Method for correcting multiple projectors, and information processing device

Abstract

To correct hue of a second projection image according to hue of a first projection image.SOLUTION: A method for correcting a plurality of projectors 100 including a first projector 100A and a second projector 100B, wherein a first area AR1 being a projection area of the first projector 100A is at least partially overlapped on a second area AR2 being a projection area of the second projector 100B includes that an image correction device 200 determines whether to correct hue of a first projection image PM1 projected by the first projector 100A, that the image correction device 200 acquires a picked-up image PD obtained by imaging the first projection image PM1 after the image correction device 200 corrects the hue of the first projection image PM1, and the image correction device 200 corrects hue of a second projection image PM2 projected by the second projector 100B on the basis of the picked-up image PD.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a correction method for multiple projectors and an information processing device. [Background technology]

[0002] BACKGROUND ART Conventionally, technology relating to projectors is known (see, for example, Patent Document 1). Patent Document 1 discloses the following technology: By evaluating a deterioration information display unit provided in a liquid crystal device, the deterioration state of the liquid crystal panel can be ascertained and it can be determined whether the liquid crystal device can be reused. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-258405 Summary of the Invention [Problem to be solved by the invention]

[0004] However, Patent Document 1 does not describe stacking projection or tiling projection using a plurality of projectors. For example, consider a projection system that uses a first projector and a second projector for stacking or tiling projection. If the first projector used in this projection system breaks down and a new third projector is purchased to replace the first projector, there will be a difference in the deterioration state of the liquid crystal panel of the second projector and the third projector. Therefore, when stacking projection or tiling projection is performed using a plurality of projectors, there is a possibility that users may become more aware of changes in color tone that occur due to deterioration of the liquid crystal panel, etc. [Means for solving the problem]

[0005] One aspect of the present disclosure is a method for correcting multiple projectors including a first projector and a second projector, wherein a first projection area that is the projection area of ​​the first projector at least partially overlaps with a second projection area that is the projection area of ​​the second projector, the method including: an information processing device configured to be able to communicate with the multiple projectors determining whether to correct a color tone of a first projection image projected by the first projector; after the information processing device corrects the color tone of the first projection image, the information processing device acquiring a captured image that captures the first projection image; and the information processing device correcting the color tone of a second projection image projected by the second projector based on the captured image.

[0006] Another aspect of the present disclosure is an information processing device configured to be able to communicate with multiple projectors including a first projector and a second projector, wherein a first projection area that is the projection area of ​​the first projector at least partially overlaps with a second projection area that is the projection area of ​​the second projector, and the information processing device performs the following operations: determining whether to correct a color tone of a first projection image projected by the first projector; acquiring a captured image by capturing the first projection image after correcting the color tone of the first projection image; and correcting the color tone of a second projection image projected by the second projector based on the captured image. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of an image projection system according to a first embodiment. [Figure 2] FIG. 1 is a diagram showing an example of the configuration of a projector according to a first embodiment. [Figure 3] FIG. 1 is a diagram showing an example of the configuration of an image correction device according to a first embodiment. [Figure 4] 3A to 3C are views showing examples of a first pattern image and a second pattern image according to the first embodiment. [Figure 5]6 is a flowchart showing an example of a correction necessity determination process of the image correction device according to the first embodiment. [Figure 6] 5 is a flowchart showing an example of a first correction process of the image correction device according to the first embodiment. [Figure 7] 6 is a flowchart showing an example of a second correction process of the image correction device according to the first embodiment. [Figure 8] 6 is a flowchart showing an example of a second correction process of the image correction device according to the first embodiment. [Figure 9] FIG. 10 is a diagram showing an example of the configuration of an image projection system according to a second embodiment. [Figure 10] 10 is a flowchart showing an example of correction processing of an image correction device according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] The present embodiment will be described below with reference to the drawings, including a first embodiment described with reference to Figures 1 to 8 and a second embodiment described with reference to Figures 9 and 10.

[0009] First Embodiment First, an image projection system 1 according to the first embodiment will be mainly described with reference to Figures 1 to 8. Figure 1 is a diagram showing an example of the configuration of the image projection system 1 according to the first embodiment. The image projection system 1 includes a projector 100 and an image correction device 200. The projector 100 includes a first projector 100A and a second projector 100B. FIG. 1 illustrates three mutually orthogonal axes: the X-axis, the Y-axis, and the Z-axis. The direction along the X-axis is referred to as the "X-direction," the direction along the Y-axis as the "Y-direction," and the direction along the Z-axis as the "Z-direction." In this embodiment, the vertical direction is referred to as the Z-direction, the horizontal direction of the screen SC in FIG. 1 as the X-direction, and the normal direction of the screen SC as the Y-direction. The tip of the arrow in each axial direction is also referred to as the "plus side," and the base of the arrow as the "minus side." In the following drawings, dimensions and scales may be different from those in FIG. 1 for ease of understanding. FIG. 9 also illustrates the same X-axis, Y-axis, and Z-axis as FIG. 1.

[0010] Furthermore, the first projector 100A and the second projector 100B are communicably connected to the image correction device 200. The first projector 100A and the second projector 100B are communicably connected to the image correction device 200 via, for example, an Ethernet (registered trademark) cable.

[0011] In the first embodiment, the first projector 100A and the second projector 100B are connected to the image correction device 200 so as to be able to communicate via a wired connection using an Ethernet (registered trademark) cable or the like, but may also be connected so as to be able to communicate wirelessly using Wi-Fi (registered trademark) or the like.

[0012] Image correction device 200 is configured by, for example, a personal computer or the like, and controls each of first projector 100A and second projector 100B. Image correction device 200 corrects the color of the projection images projected by each of first projector 100A and second projector 100B. The image correction device 200 corresponds to an example of an "information processing device."

[0013] The first projector 100A and the second projector 100B are arranged, for example, in the X-axis direction in Fig. 1. Specifically, the first projector 100A and the second projector 100B are arranged along a direction parallel to the screen SC, but the arrangement of the first projector 100A and the second projector 100B is not limited to this.

[0014] In the first embodiment, the first projector 100A projects the first image light PL1 onto a first area AR1 of the screen SC to display a first projection image PM1 on the screen SC. The second projector 100B projects the second image light PL2 onto a second area AR2 of the screen SC to display a second projection image PM2 on the screen SC. 1, the first projected image PM1 and the second projected image PM2 are arranged in the left-right direction, and the first projected image PM1 and the second projected image PM2 form one projected image PM. The first area AR1 corresponds to an example of a "first projection area." The second area AR2 corresponds to an example of a "second projection area."

[0015] The third area AR3 is an area where the first area AR1 and the second area AR2 overlap, and an area where the first projected image PM1 and the second projected image PM2 overlap. The first image light PL1 and the second image light PL2 projected onto the third area AR3 are subjected to a so-called edge blending process, so that the first projected image PM1 and the second projected image PM2 are smoothly connected. In the following description, when there is no need to distinguish between the first image light PL1 and the second image light PL2, they may be referred to as image light PL.

[0016] In the first embodiment, the first projector 100A and the second projector 100B perform so-called tiling projection of the first projected image PM1 and the second projected image PM2. Tiling projection is, for example, displaying a larger image than can be displayed by a single projector by using multiple projectors to project images side by side.

[0017] In the first embodiment, a case will be described in which the first projector 100A and the second projector 100B perform tiling projection, but the first projector 100A and the second projector 100B may perform stacking projection. Stacking projection refers to, for example, projecting the same image in a superimposed manner using multiple projectors, thereby displaying a single image brighter than if it were displayed using a single projector. Stacking projections are further described with reference to FIG.

[0018] FIG. 2 is a diagram showing an example of the configuration of the projector 100 according to the first embodiment. Since the first projector 100A and the second projector 100B have substantially the same configuration, the configuration of the first projector 100A will be described with reference to Fig. 2, and a description of the configuration of the second projector 100B will be omitted. In the following description, when there is no need to distinguish between the first projector 100A and the second projector 100B, they may be referred to as projectors 100.

[0019] 2, the projector 100 includes a projection unit 110 and a drive unit 120 that drives the projection unit 110. The projection unit 110 forms an optical image and projects first image light PL1 onto the screen SC. In the first embodiment, the projection unit 110 projects the first image light PL1 corresponding to image data from the image correction device 200 onto the screen SC. The projection unit 110 includes a light source unit 111, a light modulation device 112, and a projection optical system 113. The drive unit 120 includes a light source drive unit 121 and a light modulation device drive unit 122.

[0020] The light source unit 111 includes a solid-state light source such as an LED (Light Emitting Diode) or a laser light source. In the first embodiment, the light source unit 111 is described as including a solid-state light source, but is not limited to this. Instead of the solid-state light source, the light source unit 111 may include a lamp light source such as a halogen lamp, a xenon lamp, or an ultra-high pressure mercury lamp. The solid-state light source may be referred to as a light source in the following description.

[0021] The light sources include, for example, a red light source 111R, a green light source 111G, and a blue light source 111B. The red light source 111R emits red light. The green light source 111G emits green light. The blue light source 111B emits blue light.

[0022] The light source unit 111 may also include a reflector and an auxiliary reflector that guide the light emitted by the light source to the light modulation device 112. Furthermore, the light source unit 111 may also include a group of lenses for improving the optical characteristics of the projected light, a polarizing plate, or a dimming element that reduces the amount of light emitted by the light source on the path leading to the light modulation device 112. The light source driving unit 121 is connected to the internal bus 107, and controls the output of the light source by turning on and off the light source of the light source unit 111 in accordance with instructions from a first control unit 150 also connected to the internal bus 107. In the first embodiment, the light source driving unit 121 controls the output of the light source in accordance with instructions from an image correction device 200, which will be described with reference to FIG.

[0023] The light modulation device 112 includes, for example, three liquid crystal panels 115 corresponding to the three primary colors of R, G, and B. R indicates red, G indicates green, and B indicates blue. That is, the light modulation device 112 includes a red liquid crystal panel 115R corresponding to R light, a green liquid crystal panel 115G corresponding to G light, and a blue liquid crystal panel 115B corresponding to B light. Each of the red light, green light, and blue light emitted by light source unit 111 is incident on a corresponding liquid crystal panel 115. That is, the red light emitted by red light source 111R is incident on red liquid crystal panel 115R. The green light emitted by green light source 111G is incident on green liquid crystal panel 115G. The blue light emitted by blue light source 111B is incident on blue liquid crystal panel 115B.

[0024] Each of the three liquid crystal panels 115 is a transmissive liquid crystal panel that modulates light passing through it to generate a first image light PL1. The first image light PL1 includes a first red image light PLR, a first green image light PLG, and a first blue image light PLB. The first red image light PLR is red image light modulated after passing through the red liquid crystal panel 115R. The first green image light PLG is green image light modulated after passing through the green liquid crystal panel 115G. The first blue image light PLB is blue image light modulated after passing through the blue liquid crystal panel 115B. The first red image light PLR, the first green image light PLG, and the first blue image light PLB are combined by a combining optical system such as a cross dichroic prism to generate the first image light PL1, and the first image light PL1 is emitted to the projection optical system 113. In the first embodiment, the light modulation device 112 is described as having a transmissive liquid crystal panel 115 as a light modulation element, but is not limited to this. The light modulation element may be a reflective liquid crystal panel or a digital micromirror device.

[0025] The light modulation device 112 is driven by a light modulation device driving unit 122. The light modulation device driving unit 122 is connected to the image processing unit 145. Image data corresponding to each of the primary colors R, G, and B is input to the light modulation device driving unit 122 from the image processing unit 145. The light modulation device driving unit 122 converts the input image data into a data signal suitable for the operation of the liquid crystal panel 115. Based on the converted data signal, the light modulation device driving unit 122 applies a voltage to each pixel of each liquid crystal panel 115, and draws an image on each liquid crystal panel 115.

[0026] The projection optical system 113 includes a projection lens, a mirror, etc. that form an image of the incident first image light PL1 on the screen SC. The projection optical system 113 also includes a zoom mechanism that enlarges or reduces the image projected onto the screen SC, a focus adjustment mechanism that adjusts the focus, and a lens shift mechanism that adjusts the projection direction of the first image light PL1.

[0027] The projector 100 also includes a camera 160 . The camera 160 includes an imaging element such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS). The camera 160 captures an image of the screen SC and generates a captured image PD in accordance with instructions from the first control unit 150. The first control unit 150 causes the camera 160 to generate the captured image PD. The camera 160 also transmits the generated captured image PD to the first control unit 150. The first control unit 150 transmits the captured image PD to the image correction device 200. The captured image PD includes a projected image PM. The camera 160 is disposed, for example, near the projection lens of the projector 100.

[0028] The projector 100 further includes an operation unit 131, a remote control receiver 133, an input interface 135, a storage unit 137, a first communication interface 141, a frame memory 143, an image processing unit 145, and a first control unit 150. The input interface 135, the storage unit 137, the first communication interface 141, the image processing unit 145, the first control unit 150, and the camera 160 are connected to each other via an internal bus 107 so as to be able to communicate data with each other.

[0029] The operation unit 131 includes various buttons and switches provided on the surface of the housing of the projector 100, generates operation signals corresponding to the operation of these buttons and switches, and outputs the operation signals to the input interface 135. The input interface 135 includes a circuit that outputs the operation signals input from the operation unit 131 to the first control unit 150.

[0030] The remote control light receiving unit 133 receives an infrared signal transmitted from the remote control 5, decodes the received infrared signal, and generates an operation signal. The remote control light receiving unit 133 outputs the generated operation signal to the input interface 135. The input interface 135 includes a circuit that outputs the operation signal input from the remote control light receiving unit 133 to the first control unit 150.

[0031] The storage unit 137 is, for example, a magnetic recording device such as an HDD (Hard Disk Drive), or a storage device using a semiconductor storage element such as a flash memory or an SSD (Solid State Drive). The storage unit 137 stores programs executed by the first control unit 150, data processed by the first control unit 150, image data, etc.

[0032] The first communication interface 141 is a communication interface that communicates with the image correction device 200 in accordance with the Ethernet (registered trademark) standard. The first communication interface 141 includes a connector for connecting an Ethernet (registered trademark) cable and an interface circuit for processing signals transmitted through the connector. The first communication interface 141 is an interface board having a connector and an interface circuit, and is connected to a main board on which the first processor 150A and the like of the first control unit 150 are mounted. Alternatively, the connector and interface circuit that constitute the first communication interface 141 are mounted on the main board of the first control unit 150. The first communication interface 141 receives various instruction information from the image correction device 200. The first communication interface 141 also transmits the captured image PD and the like to the image correction device 200.

[0033] The first control unit 150 includes a first memory 150B and a first processor 150A. The first memory 150B is a storage device that nonvolatilely stores programs and data executed by the first processor 150A. The first memory 150B is configured by a semiconductor storage element such as a magnetic storage device or a flash ROM (Read Only Memory), or other types of nonvolatile storage device. The first memory 150B may also include a RAM (Random Access Memory) that configures the work area of ​​the first processor 150A. The first memory 150B stores data processed by the first control unit 150, the first control program PG1 executed by the first processor 150A, and the like.

[0034] The first processor 150A may be configured as a single processor, or multiple processors may function as the first processor 150A. The first processor 150A executes a first control program PG1 to control each unit of the projector 100. For example, the first processor 150A outputs to the image processing unit 145 an instruction to execute image processing corresponding to operations received via the operation unit 131 and the remote control 5, and parameters used for this image processing. The parameters include, for example, geometric correction parameters for correcting geometric distortion of the image projected onto the screen SC. In addition, the first processor 150A controls the light source driving unit 121 to turn on and off the light source unit 111 in accordance with instructions from the image correction device 200, and also adjusts the output of the light source unit 111, i.e., the light intensity.

[0035] The first processor 150A may be configured as a system on chip (SoC) integrated with part or all of the first memory 150B and other circuits. The first processor 150A may also be configured as a combination of a central processing unit (CPU) that executes programs and a digital signal processor (DSP) that executes predetermined arithmetic processing. All of the functions of the first processor 150A may be implemented in hardware, or may be configured using a programmable device.

[0036] The image processing unit 145 and the frame memory 143 can be configured, for example, by an integrated circuit. Integrated circuits include large-scale integration (LSI), application-specific integrated circuits (ASIC), and programmable logic devices (PLD). PLDs include, for example, field-programmable gate arrays (FPGA). An integrated circuit may also include an analog circuit as part of its configuration, or may be a combination of a processor and an integrated circuit. The combination of a processor and an integrated circuit is called a microcontroller (MCU), a system-on-a-chip (SoC), a system LSI, a chipset, or the like.

[0037] The image processing unit 145 expands the image data input from the first communication interface 141 into the frame memory 143. The frame memory 143 includes a plurality of banks. Each bank has a storage capacity capable of writing image data for one frame. The frame memory 143 is configured, for example, by an SDRAM (Synchronous Dynamic Random Access Memory).

[0038] The image processing unit 145 performs image processing such as resolution conversion, resizing, distortion correction, shape correction, and digital zooming on the image data stored in the frame memory 143 . The image processing unit 145 also generates a vertical synchronization signal by converting the input frame frequency of the vertical synchronization signal into a drawing frequency. The generated vertical synchronization signal is called an output synchronization signal. The image processing unit 145 outputs the generated output synchronization signal to the light modulation device driving unit 122.

[0039] Next, the configuration of image correction device 200 according to the first embodiment will be described with reference to Fig. 3. Fig. 3 is a diagram showing an example of the configuration of image correction device 200. Image correction device 200 corrects the color tone and brightness of the projection images projected by each of first projector 100A and second projector 100B.

[0040] 3, the image correction device 200 includes a second control unit 20. The second control unit 20 controls the operation of each unit of the image correction device 200. The second control unit 20 includes a second memory 22 and a second processor 21. The second memory 22 is a storage device that non-volatilely stores programs and data executed by the second processor 21. The second memory 22 is configured by a magnetic storage device, a semiconductor storage element such as a flash ROM, or other types of non-volatile storage device. The second memory 22 may also include RAM that configures the work area of ​​the second processor 21. The second memory 22 stores data processed by the second control unit 20, the second control program PG2 executed by the second processor 21, and the like.

[0041] The second processor 21 may be configured as a single processor, or may be configured such that multiple processors function as the second processor 21. The second processor 21 executes the second control program PG2 to control each unit of the image correction device 200. The second processor 21 also executes the second control program PG2 to correct the color and brightness of the projection images projected by each of the first projector 100A and the second projector 100B.

[0042] The second processor 21 may be configured as an SoC integrated with part or all of the second memory 22 and other circuits. The second processor 21 may also be configured as a combination of a CPU that executes programs and a DSP that executes predetermined arithmetic processing. All of the functions of the second processor 21 may be implemented in hardware, or may be configured using a programmable device.

[0043] In the following description, a case will be described in which the second processor 21 executes the second control program PG2 to correct the color tone of the projection images projected by each of the first projector 100A and the second projector 100B. In the following description, the "brightness" of a projected image will be described as constituting part of the "color tone of a projected image."

[0044] The second control unit 20 includes a correction necessity determining unit 211, a first corrector 212, a second corrector 213, a projection control unit 214, an image storage unit 221, a correction value storage unit 222, and a setting value storage unit 223. Specifically, the second processor 21 of the second control unit 20 executes the second control program PG2 stored in the second memory 22, thereby functioning as a correction necessity determination unit 211, a first correction unit 212, a second correction unit 213, and a projection control unit 214. Furthermore, the second processor 21 of the second control unit 20 executes the second control program PG2 stored in the second memory 22, thereby causing the second memory 22 to function as an image storage unit 221, a correction value storage unit 222, and a setting value storage unit 223.

[0045] The image storage unit 221 stores a first pattern image P1 and a second pattern image P2 in advance. The image storage unit 221 also stores a first white image PW1 and a second white image PW2 in advance. The first pattern image P1 is projected from the first projector 100A in accordance with an instruction from the first correction unit 212. The second pattern image P2 is projected from the second projector 100B in accordance with an instruction from the first correction unit 212. The first white image PW1 is projected from the first projector 100A in accordance with an instruction from the second correction unit 213. The second white image PW2 is projected from the second projector 100B in accordance with an instruction from the second correction unit 213. Each of the first white image PW1 and the second white image PW2 is an image made up of only white color. The first pattern image P1 and the first white image PW1 each correspond to an example of the first projection image PM1. The second pattern image P2 and the second white image PW2 each correspond to an example of the second projection image PM2.

[0046] The first pattern image P1 includes a first red pattern image P1R, a first green pattern image P1G, and a first blue pattern image P1B. The first pattern image P1 is projected by the first projector 100A. The first red pattern image P1R includes a red image region with multiple gradations. The first green pattern image P1G includes a green image region with multiple gradations. The first blue pattern image P1B includes a blue image region with multiple gradations. In the first embodiment, the multiple gradations are, for example, six gradations. The first pattern image P1 will be further described with reference to FIG.

[0047] The second pattern image P2 includes a second red pattern image P2R, a second green pattern image P2G, and a second blue pattern image P2B. The second pattern image P2 is projected by the second projector 100B. The second red pattern image P2R includes a red image region with multiple gradations. The second green pattern image P2G includes a green image region with multiple gradations. The second blue pattern image P2B includes a blue image region with multiple gradations. In the first embodiment, the multiple gradations are, for example, six gradations. The second pattern image P2 will be further described with reference to FIG.

[0048] The correction value storage unit 222 stores a first correction value C1 and a second correction value C2. The first correction value C1 includes a first red correction value CR1, a first green correction value CG1, and a first blue correction value CB1. The second correction value C2 includes a second red correction value CR2, a second green correction value CG2, and a second blue correction value CB2. The first correction value C1 is a correction value for the first projector 100A. The second correction value C2 is a correction value for the second projector 100B. The first correction value C1 and the second correction value C2 are calculated by the first correction unit 212. Furthermore, the first correction value C1 and the second correction value C2 are stored in the correction value storage unit 222 by the first correction unit 212.

[0049] The set value storage unit 223 stores a first luminance setting value B1 and a second luminance setting value B2. The first luminance setting value B1 is the luminance setting value of the first projector 100A. The second luminance setting value B2 is the luminance setting value of the second projector 100B. The first luminance setting value B1 and the second luminance setting value B2 are calculated by the second correction unit 213 and stored in the set value storage unit 223 by the second correction unit 213.

[0050] The correction necessity determination unit 211 acquires a first accumulated irradiation time SL1 from the first projector 100A. The first accumulated irradiation time SL1 is an accumulated value of the time during which the light source of the first projector 100A is in an irradiating state. The correction necessity determination unit 211 determines whether to correct the color tone of the first projector 100A based on the first accumulated irradiation time SL1.

[0051] Furthermore, the correction necessity determination unit 211 acquires a second accumulated irradiation time SL2 from the second projector 100B. The second accumulated irradiation time SL2 is the accumulated value of the time during which the light source of the second projector 100B is in an irradiating state. The correction necessity determination unit 211 determines whether or not to correct the color tone of the second projector 100B based on the second accumulated irradiation time SL2. The processing of the correction necessity determination unit 211 will be further described with reference to FIG.

[0052] The first correction unit 212 causes the first projector 100A to project the first pattern image P1 onto the screen SC. Furthermore, the first correction unit 212 causes the camera 160 of the first projector 100A to capture the first pattern image P1 projected onto the screen SC and generate a first captured image PD1. Then, the first correction unit 212 estimates the maximum luminance value ML of each of the R, G, and B colors of the first projector 100A based on the first captured image PD1. Then, the first correction unit 212 calculates the first correction value C1 based on the maximum luminance value ML of each of the R, G, and B colors of the first projector 100A, and corrects the color tone of the first projector 100A.

[0053] The first correction unit 212 also causes the second projector 100B to project the second pattern image P2 onto the screen SC. The first correction unit 212 also causes the camera 160 of the second projector 100B to capture the second pattern image P2 projected onto the screen SC and generate a second captured image PD2. Then, the first correction unit 212 determines whether or not to correct the color tone of the second projector 100B based on the second captured image PD2. When the first correction unit 212 determines that the color tone of the second projector 100B should be corrected, the first correction unit 212 estimates the maximum saturation value MS of each of the R, G, and B colors of the second projector 100B. Then, the first correction unit 212 calculates a second correction value C2 based on the maximum saturation value MS of each of the R, G, and B colors of the second projector 100B, and corrects the color tone of the second projector 100B.

[0054] The second correction unit 213 corrects the first white image PW1 using the first correction value C1 and causes the first projector 100A to project the corrected first white image PW1. The second correction unit 213 also causes the camera 160 of the first projector 100A to capture the first white image PW1 projected on the screen SC and generate a third captured image PD3. The second correction unit 213 acquires the third captured image PD3. The first correction unit 212 calculates a first average luminance value AV1 based on the third captured image PD3.

[0055] The second correction unit 213 also corrects the second white image PW2 using the second correction value C2 and causes the second projector 100B to project the corrected second white image PW2. The second correction unit 213 also causes the camera 160 of the second projector 100B to capture the second white image PW2 projected on the screen SC and generate a fourth captured image PD4. The second correction unit 213 acquires the fourth captured image PD4. The second correction unit 213 calculates a second average luminance value AV2 based on the fourth captured image PD4.

[0056] The second corrector 213 determines whether the first average brightness value AV1 is equal to or less than the second average brightness value AV2. The case where the first average brightness value AV1 is equal to or less than the second average brightness value AV2 will be described below. If the first luminance setting value B1 is equal to or less than the first maximum luminance setting value BM1, the second correction unit 213 changes the first luminance setting value B1 to the first maximum luminance setting value BM1 and generates a first white image PW1 corresponding to the changed first luminance setting value B1. The second correction unit 213 causes the first projector 100A to project the first white image PW1. The second correction unit 213 also causes the camera 160 of the first projector 100A to capture the first white image PW1 projected on the screen SC and generate a fifth captured image PD5. The second correction unit 213 calculates a first average luminance value AV1 based on the fifth captured image PD5. The second correction unit 213 then calculates a first luminance setting value B1 based on the first average luminance value AV1. The second correction unit 213 also calculates a second luminance setting value B2 based on the first luminance setting value B1. In this way, the second corrector 213 corrects the color tone of the second projector 100B by calculating the second luminance setting value B2 based on, for example, the fifth captured image PD5. The fifth captured image PD5 corresponds to an example of a "captured image."

[0057] Next, a case where the first average brightness value AV1 is not equal to or less than the second average brightness value AV2 will be described below. If the second luminance setting value B2 is equal to or less than the second maximum luminance setting value BM2, the second correction unit 213 changes the second luminance setting value B2 to the second maximum luminance setting value BM2 and generates a second white image PW2 corresponding to the changed second luminance setting value B2. The second correction unit 213 causes the second projector 100B to project the second white image PW2. The second correction unit 213 also causes the camera 160 of the second projector 100B to capture the second white image PW2 projected on the screen SC and generate a sixth captured image PD6. The second correction unit 213 calculates a second average luminance value AV2 based on the sixth captured image PD6. The second correction unit 213 then calculates a second luminance setting value B2 based on the second average luminance value AV2. The second correction unit 213 also calculates a first luminance setting value B1 based on the second luminance setting value B2.

[0058] The projection control unit 214 corrects the first projection image PM1 based on the first correction value C1, sets the brightness of the first projection image PM1 according to the first brightness setting value B1, and causes the first projector 100A to project the first projection image PM1. In addition, the projection control unit 214 corrects the second projection image PM2 based on the second correction value C2, sets the brightness of the second projection image PM2 according to the second brightness setting value B2, and causes the second projector 100B to project the second projection image PM2.

[0059] Next, a first pattern image P1 and a second pattern image P2 according to the first embodiment will be described with reference to Fig. 4. Fig. 4 is a diagram showing an example of the first pattern image P1 and the second pattern image P2. As shown in Fig. 4, the first pattern image P1 is composed of a first gradation region P11, a second gradation region P12, a third gradation region P13, a fourth gradation region P14, a fifth gradation region P15, and a sixth gradation region P16. Each of the first gradation region P11, the second gradation region P12, the third gradation region P13, the fourth gradation region P14, the fifth gradation region P15, and the sixth gradation region P16 is set to a uniform color.

[0060] For example, if the first pattern image P1 is a first red pattern image P1R, the color value of the first gradation region P11 is, for example, (255,0,0). The color values ​​are written as (R color value, G color value, B color value). Each of the R color value, G color value, and B color value is a value in the range of 0 to 255. The color value of the second gradation region P12 is, for example, (204,0,0). The color value of the third gradation region P13 is, for example, (153,0,0). The color value of the fourth gradation region P14 is, for example, (102,0,0). The color value of the fifth gradation region P15 is, for example, (51,0,0). The color value of the sixth gradation region P16 is, for example, (0,0,0).

[0061] Similarly to the first pattern image P1, the second pattern image P2 is also composed of a first gradation region P21, a second gradation region P22, a third gradation region P23, a fourth gradation region P24, a fifth gradation region P25, and a sixth gradation region P26. Each of the first gradation region P21, the second gradation region P22, the third gradation region P23, the fourth gradation region P24, the fifth gradation region P25, and the sixth gradation region P26 is set to a uniform color.

[0062] For example, when the second pattern image P2 is a second green pattern image P2G, the color value of the first gradation region P21 is, for example, (0,255,0). The color value of the second gradation region P22 is, for example, (0,204,0). The color value of the third gradation region P23 is, for example, (0,153,0). The color value of the fourth gradation region P24 is, for example, (0,102,0). The color value of the fifth gradation region P25 is, for example, (0,51,0). The color value of the sixth gradation region P26 is, for example, (0,0,0).

[0063] Next, the processing of the image correction device 200 will be described with reference to FIGS. First, the "correction necessity determination process" of the image correction device 200 will be described with reference to Fig. 5. Fig. 5 is a flowchart showing an example of the "correction necessity determination process" of the image correction device 200. The "correction necessity determination process" is a process for determining whether or not to correct the color tone of the first projector 100A and whether or not to correct the color tone of the second projector 100B. The "correction necessity determination process" is executed by the correction necessity determination unit 211.

[0064] 5, in step S101, the correction necessity determination unit 211 acquires a first accumulated irradiation time SL1 from the first projector 100A. The first accumulated irradiation time SL1 is the accumulated value of the time during which the light source of the first projector 100A is in an irradiating state. Next, in step S103, the correction necessity determination unit 211 determines whether the first accumulated irradiation time SL1 is equal to or greater than a time threshold value TM. The time threshold value TM is, for example, the minimum value of the first accumulated irradiation time SL1 at which deterioration of components such as the light source of the first projector 100A or the liquid crystal panel 115 begins. The time threshold value TM is, for example, "1000 hours."

[0065] When the correction necessity determining section 211 determines that the first cumulative irradiation time SL1 is not equal to or greater than the time threshold value TM (step S103; NO), the process proceeds to step S105. Then, in step S105, the correction necessity determining section 211 determines that the color tone of the first projector 100A is not to be corrected. After that, the process proceeds to step S109. When the correction necessity determining section 211 determines that the first accumulated irradiation time SL1 is equal to or greater than the time threshold value TM (step S103; YES), the process proceeds to step S107. Then, in step S107, the correction necessity determining section 211 determines that the color tone of the first projector 100A is to be corrected. After that, the process proceeds to step S109.

[0066] Next, in step S109, the correction necessity determination unit 211 acquires the second accumulated irradiation time SL2 from the second projector 100B. The second accumulated irradiation time SL2 is the accumulated value of the time during which the light source of the second projector 100B is in an irradiating state. Next, in step S111, the correction necessity determining unit 211 determines whether the second accumulated irradiation time SL2 is equal to or greater than the time threshold value TM.

[0067] When the correction necessity determining section 211 determines that the second accumulated irradiation time SL2 is not equal to or greater than the time threshold value TM (step S111; NO), the process proceeds to step S113. Then, in step S113, the correction necessity determining section 211 determines that the color tone of the second projector 100B is not to be corrected. Then, the process ends. When the correction necessity determining section 211 determines that the second accumulated irradiation time SL2 is equal to or greater than the time threshold value TM (step S111; YES), the process proceeds to step S115. Then, in step S115, the correction necessity determining section 211 determines that the color tone of the second projector 100B is to be corrected, and then the process ends.

[0068] Next, the "first correction process" of the image correction device 200 will be described with reference to FIG. 6. FIG. 6 is a flowchart showing an example of the "first correction process" of the image correction device 200. The "first correction process" is a process for calculating a first correction value C1 and a second correction value C2. The first correction value C1 is a correction value for correcting the hue of the first projection image PM1 projected by the first projector 100A. The second correction value C2 is a correction value for correcting the hue of the second projection image PM2 projected by the second projector 100B. The first correction value C1 includes a first red correction value CR1, a first green correction value CG1, and a first blue correction value CB1. The second correction value C2 includes a second red correction value CR2, a second green correction value CG2, and a second blue correction value CB2. The "first correction process" is executed by the first correction unit 212, for example, when it is determined in the "correction necessity determination process" shown in FIG. 5 that the color tone of at least one of the first projector 100A and the second projector 100B is to be corrected.

[0069] 6, first, in step S201, the first correction unit 212 causes the first projector 100A to project a first pattern image P1 onto the screen SC. The first pattern image P1 includes a first red pattern image P1R, a first green pattern image P1G, and a first blue pattern image P1B. In the following description, a case will be described in which the first pattern image P1 is the first red pattern image P1R. Next, in step S203, the first correction unit 212 causes the camera 160 of the first projector 100A to capture the first red pattern image P1R projected on the screen SC and generate a first captured image PD1. Then, the first correction unit 212 acquires the generated first captured image PD1.

[0070] During the period from step S201 to step S203, the first correction unit 212 causes the second projector 100B to project a black image. Instead of causing the second projector 100B to project a black image, the first correction unit 212 may turn off the light source of the second projector 100B.

[0071] Next, in step S205, the first corrector 212 estimates the maximum saturation value MS of the R color of the first projector 100A based on the first captured image PD1. For example, if the average gradation values ​​of the first gradation region P11 to the sixth gradation region P16 of the first red pattern image P1R in the first captured image PD1 are "204," "204," "153," "102," "51," and "0," respectively, the first corrector 212 estimates the red maximum saturation value MSR to be "204." That is, the first corrector 212 estimates the red maximum saturation value MSR to be, for example, the maximum value of the average gradation values ​​of the first to sixth gradation regions P11 to P16 of the first red pattern image P1R in the first captured image PD1.

[0072] The processing from steps S201 to S205 has been described assuming that the first pattern image P1 is the first red pattern image P1R. The first correction unit 212 also executes the processing from steps S201 to S205 described above when the first pattern image P1 is the first green pattern image P1G to calculate the green maximum saturation value MSG. The first correction unit 212 also executes the processing from steps S201 to S205 described above when the first pattern image P1 is the first blue pattern image P1B to calculate the blue maximum saturation value MSB. The first correction unit 212 estimates the green maximum saturation value MSG to be, for example, "255." The first correction unit 212 also estimates the blue maximum saturation value MSB to be, for example, "255."

[0073] Next, in step S207, the first correction unit 212 calculates a first red correction value CR1, a first green correction value CG1, and a first blue correction value CB1 based on the red maximum saturation value MSR, the green maximum saturation value MSG, and the blue maximum saturation value MSB. For example, the first red correction value CR1 is "1", the first green correction value CG1 is "0.8", and the first blue correction value CB1 is "0.8".

[0074] The first correction unit 212 calculates the first red correction value CR1, the first green correction value CG1, and the first blue correction value CB1, for example, as follows. First, the first correction unit 212 calculates the smallest maximum saturation value MS among the red maximum saturation value MSR, the green maximum saturation value MSG, and the blue maximum saturation value MSB. Here, the smallest maximum saturation value MS is the red maximum saturation value MSR, which is "204." Then, the first correction unit 212 calculates the first red correction value CR1 by dividing the smallest maximum saturation value MS by the red maximum saturation value MSR. Furthermore, the first correction unit 212 calculates the first green correction value CG1 by dividing the smallest maximum saturation value MS by the green maximum saturation value MSG. Furthermore, the first correction unit 212 calculates the first blue correction value CB1 by dividing the smallest maximum saturation value MS by the blue maximum saturation value MSB. As a result, the first red correction value CR1 is calculated as "1 (=204 / 204)", the first green correction value CG1 is calculated as "0.8 (=204 / 255)", and the first blue correction value CB1 is calculated as "0.8 (=204 / 255)".

[0075] Next, in step S209, the first correction unit 212 causes the second projector 100B to project the second pattern image P2 onto the screen SC. The second pattern image P2 includes a second red pattern image P2R, a second green pattern image P2G, and a second blue pattern image P2B. In the following description, the case where the second pattern image P2 is the second red pattern image P2R will be described. Next, in step S211, the first correction unit 212 causes the camera 160 of the second projector 100B to capture the second red pattern image P2R projected on the screen SC and generate a second captured image PD2. Then, the first correction unit 212 acquires the generated second captured image PD2.

[0076] During the period from step S209 to step S211, the first correction unit 212 causes the first projector 100A to project a black image. Instead of causing the first projector 100A to project a black image, the first correction unit 212 may turn off the light source of the first projector 100A.

[0077] Next, in step S213, the first corrector 212 estimates the maximum saturation value MS of the R color of the second projector 100B based on the second captured image PD2. For example, if the average gradation values ​​of the first gradation region P21 to the sixth gradation region P26 of the second red pattern image P2R in the second captured image PD2 are "255," "204," "153," "102," "51," and "0," respectively, the first corrector 212 estimates the red maximum saturation value MSR to be "255." That is, the first corrector 212 estimates the red maximum saturation value MSR to be, for example, the maximum value of the average gradation values ​​of the first to sixth gradation regions P21 to P26 of the second red pattern image P2R in the second captured image PD2.

[0078] Steps S209 to S211 have been described for the case where the second pattern image P2 is the second red pattern image P2R. The first correction unit 212 also performs the processes of steps S209 to S211 described above when the second pattern image P2 is the second green pattern image P2G to calculate the green maximum saturation value MSG. The first correction unit 212 also performs the processes of steps S209 to S211 described above when the second pattern image P2 is the second blue pattern image P2B to calculate the blue maximum saturation value MSB. The first correction unit 212 estimates the green maximum saturation value MSG to be, for example, "255." The first correction unit 212 also estimates the blue maximum saturation value MSB to be, for example, "255."

[0079] Next, in step S215, the first correction unit 212 calculates a second red correction value CR2, a second green correction value CG2, and a second blue correction value CB2 based on the red maximum saturation value MSR, the green maximum saturation value MSG, and the blue maximum saturation value MSB. For example, the second red correction value CR2 is "1", the second green correction value CG2 is "1", and the second blue correction value CB2 is "1".

[0080] The first corrector 212 calculates the second red corrected value CR2, the second green corrected value CG2, and the second blue corrected value CB2, for example, in the same manner as in step S213. As a result, the second red correction value CR2 is calculated as “1 (=255 / 255)”, the second green correction value CG2 is calculated as “1 (=255 / 255)”, and the second blue correction value CB2 is calculated as “1 (=255 / 255)”. Then, the process ends.

[0081] Next, the "second correction process" of the image correction device 200 will be described with reference to Figs. 7-8. Figs. 7-8 are flowcharts showing an example of the "second correction process" of the image correction device 200. The "second correction process" is a process for setting a first luminance setting value B1 and a second luminance setting value B2. The first luminance setting value B1 is a setting value of luminance when the first projector 100A is caused to project the first projection image PM1. The second luminance setting value B2 is a setting value of luminance when the second projector 100B is caused to project the second projection image PM2. The "second correction process" is executed by the second correction unit 213 when the "first correction process" is completed.

[0082] As shown in FIG. 7, first, in step S301, the second corrector 213 corrects the first white image PW1 using the first correction value C1. Next, in step S303, the second corrector 213 causes the first projector 100A to project the corrected first white image PW1 onto the screen SC. Next, in step S305, the second correction unit 213 causes the camera 160 of the first projector 100A to capture the corrected first white image PW1 projected on the screen SC and generate a third captured image PD3. Then, the second correction unit 213 acquires the generated third captured image PD3.

[0083] During the period from step S303 to step S305, the second correction unit 213 causes the second projector 100B to project a black image. Instead of causing the second projector 100B to project a black image, the second correction unit 213 may turn off the light source of the second projector 100B.

[0084] Next, in step S307, the second corrector 213 calculates a first average luminance value AV1 based on the third captured image PD3. The first average luminance value AV1 is the average value of the luminance values ​​of the third captured image PD3. The first average luminance value AV1 is, for example, "40."

[0085] Next, in step S309, the second corrector 213 corrects the second white image PW2 using the second correction value C2. Next, in step S311, the second corrector 213 causes the second projector 100B to project the corrected second white image PW2 onto the screen SC. Next, in step S313, the second correction unit 213 causes the camera 160 of the second projector 100B to capture the corrected second white image PW2 projected on the screen SC and generate a fourth captured image PD4. Then, the second correction unit 213 acquires the generated fourth captured image PD4.

[0086] During the period from step S311 to step S313, the second correction unit 213 causes the first projector 100A to project a black image. Instead of causing the first projector 100A to project a black image, the second correction unit 213 may turn off the light source of the first projector 100A.

[0087] Next, in step S315, the second corrector 213 calculates a second average luminance value AV2 based on the fourth captured image PD4. The second average luminance value AV2 is the average value of the luminance values ​​of the fourth captured image PD4. The second average luminance value AV2 is, for example, "50."

[0088] 8, in step S317, the second correction unit 213 determines whether the first average brightness value AV1 is equal to or less than the second average brightness value AV2. If the second correction unit 213 determines that the first average brightness value AV1 is equal to or less than the second average brightness value AV2 (step S317; YES), the process proceeds to step S333. If the second correction unit 213 determines that the first average brightness value AV1 is not equal to or less than the second average brightness value AV2 (step S317; NO), the process proceeds to step S319. In the first embodiment, the first average brightness value AV1 is, for example, "40," and the second average brightness value AV2 is, for example, "50," so the process proceeds to step S333. Note that the processes from step S319 to step S331 will be explained after the processes from step S333 to step S345 have been explained.

[0089] Next, in step S333, the second correction unit 213 calculates the changed first brightness setting value B1 based on, for example, a preset first brightness setting value B1, the brightness value of the first captured image PD1, and the brightness value of the second captured image PD2. The preset first brightness setting value B1 is, for example, the first brightness setting value B1 set in the "second correction process" before the previous time. Furthermore, when the "second correction process" is executed for the first time, the preset first brightness setting value B1 is, for example, the first brightness setting value B1 set in the adjustment executed before shipping the first projector 100A from the manufacturer. The preset first brightness setting value B1 is, for example, "50," and the changed first brightness setting value B1 is, for example, "62.5."

[0090] Next, in step S335, the second corrector 213 determines whether the first brightness setting value B1 is greater than the first maximum brightness setting value BM1. The first maximum brightness setting value BM1 indicates the maximum value of the first brightness setting value B1. If the second corrector 213 determines that the first brightness setting value B1 is not greater than the first maximum brightness setting value BM1 (step S335; NO), the process then ends. The first brightness setting value B1 is, for example, "62.5." The first maximum brightness setting value BM1 is, for example, "100." In this case, the first brightness setting value B1 is set to "62.5," which is the changed first brightness setting value B1, and the process then ends. If the second corrector 213 determines that the first luminance setting value B1 is greater than the first maximum luminance setting value BM1 (step S335; YES), the process proceeds to step S337. Then, in step S337, the second corrector 213 changes the first brightness setting value B1 to the first maximum brightness setting value BM1. The first brightness setting value B1 is, for example, "112.5." The first maximum brightness setting value BM1 is, for example, "100." In this case, the second corrector 213 changes the first brightness setting value B1 from "112.5" to "100."

[0091] Next, in step S339, the second corrector 213 causes the first projector 100A to project the first white image PW1 onto the screen SC using the first luminance setting value B1 changed in step S337. Next, in step S341, the second correction unit 213 causes the camera 160 of the first projector 100A to capture the first white image PW1 projected on the screen SC and generate a fifth captured image PD5. Then, the second correction unit 213 acquires the generated fifth captured image PD5.

[0092] During the period from step S339 to step S341, the second correction unit 213 causes the second projector 100B to project a black image. Instead of causing the second projector 100B to project a black image, the second correction unit 213 may turn off the light source of the second projector 100B.

[0093] Next, in step S343, the second corrector 213 calculates a first average luminance value AV1 based on the fifth captured image PD5. The first average luminance value AV1 is the average value of the luminance values ​​of the fifth captured image PD5. Next, in step S345, the second corrector 213 calculates a second brightness setting value B2 based on the first brightness setting value B1, the second brightness setting value B2, and the first average brightness value AV1. The second brightness setting value B2 is, for example, "45." Then, the process ends.

[0094] Next, the processing from step S319 to step S331 will be described. If the second corrector 213 determines that the first average brightness value AV1 is not equal to or less than the second average brightness value AV2 (step S317; NO), the process proceeds to step S319. Then, in step S319, the second correction unit 213 calculates the changed second brightness setting value B2, for example, based on the preset second brightness setting value B2, the brightness value of the first captured image PD1, and the brightness value of the second captured image PD2. The preset second brightness setting value B2 is, for example, the second brightness setting value B2 that was set in the "second correction process" before the previous time. Furthermore, when the "second correction process" is executed for the first time, the preset second brightness setting value B2 is, for example, the second brightness setting value B2 that was set in the adjustment that was executed before shipping the second projector 100B from the manufacturer.

[0095] Next, in step S321, the second corrector 213 determines whether the second brightness setting value B2 is greater than the second maximum brightness setting value BM2. The second maximum brightness setting value BM2 indicates the maximum value of the second brightness setting value B2. If the second corrector 213 determines that the second brightness setting value B2 is not greater than the second maximum brightness setting value BM2 (step S321; NO), the process then ends. The second brightness setting value B2 is, for example, "50." The second maximum brightness setting value BM2 is, for example, "100." In this case, the second brightness setting value B2 is set to "50," which is the changed second brightness setting value B2, and the process then ends. If the second corrector 213 determines that the second brightness setting value B2 is greater than the second maximum brightness setting value BM2 (step S321; YES), the process proceeds to step S323. Then, in step S323, the second corrector 213 changes the second brightness setting value B2 to the second maximum brightness setting value BM2.

[0096] Next, in step S325, the second corrector 213 causes the second projector 100B to project the second white image PW2 onto the screen SC using the second luminance setting value B2 changed in step S323. Next, in step S327, the second correction unit 213 causes the camera 160 of the second projector 100B to capture the second white image PW2 projected on the screen SC and generate a sixth captured image PD6. Then, the second correction unit 213 acquires the generated sixth captured image PD6.

[0097] During the period from step S325 to step S327, the second correction unit 213 causes the first projector 100A to project a black image. Instead of causing the first projector 100A to project a black image, the second correction unit 213 may turn off the light source of the first projector 100A.

[0098] Next, in step S329, the second corrector 213 calculates a second average luminance value AV2 based on the sixth captured image PD6. The second average luminance value AV2 is the average value of the luminance values ​​of the sixth captured image PD6. Next, in step S331, the second corrector 213 calculates the first brightness setting value B1 based on the first brightness setting value B1, the second brightness setting value B2, and the second average brightness value AV2. Then, the process ends.

[0099] Second Embodiment Next, an image projection system 1A according to a second embodiment will be described with reference to FIGS. Fig. 9 is a diagram showing an example of the configuration of an image projection system 1A according to the second embodiment. As shown in Fig. 9, the image projection system 1A includes a projector 100 and an image correction device 200. The projector 100 includes a first projector 100A and a second projector 100B.

[0100] In the second embodiment, an image projection system 1A differs from the image projection system 1 shown in FIG. 1 in that a first projector 100A and a second projector 100B perform stacking projection. That is, in the second embodiment, the first projector 100A projects the first image light PL1 onto the first area AR1 of the screen SC, and displays the first projection image PM1 on the screen SC. The second projector 100B projects the second image light PL2 onto the second area AR2 of the screen SC, and displays the second projection image PM2 on the screen SC. 9, the second projected image PM2 is the same image as the first projected image PM1, and the second area AR2 coincides with the first area AR1. In this way, the first projector 100A and the second projector 100B project the same image in an overlapping manner, thereby displaying a single image brighter than when it is displayed by a single projector.

[0101] The configurations of the first projector 100A and the second projector 100B in the image projection system 1A are the same as the configuration of the projector 100 described with reference to Fig. 2. Therefore, a description of the configurations of the first projector 100A and the second projector 100B will be omitted.

[0102] 3. Image correction device 200 in image projection system 1A differs from the configuration of image correction device 200 described with reference to FIG. Furthermore, first correction unit 212 of image correction device 200 in image projection system 1A differs from the configuration of image correction device 200 described with reference to Fig. 3 in that it executes the "correction process" that will be described with reference to Fig. 10. In other words, while first correction unit 212 of image correction device 200 described with reference to Fig. 3 executes the "first correction process" shown in Fig. 6, first correction unit 212 of image correction device 200 according to the second embodiment executes the "correction process" shown in Fig. 10. The "correction process" will be further explained with reference to FIG.

[0103] Next, processing by the image correction device 200 according to the second embodiment will be described with reference to Fig. 10. Fig. 10 is a flowchart showing an example of the "correction processing" by the image correction device 200 according to the second embodiment. The "correction processing" is processing for correcting the color tone of the first projected image PM1 of the first projector 100A and correcting the color tone of the second projected image PM2 of the second projector 100B. Note that the image correction device 200 according to the second embodiment executes the "correction necessity determination process" described with reference to Fig. 5 before executing the "correction process" shown in Fig. 10. The "correction necessity determination process" is a process for determining whether or not to correct the color tone of the first projector 100A and whether or not to correct the color tone of the second projector 100B. The "correction necessity determination process" is executed by the correction necessity determination unit 211.

[0104] The "correction process" shown in FIG. 10 is executed when it is determined in the "correction necessity determination process" that the color tone of the first projector 100A is to be corrected. 10, first, in step S401, the first correction unit 212 corrects the color tone of the first projection image PM1 of the first projector 100A. Note that before executing the process of step S401, the first correction unit 212 executes, for example, the processes of steps S201 to S207 in FIG. 6 to calculate a first correction value C1. Then, the first correction unit 212 corrects the color tone of the first projection image PM1 of the first projector 100A based on the first correction value C1.

[0105] Next, in step S403, the first correction unit 212 determines whether the first maximum luminance value ML1 is equal to or greater than the first target luminance value AL1. The first maximum luminance value ML1 indicates the maximum value of the luminance of the first projection image PM1 projected by the first projector 100A. The first target luminance value AL1 is a luminance value used to determine whether the projector 100 is malfunctioning. If the first corrector 212 determines that the first maximum luminance value ML1 is not equal to or greater than the first target luminance value AL1 (step S403; NO), the process proceeds to step S405. Then, in step S405, the first correction unit 212 notifies that the first projector 100A is malfunctioning. For example, the first correction unit 212 displays a text image indicating that the first projector 100A is malfunctioning on a display such as an LCD (Liquid Crystal Display) communicably connected to the image correction device 200. Alternatively, for example, the first correction unit 212 may cause the second projector 100B to display a text image indicating that the first projector 100A is malfunctioning using an OSD (On Screen Display) function. Then, the processing ends.

[0106] If the first corrector 212 determines that the first maximum luminance value ML1 is equal to or greater than the first target luminance value AL1 (step S403; YES), the process proceeds to step S407. Then, in step S407, the first correction unit 212 determines whether the first maximum luminance value ML1 is equal to or greater than the second target luminance value AL2. The second target luminance value AL2 is a luminance value that determines whether the luminance value of the first projected image PM1 after the color correction of the first projector 100A is equal to or greater than the luminance value of the stack image desired by the user. The second target brightness value AL2 corresponds to an example of a "predetermined threshold value." If the first correction unit 212 determines that the first maximum brightness value ML1 is equal to or greater than the second target brightness value AL2 (step S407; YES), the first correction unit 212 determines that stack projection is not necessary, and then the processing ends.If the first correction unit 212 determines that the first maximum brightness value ML1 is not equal to or greater than the second target brightness value AL2 (step S407; NO), the processing proceeds to step S409.

[0107] Then, in step S409, the first corrector 212 causes the first projector 100A to project the corrected first projection image PM1 onto the screen SC. Next, in step S411, the first correction unit 212 causes the camera 160 of the first projector 100A to capture the first projection image PM1 and generate a captured image PD. The first correction unit 212 also acquires the captured image PD from the first projector 100A. Next, in step S413, the first corrector 212 corrects the color tone of the second projected image PM2 of the second projector 100B based on the captured image PD. For example, the first corrector 212 corrects the color tone of the second projected image PM2 so that the color tone of the second projected image PM2 matches the color tone of the captured image PD.

[0108] Next, in step S415, the first corrector 212 determines whether the second maximum luminance value ML2 is equal to or greater than the second target luminance value AL2. The second maximum luminance value ML2 indicates the sum of the maximum luminance value of the first projection image PM1 projected by the first projector 100A and the maximum luminance value of the second projection image PM2 projected by the second projector 100B. If the first corrector 212 determines that the second maximum luminance value ML2 is not equal to or greater than the second target luminance value AL2 (step S415; NO), the process proceeds to step S417. Then, in step S417, the first correction unit 212 notifies the user that the first projector 100A and the second projector 100B cannot display a projection image with the brightness desired by the user. For example, the first correction unit 212 displays a text image indicating that the first projector 100A and the second projector 100B cannot display a projection image with the brightness desired by the user on a display such as an LCD connected to the image correction device 200 so as to be able to communicate with the image correction device 200. Furthermore, for example, the first correction unit 212 may cause the second projector 100B to display a text image indicating that the first projector 100A and the second projector 100B cannot display a projection image with the brightness desired by the user using an OSD (On Screen Display) function. Then, the processing ends. If the first corrector 212 determines that the second maximum luminance value ML2 is equal to or greater than the second target luminance value AL2 (step S415; YES), the process then ends.

[0109] [Embodiment and Effects] As described above with reference to Figures 1 to 10, the correction method for multiple projectors 100 according to this embodiment is a correction method for multiple projectors 100 including a first projector 100A and a second projector 100B, in which a first area AR1 that is the projection area of ​​the first projector 100A at least partially overlaps with a second area AR2 that is the projection area of ​​the second projector 100B, and includes the steps of: an image correction device 200 configured to be able to communicate with the first projector 100A and the second projector 100B determining whether to correct the color tone of a first projection image PM1 projected by the first projector 100A; after the image correction device 200 corrects the color tone of the first projection image PM1, the image correction device 200 acquiring a captured image PD that captures the first projection image PM1; and the image correction device 200 correcting the color tone of a second projection image PM2 projected by the second projector 100B based on the captured image PD.

[0110] That is, after correcting the color tone of the first projection image PM1 projected by the first projector 100A, a captured image PD is obtained by capturing the first projection image PM1, and based on the captured image PD, the color tone of the second projection image PM2 projected by the second projector 100B is corrected. Therefore, the color tone of the second projected image PM2 can be corrected to match the corrected color tone of the first projected image PM1. Therefore, when stacking projection or tiling projection is performed, the color tone of the first projected image PM1 and the color tone of the second projected image PM2 can be appropriately corrected.

[0111] In addition, the correction method for multiple projectors 100 includes the image correction device 200 acquiring a first accumulated irradiation time SL1, which is the accumulated value of the time during which the light source of the first projector 100A is in an irradiating state, and the image correction device 200 determining whether to correct the color tone of the first projector 100A based on the first accumulated irradiation time SL1 of the first projector 100A. Therefore, whether to correct the color tone of the first projector 100A is determined based on the first accumulated irradiation time SL1, and therefore it is possible to appropriately determine whether to correct the color tone of the first projector 100A. For example, if the first accumulated irradiation time SL1 is equal to or greater than the time threshold value TM, it is determined that the color tone of the first projector 100A is to be corrected. The time threshold value TM is, for example, the minimum value of the first accumulated irradiation time SL1 at which deterioration of parts such as the light source of the first projector 100A or the liquid crystal panel 115 begins.

[0112] Furthermore, the correction method for the multiple projectors 100 includes the image correction device 200 estimating a first maximum luminance value ML1, which is the maximum value of the luminance of the first projection image PM1 projected by the first projector 100A, the image correction device 200 determining whether the first maximum luminance value ML1 of the first projector 100A is equal to or greater than a predetermined second target luminance value AL2, and, if the image correction device 200 determines that the first maximum luminance value ML1 of the first projector 100A is not equal to or greater than the second target luminance value AL2, correcting the color tone of the second projection image PM2 projected by the second projector 100B for an area of ​​the second area AR2 that overlaps with the first area AR1. Therefore, it is possible to appropriately determine whether to correct the color tone of the second projection image PM2 projected by the second projector 100B. In other words, when the first maximum luminance value ML1 is not equal to or greater than the second target luminance value AL2, the luminance of the area of ​​the second area AR2 that overlaps with the first area AR1 can be made equal to or greater than the second target luminance value AL2 by superimposing the first projection image PM1 and the second projection image PM2.

[0113] In addition, the correction method for the multiple projectors 100 includes, when it is determined that the first maximum brightness value ML1 of the first projector 100A is not greater than or equal to the second target brightness value AL2, the image correction device 200 acquiring a captured image PD that captures the first projection image PM1, and the image correction device 200 correcting the color tone of the second projection image PM2 projected by the second projector 100B based on the captured image PD. Therefore, the color tone of the second projection image PM2 projected by the second projector 100B is corrected based on the captured image PD, and therefore the color tone of the second projection image PM2 can be appropriately corrected. For example, by correcting the color tone of the second projection image PM2 so that it matches the color tone of the captured image PD, the color tone of the second projection image PM2 can be appropriately corrected.

[0114] Furthermore, in the correction method for the multiple projectors 100, the first area AR1 partially overlaps with the second area AR2. Therefore, the first projected image PM1 projected by the first projector 100A and the second projected image PM2 projected by the second projector 100B can be tiled and projected.

[0115] In addition, in the correction method for the multiple projectors 100, the first area AR1 coincides with the second area AR2. Therefore, the first projected image PM1 projected by the first projector 100A and the second projected image PM2 projected by the second projector 100B can be stacked and projected.

[0116] The image correction device 200 of this embodiment is an image correction device 200 configured to be able to communicate with a first projector 100A and a second projector 100B, and a first area AR1, which is the projection area of ​​the first projector 100A, at least partially overlaps with a second area AR2, which is the projection area of ​​the second projector 100B, and performs the following operations: determining whether to correct the color tone of a first projection image PM1 projected by the first projector 100A; after the image correction device 200 corrects the color tone of the first projection image PM1, the image correction device 200 acquires a captured image PD that captures the first projection image PM1; and correcting the color tone of a second projection image PM2 projected by the second projector 100B based on the captured image PD. Therefore, the image correction device 200 according to this embodiment can achieve the same effects as the correction method for the projector 100 according to this embodiment.

[0117] [Other embodiments] The above-described embodiment is a preferred embodiment, but is not limited to the above-described embodiment, and various modifications are possible within the scope of the gist of the present invention.

[0118] In this embodiment, a case will be described in which the "plurality of projectors" is configured with a first projector 100A and a second projector 100B, but the "plurality of projectors" may be configured with three or more projectors.

[0119] In this embodiment, the image correction device 200 is configured as a personal computer, but the image correction device 200 may also be configured as a tablet terminal, a smartphone, or the like.

[0120] In this embodiment, a case will be described in which each of the first projector 100A and the second projector 100B includes the camera 160, but the camera 160 may be configured as a separate entity from each of the first projector 100A and the second projector 100B. In this case, the camera 160 is connected to the image correction device 200 so as to be able to communicate with it.

[0121] 2 and 3 show functional configurations, and the specific implementation form is not particularly limited. In other words, it is not necessary to implement hardware corresponding to each functional unit individually, and it is also possible to implement a configuration in which a single processor executes a program to realize the functions of multiple functional units. Also, some of the functions realized by software in the above embodiments may be realized by hardware, or some of the functions realized by hardware may be realized by software. In addition, the specific detailed configurations of each unit of projector 100 and image correction device 200 can be changed as desired without departing from the spirit of the invention.

[0122] 5-8 and 10 are divided according to the main processing content in order to facilitate understanding of the processing of second control unit 20 of image correction device 200. The division method and names of the processing units shown in the flowcharts of FIGS. 5-8 and 10 are not limiting, and the processing can be divided into more processing units according to the processing content, or one processing unit can be divided to include more processes. Furthermore, the processing order of the above flowcharts is not limited to the example shown in the drawings.

[0123] Furthermore, the correction method for projector 100 can be realized by having second processor 21 of second control unit 20 of image correction device 200 execute a second control program PG2 that corresponds to the correction method for projector 100. Furthermore, the second control program PG2 can also be recorded on a computer-readable recording medium. The recording medium may be a magnetic or optical recording medium or a semiconductor memory device. Specific examples include portable or fixed recording media such as a flexible disk, HDD, CD-ROM (Compact Disk Read Only Memory), DVD, Blu-ray (registered trademark) Disc, magneto-optical disk, flash memory, and card-type recording medium. The recording medium may also be a non-volatile storage device such as RAM, ROM, or HDD, which is an internal storage device provided in the image correction device 200. The correction method for the projector 100 can also be realized by storing the second control program PG2 in a server device or the like and downloading the second control program PG2 from the server device to the image correction device 200.

[0124] [Note] A summary of this disclosure is provided below. (Appendix 1) A correction method for multiple projectors including a first projector and a second projector, wherein a first projection area that is the projection area of ​​the first projector at least partially overlaps with a second projection area that is the projection area of ​​the second projector, the correction method for multiple projectors including: an information processing device configured to be able to communicate with the multiple projectors determining whether to correct a color tone of a first projection image projected by the first projector; after the information processing device corrects the color tone of the first projection image, the information processing device acquiring a captured image that captures the first projection image; and, based on the captured image, the information processing device correcting the color tone of a second projection image projected by the second projector.

[0125] This allows the color tone of the second projected image to be corrected to match the corrected color tone of the first projected image, and therefore, when stacking projection or tiling projection is performed, the color tone of the first projected image and the color tone of the second projected image can be properly corrected.

[0126] (Appendix 2) A method for correcting multiple projectors as described in Appendix 1, including: the information processing device acquiring a cumulative irradiation time, which is a cumulative value of the time during which the light source of the first projector is in an irradiating state; and the information processing device determining whether to correct the color tone of the first projection image projected by the first projector based on the cumulative irradiation time of the first projector.

[0127] As a result, whether or not to correct the color tone of the first projector is determined based on the cumulative irradiation time, and therefore, whether or not to correct the color tone of the first projector can be determined appropriately.

[0128] (Appendix 3) A correction method for multiple projectors described in Appendix 1 or Appendix 2, including: the information processing device estimating a maximum luminance value that is the maximum value of the luminance of the first projection image projected by the first projector; the information processing device determining whether the maximum luminance value of the first projector is equal to or greater than a predetermined threshold; and, if the information processing device determines that the maximum luminance value of the first projector is not equal to or greater than the threshold, correcting a color tone of the second projection image projected by the second projector for an area of ​​the second projection area that overlaps with the first projection area.

[0129] This makes it possible to properly determine whether to correct the color tone of the second projection image projected by the second projector. In other words, if the maximum luminance value of the first projector is not equal to or greater than a preset threshold, the luminance of the area of ​​the second projection area that overlaps with the first projection area can be made equal to or greater than the threshold by superimposing the first projection image and the second projection image.

[0130] (Appendix 4) A method for correcting multiple projectors as described in Appendix 3, including, when it is determined that the maximum luminance value of the first projector is not greater than the threshold, the information processing device acquiring a captured image of the first projection image, and the information processing device correcting the color tone of the second projection image projected by the second projector based on the captured image.

[0131] This allows the color tone of the second projection image projected by the second projector to be corrected based on the captured image obtained by capturing the first projection image, so that the color tone of the second projection image can be appropriately corrected.

[0132] (Appendix 5) 5. The method for correcting multiple projectors according to claim 1, wherein the first projection area partially overlaps with the second projection area.

[0133] This allows tiling projection of the first projection image projected by the first projector and the second projection image projected by the second projector.

[0134] (Appendix 6) 6. The method for correcting multiple projectors according to any one of Supplementary Note 1 to Supplementary Note 5, wherein the first projection area coincides with the second projection area.

[0135] This allows stacking projection of the first projection image projected by the first projector and the second projection image projected by the second projector.

[0136] (Appendix 7) An information processing device configured to be able to communicate with a plurality of projectors including a first projector and a second projector, wherein a first projection area that is the projection area of ​​the first projector at least partially overlaps with a second projection area that is the projection area of ​​the second projector, and the information processing device executes the following operations: determining whether to correct a color tone of a first projection image projected by the first projector; acquiring a captured image by capturing the first projection image after correcting the color tone of the first projection image; and correcting the color tone of a second projection image projected by the second projector based on the captured image.

[0137] As a result, the information processing device described in Supplementary Note 7 has the same effect as the method for correcting a plurality of projectors described in Supplementary Note 1. [Explanation of symbols]

[0138] 1, 1A...image projection system, 100...projector, 100A...first projector, 100B...second projector, 111...light source unit, 115...liquid crystal panel, 150...first control unit, 150A...first processor, 150B...first memory, 160...camera, 200...image correction device (information processing device), 20...second control unit, 21...second processor, 22...second memory, 211...correction necessity determination unit, 212...first correction unit, 213...second correction unit, 214...projection control unit, 221...image storage unit , 222...correction value memory unit, 223...setting value memory unit, AL1...first target brightness value, AL2...second target brightness value (predetermined threshold value), AR1...first area (first projection area), AR2...second area (second projection area), AR3...third area, ML1...first maximum brightness value, ML2...second maximum brightness value, P1...first pattern image, P2...second pattern image, PD...captured image, PG2...second control program, PM1...first projection image, PM2...second projection image, SL1...first cumulative irradiation time, SL2...second cumulative irradiation time.

Claims

1. A method for correcting a plurality of projectors including a first projector and a second projector, a first projection area that is a projection area of ​​the first projector at least partially overlaps with a second projection area that is a projection area of ​​the second projector; an information processing device configured to be able to communicate with the plurality of projectors determines whether or not to correct a color tone of a first projection image projected by the first projector; After the information processing device corrects the color tone of the first projection image, the information processing device acquires a captured image by capturing the first projection image; the information processing device corrects a color tone of a second projection image projected by the second projector based on the captured image; Multiple projector calibration methods, including:

2. the information processing device acquires an accumulated irradiation time that is an accumulated value of time during which a light source of the first projector is in an irradiating state; the information processing device determines whether or not to correct a color tone of a first projection image projected by the first projector based on the accumulated irradiation time of the first projector; The method of claim 1 , comprising:

3. the information processing device estimates a maximum luminance value that is a maximum value of luminance of a first projection image projected by the first projector; the information processing device determining whether or not a maximum luminance value of the first projector is equal to or greater than a preset threshold; when the information processing device determines that the maximum luminance value of the first projector is not equal to or greater than the threshold value, correcting a color tone of a second projection image projected by the second projector for an area of ​​the second projection area that overlaps with the first projection area; The method for correcting a plurality of projectors according to claim 1 or claim 2, comprising:

4. when it is determined that the maximum luminance value of the first projector is not equal to or greater than the threshold value, the information processing device acquires a captured image obtained by capturing the first projection image; the information processing device corrects a color tone of a second projection image projected by the second projector based on the captured image; The method of claim 3 , comprising:

5. The first projection area partially overlaps with the second projection area. The method of correcting multiple projectors according to claim 1 .

6. The first projection area coincides with the second projection area. The method of correcting multiple projectors according to claim 1 .

7. An information processing device configured to be able to communicate with a plurality of projectors including a first projector and a second projector, a first projection area that is a projection area of ​​the first projector at least partially overlaps with a second projection area that is a projection area of ​​the second projector; determining whether to correct a color tone of a first projection image projected by the first projector; acquiring a captured image by capturing the first projection image after correcting the color tone of the first projection image; correcting a color tone of a second projection image projected by the second projector based on the captured image; An information processing device that executes the above.

Images