoothing, edge smoothing, aliasing distortion removal, and the like accompanying this processing. Note that the reduction / enlargement magnification necessary for the keystone correction is determined according to the inclination angle of the projection optical axis with respect to the screen of the projection apparatus 100 detected by the inclination sensor 121.

  When the image reduction process is performed by the filter 43, a non-signal portion is generated. The masking unit 44 adds a mask signal such as blanking to the non-signal portion. The output of the masking unit 44 is sent to the double speed processing unit 32.

  With reference to FIG. 5, the operation of the trapezoidal correction unit 31 will be specifically described. FIG. 5 shows an example of division and deformation of a total of four divided images obtained by dividing the original image into two vertically and horizontally. That is, FIG. 5 also shows the relationship between the input images of the image processing units 117 to 120 and the output images (divided images) of the image processing units 117 to 120. In FIG. 5, broken lines indicate equal dividing lines or equal dividing boundary lines that equally divide the original image vertically and horizontally, and alternate long and short dashed lines indicate substantial dividing lines or substantial dividing boundary lines that divide the trapezoid correction target range. The substantial dividing line moves from the position of the uniform dividing line by an amount corresponding to the amount of inclination of the projection apparatus 100 with respect to the screen 300.

  For the two-dimensional filter processing (spatial filter processing) of the filter 43 of the trapezoid correction unit 31, not only image data in the target range but also surrounding pixel data is required. In the following description, the image data of the target range is described as being input to the filter 43 for easy understanding, but actually, the pixel data of a certain range outside the image data of the target range is also included. Input to the filter 43.

  The control unit 101 determines a substantial division boundary line of the original image to be trapezoidally corrected according to the direction and degree of inclination of the projection apparatus 100 with respect to the screen 300. FIG. 5A shows an input image (original image) when the projection apparatus 100 is tilted upward with respect to the screen 300, and FIG. 5B shows a trapezoidal correction result. When the projection apparatus 100 is tilted upward with respect to the screen 300, as shown in FIG. 5A, the vertical division boundary line is raised upward from the center position of the original image according to the tilt angle of the projection apparatus 100. It is necessary to shift by the amount.

  The image dividing unit 132 divides the input image (original image) by equal dividing lines that equally divide the image vertically and horizontally into four divided images having the same size. That is, the image dividing unit 132 generates a divided image made up of the regions 501 and 502, a divided image made up of the region 503, a divided image made up of the regions 504 and 505, and a divided image made up of the region 506. The boundary lines between the regions 502 and 505 and the regions 503 and 506 are substantially divided boundary lines that define the target range for trapezoidal correction, and the control unit 101 depends on the direction and degree of inclination of the projection apparatus 100 with respect to the screen 300. To decide.

  The image dividing unit 132 supplies the divided image including the regions 501 and 502 to the image processing unit 117 and supplies the divided image including the region 503 to the image processing unit 118. The image dividing unit 132 also supplies the divided image including the regions 504 and 505 to the image processing unit 119 and supplies the divided image including the region 506 to the image processing unit 120. However, as described above, pixel data located outside the target range is also required for the two-dimensional filter processing, so that the image dividing unit 132 to each of the image processing units 117 to 120 includes other than the divided image. The surrounding pixel data is also supplied.

  In the trapezoid correction unit 31 of the image processing unit 117, the filter 43 deforms and reduces the image portion of the region 501 and converts it into the shape of the region 507 shown in FIG. The masking unit 44 adds blanking to the area 541 (FIG. 5B) that is vacated by the filter processing of the filter 43.

  The trapezoid correction unit 31 of the image processing unit 118 receives the image portion of the region 502 from the image processing unit 117 via the communication unit 46. The filter 43 transforms and reduces the image portion of the region 502 from the image processing unit 117 and the image portion of the region 503 from the image dividing unit 132, and converts them into the shape of the region 508 shown in FIG. To do. The masking unit 44 adds blanking to a region 542 (FIG. 5B) that is freed by the filter processing of the filter 43.

  In the trapezoid correction unit 31 of the image processing unit 119, the filter 43 deforms and reduces the image portion of the region 504 and converts it into the shape of the region 509 shown in FIG. The masking unit 44 adds blanking to the area 543 (FIG. 5B) that is vacated by the filter processing of the filter 43.

  The trapezoid correction unit 31 of the image processing unit 120 receives the image portion of the area 505 from the image processing unit 119 via the communication unit 46. The filter 43 deforms and reduces the image portion of the region 505 from the image processing unit 119 and the image portion of the region 506 from the image dividing unit 132, and converts them into the shape of the region 510 shown in FIG. To do. The masking unit 44 adds blanking to a region 544 (FIG. 5B) that is freed by the filter processing of the filter 43.

  As described above, in this embodiment, the image processing units 117 to 120 trapezoidally correct the divided images divided by the division boundary lines determined according to the direction and degree of inclination of the projection apparatus 100 with respect to the screen 300. In FIG. 5A, the image processing unit 117 corrects the area 501 with a keystone, and the image processing unit 118 corrects the areas 502 and 503 with a keystone. In addition, the image processing unit 119 corrects the keystone of the region 504, and the image processing unit 120 corrects the keystones of the regions 505 and 506.

  As described above, for the two-dimensional filter processing by the filter 43, in addition to the image data in the target range, the surrounding pixel data is also required. For example, when the image processing unit 118 performs two-dimensional filter processing on the image data portion composed of the regions 502 and 503, pixel data at the lower end of the region 501, the right end of the region 505, and the right end pixel of the region 506 are used to generate image data at the end. is necessary. The image processing unit 118 receives the image data portion of the area 502 and the surrounding pixel data (the lower end of the area 501 and the right end of the area 505) from the image processing section 117. Since the pixel data at the right end of the area 506 is supplied from the image dividing unit 132, it is not necessary to receive it from the other image processing units 117, 119, and 120.

  FIG. 5C shows an input image (original image) when the projection apparatus 100 is tilted downward with respect to the screen 300, and FIG. 5B shows a trapezoidal correction result. When the projection apparatus 100 is tilted downward with respect to the screen 300, as shown in FIG. 5C, the vertical division boundary line is moved downward from the center position of the original image according to the tilt angle of the projection apparatus 100. Need to shift by the same amount.

  Also at this time, the image dividing unit 132 divides the input image (original image) by equal dividing lines that equally divide the input image into two vertically and horizontally, and generates four divided images having the same size. In other words, the image dividing unit 132 generates a divided image composed of the area 511, a divided image composed of the areas 512 and 513, a divided image composed of the area 514, and a divided image composed of the areas 515 and 516. The boundary lines between the areas 512 and 515 and the areas 513 and 516 are substantially divided boundary lines that define the target range of trapezoidal correction, and the control unit 101 determines the direction and degree of inclination of the projection apparatus 100 with respect to the screen 300. Decide accordingly.

  The image dividing unit 132 supplies the divided image including the region 511 to the image processing unit 117 and supplies the divided image including the regions 512 and 513 to the image processing unit 118. The image dividing unit 132 also supplies the divided image including the region 514 to the image processing unit 119 and supplies the divided image including the regions 515 and 516 to the image processing unit 120. As in the case of FIGS. 5A and 5B, in addition to the divided image, the surrounding pixel data is also supplied from the image dividing unit 132 to each of the image processing units 117 to 120 for the two-dimensional filter processing. The

  The keystone correction unit 31 of the image processing unit 117 receives the image portion of the region 512 from the image processing unit 118 via the communication unit 46. The filter 43 transforms the image portion of the region 512 from the image processing unit 118 and the image portion of the region 511 from the image dividing unit 132 into a shape of the region 517 shown in FIG. To do. The masking unit 44 adds blanking to a region 545 (FIG. 5D) that is vacated by the filter processing of the filter 43.

  In the trapezoidal correction unit 31 of the image processing unit 118, the filter 43 transforms and reduces the image portion of the region 513 into the shape of the region 518 shown in FIG. The masking unit 44 adds blanking to a region 546 (FIG. 5D) vacated by the filter processing of the filter 43.

  The trapezoid correction unit 31 of the image processing unit 119 receives the image portion of the region 515 from the image processing unit 120 via the communication unit 46. The filter 43 deforms and reduces the image portion of the region 515 from the image processing unit 120 and the image portion of the region 514 from the image dividing unit 132, and converts them into the shape of the region 519 shown in FIG. To do. The masking unit 44 adds blanking to a region 547 (FIG. 5D) that is vacant by the filter processing of the filter 43.

  In the trapezoidal correction unit 31 of the image processing unit 120, the filter 43 transforms and reduces the image portion of the region 516 into the shape of the region 520 shown in FIG. The masking unit 44 adds blanking to a region 548 (FIG. 5D) that is vacated by the filter processing of the filter 43.

  FIG. 5E shows an input image (original image) when the projection apparatus 100 is tilted to the right with respect to the screen 300, and FIG. 5F shows a trapezoidal correction result. When the projection apparatus 100 is tilted to the right with respect to the screen 300, as shown in FIG. 5E, the horizontal dividing boundary line is set to the right from the center position of the original image according to the tilt angle of the projection apparatus 100. It is necessary to shift by the amount.

  The image dividing unit 132 divides the input image (original image) by equal dividing lines that equally divide the image vertically and horizontally into four divided images having the same size. That is, the image dividing unit 132 generates a divided image including the areas 521 and 522, a divided image including the areas 523 and 524, a divided image including the area 525, and a divided image including the area 526. The boundary lines between the areas 521 and 523 and the areas 522 and 524 are substantially divided boundary lines that define the target range of the trapezoidal correction, and the control unit 101 depends on the direction and degree of inclination of the projection apparatus 100 with respect to the screen 300 To decide.

  The image dividing unit 132 supplies the divided image including the regions 521 and 522 to the image processing unit 117 and supplies the divided image including the regions 523 and 524 to the image processing unit 118. The image dividing unit 132 also supplies the divided image including the region 525 to the image processing unit 119 and supplies the divided image including the region 526 to the image processing unit 120. However, as described above, pixel data located outside the target range is also required for the two-dimensional filter processing, so that the image dividing unit 132 to each of the image processing units 117 to 120 includes other than the divided image. The surrounding pixel data is also supplied.

  In the trapezoidal correction unit 31 of the image processing unit 117, the filter 43 transforms and reduces the image portion of the region 521 into the shape of the region 527 shown in FIG. The masking unit 44 adds blanking to a region 549 (FIG. 5 (f)) freed by the filter processing of the filter 43.

  In the trapezoidal correction unit 31 of the image processing unit 118, the filter 43 transforms and reduces the image portion of the region 523 into the shape of the region 528 shown in FIG. The masking unit 44 adds blanking to a region 550 (FIG. 5 (f)) freed by the filter processing of the filter 43.

  The trapezoid correction unit 31 of the image processing unit 119 receives the image portion of the region 522 from the image processing unit 117 via the communication unit 46. The filter 43 deforms and reduces the image portion of the region 522 from the image processing unit 117 and the image portion of the region 525 from the image dividing unit 132, and converts them into the shape of the region 529 shown in FIG. To do. The masking unit 44 adds blanking to the area 551 (FIG. 5 (f)) freed by the filter processing of the filter 43.

  The trapezoid correction unit 31 of the image processing unit 120 receives the image portion of the region 524 from the image processing unit 118 via the communication unit 46. The filter 43 transforms and reduces the image portion of the region 524 from the image processing unit 118 and the image portion of the region 526 from the image dividing unit 132, and converts them into the shape of the region 530 shown in FIG. To do. The masking unit 44 adds blanking to a region 552 (FIG. 5 (f)) freed by the filter processing of the filter 43.

  FIG. 5G shows an input image (original image) when the projection apparatus 100 is tilted leftward with respect to the screen 300, and FIG. 5H shows a trapezoidal correction result. When the projection apparatus 100 is tilted to the left with respect to the screen 300, as shown in FIG. 5G, the horizontal dividing boundary line is leftward from the center position of the original image according to the tilt angle of the projection apparatus 100. It is necessary to shift by the amount.

  The image dividing unit 132 divides the input image (original image) by equal dividing lines that equally divide the image vertically and horizontally into four divided images having the same size. That is, the image dividing unit 132 generates a divided image made up of the region 531, a divided image made up of the region 532, a divided image made up of the regions 533 and 534, and a divided image made up of the regions 535 and 536. The boundary lines between the regions 533 and 535 and the regions 534 and 536 are substantially divided boundary lines that define the target range of the trapezoidal correction, and the control unit 101 depends on the direction and degree of inclination of the projection device 100 with respect to the screen 300. To decide.

  The image dividing unit 132 supplies the divided image including the region 531 to the image processing unit 117, and supplies the divided image including the region 532 to the image processing unit 118. The image dividing unit 132 also supplies the divided image including the regions 533 and 534 to the image processing unit 119 and supplies the divided image including the regions 535 and 536 to the image processing unit 120. However, as described above, pixel data located outside the target range is also required for the two-dimensional filter processing, so that the image dividing unit 132 to each of the image processing units 117 to 120 includes other than the divided image. The surrounding pixel data is also supplied.

  The keystone correction unit 31 of the image processing unit 117 receives the image portion of the region 533 from the image processing unit 119 via the communication unit 46. The filter 43 transforms the image portion of the region 533 from the image processing unit 119 and the image portion of the region 531 from the image dividing unit 132 into a shape of the region 537 shown in FIG. To do. The masking unit 44 adds blanking to a region 553 (FIG. 5 (h)) vacated by the filter processing of the filter 43.

  The trapezoid correction unit 31 of the image processing unit 118 receives the image portion of the region 535 from the image processing unit 120 via the communication unit 46. The filter 43 deforms and reduces the image portion of the region 535 from the image processing unit 120 and the image portion of the region 532 from the image dividing unit 132, and converts them into the shape of the region 538 shown in FIG. To do. The masking unit 44 adds blanking to a region 554 (FIG. 5 (h)) vacated by the filter processing of the filter 43.

  In the trapezoidal correction unit 31 of the image processing unit 119, the filter 43 transforms and reduces the image portion of the region 534 into the shape of the region 539 shown in FIG. The masking unit 44 adds blanking to a region 555 (FIG. 5 (h)) that is freed by the filter processing of the filter 43.

  In the trapezoidal correction unit 31 of the image processing unit 120, the filter 43 transforms and reduces the image portion of the region 536 into the shape of the region 540 shown in FIG. The masking unit 44 adds blanking to the area 556 (FIG. 5 (h)) vacated by the filter processing of the filter 43.

  FIGS. 6A and 6B are time charts of operations of taking the divided image data from the image dividing unit 132, performing trapezoid correction by the image processing units 117 to 120, and outputting the divided image data in the example shown in FIGS. 5A and 5B. FIG. 6A is a time chart of an operation for writing the divided image data in the memory 35 of the image processing units 117 to 120.

  In synchronization with the vertical synchronization signal (VSNYC), the image data composed of the areas 501 and 502 from the image dividing unit 132 is written in the memory 35 of the image processing unit 117 in order from the top to the bottom of the screen. In the memory 35 of the image processing unit 118, the image data of the area 503 from the image dividing unit 132 is written in the order from the top to the bottom of the screen. In the memory 35 of the image processing unit 119, the image data of the areas 504 and 505 from the image dividing unit 132 are written in the order from the top to the bottom of the screen. In the memory 35 of the image processing unit 120, the image data of the area 506 from the image dividing unit 132 is written in the order from the top to the bottom of the screen.

  FIG. 6B is a time chart of an operation of reading image data from the memory 35 of the image processing units 117 to 120.

  In synchronization with the vertical synchronization signal (VSNYC), the image data of the area 502 to be transmitted to the image processing unit 118 is first read from the memory 35 of the image processing unit 117. The communication unit 46 of the image processing unit 117 transfers the image data in the area 502 read from the memory 35 to the communication unit 46 of the image processing unit 118. Subsequently, the image data in the area 502 is written into the memory 35 of the image processing unit 118 under the control of the memory control unit 45 of the image processing unit 118.

  Subsequently, the image processing unit 117 reads the image data of the area 501 from the memory 35 and corrects the keystone, and generates the corrected image data of the area 507 and the masking of the area 541 as described above. At the same time, the image processing unit 118 reads the image data of the area 502 and the image data of the area 503 from the image processing unit 117 from the memory 35 and corrects the keystone, and as described above, the corrected image data of the area 508 and the corrected image data of the area 542 Masking is generated.

  Since the operations of the image processing units 119 and 120 are the same, description thereof will be omitted.

  The image processing units 118 and 120 process the image data from the image processing units 117 and 119 in addition to the image data written in the respective memories 35. Therefore, in order to complete the trapezoidal correction process in one vertical period, it is necessary to read data from the memory 35 at a higher speed than at the time of writing.

  The cases shown in FIGS. 5C to 5H are basically performed in the same manner as in FIGS. 6A and 6B.

  FIG. 7 is a flowchart showing the operation of this embodiment.

  In step S <b> 702, the control unit 101 acquires inclination data or an inclination detection value from the inclination sensor 121. Instead of using the tilt sensor 121, a test image for calculating the tilt amount is projected, the projected image of the screen 300 is captured by the imaging unit 124, and the shape of the projected image is analyzed by the control unit 101 to determine the tilt. it can.

  In step S <b> 703, the video signal from the signal source 200 is input to the projection apparatus 100. In step S704, the image dividing unit 132 divides each screen of the video signal, and writes the corresponding image data in the memory 35 of each of the image processing units 117 to 120.

  In step S <b> 705, the control unit 101 determines the range of image data (for example, the position of the substantial dividing line) to be exchanged between the image processing units 117 to 120 from the tilt data from the tilt sensor 121. In other words, when there is an inclination, keystone correction is performed, so that it is necessary to transmit / receive image data between the image processing units 117 to 120 as described above.

  In step S706, the control unit 101 determines whether each of the image processing units 117 to 120 receives or transmits image data from the other image processing units 117 to 120 from the direction of inclination. As an example, the image processing unit 117 is considered as a reference. When the projection apparatus 100 is tilted upward with respect to the screen 300, the image processing unit 117 transmits the image data of the region 502 to the image processing unit 118 as illustrated in FIG. When the projection apparatus 100 is inclined downward with respect to the screen 300, the image processing unit 117 receives the image data of the region 512 from the image processing unit 118, as shown in FIG. When the projection apparatus 100 is tilted to the right with respect to the screen 300, the image processing unit 117 transmits the image data of the region 522 to the image processing unit 119 as illustrated in FIG. When the projection apparatus 100 is tilted leftward with respect to the screen 300, the image processing unit 117 receives the image data of the region 533 from the image processing unit 119, as illustrated in FIG.

  When passing image data to another image processing unit, the control unit 101 reads out image data of an area to be passed to the other image processing unit from the memory 35 in step S707 as described with reference to FIG. The read image data is transferred to the destination image processing unit (the memory 35) via the communication unit 46. In step S708, the image data of the remaining area is read from the memory 35, and keystone correction is executed.

  When receiving image data from another image processing unit in step S706, the control unit 101 proceeds to step S709, and the image data of the area received by the communication unit 46 is written in the memory 35. In step S710, image data of an area received from another is read from the memory 35, and keystone correction is performed. Subsequently, in step S711, the image data of the area written in the memory 35 in step S704 is read, and keystone correction is performed.

  If it is determined in step S705 that there is no inclination and image data communication between the image processing units is unnecessary, the image data is read from the memory 35 in step S712. At this time, the keystone correction is not executed.

  In step S713, the control unit 101 determines whether or not an operation to instruct the end is performed by the operation unit 102. If not, the control unit 101 returns to step S703, continues projection, and ends the operation if there is an instruction to end. .

  As described above, in this embodiment, the original image is divided into a plurality of divided images of the same size and sent to the image processing unit, and the image data of the portion necessary for keystone correction is transferred between the image processing units. . As a result, the memory capacity required for keystone correction in each image processing unit is such that it can accommodate divided image data of the same size and image data that is supplementarily transferred between the image processing units for keystone correction. Get better. As a result, the memory capacity of the memory provided for each keystone correction in each image processing unit can be reduced as compared with the conventional case.

  In the present embodiment, the original image is divided into four and is divided and processed by the four image processing units. However, the number of divided images and the number of image dividing units are not limited to this example. That is, generally, N image processing units are provided, and image data of a partial area is transferred between the Mth image processing unit and the Lth image processing unit. Furthermore, there may be a transfer involving the Kth image processing unit. M is an integer from 1 to N, L is an integer from 1 to N excluding M, and K is an integer from 1 to N excluding M and L.

  Although an example in which the image dividing unit 132 divides the image vertically and horizontally has been described, the present invention is not limited thereto, and image division only in the vertical direction or only in the horizontal direction may be performed.

  As an illustrative example, the trapezoidal correction with respect to the vertical inclination and the trapezoidal correction with respect to the horizontal inclination have been described. However, it is obvious that the present embodiment can also be applied to a combined inclination of both.

  The present invention is not limited to a projector incorporating a liquid crystal panel. That is, the present invention can also be applied to a projector incorporating another panel such as a DMD panel.

  A second embodiment of the present invention will be described. In the first embodiment, each image processing unit has one memory, and data transfer between the image processing units and the keystone correction process are performed with a time shift by read / write address control. On the other hand, in this embodiment, a memory for data transfer between the image processing units is provided independently, and the data transfer between the image processing units and the keystone correction process are performed in parallel.

  FIG. 8 shows a schematic block diagram of a configuration in which a data transfer memory is provided in the image processing units 117 to 120. The same components as those in FIG. 3 are denoted by the same reference numerals, and description thereof is omitted. The memory 35 includes a main memory 81 and a sub memory 82 that can be accessed independently and simultaneously.

  The divided image data sent from the image dividing unit 132 is written into the main memory 81. On the other hand, the image data transferred from the other image processing unit is written in the sub memory 82.

  FIG. 9 shows a schematic block diagram of the trapezoidal correction unit 31 corresponding to the configuration shown in FIG. The same components as those in FIG. 4 are denoted by the same reference numerals, and description thereof is omitted.

  The memory control unit 91 controls memory access of the main memory 81 and the sub memory 82 in accordance with instructions from the control unit 101. The communication unit 92 exchanges image data stored in the sub memory 82 of another image processing unit.

  Also in this embodiment, the input image and the output image of the image processing units 117 to 120 are the same as the example shown in FIG. The data writing timing to the main memory 81 of the image processing units 117 to 120 is the same as that in FIG.

  FIG. 10 is a time chart corresponding to the example shown in FIG. 5A, and is a time chart when image data is read from the main memory 81 and read / written to / from the sub memory 82 in this embodiment.

  In synchronization with the vertical synchronization signal (VSNYC), the image data in the area 502 to be transferred to the image processing unit 118 is read from the main memory 81 of the image processing unit 117. The image data in the area 502 read from the main memory 81 of the image processing unit 117 is transferred from the communication unit 92 of the image processing unit 117 to the communication unit 92 of the image processing unit 118. Then, under the control of the memory control unit 91 of the image processing unit 118, the data is written in the sub memory 82 of the image processing unit 118.

  At the same time, the image processing unit 118 reads the image data of the region 503 from the main memory 81, reads the image data of the region 502 received from the image processing unit 117, performs keystone correction, and obtains the corrected image data of the regions 508 and 542. Generate. At this time, trapezoidal correction can be continuously performed on the areas 502 and 503 by reading out data from the lower part of the screen by address control of the memory control unit 91. At this time, the generated image is inverted upside down, but the liquid crystal driving unit 105 may perform upside down processing again.

  When the image processing unit 117 finishes reading the image data in the area 502, it reads out the image data in the area 501 from the main memory 81, performs keystone correction, and generates corrected image data in the areas 507 and 541 as described above.

  Since the operations of the image processing units 119 and 120 are the same, description thereof will be omitted. However, the image processing units 118 and 120 process the image data received from the image processing units 117 and 119 and written to the sub memory 82 in addition to the image data written to the main memory 81, respectively. Therefore, in order to complete the trapezoid correction process in one vertical period, it is necessary to read data from the main memory 81 and the sub memory 82 at a higher speed than at the time of writing.

  The trapezoidal correction is performed by the same operation in both the case where the projection apparatus 100 is tilted downward with respect to the screen 300 (FIG. 5C) and the case where the projection apparatus 100 is tilted laterally (FIGS. 5E and 5G). Is called.

  FIG. 11 shows an operation flowchart of this embodiment. In step S <b> 1102, the control unit 101 acquires tilt data from the tilt sensor 121. Instead of using the tilt sensor 121, a test image for calculating the tilt amount is projected, the projected image of the screen 300 is captured by the imaging unit 124, and the shape of the projected image is analyzed by the control unit 101 to determine the tilt. it can.

  In step S <b> 1103, the video signal from the signal source 200 is input to the projection apparatus 100. In step S <b> 1104, the image dividing unit 132 divides each screen of the video signal, and writes the data of the area handled by each memory into the main memory 81 of each image processing unit 117 to 120.

  In step S <b> 1105, the control unit 101 determines the range of image data (for example, the position of the substantial dividing line) to be exchanged between the image processing units 117 to 120 from the tilt data from the tilt sensor 121. In other words, when there is an inclination, keystone correction is performed, so that it is necessary to transmit / receive image data between the image processing units 117 to 120 as described above.

  In step S1106, the control unit 101 determines whether each of the image processing units 117 to 120 receives or transmits image data from the other image processing units 117 to 120 from the direction of inclination. Furthermore, it is determined which image processing unit is to exchange data at the same time.

  When passing image data to another image processing unit, the control unit 101 reads out image data of an area to be passed to the other image processing unit from the main memory 81 in step S1107 as described with reference to FIG. The read image data is transferred to the destination image processing unit (sub memory 82) via the communication unit 46. In step S1108, the image data of the remaining area is read from the main memory 81, and keystone correction is performed.

  When receiving image data from another image processing unit in step S1106, the control unit 101 proceeds to step S1109, and the image data of the area received by the communication unit 46 is written in the sub memory 82. In parallel with the processing in step S1109, image data is read out from the main memory 81 in the reverse order of writing in S1110, that is, from the bottom of the screen, and keystone correction is performed. When reading of the image data from the main memory 81 is completed in step S1110, the image data written in step S1109 is read from the sub memory 82 in the reverse order to the writing time, that is, from the lower part of the screen in step S1111, and the keystone correction is performed. .

  If it is determined in step S1105 that there is no inclination and image data communication between image processing units is unnecessary, image data is read from the main memory 81 in step S1112. At this time, the keystone correction is not executed.

  In step S <b> 1113, the control unit 101 determines whether an operation for instructing termination has been performed by the operation unit 102. .

  As described above, the time required for keystone correction can be shortened by providing a main memory and a sub memory that can be accessed independently.

  Further, the image data stored in the main memory and the sub memory are read out in the reverse order of writing, and the keystone correction processing is performed from the lower part of the image. Thereby, even when the data at the top of the screen is received from another image processing unit, the keystone correction process can be started without waiting for the data reception, and the calculation time can be shortened.

  Although the embodiment has been described in which the image data from the image dividing unit is stored in the main memory and the image data from other image processing units is stored in the sub memory, the present invention is not limited to such a role configuration.

Each image processing unit is provided with a two-port memory that can execute writing and reading independently, and the memory area stores an address area for storing image data from the image dividing unit and image data from other image processing units. The address area may be separated.
(Other examples)

  The object of the present invention can also be achieved by supplying a storage medium storing software program codes for realizing the functions of the above-described embodiments to the apparatus. At this time, the computer (or CPU or MPU) including the control unit of the supplied apparatus reads and executes the program code stored in the storage medium.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the program code itself and the storage medium storing the program code constitute the present invention.

  As a storage medium for supplying the program code, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

  Further, the OS (basic system or operating system) running on the apparatus performs part or all of the processing based on the instruction of the program code described above, and the functions of the above-described embodiments are realized by the processing. Cases are also included.

  Further, the program code read from the storage medium may be written into a memory provided in a function expansion board inserted into the apparatus or a function expansion unit connected to the computer, and the functions of the above-described embodiments may be realized. included. At this time, based on the instruction of the program code, the CPU or the like provided in the function expansion board or function expansion unit performs part or all of the actual processing.

Claims (6)

A projection device,
Generating means for generating a first image and a second image using a part of the input image;
Storing the first image, the first image processing means for performing keystone correction using the first image,
Storing the second image, the second image processing means for performing keystone correction using the second image,
Projecting means for projecting an image generated based on the image corrected by the first image processing means and the image corrected by the second image processing means onto the screen;
The first image processing means supplies an image corresponding to a first area of the first image to the second image processing means based on the inclination of the projection device with respect to the screen,
The projection apparatus, wherein the second image processing means performs trapezoidal correction using an image corresponding to the first region and the second image.   The projection apparatus according to claim 1, wherein the first image processing unit performs trapezoidal correction using an image corresponding to a second region of the first image.   The projection apparatus according to claim 2, wherein the first area is different from the second area. A generation step of generating a first image and a second image using a part of the input image;
Based on the inclination of the projection to the screen, a first image processing step of performing keystone correction using the first image,
The generated by the first image processing step, an image corresponding to the first region of the first image, a second image processing step of performing keystone correction using the second image,
And a projecting step of projecting an image generated based on the keystone-corrected image in the first image processing step and the image keystone-corrected in the second image processing step onto the screen. Projection method. A computer program for causing a computing device of a projection device to function as first and second image processing means of the projection device according to any one of claims 1 to 3 .   A computer-readable recording medium storing the computer program according to claim 5.

Images