Control method, projector, and program

Abstract

To improve image quality in a superimposed area of projection images.SOLUTION: A control method includes: in a corresponding area corresponding to a superimposed area where a first projection image and a second projection image are partially superimposed on each other, projecting, on a projection surface, a first image group having a first state where the brightness of the first projection image is larger than zero and the brightness of the second projection image is zero; picking up an image of the corresponding area with an imaging apparatus in a state where the first image group is projected on the projection surface, to acquire first imaging data; in the corresponding area, projecting, on the projection surface, a second image group having a second state where the brightness of the first projection image is zero and the brightness of the second projection image is larger than zero; picking up an image of the corresponding area with the imaging apparatus in a state where the second image group is projected on the projection surface, to acquire second imaging data; and analyzing the first imaging data and the second imaging data to detect displacement between the first projection image and the second projection image in a range of the superimposed area.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a control method, a projector, and a program.

Background Art

[0002] For example, Patent Document 1 discloses an acquisition unit that acquires an acquired image obtained by imaging a region of a projection surface that includes at least an overlapping region where a first projection image projected by a first projector on the projection surface and a second projection image projected by a second projector on the projection surface overlap, and a detection unit that analyzes the acquired image and detects the magnitude and direction of the positional deviation between the first projection image and the second projection image in the overlapping region. The detection unit detects the deviation based on a frequency spectrum image obtained by applying two-dimensional Fourier transform processing to the acquired image.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the technique described in Patent Document 1, depending on the type of the projection image, it is not possible to generate an accurate frequency spectrum during the above-described two-dimensional Fourier transform processing, and as a result, there is a problem that the detection accuracy of the detection unit decreases.

Means for Solving the Problems

[0005] A control method according to an aspect of the present disclosure is a control method in a multi-projection system in which a superimposed region is set where a part of a first projection image projected from a first projector overlaps with a part of a second projection image projected from a second projector on a projection surface, the method including: projecting a first image group having a first state, in a corresponding region corresponding to the superimposed region, where the brightness of the first projection image is greater than zero and the brightness of the second projection image is zero, onto the projection surface; acquiring first imaging data by imaging the corresponding region in a state where the first image group is projected onto the projection surface; projecting a second image group having a second state, in the corresponding region, where the brightness of the first projection image is zero and the brightness of the second projection image is greater than zero, onto the projection surface; acquiring second imaging data by imaging the corresponding region in a state where the second image group is projected onto the projection surface; and detecting a deviation between the first projection image and the second projection image in the range of the superimposed region by analyzing the first imaging data and the second imaging data.

[0006] A projector according to another aspect of the present disclosure is a projector used as the first projector in a multi-projection system in which an overlapping region is set for a part of each of a first projection image projected from a first projector and a second projection image projected from a second projector to overlap on a projection surface. The projector includes an optical device and a processing device. The processing device controls the operation of the optical device and the operation of the second projector so that a first image group having a first state in which the brightness of the first projection image is greater than zero and the brightness of the second projection image is zero is projected onto the projection surface in a corresponding region corresponding to the overlapping region, acquires first imaging data by causing an imaging device to image the corresponding region in a state where the first image group is projected onto the projection surface, controls the operation of the optical device and the operation of the second projector so that a second image group having a second state in which the brightness of the first projection image is zero and the brightness of the second projection image is greater than zero is projected onto the projection surface in the corresponding region, acquires second imaging data by causing the imaging device to image the corresponding region in a state where the second image group is projected onto the projection surface, and detects a deviation between the first projection image and the second projection image in the range of the overlapping region by analyzing the first imaging data and the second imaging data.

[0007] A program according to an aspect of the present disclosure is a program used for a multi-projection system in which an overlapping region is set for a part of each of a first projection image projected from a first projector and a second projection image projected from a second projector to overlap on a projection surface. The program causes a computer to perform the following operations: project a first image group having a first state, in a corresponding region corresponding to the overlapping region, where the brightness of the first projection image is greater than zero and the brightness of the second projection image is zero, onto the projection surface; acquire first imaging data by imaging, with an imaging device, the corresponding region while the first image group is projected onto the projection surface; project a second image group having a second state, in the corresponding region, where the brightness of the first projection image is zero and the brightness of the second projection image is greater than zero, onto the projection surface; acquire second imaging data by imaging, with the imaging device, the corresponding region while the second image group is projected onto the projection surface; and detect a deviation between the first projection image and the second projection image in the range of the overlapping region by analyzing the first imaging data and the second imaging data.

Brief Description of the Drawings

[0008]

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Embodiments for Carrying Out the Invention

[0009] Hereinafter, preferred embodiments according to the present disclosure will be described with reference to the accompanying drawings. Note that the dimensions and scales of each part in the drawings are appropriately different from the actual ones, and there are also some parts schematically shown for easy understanding. Also, the scope of the present disclosure is not limited to these embodiments unless otherwise specified in the following description. 1. First Embodiment 1-1. Overview of the Multi-Projection System FIG. 1 is a diagram showing an overview of a multi-projection system 100 used in the control method according to the first embodiment. As shown in FIG. 1, the multi-projection system 100 includes a first projector 10-1, a second projector 10-2, and a terminal device 30. The first projector 10-1 is an example of a "projector". Hereinafter, the first projector 10-1 and the second projector 10-2 may be referred to as the projector 10 without distinction.

[0010] The multi-projection system 100 projects an image group GG onto a projection surface SC using a plurality of projectors 10. In the example shown in FIG. 1, the multi-projection system 100 projects an image group GG including a first projection image G1 and a second projection image G2 onto the projection surface SC using two projectors 10. The projection surface SC is the surface of an object such as a screen. In the example shown in FIG. 1, the projection surface SC is a plane.

[0011] Note that the projection surface SC is not limited to a plane and may be, for example, a curved surface. Also, in the present embodiment, an aspect in which the number of projectors 10 included in the multi-projection system 100 is two is illustrated, but it is not limited to this aspect, and the number may be three or more. That is, the image group GG may include images projected from three or more projectors 10.

[0012] The first projector 10-1 is a display device that projects the first projection image G1 shown in the video data IMG1 output from the terminal device 30 onto the projection surface SC. On the other hand, the second projector 10-2 is a display device that projects the second projection image G2 shown in the video data IMG2 output from the terminal device 30 onto the projection surface SC.

[0013] The first projection image G1 and the second projection image G2 are arranged in the arrangement direction DR in this order. Here, the first projection image G1 and the second projection image G2 are projected onto the projection surface SC in a state where they are joined together so that the image group GG displays one image. In the example shown in FIG. 1, the first projection image G1 is projected onto the left region in FIG. 1 of the projection surface SC, while the second projection image G2 is projected onto the right region in FIG. 1 of the projection surface SC. Then, the right end portion of the first projection image G1 in FIG. 1 and the left end portion of the second projection image G2 in FIG. 1 are joined together. That is, the right end portion of the first projection image G1 in FIG. 1 overlaps the left end portion of the second projection image G2 in FIG. 1.

[0014] A part of the first projected image G1 and the second projected image G2 overlap each other in the overlapping region R. The overlapping region R is a region where the following blending process is performed to make the joint between the first projected image G1 and the second projected image G2 inconspicuous. Thus, in the multi-projection system 100, an overlapping region R is set for a part of the first projected image G1 projected from the first projector 10-1 and a part of the second projected image G2 projected from the second projector 10-2 to overlap each other on the projection surface SC.

[0015] In the present embodiment, the first projector 10-1 is the main device and controls the operation of the second projector 10-2 which is the sub-device. Further, the first projector 10-1 has a correction function for correcting the positional deviation between the second projected image G2 and the first projected image G1. The second projector 10-2 is configured in the same manner as the first projector 10-1 except that it does not have the correction function. Note that the second projector 10-2 may have a configuration that can be controlled by the first projector 10-1, and may have a configuration different from that of the first projector 10-1. When the number of projectors 10 included in the multi-projection system 100 is three or more, among the three or more projectors 10, one projector 10 is the main device, and each of the other two or more projectors 10 is a sub-device.

[0016] The terminal device 30 is a device having a function of dividing video data showing one image into a plurality of video data to be projected onto a plurality of projectors 10, and a function of supplying each video data obtained by the division process to the corresponding projector 10.

[0017] The terminal device 30 of the present embodiment divides the video data showing one image into video data IMG1 and video data IMG2, and then supplies the video data IMG1 to the first projector 10-1 and the video data IMG2 to the second projector 10-2.

[0018] In the example shown in FIG. 1, the terminal device 30 is a notebook computer. Note that the terminal device 30 is not limited to a notebook computer, and may be, for example, a desktop computer, a smartphone, or a tablet terminal, etc., or may be a video playback device, a DVD (Digital Versatile Disk) player, a Blu-ray disk player, a hard disk recorder, a television tuner device, a set-top box for CATV (Cable television), a video game machine, etc.

[0019] 1-2. Projector FIG. 2 is a block diagram of the first projector 10-1 according to the first embodiment. In FIG. 2, in addition to the first projector 10-1, the connection states of the second projector 10-2 and the terminal device 30 with respect to the first projector 10-1 are shown. Note that in FIG. 2, the configuration of the first projector 10-1 is typically shown, but the configuration of the second projector 10-2 is the same as that of the first projector 10-1 except that it does not have a correction function, and in the following description of the components, the video data IMG1 may be replaced with the video data IMG2. In the following, for the components of the projector 10, the components of the first projector 10-1 are distinguished from the components of the second projector 10-2 by adding the subscript "-1" to the reference numerals of the components of the first projector 10-1 or adding the subscript "-2" to the reference numerals of the components of the second projector 10-2.

[0020] As shown in FIG. 2, the first projector 10-1 includes a storage device 11, a processing device 12, a communication device 13, an image processing circuit 14, an optical device 15, an operating device 16, an imaging device 17, and a temperature sensor 18. These are connected to be communicable with each other.

[0021] The storage device 11 is a storage device that stores programs executed by the processing device 12 and data processed by the processing device 12. The storage device 11 is configured to include, for example, a hard disk drive or a semiconductor memory. Note that part or all of the storage device 11 may be provided in an external storage device or a server, etc., outside the first projector 10-1.

[0022] The storage device 11 stores a program PR1, first imaging data D1, second imaging data D2, and correction amount information PA.

[0023] The program PR1 is a program for executing a control method to be described in detail later. The first imaging data D1 is data indicating an image obtained by the imaging device 17 imaging a corresponding region RC, which will be described later, corresponding to the overlapping region R in a state where a first projected image G1 to be described later is projected onto the projection surface SC. The second imaging data D2 is data indicating an image obtained by the imaging device 17 imaging the corresponding region RC, which will be described later, in a state where a second projected image G2 to be described later is projected onto the projection surface SC. The correction amount information PA is information indicating a correction amount for correcting the deviation between the first projected image G1 and the second projected image G2 in the range of the overlapping region R.

[0024] The processing device 12 is a processing device having a function of controlling each part of the first projector 10-1 and a function of processing various data. The processing device 12 is configured to include, for example, a processor such as a CPU (Central Processing Unit). Note that the processing device 12 may be configured by a single processor or a plurality of processors. Also, part or all of the functions of the processing device 12 may be realized by hardware such as a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array). Further, the processing device 12 may be integrated with the image processing circuit 14.

[0025] The communication device 13 is a communication device capable of communicating with various devices, and acquires video data IMG1 from the terminal device 30 or communicates with the second projector 10-2. For example, the communication device 13 is a wired communication device such as a wired LAN (Local Area Network), USB (Universal Serial Bus), HDMI (High Definition Multimedia Interface), or a wireless communication device such as LPWA (Low Power Wide Area), a wireless LAN including Wi-Fi, or Bluetooth. Each of "HDMI", "Wi-Fi", and "Bluetooth" is a registered trademark.

[0026] The image processing circuit 14 is a circuit that performs necessary processing on the video data IMG1 from the communication device 13 and inputs it to the optical device 15. The image processing circuit 14 has, for example, a frame memory (not shown), expands the video data IMG1 in the frame memory, and appropriately executes various processes such as resolution conversion processing, resizing processing, and distortion correction processing, and inputs the result to the optical device 15. Further, the image processing circuit 14 executes a process of correcting the deviation between the first projection image G1 and the second projection image G2 at least in the range of the overlapping region R based on the correction amount information PA stored in the storage device 11. Note that the image processing circuit 14 may execute a process such as OSD (On Screen Display) processing that generates image information for menu display or operation guidance and synthesizes it with the video data IMG1 as necessary. Further, the image processing circuit 14 may execute a process of correcting the deviation between the entire first projection image G1 and the entire second projection image G2 based on the correction amount information PA stored in the storage device 11.

[0027] The optical device 15 is a device that projects image light onto the projection surface SC. The optical device 15 includes a light source 15a, a light modulator 15b, and a projection optical system 15c. The projection optical system 15c of the first projector 10-1 is an example of the "first optical system". Although not shown, the second projector 10-2 has a projection optical system 15c similar to that of the first projector 10-1, and the projection optical system 15c of the second projector 10-2 is an example of the "second optical system".

[0028] The light source 15a is configured to include a light source such as a halogen lamp, a xenon lamp, an ultra-high pressure mercury lamp, an LED (Light Emitting Diode), or a laser light source, and emits red, green, and blue light respectively. The light modulator 15b draws an image based on the video data IMG1 supplied from the terminal device 30. The light modulator 15b of the first projector 10-1 is an example of the drawing panel of the first projector. Note that the light modulator 15b of the first projector 10-1 may be referred to as the first drawing panel, and the light modulator 15b of the second projector 10-2 may be referred to as the second drawing panel. The light modulator 15b includes three light modulation elements provided corresponding to red, green, and blue. Each light modulation element includes, for example, a transmissive liquid crystal panel, a reflective liquid crystal panel, or a DMD (Digital Micromirror Device), and generates image light of each color by modulating the light of the corresponding color. The image light of each color generated by the light modulator 15b is synthesized by a color synthesis optical system to become full-color image light. The projection optical system 15c is an optical system including a projection lens or the like that forms and projects the full-color image light from the light modulator 15b onto the projection surface SC. The image drawn on the light modulator 15b, that is, the drawn image, is projected onto the projection surface SC through the projection lens.

[0029] The operation device 16 is a device that receives operations from the user. For example, the operation device 16 includes an operation panel (not shown) and an infrared remote control receiver. The operation panel is provided on the exterior housing of the first projector 10-1 and outputs a signal based on an operation from the user. The infrared remote control receiver receives an infrared signal from a remote control (not shown), decodes the infrared signal, and outputs a signal based on the operation of the remote control. Note that the operation device 16 is provided as necessary and may be omitted.

[0030] The imaging device 17 is a digital camera having an imaging element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). The imaging element has a plurality of pixels.

[0031] The temperature sensor 18 is a temperature sensor such as a thermistor that detects the temperature of the projection optical system 15c. The temperature sensor 18 is built into the projector 10 and is fixed at a predetermined location near the projection optical system 15c inside the housing of the projector 10. When using the temperature sensors 18 of both the first projector 10-1 and the second projector 10-2, the temperatures of the projection optical systems 15c of both the first projector 10-1 and the second projector 10-2 can be detected.

[0032] In the above first projector 10-1, the processing device 12 functions as a projection control unit 12a, an imaging control unit 12b, and a correction unit 12c by executing the program PR1 stored in the storage device 11. Therefore, the processing device 12 includes the projection control unit 12a, the imaging control unit 12b, and the correction unit 12c.

[0033] The projection control unit 12a controls the operations of the image processing circuits 14 and the optical devices 15 of the first projector 10-1 and the second projector 10-2 respectively. More specifically, the projection control unit 12a causes the first image group GG1 described later to be projected onto the projection surface SC, or causes the second image group GG2 described later to be projected onto the projection surface SC.

[0034] The imaging control unit 12b controls the operation of the imaging device 17 of one or both of the first projector 10-1 and the second projector 10-2. More specifically, the imaging control unit 12b causes the imaging device 17 to image the corresponding region RC described later in a state where the first image group GG1 described later is projected onto the projection plane SC, or causes the imaging device 17 to image the corresponding region RC described later in a state where the second image group GG2 described later is projected onto the projection plane SC, thereby acquiring the first imaging data D1 and the second imaging data D2.

[0035] The correction unit 12c generates correction amount information PA based on the first imaging data D1 and the second imaging data D2. More specifically, the correction unit 12c analyzes the first imaging data D1 and the second imaging data D2 to detect the deviation between the first projection image G1 and the second projection image G2 in the range of the overlapping region R, and generates the correction amount information PA based on the detection result.

[0036] 1-3. Control Method FIG. 3 is a flowchart showing the flow of the control method according to the first embodiment. The control method is performed using the above-described multi-projection system 100.

[0037] In the control method of the present embodiment, first, as shown in FIG. 3, in step S10, the processing device 12 performs initial alignment of the coordinate system of the imaging device 17 and the coordinate system of the optical device 15. Although this will be described in detail later with reference to FIG. 4, this initial alignment is performed by associating the coordinate system of the imaging device 17 of the first projector 10-1 with the coordinate system of the optical device 15 of each of the first projector 10-1 and the second projector 10-2, and the coordinate system of the imaging device 17 of the first projector 10-1.

[0038] After step S10, in step S20, the projection control unit 12a causes the first image group GG1, which will be described in detail later, to be projected onto the projection surface SC. Although it will be described in detail later with reference to FIG. 5, the first image group GG1 is an image group GG having a first state in which the brightness BR1 of the first projection image G1 is greater than zero and the brightness BR2 of the second projection image G2 is zero in at least a part of the corresponding region RC corresponding to the overlapping region R. Step S20 of the present embodiment includes a step S21 of reducing a blend range, which is a range in which blending processing of the first projection image G1 and the second projection image G2 is performed.

[0039] After step S20, in step S30, the imaging control unit 12b acquires the first imaging data D1. Although it will be described in detail later with reference to FIG. 5, this acquisition is performed by causing the imaging device 17 to image the corresponding region RC in a state where the first image group GG1 is projected onto the projection surface SC. Step S30 of the present embodiment includes a step S31 of imaging a first state region R1a, which will be described later.

[0040] After step S30, in step S40, the projection control unit 12a causes the second image group GG2, which will be described in detail later, to be projected onto the projection surface SC. Although it will be described in detail later with reference to FIG. 6, the second image group GG2 is an image group GG having a second state in which the brightness BR1 of the first projection image G1 is zero and the brightness BR2 of the second projection image G2 is greater than zero in at least a part of the corresponding region RC.

[0041] After step S40, in step S50, the imaging control unit 12b acquires the second imaging data D2. Although it will be described in detail later with reference to FIG. 6, this acquisition is performed by causing the imaging device 17 to image the corresponding region RC in a state where the second image group GG2 is projected onto the projection surface SC. Step S40 of the present embodiment includes a step S41 of imaging a second state region R2c, which will be described later.

[0042] After step S50, in step S60, the correction unit 12c detects the deviation between the first projection image G1 and the second projection image G2 within the range of the overlapping region R. Although this will be described in detail later with reference to FIGS. 7 to 8, this detection is performed by analyzing the first imaging data D1 and the second imaging data D2. Step S60 of the present embodiment includes, in this order, a step S61 of cutting out an analysis region RA1 described later, a step S62 of performing coordinate transformation on the analysis region RA1 described later, a step S63 of performing a matching process, and a step S64 of detecting a deviation amount and the like.

[0043] After step S60, in step S70, the correction unit 12c calculates a correction amount based on the deviation amount and the like detected in step S60. Details of this calculation will be described later with reference to FIG. 9.

[0044] After step S70, in step S80, the correction unit 12c generates correction amount information PA based on the correction amount calculated in step S70. The generated correction amount information PA is stored in the storage device 11. Thereby, the deviation between the first projection image G1 and the second projection image G2 within the range of the overlapping region R is corrected.

[0045] After step S80, in step S90, the correction unit 12c detects the temperature of the projection optical system 15c-1 based on the output from the temperature sensor 18.

[0046] Thus, in step S90, the temperature of the projection optical system 15c-1 for the first projector 10-1 to project the first projection image G1 is detected based on the output from the temperature sensor 18.

[0047] After step S90, in step S100, the correction unit 12c determines whether or not a predetermined time has elapsed, and repeats step S100 until the predetermined time has elapsed (step S100: NO).

[0048] When it is determined that a predetermined time has elapsed (step S100: YES), in step S110, the correction unit 12c determines whether or not the target temperature has been reached based on the temperature detected in step S90.

[0049] When it is determined that the target temperature has not been reached (step S110: NO), the aforementioned step S20 is executed. As a result, steps S20 to S110 are repeatedly executed until it is determined that the target temperature has been reached. At this time, the steps excluding step S100 among the aforementioned steps S20 to S110 are executed at every predetermined time by step S100. Thereby, the correction amount information PA is updated at every predetermined time so that the deviation between the first projection image G1 and the second projection image G2 due to changes in the optical characteristics of the projection optical system 15c or the like is corrected until the optical characteristics of the projection optical system 15c are stabilized.

[0050] As described above, “NO” in step S110 intermittently executes deviation detection and deviation correction until the temperature of the projection optical system 15c-1 reaches the target temperature based on the output from one or a plurality of temperature sensors 18.

[0051] When it is determined that the target temperature has been reached (step S110: NO), in step S120, the projection control unit 12a expands the blend range, which is the range where the first projection image G1 and the second projection image G2 are subjected to blend processing, to the entire area of the overlapping region R. After step S120, the processing for deviation detection and deviation correction ends. Note that step S120 is executed as necessary and may be omitted. In this case, when it is determined that the target temperature has been reached (step S110: NO), the processing for deviation detection and deviation correction ends while the blend range is maintained at the second range β.

[0052] Thus, when "YES" in step S110, based on the output from one or more temperature sensors 18, after the temperature of the projection optical system 15c-1 reaches the target temperature, the processing device 12 stops detecting the deviation and correcting the deviation. This is because the cause of the deviation between the first projection image G1 and the second projection image G2 is mainly due to the change in the optical characteristics caused by the temperature change of the projection optical system 15c. The change in the optical characteristics occurs, for example, due to the change in the amount of distortion of the projection optical system 15c.

[0053] As described above, the control method of the multi-projection system 100 is executed. Hereinafter, steps S10 to S80 will be described in detail in order.

[0054] FIG. 4 is a diagram for explaining the initial alignment. In step S10, as shown in FIG. 4, first, with the image group GG0 projected onto the projection surface SC, the imaging device 17 of the first projector 10-1 images the corresponding region RC. The corresponding region RC is a region corresponding to the overlapping region R on the projection surface SC. Specifically, the corresponding region RC is a region having the same number of pixels or width as the overlapping region R in the arrangement direction DR. The width is indicated, for example, by the metric method or the yard-pound method. In the corresponding region RC, as will be described later, the brightness of one of the first projection image G1 and the second projection image G2 may be greater than zero, and the brightness of the other may be zero. For example, if the brightness of the first projection image G1 is greater than zero throughout the corresponding region RC and the brightness of the second projection image G2 is zero throughout the corresponding region RC, that is, the second projection image G2 is a black image, then substantially only the first projection image G1 is projected onto the projection surface SC in the corresponding region RC. Therefore, the first projection image G1 does not have the overlapping region R, which is the region overlapping with the second projection image G2. On the other hand, during normal use when the user projects the desired content as the image group GG onto the projection surface SC, in the corresponding region RC, an image group GG in which the brightnesses of both the first projection image G1 and the second projection image G2 are greater than zero can be projected. Therefore, the first projection image G1 has the overlapping region R that overlaps with the second projection image G2. Therefore, the corresponding region RC is a region that can become the overlapping region R during normal use. The image group GG0 is an image group GG in which each of the first projection image G1 and the second projection image G2 has a state including the color code pattern PT.

[0055] Note that before step S10, the user adjusts how much width the first projected image G1 overlaps with the second projected image G2. For example, the user adjusts the position of the second projector 10-2 relative to the position of the first projector 10-1 so that a part of the first projected image G1 overlaps a part of the second projected image G2. Then, the user inputs information indicating the width of the overlapping region R, such as the number of pixels, into the terminal device 30, and sets the width of the overlapping region R for the first projector 10-1 and the second projector 10-2. Thereby, the control method of the multi-projection system 100 is executed with the first projector 10-1 and the second projector 10-2 knowing the number of pixels in the overlapping region R. In the control method described later, the blend region is changed to various sizes, and such control also uses the information indicating the number of pixels in the overlapping region R.

[0056] The color code pattern PT in the first projected image G1 and the color code pattern PT in the second projected image G2 are displayed discriminably in the image group GG0. The position of the color code pattern PT in the first projected image G1 is known as the coordinate value in the coordinate system of the optical device 15 of the first projector 10-1. On the other hand, the position of the color code pattern PT in the second projected image G2 is known as the coordinate value in the coordinate system of the optical device 15 of the second projector 10-2. Note that in the coordinate system of the optical device 15 of the first projector 10-1, each pixel of the light modulation element included in the optical device 15 of the first projector 10-1 is indicated by a coordinate value. In the coordinate system of the optical device 15 of the second projector 10-2, each pixel of the light modulation element included in the optical device 15 of the second projector 10-2 is indicated by a coordinate value.

[0057] In step S10, based on the captured image obtained by the imaging device 17 of the first projector 10-1 capturing the image group GG0 in this way, the coordinate system of the imaging device 17 of the first projector 10-1 is associated with the coordinate systems of the respective optical devices 15 of the first projector 10-1 and the second projector 10-2. Here, the coordinate system of the imaging device 17 of the first projector 10-1 is the two-dimensional coordinate system of the captured image acquired by the imaging device 17, and the coordinate systems of the respective optical devices 15 of the first projector 10-1 and the second projector 10-2 are the two-dimensional coordinate systems of the respective drawing panels of the first projector 10-1 and the second projector 10-2. Note that in the coordinate system of the imaging device 17 of the first projector 10-1, each pixel of the imaging element included in the imaging device 17 of the first projector 10-1 is represented by a coordinate value.

[0058] Here, as described above, since the color code pattern PT in the first projection image G1 and the color code pattern PT in the second projection image G2 are displayed discriminably in the image group GG, based on the captured image, the positions of the color code pattern PT in the first projection image G1 and the color code pattern PT in the second projection image G2 can be detected as coordinate values in the coordinate system of the imaging device 17 of the first projector 10-1.

[0059] Also, as described above, since the position of the color code pattern PT in the first projection image G1 is known as a coordinate value in the coordinate system of the optical device 15 of the first projector 10-1, the coordinate system of the imaging device 17 of the first projector 10-1 can be associated with the coordinate system of the optical device 15 of the first projector 10-1. Similarly, as described above, since the position of the color code pattern PT in the second projection image G2 is known as a coordinate value in the coordinate system of the optical device 15 of the second projector 10-2, the coordinate system of the imaging device 17 of the first projector 10-1 can be associated with the coordinate system of the optical device 15 of the second projector 10-2.

[0060] In FIG. 4, a mode of using the color code pattern PT for the image group GG0 is illustrated, but the present invention is not limited to this mode. Instead of the color code pattern PT, various patterns capable of associating the coordinate system of the imaging device 17 of the first projector 10-1 with the coordinate systems of the respective optical devices 15 of the first projector 10-1 and the second projector 10-2 may be used.

[0061] FIG. 5 is a diagram for explaining the first image group GG1. In step S20, as shown in FIG. 5, the first image group GG1 is projected onto the projection surface SC. The first image group GG1 is an image group GG having a first state in the corresponding region RC where the brightness BR1 of the first projection image G1 is greater than zero and the brightness BR2 of the second projection image G2 is zero. Note that "the brightness is zero" means the luminance value of a black image. In FIG. 5, for convenience of explanation, the characters "ABC" are displayed in the corresponding region RC of the first image group GG1.

[0062] The first projection image G1 has a non-overlapping region RN1 and a first partial region R1. The non-overlapping region RN1 is a region that does not overlap with the second projection image G2. The first partial region R1 is a region for overlapping with the second projection image G2. At least a part of the first partial region R1 is a first blend region R1b which is a region where blend processing is performed. The blend processing changes the brightness in the arrangement direction DR in which the first projection image G1 and the second projection image G2 are arranged so that the brightness of the overlapping region R when the first projection image G1 and the second projection image G2 are projected to overlap with each other in the overlapping region R matches the brightness of the non-overlapping region RN1.

[0063] On the other hand, the second projection image G2 has a non-overlapping region RN2 and a second partial region R2. The non-overlapping region RN2 is a region that does not overlap with the first projection image G1. The second partial region R2 is a region for overlapping with the first projection image G1. At least a part of the second partial region R2 is a second blend region R2b which is a region where blend processing is performed.

[0064] In step S21 of step S20, the processing device 12 changes the blending range where blending processing is performed in the first partial region R1 from the first range α to a second range β smaller than the first range α by controlling the first drawing panel. As a result, in step S21, the first partial region R1 is adjusted to include, in addition to the first blending region R1b, a first state region R1a having a first state. The first state region R1a includes a region corresponding to the analysis region RA. That is, the analysis region RA is a partial region of the first partial region R1 and is a region on the projection plane SC where the characters "ABC" are displayed among the corresponding regions RC. In the first state region R1a, the brightness BR1 of the first projection image G1 is greater than zero. In the example shown in FIG. 5, the first state region R1a is arranged at a position opposite to the arrangement direction DR with respect to the position of the first blending region R1b. In other words, in step S21 of step S20, the processing device 12 moves, that is, moves, the first blending region R1b to a position on one side (right side) with respect to the first state region R1a in the arrangement direction DR.

[0065] Similarly, in step S21 of step S20, the processing device 12 changes the blending range where blending processing is performed in the second partial region R2 from the first range α to the second range β by controlling the second drawing panel. As a result, in step S21, the second partial region R2 is adjusted to include, in addition to the second blending region R2b, a first state region R2a having a first state. The first state region R2a includes a region corresponding to the analysis region RA of the first partial region R1. In the first state region R2a, the brightness BR2 of the second projection image G2 is zero. Therefore, in the first state region R1a or the first state region R2a, it is observed that only the first projection image G1 is projected as seen from the user or the imaging device 17. Also, the brightness BR2 of the analysis region RA of the first state region R2a is zero. In the example shown in FIG. 5, the first state region R2a is arranged at a position opposite to the arrangement direction DR with respect to the position of the second blending region R2b. In other words, in step S21 of step S20, the processing device 12 moves, that is, moves, the second blending region R2b to the position on the one side (right side) with respect to the first state region R2a in the arrangement direction DR.

[0066] The first range α is, for example, the blending range applied in step S120. In the example shown in FIG. 5, the first range α is the entire area of the first partial region R1. Note that the first range α is not limited to the example shown in FIG. 5, and may be smaller than the first partial region R1 or the second partial region R2 as long as it is larger than the second range β.

[0067] In this way, in step S21, the blending range, which is the range where the blending process of the first projection image G1 and the second projection image G2 is performed, is reduced in the arrangement direction DR.

[0068] In the first blending region R1b, the brightness BR1 of the first projection image G1 changes from the brightness of the non-overlapping region RN1 to zero over the second range β as it goes in the arrangement direction DR. On the other hand, although not shown, when the blending range of the first blending region R1b is the first range α, the brightness BR1 of the first projection image G1 changes from the brightness of the non-overlapping region RN1 to zero over the first range α which is larger than the second range β as it goes in the arrangement direction DR. Therefore, in the first blending region R1b, the brightness distribution in the arrangement direction DR when the blending range is the second range β is different from the brightness distribution in the arrangement direction DR when the blending range is the first range α. Note that in the first blending region R1b, the distribution of the brightness BR1 in the arrangement direction DR, that is, the blending curve, only needs to be set so that the brightness of the overlapping region R coincides with the brightness of the non-overlapping region RN1, and is not limited to the example shown in FIG. 5.

[0069] On the other hand, in the second blending region R2b, the brightness BR2 of the second projected image G2 changes from the brightness of the non-overlapping region RN2 to zero over the second range β as it goes in the direction opposite to the arrangement direction DR. In contrast, although not shown, when the blending range of the second blending region R2b is the first range α, the brightness BR2 of the second projected image G2 changes from the brightness of the non-overlapping region RN2 to zero over the first range α which is larger than the second range β as it goes in the direction opposite to the arrangement direction DR. Therefore, in the second blending region R2b, the brightness distribution in the arrangement direction DR when the blending range is the second range β is different from the brightness distribution in the arrangement direction DR when the blending range is the first range α. Note that in the second blending region R2b, the distribution of the brightness BR2 in the arrangement direction DR, that is, the blending curve, only needs to be set such that the brightness of the overlapping region R matches the brightness of the non-overlapping region RN2, and is not limited to the example shown in FIG. 5.

[0070] In step S31 of step S30, the imaging device 17 images the corresponding region RC, that is, the first state region R1a or the first state region R2a. In this way, in step S30, the imaging device 17 images the corresponding region RC in a state where the first image group GG1 is projected onto the projection surface SC, and thus the first imaging data D1 is acquired. The first imaging data D1 includes an image of the analysis region RA as at least a part of the first partial region R1.

[0071] As described above, in the first state region R1a or the first state region R2a, since the brightness of the first projected image G1 is greater than zero and the brightness of the second projected image G2 is zero, the imaging device 17 can acquire the first imaging data D1 that is not affected by the brightness of the second projected image G2. In step S31 of step S30, a state where the blending range is the second range β is maintained for at least a part of the period during which the imaging device 17 images the first state region R1a or the first state region R2a. Note that in step S30, the region imaged by the imaging device 17 only needs to include a region corresponding to the analysis region RA1 described later.

[0072] FIG. 6 is a diagram for explaining the second image group GG2. In step S40, as shown in FIG. 6, the second image group GG2 is projected onto the projection surface SC. The second image group GG2 is an image group GG having a second state in the corresponding region RC where the brightness BR1 of the first projected image G1 is zero and the brightness BR2 of the second projected image G2 is greater than zero. In FIG. 6, for convenience of explanation, the characters "ABC" are displayed in the corresponding region RC of the second image group GG2, similar to the first image group GG1 in FIG. 5 described above.

[0073] In step S40, the first partial region R1 of the first projected image G1 is adjusted to include, in addition to the first blend region R1b, a second state region R1c having a second state. The second state region R1c includes a region corresponding to the analysis region RA. In the second state region R1c, the brightness BR1 of the first projected image G1 is zero. Also, in step S40, the range of the first blend region R1b is the second range β, similar to step S20 described above. In the example shown in FIG. 6, the second state region R1c is arranged at a position in the arrangement direction DR with respect to the first blend region R1b. In other words, in step S41 of step S40, the processing device 12 moves, that is, shifts, the first blend region R1b to a position on the other side (left side) with respect to the second state region R1c in the arrangement direction DR.

[0074] Similarly, in step S40, the second partial region R2 of the second projected image G2 is adjusted to include, in addition to the second blend region R2b, a second state region R2c having a second state. The second state region R2c includes a region corresponding to the analysis region RA of the second partial region R2. That is, the analysis region RA is a partial region of the second partial region R2 and is the region on the projection surface SC where the characters "ABC" are displayed among the corresponding regions RC. In the second state region R2c, the brightness BR2 of the second projected image G2 is greater than zero. Also, as described above, in the second state region R1c, the brightness BR1 of the first projected image G1 is zero. Therefore, in the second state region R1c or the second state region R2c, it is observed that only the second projected image G2 is projected as seen from the user or the imaging device 17. Also, in step S40, the range of the second blend region R2b is the second range β, similar to step S20 described above. In the example shown in FIG. 6, the second state region R2c is arranged at the position in the arrangement direction DR with respect to the position of the second blend region R2b. In other words, in step S41 of step S40, the processing device 12 moves, i.e., moves closer, the first blend region R1b to the position on the other side (left side) with respect to the second state region R2c in the arrangement direction DR.

[0075] In step S50, the imaging device 17 images the second state region R1c or the second state region R2c. Thus, in step S50, the imaging device 17 images the corresponding region RC in the state where the second image group GG2 is projected onto the projection surface SC, thereby obtaining the second imaging data D2. The second imaging data D2 includes at least an image of the analysis region RA as a part of the second partial region R2.

[0076] As described above, in the second state region R1c or the second state region R2c, the brightness of the first projection image G1 is zero, and the brightness of the second projection image G2 is greater than zero. Therefore, the imaging device 17 can acquire the second imaging data D2 that is not affected by the brightness of the first projection image G1. In step S51 of step S50, a state in which the blending range is the second range β is maintained at least in part of the period during which the imaging device 17 images the second state region R1c or the second state region R2c. Note that in step S50, the region imaged by the imaging device 17 only needs to include a region corresponding to the analysis region RA1 described later.

[0077] FIG. 7 is a diagram for explaining the analysis region RA1 used for calculating the correction amount and the coordinate transformation of the analysis region RA1. In step S60, first, in step S61, as shown on the left side in FIG. 7, an analysis region RA2, which is a part of the second imaging data D2, is cut out from the second imaging data D2. The analysis region RA2 is a region corresponding to the aforementioned analysis region RA in the image shown by the second imaging data D2. Here, since the image shown by the second imaging data D2 is represented in the coordinate system of the imaging device 17, the analysis region RA2 is represented in the coordinate system of the imaging device 17.

[0078] After step S61 as described above, in step S62, as shown on the right side in FIG. 7, the analysis region RA2 is transformed into the coordinate system of the first projector 10-1. Specifically, the analysis region RA2 is transformed into the coordinate system of the light modulator 15b included in the first projector 10-1. This transformation is performed based on the association obtained in step S10 described above. The analysis region RA2 transformed into the coordinate system of the first projector 10-1 is an example of the conversion data.

[0079] FIG. 8 is a diagram for explaining the matching process between the first partial region R1 and the analysis region RA2. In step S63, a matching process such as a phase-limiting method is performed on the first partial region R1 and the analysis region RA2. In FIG. 8, an aspect is exemplified in which the analysis region RA1 corresponding to the aforementioned analysis region RA in the first partial region R1 is used for the matching. The analysis region RA1 is represented in the coordinate system of the first projector 10-1, that is, the coordinate system of the first drawing panel. The analysis region RA1 is a region corresponding to the analysis region RA of the first partial region R1 in the first projected image G1. The analysis region RA1 is an example of drawing data. That is, the analysis region RA1 is data input to the first drawing panel for the first projector 10-1 to draw the first partial region R1 including the analysis region RA on the first drawing panel. The analysis region RA1 is an example of drawing data and only needs to include data corresponding to at least the analysis region RA of the first partial region R1.

[0080] Thus, each of the analysis region RA1 and the analysis region RA2 is represented by the coordinate values (x, y) in the coordinate system of the first projector 10-1. That is, in the present embodiment, the matching process for calculating the deviation between the first projected image G1 and the second projected image G2 is calculated in a unified manner in the coordinate system of the light modulator 15b (first drawing panel) of the first projector 10-1. Note that the analysis region RA1 may be obtained by being cut out from the first captured data D1 and then converted into the coordinate system of the first projector 10-1.

[0081] As described above, in the first partial region R1 of the first captured data D1, since the brightness BR1 of the first projected image G1 is greater than zero and the brightness BR2 of the second projected image G2 is zero, by using the analysis region RA1, the position of the first projected image G1 can be detected without being affected by the second projected image G2. On the other hand, as described above, in the second partial region R2 of the second captured data D2, since the brightness BR1 of the first projected image G1 is zero and the brightness BR2 of the second projected image G2 is greater than zero, by using the analysis region RA2, the position of the second projected image G2 can be detected without being affected by the first projected image G1.

[0082] In step S64, based on the result of the matching process, one or both of the amount and direction of the deviation between the first projected image G1 and the second projected image G2 are detected. In the example shown in FIG. 8, detection values (dx, dy) indicating the amount and direction of the deviation between the first projected image G1 and the second projected image G2 are obtained. Such detection values (dx, dy) are obtained for a plurality of locations in the analysis regions RA1 and RA2.

[0083] FIG. 9 is a diagram for explaining the calculation of the deviation between the first projected image G1 and the second projected image G2 in the range of the overlapping region R. In step S70, based on the deviation detected in step S60, the first projector 10-1 calculates a correction amount for correcting the first projected image G1. More specifically, in step S70, among the detection values (dx, dy) of the deviations at a plurality of locations calculated in step S60, excluding the abnormal value AB, values obtained from the relationship with other detection values around the abnormal value AB are complemented. Thereby, a more accurate correction amount is obtained. Information indicating this correction amount is stored in the storage device 11 as correction amount information PA.

[0084] In step S70 of the present embodiment, the blend range may be maintained within the second range β. Note that during the execution of step S70, the blend range may be unevenly distributed on the left side of the corresponding region RC as shown in FIG. 5, may be unevenly distributed on the right side of the corresponding region RC as shown in FIG. 6, or may be located at the center of the corresponding region RC as shown in FIG. 10 described later. Further, the blend range may move within the corresponding region RC. In this case, it is preferable that the movement of the blend range is synchronized with the vertical synchronization signal of the video data IMG1. Also, during the execution of step S70, the blend range may be smaller than the second range β.

[0085] FIG. 10 is a diagram for explaining a blend range during a period in which a correction amount is calculated. In step S80, the first projector 10-1 is controlled based on the correction amount calculated in step S70. As a result, in step S80, as shown in FIG. 10, the image group GG3 is projected onto the projection surface SC. The image group GG3 is an image group GG in which the deviation between the first projection image G1 and the second projection image G2 is corrected based on the correction amount information PA. This correction is performed by adjusting the position of the first projection image G1 with respect to the position of the second projection image G2. For example, at least one of the shape, position, or orientation of the drawn image drawn on the light modulator 15b of the first projector 10-1 is corrected so that the position of the first projection image G1 coincides with the position of the second projection image G2.

[0086] In the example shown in FIG. 10, the first blend region R1b and the second blend region R2b are arranged at the center of the corresponding region RC. Also, the blend range of the first blend region R1b and the second blend region R2b is the second range β. Note that the blend range in step S80 is not limited to the example shown in FIG. 10, and may be unevenly distributed on the left side of the corresponding region RC as shown in FIG. 5, or may be unevenly distributed on the right side of the corresponding region RC as shown in FIG. 6.

[0087] As described above, the control method in the multi-projection system 100 includes step S20, step S30, step S40, step S50, and step S60.

[0088] Here, the first projector 10-1 used in the control method of this embodiment includes an optical device 15 and a processing device 12. The processing device 12 of the first projector 10-1 causes steps S20, S30, S40, S50, and S60 to be executed. Here, in step S20, the processing device 20 controls the operation of the optical device 15 of the first projector 10-1 and the operation of the second projector 10-2 so that the first image group GG1 is projected onto the projection surface SC. Also, in step S40, the processing device 12 of the first projector 10-1 controls the operation of the optical device 15 of the first projector 10-1 and the operation of the second projector 10-2 so that the second image group GG2 is projected onto the projection surface SC.

[0089] Further, the control method of this embodiment is realized by a processing device 12, which is an example of a "computer", executing a program PR1. The program PR1 causes the processing device 12 to execute steps S20, S30, S40, S50, and S60.

[0090] In the above control method, the first projector 10-1, and the program PR1, in the first state of step S20, the brightness BR1 of the first projection image G1 is greater than zero while the brightness BR2 of the second projection image G2 is zero. Therefore, the first imaging data D1 obtained in step S30 does not include noise caused by the second projection image G2. Similarly, in the second state of step S40, the brightness BR1 of the first projection image G1 is zero while the brightness BR2 of the second projection image G2 is greater than zero. Therefore, the second imaging data D2 obtained in step S50 does not include noise caused by the first projection image G1. In this way, the noise included in the first imaging data D1 and the second imaging data D2 can be reduced. As a result, the accuracy of the result of analyzing the first imaging data D1 and the second imaging data D2 in step S60 can be improved. As a result, a decrease in the detection accuracy of the deviation between the first projection image G1 and the second projection image in the range of the overlapping region R can be suppressed.

[0091] As described above, the first projected image G1 has a non-overlapping region RN1 and a first partial region R1. The non-overlapping region RN1 is a region that does not overlap with the second projected image G2. The first partial region R1 is a region for overlapping with the second projected image G2. At least a part of the first partial region R1 is a region where blending processing is performed. The blending processing changes the brightness in the arrangement direction DR in which the first projected image G1 and the second projected image G2 are arranged so that the brightness of the overlapping region R when the first projected image G1 and the second projected image G2 are projected to overlap each other in the overlapping region R matches the brightness of the non-overlapping region RN1. Step S20 includes step S21. Step S21 adjusts the first partial region R1 to include a first state region R1a having a first state and a first blend region R1b where blending processing is performed by changing the blend range where blending processing is performed in the first partial region R1 from the first range α to a second range β smaller than the first range α. Step S30 includes step S31. Step S31 captures the first state region R1a with the imaging device 17. Thus, since the first partial region R1 includes not only the first state region R1a but also the first blend region R1b, a seamless composite image can be displayed as part of the image group GG even during the period of detecting the deviation between the first projected image G1 and the second projected image in the range of the overlapping region R.

[0092] Also, as described above, the brightness distribution in the arrangement direction DR when the blend range is the second range β is different from the brightness distribution in the arrangement direction DR when the blend range is the first range α. Thereby, the brightness distribution can be changed according to the range where blending processing is performed in the first partial region R1.

[0093] Furthermore, as described above, step S60 includes step S61, step S62, step S63, and step S64. Step S61 cuts out an analysis region RA1 represented in the coordinate system of the imaging device 17 from the second imaging data D2. Step S62 converts the analysis region RA1 into the coordinate system of the first projector 10-1. Step S63 performs a matching process on a first partial region R1, which is a region for overlapping with the second projection image G2 in the first projection image G1 and is represented in the coordinate system of the first projector 10-1, and the analysis region RA1 converted into the coordinate system of the first projector 10-1. Step S64 detects one or both of the amount and direction of the deviation between the first projection image G1 and the second projection image G2 based on the result of the matching process. In this way, by including step S60, step S61, step S62, step S63, and step S64, the deviation between the first projection image G1 and the second projection image G2 in the range of the overlapping region R can be preferably detected.

[0094] Also, as described above, the control method of the present embodiment includes step S70 and step S80. Step S70 calculates a correction amount for correcting one or both of the first projection image G1 and the second projection image G2 based on the detected deviation. Step S80 controls one or both of the first projector 10-1 and the second projector 10-2 based on the correction amount. In the above aspect, the deviation between the first projection image G1 and the second projection image G2 in the range of the overlapping region R can be reduced. Thereby, the image quality of the overlapping region can be improved.

[0095] Furthermore, as described above, in step S70, the blending range is maintained within the second range β. That is, the control method of the present embodiment includes maintaining the state where the blending range is the second range β for a first period. In the above aspect, compared with the case where the first period is not provided, the change in the blending range can be made less noticeable to the user. The first period is, for example, 10 seconds, but is not particularly limited as long as it is a finite time.

[0096] Also, as described above, the control method of the present embodiment includes step S90 and step S110. Step S90 is a step of detecting the temperature of a projection optical system 15c-1, which is an example of a "first optical system" for the first projector 10-1 to project a first projection image G1, based on the output from a temperature sensor 18, which is an example of one or more "sensors". The temperature sensor 18 is, for example, a thermistor. "NO" in step S110 intermittently executes deviation detection and deviation correction until the temperature of the projection optical system 15c-1 reaches the target temperature based on the output from one or more temperature sensors 18. "YES" in step S110 stops deviation detection and deviation correction after the temperature of the projection optical system 15c-1 reaches the target temperature based on the output from one or more temperature sensors 18. Through such steps S90 and S110, the deviation correction can be periodically performed until the temperature of the projection optical system 15c-1 stabilizes. Thereby, appropriate detection of the deviation can be performed in a timely manner.

[0097] 2. Second Embodiment Hereinafter, a second embodiment of the present disclosure will be described. For elements whose actions and functions are the same as those in the first embodiment in the forms exemplified below, the reference numerals used in the description of the first embodiment are reused, and the detailed description of each is appropriately omitted.

[0098] FIG. 11 is a block diagram of the first projector 10-1 according to the second embodiment. The first projector 10-1 of the present embodiment is configured in the same manner as the first projector 10-1 of the first embodiment, except that a program PR2 is used instead of the program PR1 of the first embodiment.

[0099] In the first projector 10-1 of the present embodiment, the processing device 12 functions as a projection control unit 12d, an imaging control unit 12b, and a correction unit 12c by executing the program PR2 stored in the storage device 11.

[0100] The projection control unit 12d controls the operations of the image processing circuits 14 and the optical devices 15 of the first projector 10-1 and the second projector 10-2 in the same manner as the projection control unit 12a of the first embodiment, except that it expands the blending range after the projection of the second image group GG2.

[0101] FIG. 12 is a flowchart showing the flow of the control method according to the second embodiment. The control method of this embodiment is the same as the control method of the first embodiment, except that step S120 of the first embodiment is omitted and step S130 is added.

[0102] Step S130 is executed between step S50 and step S60. In step S130, the projection control unit 12d expands the blending range, which is the range where the blending process of the first projected image G1 and the second projected image G2 is performed, to the entire area of the overlapping region R. That is, in step S130, the projection control unit 12d changes the blending range from the second range β to the first range α.

[0103] Thus, the control method of this embodiment includes changing the blending range from the second range β to the first range α in the first partial region R1 in step S130.

[0104] FIG. 13 is a diagram for explaining the blending range during the period of calculating the correction amount. Steps S60 to S110 of this embodiment are executed after the execution of step S130 described above. Therefore, the control method of this embodiment includes maintaining the state where the blending range is the first range α over the period of calculating the correction amount in step S70, as shown in FIG. 13. In the example shown in FIG. 13, the first range α is the entire area of the corresponding region RC, but it is not limited to this. The first range α only needs to be larger than the second range β.

[0105] Also according to the above-described second embodiment, the image quality in the overlapping region R of the projected image can be improved. As described above, the control method of this embodiment further includes maintaining the state in which the blend range is the first range α over the period for calculating the correction amount. Therefore, a suitable blending process can be performed by expanding the blend range during periods other than when necessary. Thereby, the image quality of the overlapping region R can be enhanced.

[0106] 3. Modification Example Each of the embodiments illustrated above can be variously modified. Specific modification modes applicable to the above-described embodiments are illustrated below. Two or more modes arbitrarily selected from the following illustrations can be appropriately combined within a range that does not conflict with each other.

[0107] 3-1. Modification Example 1 In the above-described embodiment, a mode of performing blending processing is illustrated, but it is not limited to this mode, and the first blend region R1b and the second blend region R2b may be omitted.

[0108] 3-2. Modification Example 2 In the above-described embodiment, a mode of acquiring the first imaging data D1 and the second imaging data D2 using the imaging device 17 of the first projector 10-1 is illustrated, but it is not limited to this mode. For example, the acquisition of the first imaging data D1 and the second imaging data D2 may be performed using the imaging device 17 of the second projector 10-2 instead of or in addition to the imaging device 17 of the first projector 10-1.

[0109] 3-3. Modification Example 3 In step S70 of the foregoing embodiment, a correction amount for the first projector 10-1 to correct the first projected image G1 is calculated based on the deviation detected in step S60, but the present disclosure is not limited to this mode. For example, the second projector 10-2 has a correction function, and in step S70, a correction amount for the second projector 10-2 to correct the second projected image G2 is calculated based on the deviation detected in step S60, and the drawn image of the light modulator 15b of the second projector 10-2 may be corrected based on the correction amount. Alternatively, in step S70, both the first projector 10-1 and the second projector 10-2 have a correction function, and a correction amount for both the first projector 10-1 and the second projector 10-2 to correct the second projected image G2 is calculated based on the deviation detected in step S60. When both the first projector 10-1 and the second projector 10-2 have a correction function, the correction amount is preferably half of the correction amount when only one of the first projector 10-1 or the second projector 10-2 has a correction function. Alternatively, a correction amount for the first projector 10-1 to correct the first projected image G1 is calculated, and the drawn image of the light modulator 15b of the second projector 10-2 is corrected based on the correction amount. In this case, for example, by inverting the sign of the correction amount calculated by the first projector 10-1, the correction amount for the first projector 10-1 to correct the first projected image G1 is preferably converted into a correction amount for the second projector 10-2 to correct the drawn image of the light modulator 15b of the second projector 10-2.

[0110] Note that part or all of the method of the present disclosure including the calculation of the correction amount may be performed independently by each of the terminal device 30, the processing device 12, and the processing device of the second projector 10-2 having the same function as the processing device 12, or they may share each step included in the method of the present disclosure.

[0111] 3-4. Modification Example 4 In step S80 of the foregoing embodiment, the first projector 10-1 is controlled based on the correction amount calculated in step S70, but the present invention is not limited to this aspect. For example, the second projector 10-2 has a correction function, correction amount information PA is transmitted from the first projector 10-1 to the second projector 10-2, and the second projector 10-2 may be controlled based on the correction amount information PA. In this case, the correction of the image group GG is performed by adjusting the positions of the first projection image G1 and the second projection image G2.

[0112] 3-5. Modification Example 5 At least one of the program PR1 of Embodiment 1 or the program PR2 of Embodiment 2 may be provided in a state recorded on a computer-readable and non-transitory recording medium. The computer is, for example, the processing device 12 or the terminal device 30. Further, at least one of the program PR1 of Embodiment 1 or the program PR2 of Embodiment 2 may be provided in a manner of being downloaded from a server to a computer through a network.

[0113] 3-6. Modification Example 6 The first projector 10-1 of Embodiment 1 has the storage device 11, the processing device 12, the communication device 13, the image processing circuit 14, the optical device 15, the operation device 16, the imaging device 17, and the temperature sensor 18, but the present invention is not limited to this aspect. For example, the first projector 10-1 may have the storage device 11, the processing device 12, the communication device 13, the image processing circuit 14, and the optical device 15, and may not have the imaging device 17 and the temperature sensor 18. That is, the imaging device 17 and the temperature sensor 18 may be communicable with the first projector 10-1 and may be separate from the first projector 10-1. The same applies to the second projector 10-2.

[0114] 3-7. Modification Example 7 In the case of “YES” in step S110 of Embodiment 1, after one or both of the temperature of the projection optical system 15c-1 and the temperature of the projection optical system 15c-2 reach the target temperature based on the output from one or more temperature sensors 18, the processing device 12 stops detecting and correcting the deviation, but is not limited to this mode. For example, the processing device 12 may stop detecting and correcting the deviation when the elapsed time since the start of detecting and correcting the deviation exceeds the target time. For example, the processing device 12 may stop detecting and correcting the deviation when the correction amount becomes equal to or less than a predetermined value.

[0115] 3-8. Modification Example 8 The brightness BR1 of Embodiment 1 has a smooth change in the first blend region R1b, but is not limited to this mode. For example, the brightness BR1 of Embodiment 1 may have a stepwise change in the first blend region R1b. Further, the brightness BR1 of Embodiment 1 may not have the first blend region R1b. That is, the brightness BR1 of Embodiment 1 may change stepwise.

[0116] 3-9. Modification Example 9 In Embodiment 1, the matching process for calculating the deviation between the first projection image G1 and the second projection image G2 is calculated in a unified manner in the coordinate system of the light modulator 15b (first drawing panel) of the first projector 10-1, but is not limited to this mode. For example, the matching process may be calculated in a unified manner in the coordinate system of the imaging device 17. In this case, the deviation between the first projection image G1 and the second projection image G2 in the coordinate system of the imaging device 17 may be converted into the coordinate system of the light modulator 15b of the first projector 10-1 based on the association obtained in step S10.

[0117] 3-10. Modification Example 10 In step S90 of Embodiment 1, the temperature of the projection optical system 15c-1 is detected based on the output from the temperature sensor 18, but the present invention is not limited to this mode. For example, in step S90, the temperature of the projection optical system 15c-2 may be detected, or both the temperature of the projection optical system 15c-1 and the temperature of the projection optical system 15c-2 may be detected. That is, in step S90, at least one of the temperature of the projection optical system 15c-1 and the temperature of the projection optical system 15c-2 may be detected.

[0118] Similarly, in step S110 of Embodiment 1, it is determined whether the temperature of the projection optical system 15c-1 has reached the target temperature, but the present invention is not limited to this mode. For example, in step S110, it may be determined whether the temperature of the projection optical system 15c-2 has reached the target temperature, or it may be determined whether both the temperature of the projection optical system 15c-1 and the temperature of the projection optical system 15c-2 have reached the target temperature. That is, in step S110, it may be determined whether at least one of the temperature of the projection optical system 15c-1 and the temperature of the projection optical system 15c-2 has reached the target temperature.

[0119] 4. Supplementary Note Hereinafter, a summary of the present disclosure will be given as a supplementary note.

[0120] (Appended Note 1) The control method of the first aspect, which is a preferred example of the present disclosure, is a control method in a multi-projection system in which a superimposed area is set where a part of a first projection image projected from a first projector overlaps with a part of a second projection image projected from a second projector on a projection surface, and in a corresponding area corresponding to the superimposed area, projecting a first image group having a first state in which the brightness of the first projection image is greater than zero and the brightness of the second projection image is zero onto the projection surface; acquiring first imaging data by imaging the corresponding area in a state where the first image group is projected onto the projection surface; projecting a second image group having a second state in which the brightness of the first projection image is zero and the brightness of the second projection image is greater than zero onto the projection surface in the corresponding area; acquiring second imaging data by imaging the corresponding area in a state where the second image group is projected onto the projection surface; and detecting a deviation between the first projection image and the second projection image in the range of the superimposed area by analyzing the first imaging data and the second imaging data.

[0121] In the above aspect, since the brightness of the first projection image is greater than zero while the brightness of the second projection image is zero in the first state, noise caused by the second projection image is not included in the first imaging data in the area where the brightness of the second projection image is zero. Similarly, noise caused by the first projection image is not included in the second imaging data in the area where the brightness of the first projection image is zero. Thus, this control method can create an area in which the noise included in the first imaging data and the second imaging data is reduced. Thereby, the accuracy of the result obtained by analyzing the first imaging data and the second imaging data can be improved. As a result, it is possible to suppress a decrease in the detection accuracy of the deviation between the first projection image and the second projection image in the range of the superimposed area.

[0122] (Appendix 2) In the second aspect, which is a preferred example of the first aspect, the first projected image has a non-overlapping region that does not overlap with the second projected image and a first partial region for overlapping with the second projected image. At least a part of the first partial region is an area where blending processing is performed to change the brightness in the arrangement direction in which the first projected image and the second projected image are arranged so that the brightness of the overlapping region when the first projected image and the second projected image are projected to overlap each other in the overlapping region matches the brightness of the non-overlapping region. Projecting the first image group onto the projection surface includes adjusting the first partial region to include a first state region having the first state and a first blend region where the blending processing is performed by changing the blend range where the blending processing is performed in the first partial region from a first range to a second range smaller than the first range. Acquiring the first imaging data includes imaging the first state region. In the above aspect, since the first partial region includes not only the region in the first state but also the first blend region, a seamless composite image can be displayed in the corresponding region even during the period of detecting the deviation between the first projected image and the second projected image in the range of the overlapping region.

[0123] (Appendix 3) In the second aspect, which is a preferred example of the second aspect, the brightness distribution in the arrangement direction when the blend range is the second range is different from the brightness distribution in the arrangement direction when the blend range is the first range. In the above aspect, the brightness distribution can be changed according to the range where the blending processing is performed in the first partial region.

[0124] (Appendix 4) In a fourth aspect, which is a preferred example of any of the first to third aspects, detecting the deviation between the first projected image and the second projected image within the range of the overlapping region includes: cutting out an analysis region represented in the coordinate system of the imaging device from the second imaging data; generating conversion data obtained by converting the analysis region into the coordinate system of the drawing panel of the first projector; performing a matching process on drawing data indicating the region corresponding to the analysis region in the first projected image and represented in the coordinate system of the drawing panel and the conversion data; and detecting one or both of the amount and direction of the deviation between the first projected image and the second projected image based on the result of the matching process. In the above aspect, the deviation between the first projected image and the second projected image within the range of the overlapping region can be preferably detected.

[0125] (Appendix 5) In a fifth aspect, which is a preferred example of the second or third aspect, further includes calculating a correction amount for correcting one or both of the first projected image and the second projected image based on the detected deviation, and controlling one or both of the first projector and the second projector based on the correction amount. In the above aspect, the deviation between the first projected image and the second projected image within the range of the overlapping region can be reduced. Thereby, the image quality of the overlapping region can be improved.

[0126] (Appendix 6) In a sixth aspect, which is a preferred example of the fifth aspect, further includes changing the blend range from the second range to the first range in the first partial region, and maintaining the state where the blend range is the first range for a first period. In the above aspect, in the first period as a period other than when necessary, by setting a relatively wide blend range, a suitable blend process can be performed from the user's perspective. Thereby, the image quality of the overlapping region can be improved.

[0127] (Appendix 7) In the seventh aspect, which is a preferred example of the fifth or sixth aspect, it further includes maintaining the state where the blending range is the second range for a first period. In the above aspect, by providing the first period as the period for maintaining the state of being the second range, the change in the blending range can be made less conspicuous.

[0128] (Appendix 8) In the eighth aspect, which is a preferred example of any one of the fifth to seventh aspects, detecting the temperature of the first optical system for the first projector to project the first projected image based on the output from one or more sensors, intermittently performing the detection and correction of the deviation until the temperature of the first optical system reaches the target temperature based on the output from the one or more sensors, and stopping the detection and correction of the deviation after the temperature of the first optical system reaches the target temperature based on the output from the one or more sensors. In the above aspect, the deviation can be corrected periodically until the temperatures of the first optical system and the second optical system become stable. Thereby, the appropriate detection of the deviation can be performed in a timely manner.

[0129] (Supplementary Note 9) The projector according to the ninth aspect, which is a preferred example of the present disclosure, is a projector used as the first projector in a multi-projection system in which an overlapping region is set for a part of each of a first projection image projected from a first projector and a second projection image projected from a second projector to overlap on a projection surface. The projector includes an optical device and a processing device. The processing device controls the operation of the optical device and the operation of the second projector so that a first image group having a first state in which the brightness of the first projection image is greater than zero and the brightness of the second projection image is zero is projected onto the projection surface in a corresponding region corresponding to the overlapping region, acquires first imaging data by causing an imaging device to image the corresponding region in a state where the first image group is projected onto the projection surface, controls the operation of the optical device and the operation of the second projector so that a second image group having a second state in which the brightness of the first projection image is zero and the brightness of the second projection image is greater than zero is projected onto the projection surface in the corresponding region, acquires second imaging data by causing the imaging device to image the corresponding region in a state where the second image group is projected onto the projection surface, and detects a deviation between the first projection image and the second projection image in the range of the overlapping region by analyzing the first imaging data and the second imaging data.

[0130] In the above aspect, since the brightness of the first projection image is greater than zero while the brightness of the second projection image is zero in the first state, the first imaging data does not include noise caused by the second projection image. Similarly, the second imaging data does not include noise caused by the first projection image. Thus, the noise included in the first imaging data and the second imaging data can be reduced. As a result, the accuracy of the result obtained by analyzing the first imaging data and the second imaging data can be improved. Consequently, a decrease in the detection accuracy of the deviation between the first projection image and the second projection image in the range of the overlapping region can be suppressed.

[0131] (Appended Note 10) The program according to the tenth aspect, which is a preferred example of the present disclosure, is a program used for a multi-projection system in which an overlapping area is set for partial overlap of a first projection image projected from a first projector and a second projection image projected from a second projector on a projection surface. In a corresponding area corresponding to the overlapping area, causing a computer to project a first image group having a first state in which the brightness of the first projection image is greater than zero and the brightness of the second projection image is zero onto the projection surface; obtaining first imaging data by imaging the corresponding area with an imaging device in a state where the first image group is projected onto the projection surface; in the corresponding area, projecting a second image group having a second state in which the brightness of the first projection image is zero and the brightness of the second projection image is greater than zero onto the projection surface; obtaining second imaging data by imaging the corresponding area with the imaging device in a state where the second image group is projected onto the projection surface; and detecting a deviation between the first projection image and the second projection image in the range of the overlapping area by analyzing the first imaging data and the second imaging data.

[0132] In the above aspect, in the first state, the brightness of the first projection image is greater than zero while the brightness of the second projection image is zero, so the first imaging data does not include noise caused by the second projection image. Similarly, the second imaging data does not include noise caused by the first projection image. Thus, the noise included in the first imaging data and the second imaging data can be reduced. Thereby, the accuracy of the result of analyzing the first imaging data and the second imaging data can be improved. As a result, a decrease in the detection accuracy of the deviation between the first projection image and the second projection image in the range of the overlapping area can be suppressed.

Explanation of Reference Numerals

[0133] 10… Projector, 10-1… First Projector (Projector), 10-2… Second Projector, 11… Memory Device, 12… Processing Device, 12a… Projection Control Unit, 12b… Imaging Control Unit, 12c… Correction Unit, 12d… Projection Control Unit, 13… Communication Device, 14… Image Processing Circuit, 15… Optical Device, 15a… Light Source, 15b… Light Modulator, 15c… Projection Optical System, 15c-1… Projection Optical System (First Optical System), 15c-2… Projection Optical System (Second Optical System), 16… Operating Device, 17… Imaging Device, 18… Temperature Sensor, 20… Processing Device, 30… Terminal Device, 100… Multi-Projection System, AB… Abnormal Value, BR1… Brightness, BR2… Brightness, D1… First Imaging Data, D2… Second Imaging Data, DR… Direction, G1… First Projection Image, G2… Second Projection Image, GG… Image Group, GG0… Image Group, GG1… First Image Group, GG2… Second Image Group, GG3… Image Group, IMG1… Video Data, IMG2… Video Data, PA… Correction Amount Information, PR1… Program, PR2… Program, PT… Color Code Pattern, R… Overlap Region, R1… First Partial Region, R1a… First State Region, R1b… First Blend Region, R1c… Second State Region, R2… Second Partial Region, R2a… First State Region, R2b… Second Blend Region, R2c… Second State Region, RA… Analysis Region, RA1… Analysis Region, RA2… Analysis Region, RC… Corresponding Region, RN1… Non-Overlap Region, RN2… Non-Overlap Region, S10… Step, S20… Step, S21… Step, S30… Step, S31… Step, S40… Step, S50… Step, S60… Step, S61… Step, S62… Step, S63… Step, S64… Step, S70… Step, S80… Step, S90… Step, S100… Step, S110… Step, S120… Step, S130… Step, SC… Projection Surface, α… First Range, β… Second Range.

Claims

1. A control method in a multi - projection system in which a superimposed area is set where a part of a first projection image projected from a first projector overlaps with a part of a second projection image projected from a second projector on a projection surface, projecting, onto the projection surface, a first image group having a first state in which the brightness of the first projection image is greater than zero and the brightness of the second projection image is zero in a corresponding area corresponding to the superimposed area; acquiring first imaging data by imaging the corresponding area in a state where the first image group is projected onto the projection surface; projecting, onto the projection surface, a second image group having a second state in which the brightness of the first projection image is zero and the brightness of the second projection image is greater than zero in the corresponding area; acquiring second imaging data by imaging the corresponding area in a state where the second image group is projected onto the projection surface; detecting a deviation between the first projection image and the second projection image in the range of the superimposed area by analyzing the first imaging data and the second imaging data, including: A control method.

2. The first projection image has a non - superimposed area that does not overlap with the second projection image, and a first partial area for overlapping with the second projection image, and at least a part of the first partial area is an area where a blending process is performed to change the brightness in the arrangement direction in which the first projection image and the second projection image are arranged so that the brightness of the superimposed area when the first projection image and the second projection image are projected to overlap with each other in the superimposed area matches the brightness of the non - superimposed area, projecting the first image group onto the projection surface is By changing the blend range in which the blending process is performed in the first partial area from a first range to a second range smaller than the first range, adjusting the first partial area to include a first state area having the first state and a first blend area where the blending process is performed, Obtaining the first imaging data includes imaging the first state area, The control method according to claim 1.

3. The brightness distribution in the arrangement direction when the blend range is the second range is different from the brightness distribution in the arrangement direction when the blend range is the first range, The control method according to claim 2.

4. Detecting the deviation between the first projected image and the second projected image in the range of the overlapping area includes cutting out an analysis area represented in the coordinate system of the imaging device from the second imaging data, generating conversion data obtained by converting the analysis area into the coordinate system of the drawing panel of the first projector, performing a matching process on drawing data indicating the area corresponding to the analysis area in the first projected image and represented in the coordinate system of the drawing panel and the conversion data, detecting one or both of the amount and direction of the deviation between the first projected image and the second projected image based on the result of the matching process, The control method according to claim 1.

5. calculating a correction amount for correcting one or both of the first projected image and the second projected image based on the detected deviation, further including controlling one or both of the first projector and the second projector based on the correction amount, The control method according to claim 2.

6. changing the blend range from the second range to the first range in the first partial area; further comprising maintaining a state in which the blend range is the first range for a first period; The control method according to claim 5.

7. further comprising maintaining a state in which the blend range is the second range for a first period; The control method according to claim 5.

8. detecting the temperature of a first optical system for the first projector to project the first projected image based on an output from one or more sensors; intermittently performing the detection of the deviation and the correction of the deviation until the temperature of the first optical system reaches a target temperature based on an output from the one or more sensors; further comprising stopping the detection of the deviation and the correction of the deviation after the temperature of the first optical system reaches the target temperature based on an output from the one or more sensors; The control method according to claim 5.

9. A projector used as the first projector in a multi-projection system in which an overlapping area is set for a part of each of a first projected image projected from a first projector and a second projected image projected from a second projector to overlap on a projection surface, an optical device; a processing device; and the processing device controls the operation of the optical device and the operation of the second projector so that a first image group having a first state in which the brightness of the first projected image is greater than zero and the brightness of the second projected image is zero is projected onto the projection surface in a corresponding area corresponding to the overlapping area; acquiring first imaging data by causing an imaging device to image the corresponding area in a state where the first image group is projected onto the projection surface; Control the operation of the optical device and the operation of the second projector so that a second image group having a second state in which the brightness of the first projection image is zero and the brightness of the second projection image is greater than zero is projected onto the projection surface in the corresponding region. Acquire second imaging data by causing the imaging device to image the corresponding region in a state where the second image group is projected onto the projection surface. Detect the deviation between the first projection image and the second projection image in the range of the overlapping region by analyzing the first imaging data and the second imaging data. Projector.

10. A program used in a multi-projection system in which an overlapping region is set so that a part of a first projection image projected from a first projector and a second projection image projected from a second projector overlap on a projection surface, Project a first image group having a first state in which the brightness of the first projection image is greater than zero and the brightness of the second projection image is zero onto the projection surface in a corresponding region corresponding to the overlapping region. Acquire first imaging data by causing the imaging device to image the corresponding region in a state where the first image group is projected onto the projection surface. Project a second image group having a second state in which the brightness of the first projection image is zero and the brightness of the second projection image is greater than zero onto the projection surface in the corresponding region. Acquire second imaging data by causing the imaging device to image the corresponding region in a state where the second image group is projected onto the projection surface. Cause a computer to detect the deviation between the first projection image and the second projection image in the range of the overlapping region by analyzing the first imaging data and the second imaging data. Program.

Images