JP2019208169A - Projection apparatus, control method of the same, program, and storage medium - Google Patents

Abstract

To provide a projection apparatus capable of reducing a decrease in luminance while improving contrast and increasing resolution.SOLUTION: The projection apparatus includes: an illumination unit having a light source; a first modulation unit for modulating light from the light source; a second modulation unit for modulating light output from the first modulation unit; a moving unit for periodically moving a position at which light output from the second modulation unit is projected onto a projection plane, between a plurality of positions on the projection plane; a first generation unit for generating a sub-frame corresponding to each of a plurality of positions on the basis of an input frame; a second generation unit for generating a first modulated image for controlling the first modulation unit on the basis of each sub-frame and a second modulated image for controlling the second modulation unit on the basis of each sub-frame; a first control unit for controlling the first modulation unit on the basis of the first modulated image; and a second control unit for controlling the second modulation unit on the basis of the second modulated image. The second generation unit generates the first and second modulated images so that a change in pixel value between sub-frames of the first modulated image is smaller than that of the second modulated image.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a projection apparatus that projects an image by superimposing two or more optical modulation elements, and a control method therefor.

  In recent years, the development of display devices with increased contrast has been advanced in order to perform display close to the real thing. Among them, there is a projection technique for increasing contrast by arranging an optical modulation element (color modulation panel) for modulating a color component and an optical modulation element (luminance modulation panel) for modulating a luminance component in series with respect to a light source. This technique is referred to herein as a double modulation technique.

  On the other hand, a pixel shifting technique is known as a technique for improving the spatial resolution. This technique generates a plurality of pixel shifted images in which sampling positions are shifted from one frame image. This is a technology that realizes higher resolution than the resolution of the display panel by projecting the projection position shifted every time.

  Further, in Patent Document 1, a color modulation panel and a luminance modulation panel that are optically arranged in series are arranged with a half-pixel shift, and by alternately displaying images that have passed through the color modulation panel and the luminance modulation panel, A technique for improving the spatial resolution is disclosed.

JP 2007-241097 A

  However, in the above-described conventional technique, when a pixel-shifted image is displayed via a color modulation panel and a luminance modulation panel with different response characteristics, the luminance of the edge portion of the still image may be reduced due to the effect of the slow response panel. It was.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a projection apparatus capable of reducing a decrease in luminance while realizing improvement in contrast and higher resolution.

  The projection apparatus according to the present invention includes an illumination unit having a light source, a first modulation unit that modulates light from the light source, a second modulation unit that modulates light output from the first modulation unit, and the second modulation unit. Corresponding to each of the plurality of positions based on an input frame and a moving means for periodically moving a position at which the light output from the modulation means is projected onto the projection plane between the plurality of positions on the projection plane First generation means for generating subframes, a first modulation image for controlling the first modulation means based on each subframe, a second modulation image for controlling the second modulation means, Second generation means for generating the first modulation means, first control means for controlling the first modulation means based on the first modulated image, and second control for controlling the second modulation means based on the second modulated image. Means for providing the second life It means a change in the pixel value between the sub-frames of the first modulation image, the second to be smaller than the modulation image, and generates said first and second modulated image.

  According to the present invention, it is possible to provide a projection apparatus that can reduce a decrease in luminance while realizing improvement in contrast and higher resolution.

1 is a diagram showing an overall configuration of a projection apparatus 100 according to a first embodiment of the present invention. The figure which shows the structure of the image generation part of 1st Embodiment. The figure which shows the projection positional relationship of the pixel shift image of 1st Embodiment. The figure which shows the reduction center coordinate of the reduction division | segmentation image A of 1st Embodiment. The figure which shows the reduction | restoration center coordinate of the reduction | restoration division image B of 1st Embodiment. The figure which shows a response | compatibility with the input image of 1st Embodiment, and a reduction center image. The figure explaining operation | movement of the pixel shift image generation part and fluctuation | variation suppression image generation part of 1st Embodiment. The figure explaining operation | movement of the modulation | alteration image generation part of 1st Embodiment. The figure explaining operation | movement when not using the process of 1st Embodiment. The figure explaining the subject when not using the process of 1st Embodiment. The figure explaining the relationship of the panel and projection brightness | luminance when not using the process of 1st Embodiment. The figure explaining the relationship between the panel of 1st Embodiment, and projection brightness | luminance. The figure explaining operation | movement of 2nd Embodiment. The figure explaining the relationship between the panel of 2nd Embodiment, and projection brightness | luminance. The figure which shows the structure of the image generation part of 3rd Embodiment. The figure which shows the pixel shift image and projection position relationship of 4th Embodiment.

(First embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments. The following embodiments do not limit the invention according to the claims, and all combinations of features described in the embodiments are not necessarily essential to the solution means of the invention.

  Note that each functional block described in the following embodiments is not necessarily separate hardware. That is, for example, the functions of some functional blocks may be executed by a single piece of hardware. In addition, the function of one functional block or the functions of a plurality of functional blocks may be executed by a coordinated operation of some hardware. The function of each functional block may be realized by the CPU executing a computer program developed on the memory.

  FIG. 1 is a diagram showing an overall configuration of a projection apparatus 100 according to the first embodiment of the present invention. In FIG. 1, the projection apparatus 100 includes a CPU 110, a ROM 111, a RAM 112, an operation unit 113, an image input unit 130, an image processing unit 140, and an image generation unit 141. The projection apparatus 100 further includes light modulation element driving units 150L and 150C, light modulation elements 151L, 151R, 151G, and 151B, a light source control unit 160, a light source (illumination unit) 161, a color separation unit 162, and a color synthesis unit 163. Have The projection apparatus 100 further includes a pixel shifting device 164, a pixel shifting device control unit 165, a projection optical system control unit 170, a projection optical system 171, and a communication unit 193.

  As the light modulation elements (spatial modulation elements) 151L, 151R, 151G, and 151B, a liquid crystal panel, a digital mirror device (DMD), or the like is used. In the present embodiment, the light modulation element 151L corresponds to a luminance modulation panel, and 151R, 151G, and 151B correspond to a color modulation panel. The color modulation panel and the luminance modulation panel are arranged in series on the optical path of the light source 161. Since the light modulation elements having different structures and operation principles are used for the color modulation panel and the luminance modulation panel according to the functions required for each, the response characteristics (operation reaction speed) are generally different. In this embodiment, the color modulation panel is a digital element that expresses halftones by pulse width modulation (PWM), and the luminance modulation panel is an analog type element that expresses halftones by changing the magnitude of applied voltage. It is an element. Since the analog device has a poorer response characteristic than the digital device, the luminance modulation panel has a relatively poor response characteristic (the panel operation response speed is slower) than the color modulation panel.

  The CPU 110 controls each operation block of the projection apparatus 100, and the ROM 111 stores a control program describing the processing procedure of the CPU 110. The RAM 112 temporarily stores a control program and data as a work memory. Further, the CPU 110 can temporarily store still image data and moving image data received by the communication unit 193, and can reproduce each image and video using a program stored in the ROM 111.

  The operation unit 113 includes, for example, a switch and a dial, receives an instruction from the operator, and transmits an instruction signal to the CPU 110. Further, the operation unit 113 may be configured by, for example, a signal receiving unit (such as an infrared receiving unit) that receives a signal from a remote controller, and configured to transmit a predetermined instruction signal to the CPU 110 based on the received signal. . The CPU 110 receives a control signal input from the operation unit 113 or the communication unit 193 and controls each operation block of the projection apparatus 100.

  The image input unit 130 receives an image transmitted from an external device. Here, the external device may be any device such as a personal computer, a camera, a mobile phone, a smartphone, a hard disk recorder, or a game machine as long as it can output an image signal. Furthermore, an image recorded on a medium such as a USB flash memory or an SD card can be read.

  The image processing unit 140 includes, for example, a microprocessor for image processing, and performs a change process for changing the number of frames, the number of pixels, the pixel value, the image shape, and the like on the image signal input from the image input unit 130, thereby generating an image. The data is transmitted to the generation unit 141. Note that the image processing unit 140 does not have to be a dedicated microprocessor. For example, the CPU 110 may execute the same processing as the image processing unit 140 by a program stored in the ROM 111. The image processing unit 140 can execute functions such as frame thinning processing, frame interpolation processing, resolution conversion (scaling) processing, distortion correction processing (keystone correction processing), luminance correction processing, and color correction processing. In addition to the image signal received from the image input unit 130, the image processing unit 140 can also perform the above-described change processing on the image or video reproduced by the CPU 110.

  The image generation unit 141 generates a pixel shifted image from the image signal received from the image processing unit 140. Further, a luminance modulation image to be transmitted to the light modulation element driving unit 150L and a color modulation image to be transmitted to the light modulation element driving unit 150C are generated from the pixel shifted image. Also, the pixel shift device control unit 165 is controlled via the register bus 199. The image generation unit 141 is composed of, for example, a microprocessor for image processing. Note that the image generation unit 141 does not have to be a dedicated microprocessor. For example, the CPU 110 may execute the same processing as the image generation unit 141 by a program stored in the ROM 111. Details of the image generation unit 141 will be described later.

  The light modulation element driving units 150L and 150C control the voltages applied to the liquid crystal elements of the pixels of the light modulation elements 151L, 151R, 151G, and 151B based on the image signal output from the image generation unit 141. Thereby, the transmittance of the light modulation elements 151L, 151R, 151G, 151B is adjusted.

  The light modulation element 151L adjusts the transmittance of the white light output from the light source 161. In addition, the light modulation element 151R is a liquid crystal element corresponding to a red component, and out of the light transmitted through the light modulation element 151L, the color separation unit 162 converts the light into red (R), green (G), and blue (B). The transmittance of red light of the separated light is adjusted. Similarly, the light modulation element 151G adjusts the transmittance of the green component light, and the light modulation element 151B adjusts the transmittance of the blue component light. The light modulation element 151L can partially control the amount of light from the light source, thereby reducing the black float and improving the in-plane contrast. In this embodiment, the light modulation element 151L is disposed in front of the light modulation elements 151R, 151G, and 151G. However, even if the order of the light modulation element 151L and the light modulation elements 151R, 151G, and 151G is reversed. Good.

  The light source control unit 160 includes a control microprocessor, and controls the on / off of the light source 161 and the light amount. Note that the light source control unit 160 does not have to be a dedicated microprocessor. For example, the CPU 110 may execute the same processing as the light source control unit 160 by a program stored in the ROM 111. The light source 161 includes, for example, a halogen lamp, a xenon lamp, a high-pressure mercury lamp, an LED, and a laser, and outputs light for projecting an image on a screen (not shown). The color separation unit 162 includes, for example, a dichroic mirror or a prism, and separates the light output from the light source 161 into red (R), green (G), and blue (B). In addition, when using LED etc. corresponding to each color as the light source 161, the color separation part 162 is unnecessary.

  The color composition unit 163 is composed of, for example, a dichroic mirror or a prism, and synthesizes red (R), green (G), and blue (B) light transmitted through the light modulation elements 151R, 151G, and 151B. The light in which the red (R), green (G), and blue (B) components are combined by the color combining unit 163 is sent to the projection optical system 171 via the pixel shifting device 164 and projected onto the screen. .

  The pixel shifting device 164 is a device that can shift the projection position so that incident image light can be projected to a desired position. For example, the pixel shifting device 164 includes a parallel plate glass and two actuators. Two actuators support the top and bottom of the glass, and the attitude of the glass is changed by controlling the tilt by displacing the support point. The image light transmitted through the color composition unit 163 passes through this glass. At this time, the pixel position at the time of projection can be shifted in a predetermined direction by changing the posture of the glass with an actuator.

  The pixel shifting device control unit 165 controls the attitude of the pixel shifting device 164. The pixel shift device control unit 165 adjusts the pixel shift amount by controlling the displacement of the support point of the actuator that supports the parallel flat glass. In this embodiment, the image is shifted by 0.5 pixels in the horizontal and vertical directions every other subframe (the image is periodically moved off the subframe). The timing to shift 0.5 pixels is instructed from the image generation unit 141. Thus, by projecting images shifted every other subframe, it is possible to obtain a projected image having a resolution higher than that of the optical modulation elements 151R, 151G, and 151B.

  The pixel shifting device 164 is not limited to this configuration, and may be configured using, for example, a birefringent optical system. By changing the voltage applied to the birefringent optical system, the projection position of the image light transmitted through the birefringent optical system can be changed to perform pixel shifting. In the case of this configuration, the pixel shifting device control unit 165 controls the voltage applied to the birefringent optical system.

  The projection optical system control unit 170 includes a control microprocessor and controls the projection optical system 171. Note that the projection optical system control unit 170 does not have to be a dedicated microprocessor. For example, the CPU 110 may execute the same processing as the projection optical system control unit 170 by a program stored in the ROM 111. The projection optical system 171 includes a plurality of lenses and lens driving actuators, and projects the combined light output from the color combining unit 163 onto the screen. By driving the lens with an actuator, the projected image can be enlarged, reduced, or focused.

  The communication unit 193 includes, for example, a wireless LAN, a wired LAN, USB, Bluetooth (registered trademark), and receives control signals, still image data, moving image data, and the like from an external device. Note that the communication method is not particularly limited to these. Further, if the terminal of the image input unit 130 is, for example, an HDMI (registered trademark) terminal, it may be configured to perform CEC communication via the terminal. Here, the external device may be any device such as a personal computer, a camera, a mobile phone, a smartphone, a hard disk recorder, a game machine, or a remote controller as long as it can communicate with the projection device 100. .

  Note that the image processing unit 140, the image generation unit 141, the light modulation element driving units 150L and 150C, the light source control unit 160, and the projection optical system control unit 170 of the present embodiment perform the same processing as those of these blocks. It may consist of one or more possible microprocessors. Alternatively, for example, the CPU 110 may execute the same processing as that of each block by a program stored in the ROM 111.

  Next, the image generation unit 141 will be described with reference to FIG. In the present embodiment, the image signal input to the image generation unit 141 is an RGB 8-bit signal. For easy understanding, it is assumed that the relationship between the image signal and the light intensity is linear.

  The projection apparatus 100 of this embodiment is a projection apparatus having a pixel shifting function. The input image is divided into two reduced divided images, and the projection position is switched for each reduced divided image signal by the pixel shift device 164 and projected. The reduced divided image is distributed to the color modulation image and the luminance modulation image before being projected, which will be described later.

  The pixel shift image generation unit 201 divides the image signal input to the image generation unit 141 into two, a reduced divided image A and a reduced divided image B. The reduced divided image B is projected at a position shifted by 0.5 pixels in the horizontal direction and the vertical direction with respect to the reduced divided image A. FIG. 3 shows the pixel array projected on the projection plane.

  Next, the generation method of the reduced divided image A will be described in detail with reference to FIG. FIG. 4A is a diagram showing the positional relationship of the reduced center coordinates with respect to the input image when the reduced divided image A is generated. The reduced center coordinates represent the coordinates of the center of interpolation processing when the input image is reduced. The coordinates of the pixel represented by the thick frame in FIG. 4A are the reduced center coordinates. As shown in FIG. 4A, reduction processing is performed with the even-numbered pixel data as the center coordinates in both the horizontal and vertical directions. In the present embodiment, the pixel data itself of the reduced center coordinates is referred to as a reduced divided image A. Of course, the present invention is not limited to this configuration, and reduction processing may be performed by interpolation processing using surrounding pixel data (for example, bicubic interpolation).

  FIG. 4B is a diagram showing a panel pixel array when displaying the reduced divided image A and the display positional relationship of the reduced divided image A. As shown in FIG. 4B, the pixel size of the display panel is four times the pixel size of the input image. That is, four pixels of the input image become one pixel of the display panel. Further, the reduced divided image A that has been reduced to the reduction center coordinates shown in FIG. 4A is displayed in the pixel array shown in FIG. For example, the coordinates of (0, 0), (2, 0), (4, 0) in FIG. 4A are (0, 0), (1, 0), (2 in FIG. 4B. , 0). Although the example in the horizontal direction is shown above, the vertical direction is displayed in the same manner.

  Next, a method for generating the reduced divided image B will be described in detail. FIG. 5A is a diagram showing the positional relationship of the reduced center coordinates with respect to the input image when the reduced divided image B is generated. Unlike the reduced divided image A, the reduced divided image B is subjected to reduction processing with the odd-numbered pixel data in the horizontal and vertical directions as the center coordinates. In the present embodiment, similarly to the reduced divided image A, the pixel data itself of the reduced center coordinates is referred to as a reduced divided image B. FIG. 5B is a diagram showing the pixel arrangement of the display panel when the reduced divided image B is displayed and the display positional relationship of the reduced divided image B.

  The pixel shift image generation unit 201 outputs the reduced divided image A in the first subframe period obtained by dividing one frame period of the input image into two, and the reduced divided image B in the next subframe period. The first subframe is a first subframe, and the next subframe is a second subframe. Also, the pixel-shifted image generation unit 201 notifies the pixel shift device control unit 165 of the switching timing of the first subframe and the second subframe.

  The fluctuation suppression image generation unit 202 compares the pixel values at the same position on the display panel arrangement of the reduced divided image A and the reduced divided image B from the input image signal, and the larger of the R, G, and B values of the two pixel values. One value is selected (maximum value detection), and a Max image is generated. As described above, for example, the pixel value of the reduced divided image A corresponding to the display panel arrangement (0, 0) is the pixel value of the pre-reduction pixel arrangement (0, 0), and the pixel value of the reduced divided image B is the pre-reduction pixel arrangement. This corresponds to the pixel value of (1, 1). This process is performed on all display panel arrangements to obtain a Max image.

  The modulation image generation unit 203 generates a color modulation image and a luminance modulation image from the reduced divided image A, the reduced divided image B, and the Max image. First, the modulation image generation unit 203 performs gradation conversion on the Max image to generate a luminance modulation image. By this gradation conversion, the gradation values of the color modulation image and the luminance modulation image are distributed. A gradation conversion equation when a pixel value of the Max image is M, a pixel value of the corresponding luminance modulation image is L, and an index is k is shown below.

L = 255 × (M / 255) ^k (Formula 1)
In this embodiment, k = 0.5.

  Further, the modulated image generation unit 203 divides the R, G, and B values of the pixels of the reduced divided image A and the reduced divided image B by the corresponding pixel value L of the luminance modulated image, thereby obtaining the color modulated image A and the color modulated image. B is generated. When the R / G / B value of a pixel of the reduced divided image is x and the pixel value of the corresponding color modulated image is cx, the correspondence between the reduced divided image and the pixel value of the color modulated image is expressed by the following equation. .

cx = x / L × 255 (Formula 2)
However, when L = 0, cx = 0.

  As described above, the reduced divided image A is alternately input to the first subframe and the reduced divided image B is input to the second subframe, as described above. The modulated image generation unit 203 alternately outputs the color modulated image A as the first subframe and the color modulated image B as the second subframe according to the input order. Also, the modulated image generation unit 203 outputs the same luminance modulation image in the first subframe and the second subframe, thereby matching the timings of the luminance modulation image and the color modulation image.

  Next, the operation of this embodiment will be described with a specific example. FIG. 6A shows an input image signal to the image generation unit 141. Blocks in the figure mean pixels. Although an actual image signal has a larger number of pixels, here, in order to make the explanation easy to understand, the input image data is data of 6 pixels × 6 pixels. An example of a monochrome image will be described. The pixel values of the white blocks in the figure are 255 for RGB and 16 for the diagonally shaded blocks.

  The pixel-shifted image generation unit 201 generates a reduced divided image A and a reduced divided image B from this image. FIG. 6B shows the reduced center coordinates of the reduced divided image A as A and the reduced center coordinates of the reduced divided image B as B. As described above, in this embodiment, the pixel value of the reduced center coordinate is used as it is as the pixel value of the reduced divided images A and B. The reduced divided image A is shown in FIG. 7A, and the reduced divided image B is shown in FIG. 7B. Further, the fluctuation suppression image generation unit 202 generates a Max image from the input image signal. Since the Max image is an image in which the larger pixel value in FIGS. 7A and 7B is selected, the Max image is as shown in FIG. 7C.

  The modulation image generation unit 203 generates a color modulation image A, a color modulation image B, and a luminance modulation image from the reduced divided image A, the reduced divided image B, and the Max image. FIG. 8A shows a color modulation image A, FIG. 8B shows a color modulation image B, and FIG. 8C shows a luminance modulation image. In the figure, the pixel value of the horizontal line block is 64. In the color modulation image B of FIG. 8B, the pixel values of the three pixels at the lower right are pixel values 16 represented by diagonal lines instead of 64 represented by horizontal lines. This is to adjust that the pixel becomes too bright when the Max image of the same is output in the first and second subframes in common. The color modulation image A and the color modulation image B are used for driving the color modulation panel, and the luminance modulation image is used for driving the luminance modulation panel, and are projected by the pixel shift device 164 to places where the projection positions are alternately shifted.

  Next, for comparison, an operation when the processing of this embodiment is not used will be described. When the processing of this embodiment is not used, the luminance modulation image is generated from the reduced divided image. FIG. 9A shows the luminance modulation image A generated from the reduced divided image A, and FIG. 9B shows the luminance modulation image B generated from the reduced divided image B. Further, the color modulation image A and the color modulation image B at that time are shown in FIG. 9 (c) and FIG. 9 (d).

  Attention is paid to the pixels P1 and P2 in FIG. P1 and P2 are pixels at the edge portion in the input image. The pixels P1 and P2 drive elements at the same position in the luminance modulation panel array. This luminance modulation panel is driven alternately with two pixel values P1 and P2 (255 and 64). Although the pixel value fluctuates greatly, the luminance modulation panel has poor response characteristics, causing a reduction in luminance on the projection surface. In the case of this example, the brightness of the portion illustrated by the dotted line in FIG. 10 decreases. This reduction in luminance occurs even if the input image is a still image, and is therefore conspicuous.

  This luminance reduction will be described in more detail with reference to FIG.

  FIG. 11 is a diagram illustrating the relationship between the operation for each time and the projection luminance, focusing on the modulation panel driven by the pixels P1 and P2. As shown in the figure, 255 and 64 are alternately input for each subframe as pixel values for driving the color modulation panel and the luminance modulation panel. At this time, since the color modulation panel has good response characteristics, the level changes sharply as shown in the color modulation panel modulation characteristics. On the other hand, since the luminance modulation panel has poor response characteristics, the height changes gradually as shown in the luminance modulation panel modulation characteristics. Since the projection light is modulated by the color modulation panel and the luminance modulation panel, the luminance is reduced by the amount indicated by the dotted line Q in the figure. As described above, even if the input image is a still image, the pixel values of P1 and P2 are alternately input, so that the luminance is lowered due to the influence of the response characteristic of the luminance modulation panel.

  The case where the process of this embodiment is applied is shown in FIG. As shown in FIG. 12, in the present embodiment, the pixel value of the luminance modulation image is not changed between subframes (the luminance modulation image of FIG. 8C is used in both the first and second subframes). The luminance does not decrease due to the response characteristics of the luminance modulation panel.

  As described above, in the present embodiment, a luminance modulation image is generated from the Max image, and the same luminance modulation image is used for both the first subframe and the second subframe. Thereby, it is possible to reduce a decrease in luminance due to a difference in response characteristics of the modulation panel between subframes.

(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described. In the first embodiment, the same luminance modulation image is used for both the first subframe and the second subframe. On the other hand, in the second embodiment, the reduction in luminance is reduced by reducing the difference between the pixel values of the luminance modulation images of the first subframe and the second subframe. This will be specifically described below.

  The second embodiment is different only in the operations of the fluctuation-suppressed image generation unit 202 and the modulated image generation unit 203 of the first embodiment. First, the operation of the fluctuation suppression image generation unit 202 will be described.

  The fluctuation suppression image generation unit 202 generates a BLND_A image and a BLND_B image from the reduced divided image A and the reduced divided image B. Then, the BLND_A image is output during the first subframe period, and the BLND_B image is output during the second subframe period.

  The BLND_A image and the BLND_B image are generated as follows. First, the maximum values MA and MB of R, G, and B are obtained from the pixels of the reduced divided image A and the pixels of the reduced divided image B at the same position on the display panel array. When the BLND_A image is generated, if MA is smaller than MB, the average value of MA and MB is set as the pixel value of the BLND_A image. When MA is larger than MB, MA is the pixel value of the BLND_A image. When generating a BLND_B image, if MB is smaller than MA, the average value of MA and MB is used as the pixel value of the BLND_B image. When MB is larger than MA, MB is set as the pixel value of the BLND_B image.

  Next, the operation of the modulated image generation unit 203 will be described. The modulation image generation unit 203 generates a color modulation image A and a luminance tone image A from the reduced divided image A and the BLND_A image. Further, a color modulation image B and a luminance modulation image B are generated from the reduced divided image B and the BLND_B image. The generation method is the same as that in the first embodiment except that the Max image is changed to a BLND_A image or a BLND_B image. Then, the modulation image generation unit 203 outputs the color modulation image A and the luminance modulation image A in the first subframe, and the color modulation image B and the luminance modulation image B in the second subframe.

  Next, the operation of this embodiment will be described with an example. The input image is the image shown in FIG. 6A used in the first embodiment. FIG. 13 shows a reduced divided image A, a reduced divided image B, a BLND_A image, a BLND_B image, a color modulation image A, a color modulation image B, a luminance modulation image A, and a luminance modulation image B. In the figure, the pixel value of the crossed block is 136, the thin dot block is 186, and the dark dot block is 22.

  Here, as in the case of the first embodiment, focusing on the modulation panel driven by the pixels P3 to P6, the relationship between the operation for each time and the projection luminance is shown in FIG. As shown in FIG. 14, by reducing the change amount of the pixel value between the sub-frames of the luminance modulation panel, the area of the portion indicated by Q in FIG. 14 is reduced and the reduction in luminance can be reduced.

  In this way, by reducing the difference in pixel value of the luminance modulation image between the subframes, it is possible to reduce the luminance decrease due to the difference in the response characteristics of the modulation panel.

(Third embodiment)
Hereinafter, a third embodiment of the present invention will be described. In the first embodiment, a Max image is generated from an input image. In the third embodiment, a Max image is generated from the reduced divided image. This will be specifically described below.

  The third embodiment is different from the first embodiment in the configuration of the image generation unit. FIG. 15 is a block diagram of the image generation unit 1501 according to the third embodiment. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The fluctuation suppression image generation unit 1502 generates a Max image from the reduced divided image A and the reduced divided image B. In the present embodiment, the pixel values at the same position of the reduced divided image A and the reduced divided image B are compared, and the larger value is selected to generate the Max image. As a result, the same Max image as in the first embodiment can be generated. Since other processes and operations are the same as those in the first embodiment, a description thereof will be omitted.

  In this way, by setting the luminance modulation images between the subframes to the same value, it is possible to reduce the luminance reduction due to the difference in the response characteristics of the modulation panel.

(Fourth embodiment)
The fourth embodiment of the present invention will be described below. In the first to third embodiments, the implementation method using the pixel shift that divides the input image into two and projects the image is described. In the fourth embodiment, an implementation method when an input image is divided into four and projected will be described. Since the block configuration of the projection apparatus of the fourth embodiment is the same as that of the first embodiment, description thereof is omitted. An operation of the pixel shift image generation unit 201 of the fourth embodiment will be described.

  The pixel shift image generation unit 201 generates four divided images that are switched and displayed for each subframe by the pixel shift device 164 from the input image. For example, it is divided into the following four image signals DIV1 to DIV4.

Divided image DIV1 = formed by pixel data of (horizontal: even number, vertical: even number) divided image DIV2 = formed by pixel data of (horizontal: odd number, vertical: even number) divided image DIV3 = (horizontal: odd number, Formed with pixel data of (vertical: odd number) divided image DIV4 = (formed with pixel data of (horizontal: even number, vertical: odd number)) The four divided images DIV1 to DIV4 generated are converted by the pixel shifting device 164 into FIG. As shown in FIG. 4, the position is shifted in four subframes with respect to one frame of the input frame rate. With reference to subframe 1 (DIV1), subframe 2 (DIV2) is shifted by 0.5 pixels in the horizontal direction, subframe 3 (DIV3) is 0.5 pixels in the horizontal direction, and 0. The subframe 4 (DIV4) is projected at a position shifted by 0.5 pixels in the vertical direction at a position shifted by 5 pixels.

  The fluctuation suppression image generation unit 202 compares pixel values at the same position on the display panel arrangement of the divided images DIV1 to DIV4 from the input image signal, and selects the largest value among the R, G, and B values of the four pixel values. Then, a Max image is generated.

  The modulation image generation unit 203 generates a color modulation image and a luminance modulation image from the divided images DIV1 to DIV4 and the Max image. The generation method is the same as that in the first embodiment except that the reduced divided images A and B are changed to the divided images DIV1 to DIV4. The color modulation images corresponding to the divided images DIV1 to DIV4 are referred to as color modulation images 1 to 4, respectively. As in the first embodiment, the modulated image generation unit 202 outputs the color modulated images 1 to 4 during the subframes 1 to 4, respectively. Further, as in the first embodiment, the luminance modulation image outputs the same luminance modulation image throughout the subframes 1 to 4. Since other processes are the same as those of the first embodiment, description thereof is omitted.

  As described above, even when the pixel shift for dividing the image into four is performed, the luminance decrease due to the difference in the response characteristics of the modulation panel is reduced by setting the luminance modulation image to the same value between the subframes. be able to. In addition, in the same manner as in the second embodiment, the difference in pixel value of the luminance modulation image between subframes may be reduced to reduce the luminance drop due to the difference in response characteristics of the modulation panel. .

  In each embodiment of the present invention, the case where the pixels of the luminance modulation panel and the color modulation panel correspond to 1: 1 has been described. However, in the present invention, when the pixel size of the other luminance modulation panel and the color modulation panel is different, or when the light from the luminance modulation panel pixel spreads and irradiates a wider area than the color modulation panel pixel, etc. It can also be applied. That is, even in such a case, it is possible to reduce the luminance reduction due to the difference in the response characteristics of the modulation panel by setting the luminance modulation images between the subframes to the same value or reducing the difference between the pixel values.

(Other embodiments)
In addition, the present invention supplies a program that realizes one or more functions of the above-described embodiment to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus read the program. It can also be realized by executing processing. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

100: Projector, 110: CPU, 111: ROM, 112: RAM, 113: Operation unit, 130: Image input unit, 140: Image processing unit, 141: Image generation unit, 150: Light modulation element driving unit, 151: Light modulation element, 151: Optical modulation element, 160: Light source control unit, 161: Light source, 162: Color separation unit, 163: Color synthesis unit, 164: Pixel shift device, 165: Pixel shift device control unit, 170: Projection optics System control unit, 171: projection optical system, 193: communication unit

Claims (15)

Illumination means having a light source;
First modulation means for modulating light from the light source;
Second modulation means for modulating the light output from the first modulation means;
Moving means for periodically moving a position at which the light output from the second modulation means is projected onto a projection plane between a plurality of positions on the projection plane;
First generation means for generating a subframe corresponding to each of the plurality of positions based on an input frame;
Second generation means for generating a first modulated image for controlling the first modulation means and a second modulated image for controlling the second modulation means based on each subframe;
First control means for controlling the first modulation means based on the first modulated image;
Second control means for controlling the second modulation means based on the second modulated image;
With
The second generation means generates the first and second modulated images so that a change in pixel value between the sub-frames of the first modulated image is smaller than that of the second modulated image. Projection device.   The projection apparatus according to claim 1, wherein the second generation unit includes a correction unit that reduces a difference in pixel values between subframes of the first modulated image.   The projection apparatus according to claim 2, wherein the correction unit sets a difference in pixel values between subframes of the first modulated image to zero.   The projection apparatus according to claim 3, wherein the correction unit uses the same image as a subframe of the first modulated image.   The correction means includes a maximum value detection means for obtaining a maximum value of pixel values corresponding to each of the subframes from the input frame, and the second generation means is configured to perform the first modulation based on the maximum value. The projection apparatus according to claim 3, wherein an image is generated.   The correction means includes maximum value detection means for obtaining a maximum value of corresponding pixel values between the subframes, and the second generation means generates the first modulated image based on the maximum value. The projection apparatus according to claim 3, wherein:   The first generation unit generates two subframes from an input frame, and the maximum value detection unit obtains the larger pixel value between the two subframes. The projection device described.   The said 2nd production | generation means produces | generates four sub-frames from an input frame, and the said maximum value detection means calculates | requires the maximum value of the pixel value between the said four sub-frames. The projection device described.   The first modulation unit modulates a luminance component of light from the light source, and the second modulation unit modulates a red component, a blue component, and a green component of light from the light source, respectively. Item 9. The projection device according to any one of Items 1 to 8.   10. The projection apparatus according to claim 1, wherein the first modulation unit is an analog panel that controls transmittance according to a value of an applied voltage. 11.   11. The projection apparatus according to claim 1, wherein the second modulation unit is a digital panel that controls transmittance according to a time during which a voltage is applied. Illumination means having a light source;
First modulation means for modulating light from the light source;
Second modulation means for modulating the light output from the first modulation means;
Moving means for periodically moving a position at which the light output from the second modulation means is projected onto a projection plane between a plurality of positions on the projection plane;
First generation means for generating a subframe corresponding to each of the plurality of positions based on an input frame;
Second generation means for generating a first modulated image for controlling the first modulation means and a second modulated image for controlling the second modulation means based on each subframe;
First control means for controlling the first modulation means based on the first modulated image;
Second control means for controlling the second modulation means based on the second modulated image;
With
The second generation unit is configured to change a pixel value between the sub-frames of the modulation image corresponding to the modulation unit having a slower response speed of the modulation among the first modulation unit and the second modulation unit. A projection apparatus that generates the first and second modulated images so as to be smaller than a modulated image. Illumination means having a light source, first modulation means for modulating light from the light source, second modulation means for modulating light output from the first modulation means, and light output from the second modulation means A method of controlling a projection apparatus comprising: a moving unit that periodically moves a position projected on a projection plane between a plurality of positions on the projection plane;
A first generation step of generating a subframe corresponding to each of the plurality of positions based on an input frame;
A second generation step of generating, based on each subframe, a first modulated image for controlling the first modulating means and a second modulated image for controlling the second modulating means;
A first control step of controlling the first modulation means based on the first modulated image;
A second control step of controlling the second modulation means based on the second modulated image;
Have
In the second generation step, the first and second modulated images are generated such that a change in pixel value between the sub-frames of the first modulated image is smaller than that of the second modulated image. A control method for the projection apparatus.   The program for functioning a computer as each means of the projection apparatus of any one of Claims 1 thru | or 12.   A computer-readable storage medium storing a program for causing a computer to function as each unit of the projection apparatus according to any one of claims 1 to 12.

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