JP2020008729A - Projection device, control device, projection device control method and program - Google Patents

Abstract

To suppress deterioration of visibility of an image to be composed by a plurality of images projected by a plurality of projection devices.SOLUTION: A projection device comprises: dimming means that performs processing for dimming an area where a first image to be projected to a projection surface by the projection device and a second image to be projected to the projection surface by another projection device overlap with each other; generation means that generates light-amount control information causing a light-amount change speed for changing amounts of light of the first and second images to be lowered; light source control means that controls a light source in accordance with the light-amount control information on the first image; and output means that outputs the light-amount control information on the second image to another projection device.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a projection device that controls a light source of the projection device, a control device, a control method of the projection device, and a program.

  2. Description of the Related Art A system that combines a plurality of projection devices and projects one image on a screen has been used. By projecting images projected by a plurality of projection devices as one image on a screen, a high-resolution image can be displayed in a large size. In this case, if there is a shift in the timing at which each projection device projects an image, the image projected on the screen will not be an appropriate image as a whole. To solve this problem, a technique for outputting and displaying a synchronized video from a plurality of projectors has been proposed (see Patent Document 1). In this technology, the master projector determines the maximum video signal delay time among the video signal delay times of each projector, adds the maximum video signal delay time to the moving image time information, and displays an image. Projecting images without time lag.

JP 2017-3925 A

  In the technique of Patent Literature 1, the time corresponding to the maximum video signal delay time is delayed for video synchronization, so that the delay time until the video is displayed becomes longer. If a shift in the drive timing of the light sources of a plurality of projectors (projection devices) is allowed in order to reduce the delay time, the difference in the drive timing of the light sources may cause a difference in the brightness of the image projected by each projection device. Occurs. In this case, the visibility of the entire image projected on the screen is reduced due to the luminance difference between the images projected by each projection device.

  An object of the present invention is to provide a projection device, a control device, a control method of a projection device, and a program that suppress a decrease in visibility of an image formed by a plurality of images projected by a plurality of projection devices.

  In order to achieve the above object, a projection device according to the present invention reduces a region where a first image projected by the projection device on a projection surface and a second image projected by another projection device on the projection surface are overlapped. Light reducing means for performing processing, and generating means for generating light amount control information for reducing a light amount changing speed for changing the light amount of the first image and the second image as the width of the region becomes narrower, A light source control unit that controls a light source according to the light amount control information of the first image, and an output unit that outputs the light amount control information of the second image to the other projection device.

  According to the present invention, it is possible to suppress a decrease in visibility of an image formed by a plurality of images projected by a plurality of projection devices.

FIG. 1 is a diagram illustrating a configuration example of an entire system according to each embodiment. FIG. 2 is a diagram illustrating an internal configuration of the projection device according to the first embodiment. FIG. 3 is a diagram illustrating an internal configuration of an image processing unit. 5 is a flowchart illustrating a processing flow of the projection device that operates in the master mode according to the first embodiment. FIG. 4 is a diagram illustrating a table that defines a relationship between a light amount change speed and a ratio of a width of a superimposed region. 5 is a flowchart illustrating a processing flow of the projection device that operates in the slave mode according to the first embodiment. FIG. 4 is a diagram for explaining a change and a difference in the amount of light output by each projection device when the first embodiment is not applied. FIG. 4 is a diagram for explaining a change and a difference in the amount of light output from each projection device when the first embodiment is applied. FIG. 9 is a diagram for explaining a change and a difference in the amount of light output from each projection device when the second embodiment is not applied. FIG. 11 is a diagram for explaining a change and a difference in the amount of light output from each projection device when the second embodiment is applied. 13 is a flowchart illustrating a processing flow of the projection device that operates in the master mode according to the third embodiment. FIG. 11 is a diagram for explaining a change and a difference in the amount of light output from each projection device when the third embodiment is applied.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the configurations described in the following embodiments are merely examples, and the scope of the present invention is not limited by the configurations described in the embodiments.

<First embodiment>
FIG. 1 is a diagram illustrating a configuration example of the entire system of each embodiment. 1 includes a projection device 100, a projection device 200, a screen 300, a hub 500, and a control device 600. Although the example of FIG. 1 shows a configuration example in which there are two projection devices, three or more projection devices may be used. The projection device 100 projects a projection image 1001 (first image) on a screen 300 as a projection surface. The projection device 200 projects the projection image 2001 (second image) on the screen 300. By projecting the projection image 1001 and the projection image 2001 in combination on the screen 300, one image (video) composed of the projection image 1001 and the projection image 2001 is displayed on the screen 300. The one image has a higher resolution and a larger display size than the projection image 1001 and the projection image 2001. The projection image 1001 projected by the projection device 100 partially overlaps with the projection image 2001 projected by the projection device 200, and the overlapping region is a superimposed region 3001. Further, the projector 100 and the projector 200 are connected via a hub 500 to communicate with each other.

  Hereinafter, the projector 100 and the projector 200 will be described as communicating via the hub 500. However, the hub 500 may not be used as long as the projector 100 and the projector 200 can communicate with each other. . For example, when the projection apparatus 100 and the projection apparatus 200 perform wireless communication like a wireless LAN router, the projection apparatus 100 and the projection apparatus 200 are configured to be directly connected without any other apparatus. May be. The control device 600 is connected to the hub 500. The control device 600 is, for example, a personal computer or the like. Control device 600 controls projection device 100 and projection device 200. Control device 600 and hub 500 may be configured integrally.

  FIG. 2 is a diagram showing an internal configuration of the projection device 100. Hereinafter, the projection device 100 and the projection device 200 will be described as having the same configuration. However, the projection device 100 and the projection device 200 may have different configurations. The projection device 100 includes a CPU 110, a RAM 111, a ROM 112, an operation unit 113, a communication unit 114, an image input unit 120, and an image processing unit 140. In addition, the projection apparatus 100 includes a light modulation element control unit 150, light modulation elements 170R, 170G, 170B, a light source control unit 130, a light source 160, a color separation unit 161, a color synthesis unit 180, a projection optical system 183, and a projection optical system control. It has a portion 184. Further, the projection device 100 includes a feature amount calculation unit 190 and a light amount control information generation unit 191. The CPU 110, the RAM 111, the ROM 112, the operation unit 113, the communication unit 114, the image input unit 120, the light source control unit 130, and the image processing unit 140 are mutually connected by a bus 199. Similarly, the light modulation element control unit 150, the projection optical system control unit 184, the feature amount calculation unit 190, and the light amount control information generation unit 191 are mutually connected by a bus 199.

  The CPU 110 functions as a control unit that controls each operation block of the projection device 100. The ROM 112 stores a control program describing the processing procedure of the CPU 110. The control program and data are temporarily stored in the RAM 111 as a work memory. The CPU 110 can also temporarily store the still image data and the moving image data received from the communication unit 114, and can reproduce each image and video using a program stored in the ROM 112. Further, the CPU 110 receives the control signals input via the operation unit 113 and the communication unit 114, and controls each unit of the projection device 100. The operation unit 113 receives an instruction from the user and outputs an instruction signal to the CPU 110, and includes, for example, a switch and a dial. The operation unit 113 may be, for example, a signal receiving unit (such as an infrared receiving unit) that receives a signal from a remote controller, and may output a predetermined instruction signal to the CPU 110 based on the received signal.

  The communication unit 114 is used for transmitting and receiving control signals, still image data, moving image data, and the like to and from an external device. For example, a wireless LAN, a wired LAN, a USB, Bluetooth (registered trademark), or the like can be applied. However, the communication method is not limited to the above example. Further, if the terminal of the image input unit 120 is, for example, an HDMI (registered trademark) terminal, the terminal may perform consumer electronics control (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, and a remote controller as long as the device can communicate with the projection device 100.

  The image input unit 120 receives an input of an image from an external device. 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 the like as long as it can output an image signal. Further, the image input unit 120 can also read an image recorded on a medium such as a USB flash memory or an SD card. The image input unit 120 outputs the input image data (hereinafter, input image) to the image processing unit 140. Further, the image input unit 120 can also superimpose an arbitrary OSD such as a GUI or a test pattern on the received image and output the same based on an instruction from the CPU 110. Further, the image input unit 120 can output an input image to the RAM 111 based on an instruction from the CPU 110.

  The light source control unit 130 is a light source control unit that controls ON / OFF of the light source 160 and controls the amount of light, and may be realized by a control microprocessor. The control of the light amount may be control by a voltage or current applied to the light source, or may be control by driving an iris or a mechanical shutter. Further, the function of the light source control unit 130 may be realized, for example, by causing the CPU 110 to execute a program stored in the ROM 112 and perform the same processing as the light source control unit 130. The light source 160 outputs light for projecting an image on the screen 300. The light source 160 may be, for example, a halogen lamp, a xenon lamp, a high-pressure mercury lamp, a laser, an LED, a phosphor, or the like, or a combination thereof. The light source control unit 130 controls the light amount of the light source based on the light amount control information generated by the light amount control information generation unit 191.

  The image processing unit 140 performs a process of changing the number of frames, the number of pixels, an image shape, and the like on a video signal (input image) received from the image input unit 120, and outputs the processed signal to the light modulation element control unit 150. Is realized by a microprocessor for image processing. The function of the image processing unit 140 may be realized, for example, by causing the CPU 110 to execute a program stored in the ROM 111 and perform processing similar to that of the image processing unit 140. The image processing unit 140 can execute functions such as frame thinning processing, frame interpolation processing, resolution conversion processing, color correction processing, blending processing, and distortion correction processing (keystone correction processing). Details of the internal configuration of the image processing unit 140 will be described later with reference to FIG.

  Further, the image processing unit 140 can also perform a process of extending the gradation of the video signal according to the light amount control information calculated by the light amount control information generation unit 191. The image processing unit 140 can also perform the above-described change processing on an image reproduced by the CPU 110, in addition to the video signal received from the image input unit 120.

  The light modulation element control unit 150 controls the voltage applied to the light modulation elements of the pixels of the light modulation elements 170R, 170G, and 170B based on the image signal output from the image processing unit 140, and The light modulation rates of 170G and 170B are controlled. The light modulating element 170R is a light modulating element corresponding to red, and the light output from the light source 160 is separated into red (R), green (G), and blue (B) by the color separation unit 161. Among them, the light modulation rate of red light is controlled. The light modulating element 170G is a light modulating element corresponding to green, and the light output from the light source 160 is separated into red (R), green (G), and blue (B) by the color separation unit 161. Among them, the light modulation rate of green light is controlled. The light modulating element 170B is a light modulating element corresponding to blue, out of the light output from the light source 160, of the light separated into red (R), green (G), and blue (B) by the color separating unit 161. The light modulation rate of blue light is controlled.

  The color separation unit 161 separates the light output from the light source 160 into red (R), green (G), and blue (B). For example, a dichroic mirror or a prism is applied. When LEDs or the like corresponding to each color are used as the light source 160, the color separation unit 161 is unnecessary. The color synthesizing unit 180 synthesizes red (R), green (G), and blue (B) light modulated by the light modulation elements 170R, 170G, and 170B. For example, a dichroic mirror or a prism is used. Is done.

  The projection optical system control section 184 controls the projection optical system 183. The projection optical system control unit 184 may be realized by a microprocessor for control. The projection optical system control unit 184 may be realized by, for example, executing a program stored in the ROM 112 by the CPU 110 performing the same processing as that of the projection optical system control unit 184. The projection optical system 183 projects the light combined by the color combining unit 180 onto the screen 300. The projection optical system 183 may be a plurality of lenses, a lens driving actuator, or the like. By driving the lens by the actuator, zoom (enlargement, reduction), focus adjustment, and the like of the projected image can be performed.

  The feature amount calculation unit 190 calculates a feature amount based on an input image input to the image input unit 120 or an image output from the image processing unit 140. The calculated feature amount may be, for example, APL (Average Picture Level) which is an average tone value of one frame of an image, a maximum tone value or a minimum tone value included in one frame of an image, It may be a histogram or the like. Further, the feature amount calculation unit 190 may calculate a change in the feature amount between frames as a feature amount.

  The light amount control information generation unit 191 is a generation unit that generates light amount control information. The light amount control information includes a target light amount (a set value of the light amount) that defines the light emission amount of the light source and a light amount change time that specifies how long the frame period is used to control the target light amount. including. The light amount control information generation unit 191 determines the target light amount of the light source based on the feature amount of the image to be displayed. For example, when the image is entirely dark, the target light amount is determined to be lower than when the image is bright. Thus, when displaying a dark image, it is possible to suppress a decrease in contrast caused by light emitted from a light source leaking into a dark region. The light amount control information generation unit 191 may determine the target light amount for each frame, or may determine the target light amount for each of a plurality of frames or each specific scene. The light amount control information generation unit 191 may use, as the feature amount, the feature amount calculated by the feature amount calculation unit 190 of the projection device 100 or a feature acquired from an external device via the communication unit 114 functioning as an acquisition unit. A quantity may be used, or both feature quantities may be used.

  Further, the light amount control information generation unit 191 specifies how many frame periods to control the target light amount based on the width of the superimposed area 3001 when the blend processing is performed by the blend processing unit 144 described later. The light amount change time is generated. The light amount control information generation unit 191 sets the light amount change time to be longer as the width of the superimposed area is smaller than a predetermined value. In other words, the light amount control information generation unit 191 generates the light amount control information such that the light amount change speed (light amount change speed) becomes slower as the width of the superimposition region 3001 is smaller. The light amount change speed indicates the rate of change of the light amount per time when the light amount of the light source is changed from the target light amount Xa in the previous frame to the target light amount Xb in the current frame.

  FIG. 3 is a diagram showing the internal configuration of the image processing unit 140. An image (input image) input from the image input unit 120 to the image processing unit 140 is first processed by the resolution conversion unit 141. The resolution converter 141 converts the resolution of the input image into a desired resolution. Here, the resolution conversion unit 141 converts the resolution of the input image so as to match the resolution of the light modulation element 170. For example, it is assumed that the resolution of the light modulation element 170 is 1920 × 1080 and the resolution of the input image is 1280 × 720. In this case, the resolution conversion unit 141 enlarges the vertical and horizontal size of the input image by 1.5 times, and converts the input image into a 1920 × 1080 image. Thus, when the aspect ratio of the resolution of the light modulation element 170 and the resolution of the input image is the same, the resolution conversion unit 141 simply enlarges the input image. However, for example, when the resolution of the input image is 1024 × 768 and the aspect ratio is different from that of the light modulation element 170, the resolution conversion unit 141 keeps the aspect ratio according to the ratio of the vertical or horizontal width. Enlarge the input image. Then, the resolution conversion unit 141 arranges the image at the center of the light modulation element 170, and outputs black for the remaining pixels around the light modulation element 170.

  The color correction unit 142 performs color correction such as color matrix conversion, chroma processing, gamma processing, and color space conversion, and performs correction processing so that an input image has a desired color when projected on the screen 300. The OSD generation unit 143 generates and outputs an OSD of a setting menu and a pattern for adjusting a superimposition area 3001 which is an area to be blended. When the CPU 110 is executing the process of adjusting the position of the superimposition region 3001 or executing the output process of the test pattern, the OSD generation unit 143 superimposes the pattern on the input image according to the instruction of the CPU 110, and Output to the processing unit 144.

  When one projection image is formed by partially overlapping the projection image 1001 from the projection device 100 and the projection image 2001 from the projection device 200, an area where the two projection images overlap (superimposition area 3001) is a screen. At 300. The blend processing unit 144 is a light reduction processing unit that performs light reduction processing (hereinafter, blend processing) on the superimposed area 3001. Specifically, the blend processing unit 144 performs a blend process on the width of the superimposition area 3001 designated by the CPU 110 in the image input from the OSD generation unit 143. The blending process is performed on the image projected by each projection device onto the superimposition region 3001 such that the brightness of the image projected by superimposing the projection images of the projection devices on the superimposition region 3001 is equal to the brightness of the original image. This is a process for reducing the brightness as compared with the case where each projector projects an image without performing the blending process. Information on the width of the superimposition region 3001 is input from the CPU 110 to the blend processing unit 144. The information on the width of the superimposition area 3001 is output to the light amount control information generation unit 191 according to an instruction from the CPU 110, and is used when calculating the light amount control information.

  The transformation processing unit 145 transforms the input image into an arbitrary shape. The transformation processing unit 145 transforms the image signal for each of R (red), G (green), and B (blue), and writes the transformed image signal to the frame memory 146. Upon completion of the writing, the transformation processing unit 145 reads the signal from the frame memory 146 and outputs the transformed signal. Note that the deformation processing unit 145 obtains the coordinates of the pixels before and after the deformation based on a predetermined deformation formula, and outputs a deformed image signal.

  Hereinafter, each of the projection device 100 and the projection device 200 plays one of two modes of a master mode and a slave mode as operation modes when displaying an image on the screen 300. When there are three or more projectors, one of the projectors becomes the master mode projector and one or more other projectors becomes the slave mode projector. The switching of the operation mode may be determined based on the user's designation obtained via the operation unit 113, or may be determined based on an instruction from an external device connected via the communication unit 114. Hereinafter, the description will be made assuming that the projection apparatus 100 operates in the master mode and the projection apparatus 200 operates in the slave mode. However, the projection apparatus 200 may operate in the master mode and the projection apparatus 100 may operate in the slave mode. .

  When each of the projection device 100 and the projection device 200 executes the above-described light amount adjustment to display an image, the timing of the light amount adjustment may be largely shifted. If the timing of the light amount adjustment is largely shifted, for example, when the black image region of the projection image 1001 and the black image region of the projection image 2001 are adjacent to each other, the brightness difference of the black image region is emphasized by the Mach effect and the screen 300 is increased. Is recognized by the user who is watching. The Mach effect is an effect in which, when images having a luminance difference are displayed adjacent to each other, a dark image is recognized as being darker and a bright image is recognized as being brighter, so that the luminance difference is emphasized and recognized. For example, when the projection image 1001 and the projection image 2001 are projected on the screen 300 in a tiled manner and the superimposition region 3001 does not exist, the luminance between pixels adjacent to each other across the boundary between the projection image 1001 and the projection image 2001 The difference is emphasized, making it easier to see.

  The projection device 100 and the projection device 200 perform control to reduce the difference in output luminance (light amount) between the projection image 1001 and the projection image 2001 by slowing down the light amount change speed as the width of the superimposition region 3001 becomes narrower. Do. This makes it difficult for a viewer who views the screen 300 to visually recognize the output luminance difference, so that the visibility of the image projected on the screen 300 is improved. The processing executed by CPU 110 of projection device 100 and projection device 200 will be described. The flowchart in FIG. 4 shows a processing flow of the projection device 100 operating in the master mode.

  The CPU 110 of the projection device 100 acquires information on the width of the superimposed area 3001 on which the image processing unit 140 has performed the blending process (S300). The CPU 110 outputs the acquired information on the width of the superimposition region 3001 to the light amount control information generation unit 191 and causes the light amount control information generation unit 191 to acquire the light amount change speed (S301). The light amount control information generation unit 191 may acquire the light amount change speed according to, for example, the table in FIG. The table of FIG. 5 is a table that defines the relationship between the light amount change speed and the ratio of the width of the superimposition region 3001. The horizontal axis indicates the ratio [%] of the width of the superimposition region, and the vertical axis indicates the light amount change speed [%]. / Frame]. The light amount change speed indicates a speed at which the output light amounts of the light sources 160 of the projection device 100 and the projection device 200 are changed. The ratio of the width of the superimposition region indicates the ratio of the width of the superimposition region 3001 to the width of the projection image 1001. The table of FIG. 5 shows an example in which the relationship between the light amount change speed and the ratio of the width of the superimposition region is a non-linear relationship, but the relationship between the light amount change speed and the ratio of the width of the superimposition region is linear. The relationship may be a relationship or a relationship that changes in a step-like manner.

  In the table of FIG. 5, when the ratio of the width of the superimposition region is 20%, the light amount change speed is defined as 16% / frame. As described above, the light amount control information generation unit 191 receives information on the width of the superimposition area 3001 from the CPU 110. The light amount control information generation unit 191 may acquire the light amount change speed corresponding to the information on the width of the superimposition region 3001 received from the CPU 110 based on the table in FIG. The light amount control information generation unit 191 obtains the light amount change speed by calculating the light amount change speed corresponding to the width of the superimposition region 3001 based on a predetermined mathematical formula, instead of the table as shown in FIG. Is also good.

  The relationship between the light amount change speed and the width of the superimposition region in each embodiment is such that the light amount change speed decreases as the width of the superimposition region decreases. That is, as shown in FIG. 5, the light amount changing speed has a characteristic that the light amount changing speed becomes slower as the width of the superimposed region becomes narrower. As a result, even when the luminance difference between the projected image 1001 and the projected image 2001 is large (when the difference is equal to or larger than a predetermined difference), the luminance changes smoothly inside the superimposition region 3001. For this reason, since the superimposition region 3001 plays a role of a buffer, the above-described luminance difference is difficult to be visually recognized by a viewer.

  As the width of the superimposed region 3001 becomes narrower, the luminance change inside the superimposed region 3001 becomes steeper. As the width of the superimposition region 3001 increases, the luminance change inside the superimposition region 3001 becomes smoother. Therefore, the projection device 100 performs control to decrease the light amount changing speed of the light source 160 as the width of the superimposition region 3001 decreases. This makes it difficult for the viewer to visually recognize the difference in luminance.

  As shown in FIG. 4, the CPU 110 of the projection device 100 transmits a feature amount acquisition request to all the projection devices operating in the slave mode via the communication unit 114 functioning as an output unit (S302). As described above, when an image is projected on the screen 300 by the two projectors 100 and 200, the CPU 110 of the projector 100 requests the projector 200 via the communication unit 114 to acquire a feature amount. Is transmitted. The CPU 110 determines whether feature amounts have been received from all the projection devices operating in the slave mode (S303). When determining that the feature amounts have not been received from all the projection devices operating in the slave mode (NO in S303), CPU 110 repeats step S303. When determining that the feature amounts have been received from all the projection devices operating in the slave mode (YES in S303), the CPU 110 acquires the feature amounts calculated by the feature amount calculation unit 190 (S304). The CPU 110 outputs the acquired feature amount to the light amount control information generation unit 191 and also outputs the feature amount of the projection device 200 operating in the slave mode received in S303 to the light amount control information generation unit 191.

  The CPU 110 causes the light amount control information generation unit 191 to generate light amount control information (S305). The light amount control information is information for controlling the light source 160 of the projection device operating in the master mode, and is information for controlling the light source 160 by the projection device operating in the slave mode. Here, the light amount control information is information used when the light source control unit 130 of the projection device 100 and the projection device 200 controls the light source 160. As described above, the light amount control information generating unit 191 calculates the light amount change speed in S301. The light amount control information generation unit 191 generates light amount control information based on the calculated light amount change speed. The CPU 110 outputs the light amount control information generated by the light amount control information generation unit 191 to the light source control unit 130 (S306). The light amount control information is information that causes the light source 160 to perform control to reduce the light amount change speed as the width of the superimposition region 3001 becomes narrower. The light source controller 130 controls the light source 160 based on the light amount control information.

  The CPU 110 sequentially transmits the light amount control information generated by the light amount control information generation unit 191 to all the projection devices operating in the slave mode via the communication unit 114 (S307). When the projection device that operates in the slave mode is only the projection device 200, the CPU 110 of the projection device 100 transmits light amount control information to the projection device 200 via the communication unit 114. After the processing of S307 is completed, the CPU 110 determines whether or not the operation in the master mode ends (S308). If it is determined that the operation in the master mode is to be ended (YES in S308), the process ends. If it is determined that the operation in the master mode is not completed (NO in S308), the flow returns to S302. For example, the CPU 110 may determine that the operation in the master mode does not end while an image is being input to the image input unit 120. The CPU 110 may determine that the operation in the master mode is to be ended when detecting that the operation of the operation unit 113 has been performed to end the operation.

  Next, the flow of processing executed by the CPU 110 of the projection device 200 operating in the slave mode will be described with reference to the flowchart in FIG. CPU 110 of projection device 200 determines whether a request to acquire a feature has been received from projection device 100 operating in the master mode via communication unit 114 (S320). As described above, in S302, the projection device 100 operating in the master mode transmits a feature amount acquisition request. When the CPU 110 of the projection device 200 determines that the acquisition request of the feature amount has been received (YES in S320), the feature amount calculation unit 190 of the projection device 200 calculates the feature amount (S321). The CPU 110 of the projection device 200 transmits the information on the calculated feature amount to the projection device 100 operating in the master mode via the communication unit 114 (S322). When CPU 110 of projection device 200 determines that a request to acquire a feature has not been received (NO in S320), the process of S320 is repeated.

  CPU 110 of projection device 200 determines whether or not light amount control information has been received from projection device 100 operating in the master mode via communication unit 114 (S323). As described above, in S307, the projection device 100 operating in the master mode transmits light amount control information. When CPU 110 of projection device 200 determines that light amount control information has not been received from projection device 100 (NO in S323), the process of S323 is repeated. When determining that light amount control information has been received from projection device 100 (YES in S323), CPU 110 of projection device 200 transmits the light amount control information to projection device 100 operating in the master mode via communication unit 114. (S324). The CPU 110 of the projection device 200 determines whether or not the operation in the slave mode ends (S325). When it is determined that the operation in the slave mode ends (YES in S325), the process ends. If it is determined that the operation in the slave mode does not end (NO in S325), the flow returns to S302. For example, CPU 110 of projection device 200 may determine that the operation in the slave mode does not end while an image is being input. The CPU 110 of the projection device 200 may determine that the operation in the slave mode ends when detecting that the operation of the operation unit 113 has been performed to end the operation.

  Next, a description will be given of a luminance difference caused by a synchronization shift of light source control between the light source 160 of the projection device 100 and the light source 160 of the projection device 200. FIG. 7 is a diagram illustrating a change and a difference in the amount of light output from each projection device when the present embodiment is not applied. As described above, it is assumed that projection device 100 is operating in the master mode and projection device 200 is operating in the slave mode. In the example of FIG. 7, the luminance difference due to the synchronization deviation of the light source control between the projection device 100 and the projection device 200 is large. Since there is a time when the output light amount differs between the projection device 100 and the projection device 200 and the speed of change of the output light amount is fast, the luminance difference between the projected image 1001 and the projected image 2001 on the screen 300 is visually recognized by the viewer. It will be easier. As shown in the example of FIG. 7, in the present embodiment, a difference occurs between the timing at which the output light amount of the projection device 100 changes and the timing at which the output light amount of the projection device 200 changes. Factors causing the shift include a delay in a communication path between the projector 100 and the projector 200, a delay in the hub 500, and a shift in processing start timing based on light amount control information of each projector. In the present embodiment, a description will be given on the assumption that control for correcting a timing difference between the projection device 100 and the projection device 200 is not performed. Therefore, there is no delay in the display of the projected image 1001 and the projected image 2001 due to the above-described shift correction control.

  “V_IN” in FIG. 7 represents a temporal change of an image input to the projection device 100 and the projection device 200. A dark image is input until time t1, and a bright image is input after time t1. It is assumed that among the images projected on the screen 300, an input image corresponding to the projection image 1001 including the superimposition region 3001 (the superimposition region 3001 and an image on one side (for example, the left side)) has been input to the projection device 100. . In addition, among images projected on the screen 300, an input image corresponding to the projection image 2001 including the superimposition region 3001 (the superimposition region 3001 and an image on the other side (for example, the right side)) is input to the projection device 200. And

  Each of the feature calculation units 190 of the projection device 100 and the projection device 200 calculates a feature based on the input image. The projection device 100 acquires the feature amount calculated by the projection device 200. The light amount control information generation unit 191 of the projection device 100 includes a target light amount and a light amount change time based on the feature amount acquired from the projection device 200 and the feature amount calculated by the feature amount calculation unit 190 of the projection device 100. Calculate light intensity control information. In the example of FIG. 7, at time t2, the light amount control information (first light amount control information) calculated by the light amount control information generation unit 191 of the projection device 100 is the target light amount of 100%, and the light amount change time is four frames. Is shown. The light amount control value in FIG. 7 indicates a value for controlling the output light amount of the light source 160 of the projection device 100 and the projection device 200. Until time t1, dark images have been input to the projection devices 100 and 200, so the light amount control value is a low value ("5%" in FIG. 7).

  The light source control unit 130 of the projection device 100 controls the output light amount of the light source 160 based on the first light amount control information from time t2. Therefore, the output light amount from the projection device 100 is controlled to be 100% over a period of four frames from time t2 to t6. FIG. 7 shows an example in which the amount of change in the amount of light per unit time when changing the amount of light is constant. However, if the amount of light can be controlled to the target amount of light for a predetermined change time, an arbitrary light amount change control method is applied. May be. For example, a control method of changing the amount of light stepwise to the target light amount may be applied. Further, the light amount change time may be set to the real time instead of the frame unit, and the light amount of the light source may be controlled with accuracy shorter than the frame unit.

  As described above, since the light amount control information is transmitted from the projection device 100 to the projection device 200 via the communication path, the processing based on the light amount control information of each projection device due to a delay in the communication path, a delay in the hub 500, and the like. The start timing is shifted. Accordingly, the projection device 200 is based on the light amount control information (second light amount control information) from time t3 which is delayed by one frame period from time t2 when the projection device 100 starts the light amount control based on the first light amount control information. The control of the output light quantity is started. As a result, as shown in FIG. 7, a difference occurs between the output light amount of the projection device 100 and the output light amount of the projection device 200 from time t2 to time t7. During the time corresponding to five frames from time t2 to t7, the time during which a large output light amount difference exists between the projection apparatus 100 and the projection apparatus 200 continues. For this reason, the luminance difference between the projected image 1001 and the projected image 2001 on the screen 300 increases, and the luminance difference is easily recognized by the viewer. As a result, the visibility between the projected image 1001 and the projected image 2001 on the screen 300 is reduced.

  FIG. 8 is a diagram for explaining a change and a difference in the amount of light output from each projection device when the present embodiment is applied. As described above, the light amount control information generation unit 191 of the projection device 100 acquires the light amount change speed according to the width of the superimposition region 3001 on which the light reduction processing (blending processing) is performed. The light amount control information generation unit 191 acquires the light amount change speed so as to become slower as the width of the superimposition region 3001 becomes narrower. Then, the light quantity control information generation unit 191 calculates a light quantity change time until the target light quantity of the first light quantity control information is reached, based on the acquired light quantity change speed. In the table of FIG. 5, when the width of the superimposition area 3001 is 20% of the width of the input image, the light amount change speed is 16% / frame. Therefore, in order to increase the current light amount from 5% to the target light amount of 100%, the change time of the light amount control information is 6 frames. The light source control unit 130 of the projection device 100 controls the amount of output light from the light source 160 to be 100% of the target amount of light over a period of six frames from time t2 to t8. In addition, the light source control unit 130 of the projection device 200 controls the amount of light output from the light source 160 to be 100% of the target amount of light over six frames from time t3 to t9.

  As a result, although the period during which the difference in the output light amount occurs when the present embodiment is applied is longer than the period during which the difference in the output light amount occurs when the present embodiment is not applied, the difference in the output light amount is small. Become. The broken line in FIG. 8 shows the output light amount and the difference between the output light amounts when the present embodiment is not applied, and the solid line in FIG. 8 shows the output light amount and the difference between the output light amounts when the present embodiment is applied. As shown by the solid line in FIG. 8, the difference between the output light amounts when the present embodiment is applied is smaller than the difference between the output light amounts indicated by the broken lines when the present embodiment is not applied. Accordingly, the luminance difference between the projected image 1001 and the projected image 2001 on the screen 300 is reduced, so that it is difficult for a viewer to visually recognize the luminance difference. Therefore, it is possible to suppress a decrease in visibility due to the luminance difference.

  In the above-described first embodiment, the light amount change speed is determined such that the light amount change speed decreases as the width of the superimposition region 3001 decreases. However, the light amount change speed depends on whether the width of the superimposition region 3001 is larger than a predetermined value. It is also possible to switch the light amount changing speed. Specifically, when the width of the superimposition region 3001 is larger than the threshold Th1, the light amount change speed is set to V1, and when the width of the superimposition region 3001 is equal to or less than the threshold Th1, the light amount change speed is set to V2 larger than V1. . That is, the light amount changing speeds V1 and V2 are switched according to whether the width of the superimposition region 3001 is larger than the threshold Th1. A plurality of thresholds to be compared with the width of the superimposition region 3001 may exist. As a result, when the width of the superimposed region 3001 is larger than the threshold value, the light amount changing speed is switched so as to be slower than when the width is equal to or smaller than the threshold value.

  As described above, the control mode in which the light amount change speed is determined according to the width of the superimposition region 3001 and the control mode in which the light amount change speed is controlled at a predetermined speed regardless of the width of the superimposition region 3001 are set by the user. May be selectable. The user's selection may be input via the operation unit 113, for example. The predetermined speed may be the fastest speed at which each projection device can control the light amount, or the fastest speed at which each projection device can control the light amount in common. This makes it possible to selectively use a control mode that prioritizes suppression of a luminance difference of a projected image and a control mode that prioritizes improvement of contrast, and a user determines a suitable operation according to characteristics of a projected image. It becomes possible.

<Second embodiment>
The example in which the light amount control information generation unit 191 of the first embodiment acquires the light amount change time based on the light amount change speed and the target light amount of the light amount control information has been described. Obtains the target light amount from the light amount change speed and the light amount change time of the light amount control information. FIG. 9 is a diagram for explaining a change and a difference in the amount of light output from each projection device when the present embodiment is not applied. In the example of FIG. 9, a bright image is input until time t1, and a dark image is input after time t1. In the example of FIG. 9, at time t2, the first light amount control information calculated by the light amount control information generation unit 191 of the projection device 100 indicates that the target light amount is 5% and the light amount change time is 4 frames. Therefore, the output light amount from the light source 160 of the projection device 100 is controlled to be 5% over a time period of 4 frames from time t2 to t6.

  On the other hand, since the light amount control information is transmitted from the projection apparatus 100 to the projection apparatus 200 via the communication path, a delay in the communication path and a delay in the hub 500 occur. Therefore, the projection device 200 starts the light quantity control based on the second light quantity control information from time t3 that is delayed by one frame period from the time t2 when the projection apparatus 100 starts the light quantity control based on the first light quantity control information. I do. The second light amount control information, like the first light amount control information, indicates that the target light amount is 5% and the light amount change time is four frames. As a result, as shown in “difference in output light quantity” in FIG. 9, a difference between the output light quantity from the light source 160 of the projection apparatus 100 and the output light quantity from the light source 160 of the projection apparatus 200 occurs from time t2 to t7. . The time during which a large output light amount difference exists between the projection apparatus 100 and the projection apparatus 200 continues for a time corresponding to five frames from time t2 to t7. Accordingly, the luminance difference between the projected image 1001 and the projected image 2001 on the screen 300 increases, so that the luminance difference can be easily recognized by a viewer. Therefore, visibility due to the luminance difference is reduced.

  FIG. 10 is a diagram for explaining a change and a difference in the amount of light output from each projection device when the present embodiment is applied. As described above, the CPU 110 of the projection device 100 causes the light amount control information generation unit 191 to acquire the light amount change speed according to the width of the superimposition region 3001 where the blend processing unit 144 performs the light reduction process. The light amount control information generation unit 191 acquires a light amount change speed that becomes slower as the width of the superimposition region 3001 becomes narrower. Note that the light amount change speed may be switched based on the above-described threshold value. The same applies to the following third and fourth embodiments. Then, the light amount control information generation unit 191 calculates a target light amount at which the light amount change time of the light amount control information reaches in four frames based on the acquired light amount change speed. Specifically, when the width of the superimposition area 3001 is 20% of the width of the input image, the light amount change speed is 16% / frame, so the light amount change speed reaches 4% from the current light amount of 100%. The target light quantity to be performed is 36%. Therefore, the light source 160 of the projection device 100 controls the output light amount so that the output light amount becomes 36% over a period of four frames from time t2 to time t6. Also, the light source 160 of the projection device 200 controls the output light amount so that the output light amount becomes 36% light amount over the time of four frames from time t3 to t7. As a result, as shown in “difference in output light quantity” in FIG. 10, the maximum light quantity difference during the period in which the output light quantity difference between the projection apparatus 100 and the projection apparatus 200 occurs is smaller than when the target light quantity is 5%. Therefore, the difference in luminance can be reduced. Thereby, a decrease in visibility due to the luminance difference can be suppressed.

<Third embodiment>
A third embodiment will be described. The third embodiment is an embodiment in which the first embodiment or the second embodiment is applied, and furthermore, the light amount change time of one of the projection device 100 and the projection device 200 is shortened. By applying the third embodiment, the difference between the output light amounts of the projection devices can be reduced, and the time during which the difference occurs can be shortened. Hereinafter, as in the first embodiment, a description will be given assuming that the projection apparatus 100 operates in the master mode and the projection apparatus 200 operates in the slave mode. FIG. 11 is a flowchart showing the flow of processing of the projection device 100 operating in the master mode. In the flowchart of FIG. 11, steps S700 to S704 are the same as S300 to S304 of the flowchart of FIG.

  CPU 110 of projection device 100 causes light amount control information generation section 191 to acquire first light amount control information and second light amount control information. At this time, the light amount control information generation unit 191 generates the first light amount control information based on the light amount change speed of the projection device 200 (the projection device operating in the slave mode) received in S703 and the feature amount acquired in S704. And second light amount control information. The first light amount control information is information used when the projection device 100 operating in the master mode controls the light source 160. The second light amount control information is information used when the projection device 200 operating in the slave mode controls the light source 160. Then, the light quantity control information generation unit 191 generates first light quantity control information and second light quantity control information based on the light quantity change speed acquired in S701 (S705). Further, the light quantity control information generation unit 191 of the projection device 100 controls the first light quantity control information so that the light quantity change time of the second light quantity control information is relatively shorter than the light quantity change time of the first light quantity control information. And second light amount control information.

  The CPU 110 of the projection device 100 outputs the first light amount control information generated in S705 to the light source control unit 130, and controls the light source 160 based on the first light amount control information (S706). The CPU 110 sequentially transmits the second light amount control information calculated in S705 to all the projection devices operating in the slave mode via the communication unit 114 (S707). In the present embodiment, since the only projection device that operates in the slave mode is the projection device 200, the CPU 110 of the projection device 100 transmits the second light amount control information to the projection device 200 via the communication unit 114. After the processing of S707 is completed, the CPU 110 determines whether or not the operation in the master mode ends (S708). If it is determined that the operation in the master mode is to be ended (YES in S708), the process ends. If it is determined that the operation in the master mode is not completed (NO in S708), the flow returns to S702. For example, the CPU 110 may determine that the operation in the master mode does not end while an image is being input to the image input unit 120. The CPU 110 may determine that the operation in the master mode is to be ended when detecting that the operation of the operation unit 113 has been performed to end the operation.

  On the other hand, the processing executed by the CPU 110 of the projection device 200 operating in the slave mode according to the present embodiment is the same as S320 to S325 in FIG.

  FIG. 12 is a diagram for explaining a change and a difference in the amount of light output from each projection device when the present embodiment is applied. The broken line in FIG. 12 indicates the output light amount and the difference between the output light amounts when the first embodiment is applied, and the solid line indicates the output light amount and the difference between the output light amounts when the present embodiment is applied. The light amount control information generation unit 191 of the projection device 100 according to the present embodiment further includes a time period in which the light amount change time of the second light amount control information is relatively shorter than the light amount change time of the first light amount control information in addition to the first embodiment. The first light amount control information and the second light amount control information are generated so that When the first to third embodiments are not applied, as shown in the example of FIG. 7, the change time of the first light amount control information and the second light amount control information is four frames.

  The light quantity control information generation unit 191 of the present embodiment (third embodiment) sets the change time of the first light quantity control information from 4 frames to 6 frames and the change time of the second light quantity control information from 4 frames to 5 frames. First light amount control information and second light amount control information are generated. Therefore, the output light quantity from the projection apparatus 100 takes 100% over 5 frames from time t3 to t8, while the output light quantity from the projection apparatus 200 takes 6 frames from time t2 to t8. Is controlled so that the light amount becomes. As a result, as shown in “difference in output light quantity” in FIG. 12, the period in which the difference in output light quantity between the projection device 100 and the projection device 200 occurs is reduced to a time corresponding to six frames from time t2 to t8. You. Then, as compared with the first embodiment (broken line in FIG. 12), the difference between the output light amounts of the projection device 100 and the projection device 200 is further reduced. Therefore, a difference in luminance between the projected image 1001 and the projected image 2001 on the screen 300 is less likely to be visually recognized by a viewer, and thus a decrease in visibility due to the luminance difference can be suppressed.

  In the example of FIG. 12, a one-frame period shift occurs between the drive timing of the light source 160 of the projection apparatus 100 based on the first light quantity control information and the drive timing of the light source 160 of the projection apparatus 200 based on the second light quantity control information. There is. It is assumed that the shift in the period of one frame is a delay time due to communication between the projection device 100 and the projection device 200. Since the light amount change time of the second light amount control information is shorter than the change time of the first light amount control information by an amount corresponding to the delay time, the target of the output light amount of the projection device 100 and the output light amount of the projection device 200 is reduced. The timing of reaching the light amount becomes the same.

  The light amount control information generation unit 191 may set the time during which the light amount change time of the second light amount control information is shorter than the light amount change time of the first light amount control information to an arbitrary time other than the communication delay time. By making the light amount change time of the second light amount control information shorter by an arbitrary amount of time than the light amount change time of the first light amount control information, it is possible to reduce the difference between the output light amounts. Further, in the present embodiment, an example has been described in which the light quantity control information generation unit 191 sets the light quantity change time of the second light quantity control information shorter than the light quantity change time of the first light quantity control information. May be longer than the light amount change time of the second light amount control information. Since the light amount change time of the first light amount control information is longer than the light amount change time of the second light amount control information, the difference (absolute value) between the output light amounts of the projection device 100 and the projection device 200 can be reduced. , A decrease in visibility due to the difference can be suppressed. As described above, by making the light amount change time of the second light amount control information different from the light amount change time of the first light amount control information, a decrease in visibility due to a difference in output light amount is suppressed.

  Accordingly, since the light amount change time of the second light amount control information is relatively shorter than the light amount change time of the first light amount control information, the period during which the difference between the output light amounts of the projection device 100 and the projection device 200 occurs is shortened. And the difference in output light quantity can be reduced. This makes it difficult for a viewer to visually recognize a difference in luminance according to the difference between the output light amounts of the projection device 100 and the projection device 200 on the screen 300, and can suppress a decrease in visibility. As described above, the respective units of the projection device 100 and the projection device 200 operate, so that even when an image is displayed using a plurality of projection devices, the synchronization of the light source control among the plurality of projection devices may be lost. The resulting luminance difference can be made less visible. Therefore, a decrease in visibility can be suppressed.

<Fourth embodiment>
In the first to third embodiments described above, the example in which the projection device 100 operates in the master mode has been described. However, all the projection devices may operate in the slave mode. In the fourth embodiment, all the projection devices (projection devices 100 and 200) operate in the slave mode, and the control device 600 connected to the hub 500 performs processing of the master mode projection device. Accordingly, the control device 600 has the functions of the CPU 110, the communication unit 114, the image processing unit 140, the feature amount calculation unit 190, and the light amount control information generation unit 191 in FIG.

  As described above, for example, a personal computer or the like is applied to the control device 600. The control device 600 slows down the light amount changing speed for two adjacent projection devices (projection devices that generate the superimposition region 3001 in the image projected on the screen 300) as the width of the superimposition region 3001 decreases. Transmit light amount control information. Accordingly, the luminance difference between the projected image 1001 and the projected image 2001 on the screen 300 is reduced, so that it is difficult for a viewer to visually recognize the luminance difference. Therefore, it is possible to suppress a decrease in visibility due to the luminance difference.

  In the first to fourth embodiments, the light amount control information generation unit 191 slows down the light amount change speed as the width of the superimposition region 3001 decreases. In the above-described example, as a method of slowing down the light amount change speed as the width of the superimposition region 3001 becomes narrower, a method of increasing the light amount change time or making the amount of light amount change smaller than the target light amount is applied. However, it is not limited to these methods. As described above, by operating each unit of the projection device 100 and the projection device 200 according to the first to fourth embodiments, the luminance difference caused by the synchronization deviation of the light source control among the plurality of projection devices can be visually recognized. It can be difficult. Thereby, a decrease in visibility can be suppressed.

  Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made within the scope of the gist. The present invention can also be realized by executing a program that realizes one or more functions of the above-described embodiments by an ASIC (Application Specific Integrated Circuit) or the like.

100, 200 Projection device 110 CPU
114 Communication unit 120 Image input unit 130 Light source control unit 140 Image processing unit 144 Blend processing unit 160 Light source 191 Light amount control information generation unit 3001 Overlap area

Claims (18)

A projection device,
Dimming means for performing a process of dimming an area where a first image projected by the projection device onto a projection surface and a second image projected by the other projection device onto the projection surface,
A generation unit configured to generate light amount control information that reduces a light amount change speed that changes a light amount of the first image and the second image as the width of the region decreases;
Light source control means for controlling a light source according to light amount control information of the first image;
Output means for outputting light amount control information of the second image to the other projection device;
A projection device comprising: A feature value calculating unit that calculates a feature value of the first image;
Acquiring means for acquiring a feature amount of the second image from the other projection device;
With
The generation unit generates the light amount control information based on the calculated feature amount of the first image and the acquired feature amount of the second image.
The projection device according to claim 1, wherein: The light amount control information includes a light amount set value and light amount change time information for each of the first image and the second image.
The projection device according to claim 1, wherein: The generation unit increases the light amount change time as the width of the region decreases,
The projection device according to claim 3, wherein: The generation unit changes a set value of the light amount according to a width of the region,
The projection device according to claim 3, wherein: A first light amount change time included in the light amount control information of the first image output to the light source of the projection device, and a second light amount change included in the light amount control information of the second image output to the other projection device Different from time,
The projection device according to claim 3, wherein: The second light amount change time is shorter than the first light amount change time;
The projection device according to claim 6, wherein: The time of the difference between the first light amount change time and the second light amount change time is a delay time of communication between the projector and the other projector.
The projection device according to claim 6, wherein: Dimming means for performing a process of dimming an area where a first image projected by a projection device onto a projection surface and a second image projected by the other projection device onto the projection surface are dimmed;
A generation unit configured to generate light amount control information that reduces a light amount change speed that changes a light amount of the first image and the second image as the width of the region decreases;
Output means for outputting light amount control information of the first image to the projection device, and outputting light amount control information of the second image to the other projection device;
A control device comprising: A method for controlling a projection device, comprising:
Performing a process of dimming an area where a first image projected by the projection device onto a projection surface and a second image projected by the other projection device onto the projection surface are overlapped;
A step of generating light quantity control information for decreasing a light quantity change speed for changing the light quantity of the first image and the second image as the width of the region becomes narrower;
Controlling a light source according to light amount control information of the first image;
Outputting the light amount control information of the second image to the other projection device;
A method for controlling a projection device, comprising: Calculating a feature value of the first image;
Acquiring a feature amount of the second image from the other projection device;
Has,
Generating the light amount control information based on the calculated feature amount of the first image and the acquired feature amount of the second image;
The method of controlling a projection device according to claim 10, wherein: The light amount control information includes a light amount set value and light amount change time information for each of the first image and the second image.
The method of controlling a projection device according to claim 10, wherein: As the width of the region becomes narrower, the light amount change time is increased,
The control method of a projection device according to claim 12, wherein: Changing a set value of the light amount according to a width of the region,
The control method of a projection device according to claim 12, wherein: A first light amount change time included in the light amount control information of the first image output to the light source of the projection device, and a second light amount change included in the light amount control information of the second image output to the other projection device Different from time,
The method of controlling a projection device according to claim 12, wherein: The second light amount change time is shorter than the first light amount change time;
The method for controlling a projection device according to claim 15, wherein: The time of the difference between the first light amount change time and the second light amount change time is a delay time of communication between the projector and the other projector.
The method for controlling a projection device according to claim 15, wherein:   A program for causing a computer to execute the method for controlling a projection device according to claim 10.

Images