JP2020113812A - Projector, display system, projector control method, and image correction method - Google Patents

Abstract

To improve color measurement accuracy.SOLUTION: A projector 100 includes a projection unit 110, a spectral imaging unit 137, and a control unit 150, and the control unit 150 changes the colors and gradations of an image projected by the projection unit 110 to a first color and a first gradation, the first color and a second gradation, a second color and a third gradation, and the second color and a fourth gradation while projecting an adjustment image corresponding to the changed color and gradation on the projection unit 110, sets measurement conditions corresponding to the color in the spectral imaging unit 137, and causes the spectral imaging unit 137 to capture the adjustment image projected by the projection unit 110 to obtain spectral imaging data.SELECTED DRAWING: Figure 1

Description

The present invention relates to a projector, a display system, a projector control method, and an image correction method.

BACKGROUND ART Conventionally, there is known a technique for capturing a displayed image and correcting the image based on the captured result. For example, the correction data acquisition method disclosed in Patent Document 1 sequentially displays an offset image of a black signal level, a primary color image of an arbitrary signal level, and a gradation image in which the signal level of each primary color is changed on an image display unit. .. Then, the calibration camera including the filters of the bands corresponding to the respective primary colors of red, green, and blue is used to switch between the bands for shooting. The offset correction data is calculated based on the captured image data.

JP, 2005-20581, A

However, there is a problem that a high color measurement result cannot be obtained even with a camera capable of shooting in a plurality of bands.

One aspect for solving the above problem includes a projection unit, a spectroscopic imaging unit including an imaging element and a spectroscopic element, a projection unit, and a control unit that controls the spectroscopic imaging unit, and the control unit is A color and gradation of an image projected by the projection unit are set to a first color and a first gradation, and a first image corresponding to the set first color and the first gradation is projected onto the projection unit. Then, the first measurement condition corresponding to the first color is set in the spectral image capturing unit, the first image projected by the projection unit is captured by the spectral image capturing unit, and first captured image information is acquired, The color and gradation of the image projected by the projection unit are set to the first color and the second gradation, and the second image corresponding to the set first color and the second gradation is projected on the projection unit. Then, the first measurement condition corresponding to the first color is set in the spectral imaging unit, and the second image projected by the projection unit is caused to image by the spectral imaging unit to acquire second captured image information. , Setting the color and gradation of the image projected by the projection unit to the second color and the third gradation, and projecting the third image corresponding to the set second color and the third gradation to the projection unit Then, the second measurement condition corresponding to the second color is set in the spectral image capturing unit, the third image projected by the projection unit is captured by the spectral image capturing unit, and third captured image information is acquired, The color and gradation of the image projected by the projection unit are set to the second color and the fourth gradation, and the fourth image corresponding to the set second color and the second gradation is projected on the projection unit. Then, the second measurement condition corresponding to the second color is set in the spectral image capturing unit, and the spectral image capturing unit captures the fourth image projected by the projection unit to obtain fourth captured image information. , Is a projector.

In the projector, the control unit is an element of an image projected by the projection unit based on the acquired first captured image information, the second captured image information, the third captured image information, and the fourth captured image information. The configuration may also be such that a correction parameter for correcting the following image data is generated.

In the projector, the control unit sets the wavelength range corresponding to the first color as an imaging range as the first measurement condition, and changes the spectral wavelength of the spectroscopic element for each first wavelength interval, the spectral imaging unit. To perform imaging, obtain the intensity of light corresponding to the spectral wavelength as the first captured image information and the second captured image information, and set the wavelength range corresponding to the second color as the second measurement condition. The spectral range of the spectral element is changed for each of the first wavelength intervals, and the spectral imaging unit performs imaging, and the intensity of light corresponding to the spectral wavelength is set as the imaging range and the third captured image information and the third The configuration may be such that four captured image information is acquired.

In the above projector, the control unit controls the intensity of light for each of the first wavelength intervals acquired as the first captured image information, the second captured image information, the third captured image information, and the fourth captured image information. The estimated value of the spectrum may be calculated for each second wavelength interval, which is shorter than the first wavelength interval, based on the estimation matrix used for estimating the spectrum.

In the projector, the estimation matrix is calculated based on the first captured image information, the second captured image information, the third captured image information, and the fourth captured image information output by the spectral imaging unit. May be

In the projector, the estimation matrix includes measurement data obtained by measuring the first image, the second image, the third image, and the fourth image at every second wavelength interval by a dedicated measuring device, The structure may be a determinant that minimizes the squared error from the estimated value.

In the projector, the spectroscopic element includes a pair of reflecting films facing each other, and a gap changing unit that changes a distance between the pair of reflecting films, and the control unit is a distance between the pair of reflecting films. May be changed to the gap changing section to change the spectral wavelength of the spectroscopic element.

In the projector, the control unit sets a color and a gradation of an image projected by the projection unit to a third color and a fifth gradation, and a first color corresponding to the set third color and the fifth gradation. Five images are projected on the projection unit, a third measurement condition corresponding to the third color is set on the spectral imaging unit, and the fifth image projected by the projection unit is caused to be captured by the spectral imaging unit. 5 The captured image information is acquired, the color and gradation of the image projected by the projection unit are set to the third color and the sixth gradation, and the third color and the sixth gradation corresponding to the set third color and sixth gradation are set. 6 images are projected onto the projection unit, the third measurement condition corresponding to the third color is set in the spectral imaging unit, and the sixth image projected by the projection unit is captured by the spectral imaging unit. The configuration may be such that the sixth captured image information is acquired.

In the projector, the first color is red, the first gradation has a lower gradation value than the second gradation, the second color is green, and the third gradation is the fourth floor. A tone value lower than the tone, the third color is blue, the fifth tone has a tone value lower than the sixth tone, and the first measurement condition is a wavelength range corresponding to red. The second measurement condition may be a wavelength range corresponding to green, and the third measurement condition may be a wavelength range corresponding to blue.

In the projector, the gradation values of the first gradation, the third gradation, and the fifth gradation are equal, and the gradation values of the second gradation, the fourth gradation, and the sixth gradation are The configurations may be the same.

In the projector, the control unit sets a color and a gradation of an image projected by the projection unit to a first color and a seventh gradation, and a first color corresponding to the set first color and the seventh gradation. Seven images are projected on the projection unit, a first measurement condition corresponding to the first color is set on the spectral imaging unit, and the seventh image projected by the projection unit is caused to be captured by the spectral imaging unit. (7) The captured image information is acquired, the color and gradation of the image projected by the projection unit are set to the second color and the eighth gradation, and the second color and the eighth gradation corresponding to the set second color and the eighth gradation are set. 8 images are projected onto the projection unit, the second measurement condition corresponding to the second color is set in the spectral imaging unit, and the eighth image projected by the projection unit is captured by the spectral imaging unit. Acquiring eighth captured image information, setting the color and gradation of the image projected by the projection unit to the third color and the ninth gradation, and corresponding to the set third color and the ninth gradation. A ninth image is projected on the projection unit, the third measurement condition corresponding to the third color is set on the spectral image capturing unit, and the ninth image projected by the projecting unit is captured by the spectral image capturing unit. 9th captured image information is acquired, the 7th gradation is a gradation between the 1st gradation and the 2nd gradation, and the 8th gradation is the 3rd gradation. The gradation may be between the fourth gradation and the ninth gradation may be a gradation between the fifth gradation and the sixth gradation.

Another aspect for solving the above problem is a display system including a first projector and a second projector, wherein the first projector includes a first projection unit, a first imaging element, and a first spectral element. The first spectral imaging unit and the color and gradation of the image to be projected by the first projection unit are determined, an image corresponding to the determined color and gradation is projected on the first projection unit, and the determined image of the image is displayed. A measurement condition that is determined based on color is set in the first spectral image capturing unit, and the first spectral image capturing unit captures the image projected by the first projecting unit to obtain first captured image information. 1 control unit, and the second projector includes a second projection unit, a second spectral imaging unit including a second imaging element and a second spectral element, and a color of an image projected by the second projection unit. The gradation is determined, an image corresponding to the determined color and gradation is projected on the second projection unit, and the measurement condition determined based on the determined color of the image is set in the second spectral imaging unit, A second control unit that causes the second spectral imaging unit to capture the image projected by the second projection unit and obtains second captured image information, wherein the first control unit is configured to perform the first projection. At least one of the color and the gradation of the image to be projected on the unit is changed a plurality of times to obtain a plurality of first captured image information output by the first spectral image capturing unit, and the second control unit causes the second projection unit to perform the second projection. At least one of the color and the gradation of the image to be projected on the unit is changed a plurality of times to acquire a plurality of second imaged image information output by the second spectral imaging unit, and the first control unit acquires the plurality of acquired images. A first correction parameter that corrects an image projected by the first projector based on first captured image information and a plurality of second captured image information received from the second control unit, and the second projector projects the image. And a second correction parameter for correcting the image to be displayed.

Another aspect for solving the above problem is a control method of a projector including a projection unit and a spectral imaging unit including an imaging element and a spectral element, wherein a color and gradation of an image projected by the projection unit are set. A first image corresponding to the set first color and the first gradation is set, and a first image corresponding to the set first color and the first gradation is projected on the projection unit to set a first measurement condition corresponding to the first color. The first image projected by the projection unit is set to the spectral imaging unit, the spectral imaging unit captures the first captured image information, and the color and gradation of the image projected by the projection unit are set to the first image. One color and a second gradation are set, a second image corresponding to the set first color and the second gradation is projected on the projection unit, and the first measurement condition corresponding to the first color is set. The second image is set in the spectral imaging unit, the spectral imaging unit captures the second image projected by the projection unit to acquire second captured image information, and the color and gradation of the image projected by the projection unit Two colors and a first gradation are set, a third image corresponding to the set second color and the first gradation is projected on the projection unit, and a second measurement condition corresponding to the second color is set. The third image is set in the spectral imaging unit, the third image projected by the projection unit is imaged by the spectral imaging unit to acquire third captured image information, and the color and gradation of the image projected by the projection unit are set to the second. The color and the second gradation are set, the fourth image corresponding to the set second color and the second gradation is projected on the projection unit, and the second measurement condition corresponding to the second color is set to the above-mentioned. A method of controlling a projector, which is set in a spectral imaging section, and causes the spectral imaging section to capture the fourth image projected by the projection section to acquire fourth captured image information.

Another aspect for solving the above-mentioned problem is a first projector including a first projection unit, a first spectral imaging unit including a first imaging element and a first spectral element, a second projection unit, and a second projection unit. An image correction method in a display system including a second projector including a second spectral imaging unit including an image sensor and a second spectral element, wherein the color of an image projected by the first projection unit in the first projector. And a first determination step of determining the gradation, a first projection step of projecting an image corresponding to the determined color and gradation on the first projection unit, and a measurement condition determined based on the determined color of the image. Is set in the first spectral imaging section, and the first projected image information is acquired by causing the first spectral imaging section to capture the image projected by the first projection section. A second determining step of determining a color and a gradation of an image to be projected by the second projection unit in the second projector; and a step of projecting an image corresponding to the determined color and the gradation to the second projection unit. 2 projection steps and measurement conditions determined based on the determined color of the image are set in the second spectral imaging unit, and the image projected by the second projection unit is caused to be captured by the second spectral imaging unit. A second acquisition step of acquiring second captured image information by means of the first determination step, wherein at least one of the color and gradation of the image projected by the first projection unit in the first projector is determined by the first determination step. An image changed and at least one of color and gradation is projected on the first projection unit by the first projection step, and the image projected by the first projection unit is the first acquisition step by the first acquisition step. In the second projector, at least one of the color and the gradation of the image to be projected by the second projection unit is plural by the second determination step. An image changed and at least one of color and gradation is projected on the second projection unit by the second projection step, and the image projected by the second projection unit is subjected to the second acquisition step by the second acquisition step. A plurality of the second captured image information obtained by allowing the two-spectral image capturing unit to capture the second captured image information, and the plurality of the first captured image information obtained by the first projector, and the plurality of the second captured images received from the second projector. A first correction parameter for correcting the image projected by the first projector and an image projected by the second projector based on the information. And a second correction parameter for generating an image correction method.

FIG. 3 is a block configuration diagram showing a configuration of a projector. The schematic block diagram of a spectrum imaging part. The figure which shows the display conditions and measurement conditions of an image for adjustment. 3 is a flowchart showing the operation of the projector according to the first embodiment. The figure which shows the light intensity for every spectral frequency obtained from spectral imaging data. The figure which shows the estimated value of the spectrum for every 2nd wavelength space|interval. The figure which shows the system configuration of a display system. 6 is a flowchart showing the operation of the projector of the master machine. 6 is a flowchart showing the operation of the projector of the slave machine.

[First Embodiment]
Hereinafter, embodiments will be described with reference to the accompanying drawings.
FIG. 1 is a block configuration diagram showing a configuration of the projector 100. The projector 100 generates an image light and projects it on the screen SC, an image projection system that electrically processes image data that is the basis of an optical image, and captures a projected image displayed on the screen SC. The spectral imaging unit 137 and the control unit 150 that controls these units are provided as main components.

[Image projection system]
The image projection system includes a projection unit 110 and a drive unit 120. The projection unit 110 includes a light source 111, a light modulator 113, and an optical unit 117. The drive unit 120 includes a light source drive circuit 121 and a light modulator drive circuit 123. The light source drive circuit 121 and the light modulation device drive circuit 123 are connected to the bus 101 and perform data communication with each other via the bus 101 with other components of the projector 100 which are also connected to the bus 101. For example, the control unit 150, the image processing unit 143, and the like illustrated in FIG. 1 correspond to the other components.

A solid light source such as an LED (Light Emitting Diode) or a laser light source is used as the light source 111. Further, as the light source 111, it is also possible to use a lamp such as a halogen lamp, a xenon lamp, or an ultrahigh pressure mercury lamp.

A light source drive circuit 121 is connected to the light source 111. The light source drive circuit 121 supplies a drive current or a pulse to the light source 111 to turn on the light source 111, and stops the supplied drive current or pulse to turn off the light source 111.

The light modulation device 113 includes a light modulation element that modulates the light emitted from the light source 111 to generate image light. As the light modulation element, for example, a transmissive or reflective liquid crystal panel, a digital mirror device, or the like can be used. In this embodiment, a case where the light modulation device 113 includes a transmissive liquid crystal panel 115 as a light modulation element will be described as an example. The light modulation device 113 includes three liquid crystal panels 115 corresponding to the three primary colors of red, green, and blue. The light modulated by the liquid crystal panel 115 enters the optical unit 117 as image light. Hereinafter, red is referred to as “R”, green is referred to as “G”, and blue is referred to as “B”.

A light modulator drive circuit 123 is connected to the light modulator 113. The light modulator driving circuit 123 drives the light modulator 113 to draw an image on the liquid crystal panel 115 in frame units.

The optical unit 117 includes optical elements such as lenses and mirrors, and projects the image light modulated by the light modulator 113 toward the screen SC. An image based on the image light projected by the optical unit 117 is formed on the screen SC. An image formed on the screen SC by the image light projected by the projection unit 110 is referred to as a projected image.

[Operation input system]
The projector 100 includes an operation panel 131, a remote control light receiver 133, and an input interface 135. The input interface 135 is connected to the bus 101 and performs data communication with the control unit 150 and the like via the bus 101.

The operation panel 131 is arranged in the housing of the projector 100, for example, and includes various switches. When the switch on the operation panel 131 is operated, the input interface 135 outputs an operation signal corresponding to the operated switch to the control unit 150.

The remote control light receiver 133 receives an infrared signal transmitted by the remote controller. The remote control light receiving unit 133 outputs an operation signal corresponding to the received infrared signal. The input interface 135 outputs the input operation signal to the control unit 150. This operation signal is a signal corresponding to the switch of the operated remote controller.

[Spectroscopic imaging unit]
The spectral imaging unit 137 captures the projection image displayed on the screen SC by the projection unit 110 and outputs spectral imaging data.

FIG. 2 is a schematic configuration diagram of the spectral imaging unit 137.
The configuration of the spectroscopic imaging unit 137 will be described with reference to FIG. The spectroscopic imaging unit 137 includes an incident optical system 301 on which external light is incident, a spectroscopic element 302 that disperses the incident light, and an imaging element 303 that images the light dispersed by the spectroscopic element 302.

The incident optical system 301 is composed of, for example, a telecentric optical system or the like, and guides the incident light to the spectroscopic element 302 and the image pickup element 303 so that the optical axis and the principal ray are parallel or substantially parallel. The spectroscopic element 302 is a variable wavelength interference filter including a pair of reflecting films 304 and 305 facing each other and a gap changing unit 306 capable of changing the distance between the reflecting films 304 and 305. The gap changing unit 306 is composed of, for example, an electrostatic actuator. The variable wavelength interference filter is also called an etalon.

The spectroscopic element 302 changes the voltage applied to the gap changing section 306 under the control of the control section 150, so that the spectroscopic wavelength λi (i=1, 2,. .., N) can be changed. The image pickup device 303 is a device for picking up an image of the light transmitted through the spectral element 302, and is composed of, for example, a CCD, a CMOS, or the like. The spectroscopic imaging unit 137 sequentially switches the wavelength of the light dispersed by the spectroscopic element 302 under the control of the control unit 150, takes an image of the light transmitted through the spectroscopic element 302 by the imaging element 303, and outputs the spectroscopic imaging data. The spectroscopic imaging data output by the spectroscopic imaging unit 137 is input to the control unit 150. The spectral imaging data is data output for each pixel of the image sensor 303, and is data indicating the intensity of light received by the pixel, that is, the amount of light. The spectral imaging unit 137 may be a stereo camera or a monocular camera.

[Communication part]
As shown in FIG. 1, the projector 100 includes a communication unit 139. The communication unit 139 is connected to the bus 101. As shown in FIG. 7, which will be described later, the communication unit 139 functions as an interface for connecting a plurality of projectors 100 and mutually performing data communication between the projectors 100. Although the communication unit 139 of the present embodiment is a wired interface for connecting a cable, it may be a wireless communication interface for executing wireless communication such as wireless LAN or Bluetooth. "Bluetooth" is a registered trademark.

[Image processing system]
Next, the image processing system of the projector 100 will be described.
As shown in FIG. 1, the projector 100 includes an image interface 141, an image processing unit 143, and a frame memory 145 as an image processing system. The image processing unit 143 is connected to the bus 101 and performs data communication with the control unit 150 and the like via the bus 101.

The image interface 141 is an interface that receives an image signal, and includes a connector to which the cable 3 is connected and an interface circuit that receives an image signal via the cable 3. The image interface 141 extracts the image data and the synchronization signal from the received image signal, and outputs the extracted image data and the synchronization signal to the image processing unit 143. The image interface 141 also outputs a synchronization signal to the control unit 150. The control unit 150 controls the other components of the projector 100 in synchronization with the synchronization signal. The image processing unit 143 performs image processing on the image data in synchronization with the synchronization signal.

The image supply device 200 is connected to the image interface 141 via the cable 3. As the image supply device 200, for example, a notebook PC (Personal Computer), a desktop PC, a tablet terminal, a smartphone, or a PDA (Personal Digital Assistant) can be used. Further, the image supply device 200 may be a video reproduction device, a DVD player, a Blu-ray disc player, or the like. The image signal input to the image interface 141 may be a moving image or a still image, and the data format is arbitrary.

The image processing unit 143 and the frame memory 145 are composed of, for example, an integrated circuit. The integrated circuit may be an LSI (Large-Scale Integrated Circuit), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Integrated Logic-Device), an FPGA (Frequentially Integrated Circuit), an FPGA (Frequentially Integrated Circuit), or a FPGA (Frequentially Integrated Circuit). included. Further, an analog circuit may be included in a part of the configuration of the integrated circuit.

The image processing unit 143 is connected to the frame memory 145. The image processing unit 143 expands the image data input from the image interface 141 in the frame memory 145, and performs image processing on the expanded image data.

The image processing unit 143 executes various processes including, for example, a geometric correction process for correcting a trapezoidal distortion of a projected image and an OSD process for superimposing an OSD (On Screen Display) image. The image processing unit 143 also performs image adjustment processing for adjusting the brightness and hue of the image data, resolution conversion processing for adjusting the aspect ratio and resolution of the image data according to the light modulator 113, and image processing such as frame rate conversion. To execute.

The image processing unit 143 outputs the image data that has undergone the image processing to the light modulation device drive circuit 123. The light modulator drive circuit 123 generates a drive signal for each of red, green, and blue colors based on the image data input from the image processing unit 143. The light modulator drive circuit 123 drives the liquid crystal panel 115 of the corresponding color of the light modulator 113 based on the generated drive signal of each color, and draws an image on the liquid crystal panel 115 of each color. The light emitted from the light source 111 passes through the liquid crystal panel 115 to generate image light corresponding to the image of the image data.

[Control/storage]
The control unit 150 includes a storage unit 160 and a processor 170.
The storage unit 160 is configured by, for example, a nonvolatile semiconductor memory such as a flash memory or an EEPROM, or an SSD (Solid State Drive) using a flash memory. In the present embodiment, the case where the control unit 150 includes the storage unit 160 will be described. However, for example, the storage unit 160 configured by a hard disk drive may be provided outside the control unit 150. The storage unit 160 stores a control program 161, image data such as adjustment image data 162 and pattern image data 163, setting data 164, parameters 165, and calibration data 167.

The control program 161 is a program such as an OS (Operating System) executed by the processor 170 and an application program.

The image data stored in the storage unit 160 is data that is the basis of the image displayed on the screen SC by the projector 100, and includes, for example, the pattern image data 163 and the adjustment image data 162. The pattern image data 163 is image data used when generating a projective transformation matrix 167b described below, and is image data in which marks of a predetermined shape are arranged at the four corners of the pattern image data 163. The adjustment image data 162 is monochromatic image data of R, G, and B colors. The storage unit 160 stores a plurality of different gradation image data 162 for adjustment. The adjustment image data 162 for each color of R, G, and B is prepared with the same gradation. Further, black and white adjustment image data 162 may be prepared as the adjustment image data 162. In this case, the white adjustment image data 162 is prepared with the same gradation as the R, G, and B adjustment image data 162, and the black adjustment image data 162 is prepared with one gradation.

The setting data 164 is data in which processing conditions of various processes executed by the processor 170 are set. The parameter 165 is, for example, a parameter of image processing to be executed by the image processing unit 143.

The calibration data 167 includes correction data 167a, a projective transformation matrix 167b, and an estimation matrix M. The correction data 167a is data for correcting the sensitivity distribution of the image pickup device 303 and correcting the spectral image pickup data so that the output of the image pickup device becomes uniform.
In the image pickup device 303, the output of each pixel forming the image pickup device is not uniform due to the influence of the lens aberration of the lens included in the incident optical system 301, and the output varies depending on the pixel position. That is, a sensitivity distribution is generated in the image sensor. The output of this sensitivity distribution is lower in the peripheral portion than the center of the image sensor 303. Therefore, when correcting the hue, brightness, and the like of the image based on the spectral imaging data captured by the spectral imaging unit 137, the correction may not be performed accurately due to the influence of the error. Further, the sensitivity distribution of the spectral image pickup unit 137 is affected by the ultraviolet rays coated on the lens surface and the optical filter for cutting infrared rays. That is, the output of the spectral image pickup unit 137 differs depending on the color of the image captured by the spectral image pickup unit 137.

The correction data 167a is generated when the projector 100 is manufactured, and is also generated for each pixel of the image sensor. A plurality of pieces of correction data 167a are generated corresponding to the R, G, and B color lights projected by the projection unit 110 and the spectral wavelength λi set in the spectral imaging unit 137. By generating a plurality of correction data 167a for each color light and for each spectral wavelength set in the spectral imaging unit 137, it is possible to improve the correction accuracy of the spectral sensitivity of the spectral imaging unit 137.

Further, a plurality of pieces of correction data 167a are generated corresponding to the focal length of the incident optical system 301 of the spectral image pickup unit 137. By generating the correction data 167a corresponding to the focal length of the incident optical system 301, even if the incident optical system 301 of the spectral imaging unit 137 is changed and the focal length is changed, the correction corresponding to the changed focal length is performed. The spectral imaging data can be corrected using the data 167a.

The projective transformation matrix 167b is a transformation matrix that transforms the coordinates set on the liquid crystal panel 115 of the light modulator 113 into the coordinates set on the spectral imaging data. The liquid crystal panel 115 has a configuration in which a plurality of pixels are arranged in a matrix. The coordinates set on the liquid crystal panel 115 are coordinates for specifying each pixel arranged in this matrix. The coordinates set on the liquid crystal panel 115 will be referred to as panel coordinates below. Further, the coordinates set in the spectral imaging data are coordinates for identifying each of the pixels forming the image sensor 303. The coordinates set in the spectral imaging data will be referred to as imaging coordinates below.

The estimation matrix M is a matrix used for spectrum estimation. The estimation matrix M is generated when the projector 100 is manufactured, and is stored in the storage unit 160 as a part of the calibration data 167. The estimation matrix M is generated based on the spectral imaging data captured by the spectral imaging unit 137. Optical components are mounted on the optical unit 117, and optical components are also used as components for guiding the light emitted from the light source 111 to the liquid crystal panel 115 of the light modulation device 113. Further, in the liquid crystal panel 115 as an optical component, each pixel forming the liquid crystal panel 115 has a spectral characteristic, and an error occurs in the wavelength of the image light transmitted by the pixel. Due to the optical characteristics of these optical components, an error occurs in the value of the spectral image pickup data generated by the spectral image pickup unit 137, and the color measurement accuracy deteriorates. Therefore, by calculating the estimation matrix M based on the spectral imaging data generated by the spectral imaging unit 137 and the spectral colorimetric data measured by the spectrum measuring apparatus, it is possible to obtain a determinant capable of correcting the optical characteristics. it can. The spectrum measurement device is a device dedicated to spectrum measurement, and is an external device different from the projector 100. The procedure for calculating the estimation matrix M is shown below.

[Calculation procedure of control unit/storage unit/estimation matrix M]
First, the adjustment image is displayed on the screen SC. The control unit 150 reads out the adjustment image data 162 from the storage unit 160 and outputs it to the image processing unit 143. In addition, the control unit 150 controls the image processing unit 143 and the driving unit 120 to cause the projection unit 110 to project image light and display an adjustment image on the screen SC.

Next, the displayed adjustment image is imaged by the spectral imaging unit 137 to generate spectral imaging data, and the spectrum of the adjustment image is measured by the spectrum measuring device to generate spectral colorimetric data. The spectrum measurement device is a device dedicated to spectrum measurement, and is an external device different from the projector 100. The spectrum colorimetric data is composed of a spectrum of each pixel constituting the spectrum colorimetric data, or a representative spectrum. The representative spectrum may be, for example, a spectrum of a preset pixel or may be an average value of spectra of a plurality of selected pixels.

Next, the control unit 150 is caused to change the color or gradation of the adjustment image to be displayed on the screen SC, the displayed adjustment image is imaged by the spectral imaging unit 137, and measured by the spectrum measuring device. This processing is performed for all the colors and all the gradations of the adjustment image data 162 stored in the storage unit 160, and the spectral imaging data and the spectrum measurement data are used for the colors and floors of the adjustment image data 162 prepared in advance. You get each in key.

Next, the spectral imaging data output by the spectral imaging unit 137 and the spectral measurement data measured by the spectrum measuring device are compared to generate an estimation matrix M for calculating spectral estimation data from the spectral imaging data. Here, the spectral imaging data to be compared and the spectral estimation data are data obtained by imaging or measuring colored light of the same color and the same gradation.

The estimation matrix M is calculated by the least square method. The spectrum measurement data measured by the spectrum measuring device will be referred to as “Y”, and the N×16 spectrum obtained from the spectral imaging data of the spectral imaging unit 137 will be referred to as “X”. Further, “N” indicates the learning number. For example, when an image with three colors of R, G, and B, and seven gradations for each color is displayed as an adjustment image and measured by the spectral imaging unit 137 and the spectrum measuring device, the learning number “N” is 3×. It becomes 21 with 7. The square error Δ between the spectrum estimation value “XM” obtained by integrating the estimation matrix M with the N×16 spectrum obtained from the spectral image pickup data of the spectral image pickup unit 137 and the spectrum measurement data “Y” is minimized. Then, the value of the estimation matrix M is determined. The formula for calculating the squared error Δ is shown in formula (1a). Further, an expression obtained by partially differentiating both sides of the expression (1a) with “M” as a variable is shown in (1b).

If the minimum value of the square error Δ is assumed to be “0” in the above equation (1b), the following equation (2) is established.
X ^T Y=X ^T XM (2)
“X ^T ”in Expressions (1b) and (2) is a transposed matrix of X.
Further, the value of the estimation matrix M according to the equation (2) becomes the following equation (3).
M=(X ^T X) ^-1 X ^T Y (3)

Moreover, when the value of the learning number “N” is small, the spectrum estimation will only work with the learning data. Specifically, the absolute values of the elements of the estimation matrix M become very large, which causes excessive reaction to noise. Therefore, when the learning number “N” has a small value, the regularization term “β” is introduced into the formula for calculating the squared error Δ shown in the above formula (1a). A value selected by experiment is used for the regularization term “β”. The squared error Δ introduced by the regularization term “β” is shown in equation (4a). Further, an expression in which both sides of the expression (4a) are partially differentiated with "M" as a variable is shown in (4b).

When the minimum value of the square error Δ is assumed to be “0” in the above equation (4b), the following equation (5) is established.
X ^T Y=X ^T XM-βM (5)
Therefore, the value of the estimation matrix M according to the equation (5) becomes the following equation (6).
M=(X ^T X-βI) ^-1 X ^T Y (6)
“I” shown in Expression (6) indicates an identity matrix.

[Control/Processor]
The processor 170 is an arithmetic processing unit including, for example, a CPU (Central Processing Unit), a DSP (Digital Signal Processor), and a microcomputer. The processor 170 may be configured by a single processor or may be configured by combining a plurality of processors.

In the control unit 150, the processor 170 executes arithmetic processing according to the control program 161, and realizes various functions. FIG. 1 shows functional blocks corresponding to each of the plurality of functions included in the control unit 150. The control unit 150 includes a projection control unit 171, an imaging control unit 173, an estimated value calculation unit 175, and a generation unit 177 as functional blocks.

[Controller/processor/projection controller]
The projection control unit 171 adjusts the hue and brightness of the image displayed on the screen SC by the projection unit 110. Specifically, the projection control unit 171 controls the image processing unit 143 to execute the image processing on the image data input from the image interface 141. At this time, the projection control unit 171 may read out the parameters 165 required for the processing by the image processing unit 143 from the storage unit 160 and output them to the image processing unit 143.
In addition, the projection control unit 171 controls the light source drive circuit 121 to turn on or off the light source of the light source 111 and adjust the brightness of the light source 111.

When the projection control unit 171 starts the image quality adjustment process described later, the projection control unit 171 reads the pattern image data 163 and the adjustment image data 162 from the storage unit 160 and causes the image processing unit 143 to execute the process. The projection control unit 171 also controls the image processing unit 143 and the drive unit 120 to display the pattern image corresponding to the pattern image data 163 and the adjustment image corresponding to the adjustment image data 162 on the screen SC.

Furthermore, when displaying the adjustment image data 162 on the screen SC, the projection control unit 171 selects the color and gradation of the adjustment image projected on the projection unit 110, and the adjustment image of the selected color and gradation. The data 162 is read from the storage unit 160, and the image processing unit 143 is made to process it.
For example, it is assumed that three colors R, G, and B are stored in the storage unit 160 as the adjustment image data 162. Further, it is assumed that the adjustment image data 162 for each color is prepared with seven gradation values. Further, it is assumed that the order of displaying the adjustment images is R, G, B, and that the adjustment images are displayed in order from the smallest gradation value.

The projection control unit 171 first reads out the adjustment image data 162 having the smallest gradation value from the storage unit 160 among the R adjustment image data 162, controls the image processing unit 143 and the drive unit 120, and reads the adjustment image data 162. The adjustment image corresponding to the adjustment image data 162 is displayed on the screen SC. R corresponds to an example of the "first color" in the present invention.

When the spectral image capturing unit 137 captures the displayed adjustment image and the spectral image capturing data is stored in the storage unit 160, the projection control unit 171 changes the gradation value of the R adjustment image displayed on the screen SC. To do. The projection control unit 171 reads out the adjustment image data 162 of R having the second smallest gradation value from the storage unit 160, controls the image processing unit 143 and the drive unit 120, and corresponds to the read adjustment image data 162. The adjusted image is displayed on the screen SC. After that, the projection control unit 171 repeats the same processing to display the R adjustment image on the screen SC with all of the seven gradation values prepared in advance.

According to the present invention, the magnitude relationship among the tone values of “first tone”, “second tone” and “seventh tone” is “first tone”<“seventh tone”<“second floor” Key relationship. For example, assuming that the gradation value of the adjustment image data 162 of R having the smallest gradation value corresponds to an example of the “first gradation” of the present invention, for example, the gradation values are second to sixth. The gradation value of the adjustment image data 162 having a very small R corresponds to an example of the “seventh gradation” in the present invention. Similarly, the gradation value of the R adjustment image data 162 having the third to seventh smallest gradation value corresponds to an example of the “second gradation” of the present invention.

The image displayed on the screen SC based on the adjustment image data 162 of R having the smallest gradation value corresponds to an example of the “first image” of the present invention, and is based on the adjustment image data 162. The spectral imaging data obtained by imaging the screen SC on which the image is displayed by the spectral imaging unit 137 corresponds to an example of “first captured image information” of the present invention.
The image displayed on the screen SC based on the R adjustment image data 162 having the second to sixth smallest gradation value corresponds to an example of the “seventh image” of the present invention. The spectral imaging data obtained by imaging the screen SC on which the image based on the data 162 is displayed by the spectral imaging unit 137 corresponds to an example of “seventh captured image information” of the invention.
The image displayed on the screen SC based on the R adjustment image data 162 having the third to seventh smallest gradation value corresponds to an example of the “second image” of the present invention. The spectral imaging data obtained by imaging the screen SC on which the image based on the data 162 is displayed by the spectral imaging unit 137 corresponds to an example of “second captured image information” of the invention.

When the R adjustment image is displayed on the screen SC in all seven gradations, the projection control unit 171 changes the color of the adjustment image displayed on the screen SC from R to G. G corresponds to an example of the "second color" in the present invention. The projection control unit 171 reads out the adjustment image data 162 having the smallest gradation value from the storage unit 160 among the G adjustment image data 162, controls the image processing unit 143 and the drive unit 120, and reads the read adjustment. The adjustment image corresponding to the display image data 162 is displayed on the screen SC. When the spectral image capturing unit 137 captures the displayed adjustment image and the spectral image capturing data is stored in the storage unit 160, the projection control unit 171 changes the gradation value of the G adjustment image displayed on the screen SC. To do. The projection control unit 171 reads the G adjustment image data 162 having the second smallest gradation value from the storage unit 160, controls the image processing unit 143 and the drive unit 120, and responds to the read adjustment image data 162. The adjusted image is displayed on the screen SC. After that, the projection control unit 171 repeats the same processing to display the G adjustment image on the screen SC with all of the seven gradation values prepared in advance.

According to the present invention, the relationship between the gradation values of the “third gradation”, the “fourth gradation” and the “eighth gradation” is as follows: Key relationship. For example, assuming that the gradation value of the G adjustment image data 162 having the smallest gradation value corresponds to an example of the “third gradation” of the present invention, for example, the gradation values are second to sixth. The gradation value of the G adjustment image data 162 that is extremely small corresponds to an example of the “8th gradation” in the present invention. Similarly, the gradation value of the G adjustment image data 162 having the third to seventh smallest gradation value corresponds to an example of the “fourth gradation” in the present invention.

The image displayed on the screen SC based on the G adjustment image data 162 having the smallest gradation value corresponds to an example of the “third image” of the present invention, and is based on the adjustment image data 162. The spectral imaging data obtained by imaging the screen SC on which the image is displayed by the spectral imaging unit 137 corresponds to an example of “third captured image information” of the invention.
The image displayed on the screen SC based on the G adjustment image data 162 having the second to sixth smallest gradation value corresponds to an example of the “eighth image” of the present invention. The spectral imaging data obtained by imaging the screen SC on which the image based on the data 162 is displayed by the spectral imaging unit 137 corresponds to an example of “eighth captured image information” of the invention.
The image displayed on the screen SC based on the G adjustment image data 162 having the third to seventh smallest gradation value corresponds to an example of the “fourth image” of the present invention. The spectral imaging data obtained by imaging the screen SC on which the image based on the data 162 is displayed by the spectral imaging unit 137 corresponds to an example of “fourth captured image information” of the invention.

The projection control unit 171 similarly processes the B adjustment image. B corresponds to an example of the "third color" in the present invention.
According to the present invention, the relationship between the gradation values of the “fifth gradation”, the “sixth gradation” and the “9th gradation” is “5th gradation”<“9th gradation”<“6th floor” Key relationship. For example, if it is assumed that the gradation value of the B adjustment image data 162 having the smallest gradation value corresponds to an example of the “fifth gradation” of the present invention, for example, the gradation values are second to sixth. The gradation value of the adjustment image data 162 of B that is extremely small corresponds to an example of the “9th gradation” in the present invention. Similarly, the gradation value of the B adjustment image data 162 having the third to seventh smallest gradation value corresponds to an example of the “sixth gradation” in the present invention.

The image displayed on the screen SC based on the B adjustment image data 162 having the smallest gradation value corresponds to an example of the “fifth image” of the present invention, and is based on the adjustment image data 162. The spectral imaging data obtained by imaging the screen SC on which the image is displayed by the spectral imaging unit 137 corresponds to an example of “fifth captured image information” of the present invention.
The image displayed on the screen SC based on the B adjustment image data 162 having the second to sixth smallest gradation value corresponds to an example of the “ninth image” of the present invention. The spectral imaging data obtained by imaging the screen SC on which the image based on the data 162 is displayed by the spectral imaging unit 137 corresponds to an example of the “ninth captured image information” of the invention.
The image displayed on the screen SC based on the B adjustment image data 162 having the third to seventh smallest gradation value corresponds to an example of the “sixth image” of the present invention. The spectral imaging data obtained by imaging the screen SC on which the image based on the data 162 is displayed by the spectral imaging unit 137 corresponds to an example of “sixth captured image information” of the invention.

Note that the “first gradation”, which is the gradation value of the R adjustment image data 162, the “third gradation”, which is the gradation value of the G adjustment image data 162, and the B adjustment image data. The gradation value of 162, “fifth gradation”, may be set to the same gradation value. Also, the “second gradation”, which is the gradation value of the R adjustment image data 162, the “fourth gradation”, which is the gradation value of the G adjustment image data 162, and the B adjustment image data. The gradation value of 162, “sixth gradation” may be set to the same gradation value. Similarly, the “7th gradation”, which is the gradation value of the R adjustment image data 162, the “8th gradation”, which is the gradation value of the G adjustment image data 162, and the B adjustment image. The gradation value “9th gradation” of the data 162 may be set to the same gradation value. By performing imaging with the same gradation for each color of R, G, and B, it is possible to improve the correction accuracy of color correction.

[Control unit/processor/imaging control unit]
The imaging control unit 173 causes the spectral imaging unit 137 to perform imaging. The spectral imaging unit 137 performs imaging under the control of the imaging control unit 173 and outputs spectral imaging data.
Further, the imaging control unit 173 sets a wavelength range in which the spectral imaging unit 137 performs imaging when the spectral imaging unit 137 captures the adjustment image displayed on the screen SC. When causing the spectral image capturing unit 137 to capture an image for R adjustment, the image capturing control unit 173 sets, for example, a range of 620 nm or more and 750 nm or less as a wavelength range for performing image capturing. When the G adjustment image is to be captured by the spectral imaging unit 137, the imaging control unit 173 sets, for example, a range of 495 nm or more and 570 nm or less as a wavelength range in which imaging is performed. In addition, when the spectral image capturing unit 137 captures the B adjustment image, the image capturing control unit 173 sets, for example, a range of 450 nm or more and 495 nm or less as a wavelength range for performing image capturing.

For example, the wavelength range of 620 nm or more and 750 nm or less set when the spectral adjustment unit 137 captures the R adjustment image corresponds to an example of the “first measurement condition” of the present invention. Further, the wavelength range of 495 nm or more and 570 nm or less set when the G adjustment image is captured by the spectral imaging unit 137 corresponds to an example of the “second measurement condition” of the present invention. The wavelength range of 450 nm or more and 495 nm or less when capturing the B adjustment image corresponds to an example of the “third measurement condition” of the present invention.

Further, the imaging control unit 173 changes the voltage applied to the gap changing unit 306 to change the spectral wavelength λi of the spectroscopic element 302. Thereby, the spectral imaging unit 137 performs imaging while changing the spectral wavelength λi for each preset first wavelength interval. In the present embodiment, a case will be described in which the spectral imaging unit 137 performs imaging at a wavelength interval of 20 nm. "20 nm" corresponds to an example of "first wavelength interval" of the present invention. For example, when capturing a red adjustment image, the imaging control unit 173 causes the spectral imaging unit 137 to perform imaging at intervals of 20 nm within the wavelength range of 620 nm or more and 750 nm or less. The imaging control unit 173 inputs the spectral imaging data output from the spectral imaging unit 137, and temporarily stores the input spectral imaging data in the storage unit 160.

In the present embodiment, the projector 100 sets the measurement condition corresponding to the color of the adjustment image in the spectral imaging unit 137 while changing the color and gradation of the adjustment image displayed on the screen SC by the projection unit 110. It is possible to generate spectral imaging data. It is possible to measure the light intensity at each of the first wavelength intervals in a plurality of different colors. Therefore, the projector 100 can improve the accuracy of color measurement and efficiently improve the correction accuracy of the image projected by the projector 100.
In order to improve the accuracy of color measurement, it is necessary to project a large number of color and gradation adjustment images and measure the adjustment images in a wide range and a detailed range, but this takes time and the efficiency deteriorates. In addition, if a dedicated length measuring machine is used, the control becomes complicated and the efficiency further deteriorates.

The projector 100 of the present embodiment includes a projection unit 110 and a spectral imaging unit 137, and the projection unit 110 sets, for example, three colors of an adjustment image to R, G, and B, and at least two consecutive colors are used. An image for adjustment of one gradation is projected, and an image is taken in the measurement wavelength range corresponding to the image for adjustment projected on the spectral image pickup unit 137.

FIG. 3 is a diagram showing display conditions and measurement conditions of the adjustment image.
In the present embodiment, as shown in FIG. 3 and the following (A) to (C), the adjustment image data 162 of each color is prepared as the adjustment image data 162 with seven gradation values, and the adjustment image is displayed. The order of R, G, and B is set as the order, and the adjustment images with smaller gradation values are displayed in order, and the measurement is performed under the measurement condition corresponding to the projected adjustment image. In the present embodiment, an image with a small gradation value is a dark image and an image with a large gradation value is a bright image, but an image with a small gradation value may be a bright image and an image with a large gradation value may be a dark image. .. Further, each gradation may have the same gradation value for each color.

(A) First, the color of the adjustment image is set to R, and (1) the all-red image IR1 having the gradation TR1 is projected, and the wavelength range corresponding to red is 620 nm or more and 750 nm or less. To measure. In addition, (2) the all-red image IR2 having the gradation TR2 is projected, and measurement is performed in the wavelength range of 620 nm or more and 750 nm or less, which is the wavelength range corresponding to red. In addition, (3) the all-red image IR3 having the gradation TR3 is projected, and measurement is performed in the wavelength range of 620 nm or more and 750 nm or less, which is the wavelength range corresponding to red. In addition, (4) the all-red image IR4 having the gradation TR4 is projected, and measurement is performed in the wavelength range of 620 nm or more and 750 nm or less, which is the wavelength range corresponding to red. In addition, (5) the all-red image IR5 having the gradation TR5 is projected, and measurement is performed within a wavelength range corresponding to red of 620 nm or more and 750 nm or less. Also, (6) the all-red image IR6 having the gradation TR6 is projected, and measurement is performed in the wavelength range of 620 nm or more and 750 nm or less, which is the wavelength range corresponding to red. In addition, (7) the all-red image IR7 having the gradation TR7 is projected, and measurement is performed within the wavelength range of 620 nm or more and 750 nm or less, which is the wavelength range corresponding to red.
Here, the gradation values have a relationship of TR1<TR2<TR3<TR4<TR5<TR6<TR7, and the image brightness has a relationship of IR1<IR2<IR3<IR4<IR5<IR6<IR7.

(B) The color of the image for adjustment is set to G, and (1) The all-green image IG1 with the gradation of TG1 is projected, and the measurement is performed in the wavelength range of 495 nm or more and 570 nm or less, which is the wavelength range corresponding to green. To do. Further, (2) the all-green image IG2 having the gradation of the gradation TG2 is projected, and the measurement is performed in the wavelength range corresponding to green of 495 nm or more and 570 nm or less. Further, (3) the all-green image IG3 having the gradation TG3 is projected, and measurement is performed in the wavelength range of 495 nm or more and 570 nm or less corresponding to green. Further, (4) the all-green image IG4 having the gradation TG4 is projected, and measurement is performed within a wavelength range corresponding to green of 495 nm or more and 570 nm or less. Further, (5) the all-green image IG5 having the gradation of the gradation TG5 is projected, and measurement is performed within a wavelength range corresponding to green of 495 nm or more and 570 nm or less. Also, (6) the all-green image IG6 having the gradation of the gradation TG6 is projected, and the measurement is performed in the wavelength range of 495 nm or more and 570 nm or less corresponding to green. In addition, (7) the all-green image IG7 having the gradation TG7 is projected, and measurement is performed in the wavelength range corresponding to green of 495 nm or more and 570 nm or less.
Here, the gradation values have a relationship of TG1<TG2<TG3<TG4<TG5<TG6<TG7, and the brightness of the image has a relationship of IG1<IG2<IG3<IG4<IG5<IG6<IG7.

(C) The color of the image for adjustment is set to B, and (1) The all-blue image IB1 with the gradation TB1 is projected, and measurement is performed in the wavelength range of 450 nm to 495 nm, which is the wavelength range corresponding to blue. To do. In addition, (2) the all-blue image IB2 having the gradation of the gradation TB2 is projected, and the measurement is performed in the wavelength range corresponding to blue of 450 nm or more and 495 nm or less. In addition, (3) the all-blue image IB3 having the gradation TB3 is projected, and measurement is performed within a wavelength range of 450 nm or more and 495 nm or less, which is a wavelength range corresponding to blue. Also, (4) the all-blue image IB4 having the gradation TB4 is projected, and measurement is performed in the wavelength range of 450 nm or more and 495 nm or less, which is the wavelength range corresponding to blue. Also, (5) the all-blue image IB5 having the gradation TB5 is projected, and measurement is performed within a wavelength range of 450 nm or more and 495 nm or less, which is a wavelength range corresponding to blue. In addition, (6) the all-blue image IB6 having the gradation TB6 is projected, and measurement is performed in the wavelength range of 450 nm to 495 nm, which is the wavelength range corresponding to blue. In addition, (7) the all-blue image IB7 in which the gradation is the gradation TB7 is projected, and measurement is performed in the wavelength range of 450 nm or more and 495 nm or less, which is the wavelength range corresponding to blue.
Here, the gradation values have a relationship of TB1<TB2<TB3<TB4<TB5<TB6<TB7, and the image brightness has a relationship of IB1<IB2<IB3<IB4<IB5<IB6<IB7.

[Control unit/Processor/Estimated value calculation unit]
The estimated value calculation unit 175 reads the spectral imaging data and the estimation matrix M from the storage unit 160, and based on the read spectral imaging data and the estimation matrix M, the spectrum for each second wavelength interval that is shorter than the first wavelength interval. Calculate the estimated value of. The estimated value calculation unit 175 calculates the estimated value of the spectrum for each second wavelength interval by integrating the intensity I of the wavelength λ component obtained from the spectral imaging data with the estimation matrix M.

[Control/Processor/Generator]
The generation unit 177 generates a correction parameter used by the image processing unit 143 for image processing based on the estimated value of the spectrum calculated by the estimated value calculation unit 175. The correction parameter is used when the image processing unit 143 processes the image data input from the image interface 141. A specific method of generating the correction parameter will be described with reference to the flowchart shown in FIG.

[Projector operation]
FIG. 4 is a flowchart showing the operation of the projector 100 of the first embodiment.
The operation of the projector 100 will be described with reference to the flowchart of FIG.
The control unit 150 first determines whether or not an operation for selecting image quality adjustment has been received (step S1). The control unit 150 determines whether or not an operation of selecting image quality adjustment has been received based on an operation signal input from the input interface 135 (step S1). When the operation of selecting the image quality adjustment is not accepted (step S1/NO), the control unit 150 waits for the start of the operation until the operation is accepted. Further, when the control unit 150 receives an operation instructing the execution of another process, the control unit 150 executes the operation corresponding to the received operation and returns to the determination of step S1.

The image quality adjustment is an adjustment for correcting the image quality deterioration of the projection image displayed on the screen SC and returning it to the image quality at the time of manufacturing the projector 100. For example, since the characteristics of the light source 111 change due to temperature change, deterioration over time, and the like, it is necessary to correct the light amount so that a desired image brightness can be obtained. In addition, the image quality of the projector 100 is adjusted by correcting the tint of the screen SC or the environment lighting to correct the tint of the projected image to a preset tint, or the projected images displayed by the plurality of projectors 100. There are adjustments to match the color shades of. For these image quality adjustments, the correction data 167a can be generated by the same procedure as described below.

When the control unit 150 receives the operation of selecting the image quality adjustment (step S1/YES), first, the projective transformation matrix 167b is calculated. The projective transformation matrix 167b is a matrix that transforms the panel coordinates of the liquid crystal panel 115 into imaging coordinates of the spectral imaging data generated by the spectral imaging unit 137. The control unit 150 reads the pattern image data 163 from the storage unit 160 and controls the image processing unit 143 and the drive unit 120 to display the pattern image corresponding to the pattern image data 163 on the screen SC (step S2).

Next, the control unit 150 controls the spectral imaging unit 137 to capture the screen SC on which the pattern image is displayed. Here, it is preferable that the imaging data captured by the spectral imaging unit 137 is data captured by the spectroscopic element 302 in a state where the wavelength of light is not dispersed. The spectral imaging unit 137 generates imaging data (step S3) and outputs the generated imaging data to the control unit 150. The control unit 150 stores the input imaging data in the storage unit 160.

Next, the control unit 150 associates the imaging coordinates with the panel coordinates (step S4). The control unit 150 reads the image pickup data from the storage unit 160, analyzes the read image pickup data, and detects a mark having a predetermined shape. When the control unit 150 detects the mark from the imaged data, the control unit 150 associates the pixel at the detection position of the mark with the pixel of the liquid crystal panel 115 on which the mark is drawn. That is, the control unit 150 associates the coordinates of the pixel at the mark detection position with the coordinates of the pixel of the liquid crystal panel 115 on which the mark is drawn. Further, when the control unit 150 detects the four marks from the imaged data, the projective transformation matrix that transforms the panel coordinates of the liquid crystal panel 115 into the imaged coordinates based on the imaged coordinates and the panel coordinates of the associated four marks. Calculate 167b.

In this flowchart, a case where the process of obtaining the projective transformation matrix 167b is performed before the adjustment image is displayed on the screen SC will be described. However, the projective transformation matrix 167b is calculated in advance and stored in the storage unit 160. It may be. Further, in this flowchart, the case where the imaging coordinates and the panel coordinates are associated with each other has been described, but the imaging coordinates may be associated with the coordinates set in the pixels of the frame memory 145.

Next, the control unit 150 determines the focal length of the spectral image pickup unit 137 based on the angle-of-view information of the image pickup data picked up in step S3 (step S5). After determining the focal length, the control unit 150 adjusts the lens position and zoom magnification of the incident optical system 301 of the spectral imaging unit 137 based on the determined focal length. Further, when the spectral imaging unit 137 includes a plurality of single focus lenses, the control unit 150 selects one of the single focus lenses based on the determined focal length.

Next, the control unit 150 selects the color and gradation of the adjustment image and reads the adjustment image data 162 of the selected color and gradation from the storage unit 160. When the control unit 150 reads the adjustment image data 162 from the storage unit 160, the control unit 150 controls the image processing unit 143 and the driving unit 120 to display the adjustment image corresponding to the adjustment image data 162 on the screen SC (step S6). ). Step S6 corresponds to an example of the "first projection step" and the "second projection step" of the present invention. Here, it is preferable that the light used for generating the image light that is the source of the adjustment image is, for example, uniform light having a uniform wavelength with an integrating sphere or the like. By projecting light with a uniform wavelength on the screen SC, the accuracy of image quality adjustment can be improved.

Next, the control unit 150 determines the wavelength range in which the spectral imaging unit 137 performs imaging based on the color of the adjustment image displayed in step S6 (step S7). When the wavelength range is determined, the control unit 150 sets the set spectral wavelength λi set in the spectroscopic element 302 to the minimum value within the determined wavelength range, and causes the spectral imaging unit 137 to perform imaging to generate spectral imaging data. (Step S8). Step S8 corresponds to an example of the "first acquisition step" and the "second acquisition step" of the present invention.

Next, the control unit 150 changes the value of the set spectral wavelength λi to a value larger by a preset value (step S9), and determines whether the set spectral wavelength λi exceeds the wavelength range (step S10). ). When the set spectral wavelength λi does not exceed the wavelength range (step S10/NO), the control unit 150 sets the set spectral wavelength λi in the spectroscopic element 302 and causes the spectral image pickup unit 137 to perform image pickup to obtain spectral image pickup data. It is generated (step S8).

In addition, when the set spectral wavelength λi exceeds the wavelength range (step S10/YES), the control unit 150 causes the adjustment images of all colors to be displayed on the screen SC at all gradations, and the spectral imaging unit 137 It is determined whether or not an image has been captured (step S11). When there is a gradation or color adjustment image that has not been captured by the spectral imaging unit 137 (step S11/NO), the control unit 150 determines the color and gradation of the adjustment image to be displayed next (step S12). ). The control unit 150 changes at least one of the color and gradation of the adjustment image, and determines the changed color and gradation as the color and gradation of the adjustment image to be displayed next. Step S12 corresponds to an example of the "first determining step" and the "second determining step" of the present invention. The control unit 150 reads out the adjustment image data 162 of the determined color and gradation from the storage unit 160, controls the image processing unit 143 and the driving unit 120, and screens the adjustment image corresponding to the adjustment image data 162. Display on SC.

In addition, the control unit 150 determines that the color measurement processing is completed when the adjustment images of all colors are displayed in all gradations and the spectral imaging data is generated (step S11/YES). The control unit 150 reads the spectral imaging data from the storage unit 160 and corrects the read spectral imaging data (step S13). The control unit 150 first selects one of the panel coordinates and obtains imaging coordinates corresponding to the selected panel coordinates. The control unit 150 converts the selected panel coordinates into imaging coordinates by the projective transformation matrix 167b generated in step S4. The selected panel coordinates are written as (xp, yp), and the imaging coordinates are written as (xc, yc). Further, the projective transformation matrix 167b is expressed as "Φ". The control unit 150 calculates the imaging coordinates according to the following equation (7).
(Xc, yc)=Φ·(xp, yp) (7)

Next, the control unit 150 reads the correction data 167a associated with the calculated image pickup coordinates from the storage unit 160, and corrects the spectral image pickup data by the read correction data 167a (step S13). A formula for correcting the spectral imaging data with the correction data 167a is shown in the following formula (8).
post(xc,yc,r,λ,I)=pre(xc,yc,r,λ,I)·k(xc,yc,r,λ,coeff) (8)

In the equation (8), “post(xc, yc, r, λ, I)” is the intensity I of the wavelength λ component imaged in the spectral image data and represents the value after correction by the correction data 167a.
Further, “pre(xc, yc, r, λ, I)” is the intensity I of the wavelength λ component at the imaging coordinates (xc, yc) of the spectral imaging data of the R light adjustment image.
Further, “k(xc, yc, r, λ, coeff)” is correction data 167a that corrects the wavelength λ component of the spectral image data obtained by capturing the R light at the image capturing coordinates (xc, yc).

Expression (8) shows a case where the intensity I of the wavelength λ component of the spectral image data obtained by capturing the R light adjustment image is corrected, but the control unit 150 controls the R light, G light, and B light adjustment images. With respect to the spectral imaging data obtained by imaging the image, the correction data 167a is corrected at all wavelengths λi.

Next, the control unit 150 multiplies the spectral imaging data corrected by the correction data 167a by the estimation matrix M to estimate the spectrum for each second wavelength interval (step S14). An equation for obtaining the estimated value of the spectrum for each second wavelength interval is shown in (9) below.
Spectral(xc, yc, λ)=M·post(xc, yc, λ) (9)

In Expression (9), Spectral(xc, yc, λ) represents the estimated value of the spectrum at the coordinates (xc, yc). By multiplying post(xc, yc, λ) by the estimation matrix M, it is possible to obtain an estimated value that estimates the light intensity I at a wavelength interval of 1 nm, for example.

FIG. 5 is a diagram showing the light intensity for each spectral frequency obtained from the spectral imaging data. The horizontal axis of FIG. 5 indicates the wavelength nm, and the vertical axis indicates the light intensity I. The black circles shown in FIG. 5 indicate the values obtained from the spectral imaging data. FIG. 5 shows the light intensity obtained from the spectral imaging data captured at the spectral wavelength interval of 20 nm.
Further, FIG. 6 is a diagram showing an estimated value of the spectrum calculated by the control unit 150. The horizontal axis of FIG. 6 indicates the wavelength nm, and the vertical axis indicates the light intensity I. FIG. 6 shows the estimated values of the spectrum obtained at the wavelength interval of 1 nm.

Next, the control unit 150 determines the spectrum estimated value based on the spectrum estimated value and the CIE1931XYZ color matching functions x(λ), y(λ) and z(λ) based on the tristimulus value X of the XYZ color system. , Y, Z (step S15). The conversion formulas for the tristimulus values X, Y, and Z are shown as formulas (10a), (10b), and (10c).

In formulas (10a), (10b), and (10c), X(xp,yp), Y(xp,yp), and Z(xp,yp) are associated with the imaging coordinates (xc,yc). The stimulus value at coordinates (xp, yp) is shown. The control unit 150 causes the storage unit 160 to store the calculated tristimulus values X(xp, yp), Y(xp, yp), and Z(xp, yp). Hereinafter, X(xp, yp), Y(xp, yp), and Z(xp, yp) are collectively referred to as Fin_XYZ(xp, yp).

Next, the control unit 150 determines whether or not the tristimulus value Fin_XYZ(xp, yp) has been calculated for all panel coordinates of the liquid crystal panel 115 (step S16). When the tristimulus value Fin_XYZ(xp, yp) has not been calculated for all panel coordinates (step S16/NO), the control unit 150 returns to step S13, selects the panel coordinates, and corrects the selected panel coordinates. The spectral imaging data is corrected by the data 167a.

Further, when the control unit 150 calculates the tristimulus value Fin_XYZ(xp, yp) for all panel coordinates (step S16/YES), the control unit 150 acquires the target value for image quality adjustment from the storage unit 160 (step S17). Here, a case will be described in which the tristimulus values obtained by converting the spectral colorimetric data measured by the spectrum measuring device by the above-described formulas (10a), (10b), and (10c) are used as target values. Alternatively, the adjustment image may be corrected using the correction parameter obtained in the previous image quality adjustment, and the tristimulus value obtained based on the corrected adjustment image may be set as the target value for image quality adjustment. That is, the gradation value of the adjustment image is corrected by the correction parameter obtained in the previous image quality adjustment, the adjustment image with the corrected gradation value is displayed on the screen SC, and the spectral image capturing unit 137 captures the image. Generate data. After that, the tristimulus value Fin_XYZ(xp, yp) is obtained in accordance with the procedure of steps S13 to S15 described above, and the obtained tristimulus value is set as the target value for image quality adjustment.

Next, the control unit 150 obtains an inverse function of the tristimulus value Fin_XYZ(xp,yp) calculated in step S15. In addition, the control unit 150 integrates the obtained inverse function with the target value acquired in step S17 to calculate the adjustment ratio for each of R, G, and B colors. The target value acquired in step S17 is described as Target_XYZ. The formula for calculating the correction parameter is shown in the following formula (11).
Coef_RGB(xp, yp)=Fin_XYZ(xp, yp) ⁻¹ ·Target_XYZ (11)

Next, the control unit 150 acquires the correction data 167a for correcting the gradation value of the image data by referring to the gamma correction table. The gamma correction table is a table stored in the storage unit 160, and the gradation value of image data and the transmittance of the liquid crystal panel 115 are registered in association with each other. The control unit 150 refers to the gamma correction table and acquires the gradation value of the image data corresponding to the transmittance of the liquid crystal panel 115 when the adjustment image is displayed on the screen SC in step S6. Further, the control unit 150 refers to the gamma correction table to obtain the gradation value of the image data corresponding to the adjusted transmittance of the liquid crystal panel 115 based on the calculated adjustment ratio. The control unit 150 calculates the difference in gradation value of the acquired image data as a correction parameter for correcting the image data (step S18). The correction parameter is a parameter for correcting the RGB ratio of each pixel forming the image data.

The control unit 150 may generate the correction parameter in units of pixels forming the liquid crystal panel 115, or may generate the correction parameters in units of a plurality of pixels. When the correction parameter is generated with a plurality of pixels as one unit, the correction parameter of the pixel for which the correction parameter is not generated may be obtained by, for example, interpolation calculation by linear interpolation.

Next, the control unit 150 determines whether or not the calculated correction parameter is valid data (step S19). For example, the control unit 150 calculates a difference between the correction parameter calculated in the previous image quality adjustment and the correction parameter calculated this time, and calculates the calculated difference between the first threshold value and the prepared first threshold value. Compare with the second threshold. When the difference between the calculated values is larger than the first threshold value, the control unit 150 determines that the correction parameter calculated this time is invalid. The control unit 150 also determines that the correction parameter calculated this time is invalid even when the difference between the calculated values is smaller than the second threshold value. The second threshold value is a threshold value smaller than the first threshold value.

When the calculated correction parameter is valid data, the control unit 150 stores the calculated correction parameter in the storage unit 160 (step S20). Further, when the calculated correction parameter is not valid data, the control unit 150 may perform the process again from step S2 or S6.

When the supply of the image signal from the image supply device 200 is started, the control unit 150 reads the correction parameter from the storage unit 160 and outputs it to the image processing unit 143. When the image interface 141 starts receiving an image signal and image data is input from the image interface 141, the image processing unit 143 expands the input image data in the frame memory 145. The image processing unit 143 corrects the image data with the correction parameter input from the control unit 150 (step S21).

The image processing unit 143 outputs the image data that has undergone the image processing to the light modulation device drive circuit 123. The light modulator drive circuit 123 generates a drive signal based on the image data input from the image processing unit 143, drives the liquid crystal panel 115 based on the generated drive signal, and draws an image on the liquid crystal panel 115. The light emitted from the light source 111 passes through the liquid crystal panel 115 to generate image light corresponding to the image of the image data, and the generated image light is projected on the screen SC by the optical unit 117 (step S22). ..

As described above, the projector 100 according to the first embodiment includes the projection unit 110, the spectral imaging unit 137, and the control unit 150. The spectral imaging unit 137 includes an image sensor 303 and a spectral element 302. The control unit 150 controls the projection unit 110 and the spectral imaging unit 137.

The control unit 150 sets the color and gradation of the adjustment image to the first color and the first gradation, and causes the projection unit 110 to project the adjustment image corresponding to the set first color and first gradation. Further, the control unit 150 sets the first measurement condition corresponding to the first color in the spectral imaging unit 137, causes the spectral imaging unit 137 to capture the adjustment image projected by the projection unit 110, and acquires the spectral imaging data. ..

Further, the control unit 150 sets the color and gradation of the adjustment image to the first color and the second gradation, and projects the adjustment image corresponding to the set first color and second gradation on the projection unit 110. Let Further, the control unit 150 sets the first measurement condition corresponding to the first color in the spectral imaging unit 137, causes the spectral imaging unit 137 to capture the adjustment image projected by the projection unit 110, and acquires the spectral imaging data. ..

Further, the control unit 150 sets the color and gradation of the adjustment image to the second color and the third gradation, and projects the adjustment image corresponding to the set second color and third gradation on the projection unit 110. Let The control unit 150 sets the second measurement condition corresponding to the second color in the spectral imaging unit 137, causes the spectral imaging unit 137 to capture the adjustment image projected by the projection unit 110, and acquires the spectral imaging data.

Further, the control unit 150 sets the color and gradation of the adjustment image to the second color and the fourth gradation, and projects the adjustment image corresponding to the set second color and fourth gradation on the projection unit 110. Let In addition, the control unit 150 sets the second measurement condition corresponding to the second color in the spectral imaging unit 137, causes the spectral imaging unit 137 to capture the adjustment image projected by the projection unit 110, and acquires the spectral imaging data. ..

Therefore, in the present embodiment, while changing the color and gradation of the adjustment image displayed on the screen SC, the measurement condition corresponding to the color of the adjustment image is set in the spectral imaging unit, and the spectral imaging unit performs the spectral imaging. Data can be generated. Therefore, the accuracy of color measurement can be improved, and the accuracy of color correction of the image projected by the projector can be improved.

In addition, the control unit 150 controls the spectral imaging unit for each of the acquired first color and first gradation, first color and second gradation, second color and third gradation, second color and fourth gradation. Imaging is performed by 137, and spectral imaging data is obtained. A correction parameter for correcting the image data which is the basis of the image projected by the projection unit 110 is generated based on the obtained plurality of spectral imaging data. Therefore, the color correction of the image can be accurately performed based on the color measurement result.

The control unit 150 sets the wavelength range corresponding to the color indicated by the first color as the imaging range as the first measurement condition, and causes the spectral imaging unit 137 to perform imaging while changing the spectral wavelength of the spectroscopic element 302 for each first wavelength interval. Let it run. Then, the control unit 150 acquires the intensity of light corresponding to the spectral wavelength as spectral imaging data.
In addition, as the second measurement condition, the control unit 150 sets the wavelength range corresponding to the color indicated by the second color as the imaging range, and causes the spectral imaging unit 137 to change the spectral wavelength of the spectroscopic element 302 for each first wavelength interval. Perform imaging. Then, the control unit 150 acquires the intensity of light corresponding to the spectral wavelength as spectral imaging data.
Therefore, it is possible to measure the light intensity for each of the first wavelength intervals with a plurality of different colors.

In addition, the control unit 150, based on the light intensity for each first wavelength interval acquired from the spectral imaging data and the estimation matrix M used for estimating the spectrum, for each second wavelength interval that is shorter than the first wavelength interval. Calculate an estimate of the spectrum of.
It is possible to calculate an estimated value of a spectrum for each second wavelength interval that is shorter than the first wavelength interval captured by the spectral imaging unit 137, and to perform color measurement of an image with high accuracy. Further, since the spectral imaging unit 137 can perform imaging at the first wavelength interval that is longer than the second wavelength interval, it is possible to reduce the time required to generate the spectral imaging data. Further, by calculating a correction parameter for correcting the image data based on the calculated estimated value of the spectrum, it is possible to accurately perform the color correction of the image.

Further, the estimation matrix M is calculated based on the spectral imaging data captured by the spectral imaging unit 137. The spectral imaging data generated by the spectral imaging unit 137 contains an error due to the optical characteristics of the optical components included in the projector 100. However, by calculating the estimation matrix M based on the spectral imaging data generated by the spectral imaging unit 137 and the spectral colorimetric data measured by the dedicated spectrum measuring device, the optical characteristics are corrected and the spectrum is estimated accurately. The value can be calculated.

Further, the estimation matrix M is an estimation of the spectrum obtained based on the measurement data obtained by measuring the adjustment image displayed on the screen SC at every second wavelength interval by a dedicated spectrum measuring device and the spectral imaging data. It is a determinant that minimizes the squared error from the image sensor value.
Therefore, it is possible to suppress an error generated in the spectral imaging data generated by the spectral imaging unit 137 and calculate an accurate spectrum estimated value.

Further, the spectroscopic imaging unit 137 changes the spectroscopic wavelength of the spectroscopic element 302 by changing the distance between the pair of reflection films 304 and 305 facing each other provided in the spectroscopic element 302, and spectroscopic imaging data for each first wavelength interval. Is output.
Therefore, the accuracy of setting the spectral wavelength of the spectral element 302 can be improved.

[Second Embodiment]
A second embodiment will be described with reference to the accompanying drawings. The second embodiment is an embodiment corresponding to the “display system” and the “image correction method”.
The second embodiment is an embodiment of a display system 1 in which a plurality of projectors 100 are connected by a cable 3 and data communication is performed between the projectors 100. In the second embodiment, data communication is performed between a plurality of projectors 100, and color matching of images displayed by each projector 100 is performed. In addition, in the second embodiment, a case where a plurality of projectors 100 are connected by wire will be described, but the connection between the projectors 100 may be wireless.

FIG. 7 is a system configuration diagram of the display system 1.
The display system 1 includes two projectors 100. When viewed from the direction facing the screen SC, the projector 100 that displays an image on the left side of the screen SC is referred to as a projector 100A, and the projector 100 that displays an image on the right side of the screen SC is referred to as a projector 100B. The projector 100A and the projector 100B configure a multi-projection system that displays images on the left and right sides of the screen SC and displays one image, respectively. FIG. 7 shows a configuration in which the display system 1 includes two projectors 100, but the number of connected projectors 100 is not limited to two, and n projectors 100 can be connected. Note that “n” is a natural number of 2 or more.

Since the configurations of the projector 100A and the projector 100B are almost the same as the configuration of the projector 100 shown in FIG. 1, description of the configurations of the projector 100A and the projector 100B will be omitted. Further, among the components of the projector 100 shown in the block diagram of FIG. 1, the components of the projector 100A are denoted by the reference symbol “A”, and the components of the projector 100B are denoted by the symbol “B”. For example, the control unit 150 of the projector 100A is described as “control unit 150A”, and the control unit 150 of the projector 100B is described as “control unit 150B”. The projector 100A and the projector 100B are respectively connected to the image supply device 200 via the cable 3 and display an image based on the image signal supplied from the image supply device 200 on the screen SC.

The projector 100A operates as a master machine, and the projector 100B operates as a slave machine. That is, the projector 100B operates according to the control of the projector 100A. The projector 100A, which is a master machine, instructs the projector 100B to calculate the tristimulus value described in the first embodiment, or generates a correction parameter and transmits the correction parameter to the projector 100B.

The area where the projector 100A projects the image light is referred to as the projection area 10, and the area where the projector 100B projects the image light is referred to as the projection area 20. The projection area 10 and the projection area 20 partially overlap each other.

In the second embodiment, the projector 100A corresponds to an example of the “first projector” of the present invention, and the projector 100B corresponds to an example of the “second projector” of the present invention. The projection unit 110A corresponds to an example of the “first projection unit” of the present invention, and the projection unit 110B corresponds to an example of the “second projection unit” of the present invention. The spectral imaging section 137A corresponds to an example of the “first spectral imaging section” of the present invention, and the spectral imaging section 137B corresponds to an example of the “second spectral imaging section” of the present invention. The image pickup element 303A corresponds to an example of the “first image pickup element” of the present invention, and the image pickup element 303B corresponds to an example of the “second image pickup element” of the present invention. The spectroscopic element 302A corresponds to the “first spectroscopic element” of the present invention, and the spectroscopic element 302B corresponds to the “second spectroscopic element” of the present invention. The control unit 150A corresponds to an example of the “first control unit” of the present invention, and the control unit 150B corresponds to an example of the “second control unit” of the present invention. The estimated value calculation unit 175A corresponds to an example of the “first estimated value calculation unit” of the present invention, and the estimated value calculation unit 175B corresponds to an example of the “second estimated value calculation unit” of the present invention. The storage unit 160A corresponds to an example of the "first storage unit" of the present invention, and the storage unit 160B corresponds to an example of the "second storage unit" of the present invention.

FIG. 8 is a flowchart showing the operation of the projector 100A.
The operation of the projector 100A will be described with reference to the flowchart shown in FIG.
The control unit 150A determines whether or not an operation for selecting color matching has been received (step T1). The control unit 150A determines whether or not an operation for selecting color matching has been received based on an operation signal input from the input interface 135A (step S1). When the operation of selecting the color matching is not accepted (step S1/NO), the control unit 150A waits for the operation to be started until the operation is accepted. Further, when the control unit 150A receives an operation instructing execution of another process, the control unit 150A executes an operation corresponding to the received operation and returns to the determination of step S1.

When the control unit 150A receives the operation of selecting the color matching (step T1/YES), the control unit 150A executes the processes of steps S2 to S16 to calculate tristimulus values at all panel coordinates of the liquid crystal panel 115A. (Step T2). The step T2 includes the “first determination step”, the “first projection step”, and the “first acquisition step” of the present invention.

Next, the control unit 150A transmits a signal instructing the calculation of the tristimulus value to the projector 100B, and instructs the projector 100B to calculate the tristimulus value (step T3). When the control unit 150A instructs the projector 100B to calculate the tristimulus value, the control unit 150A determines whether or not a signal for notifying the completion of the calculation of the tristimulus value has been received from the projector 100B (step T4). When the control unit 150A has not received the signal notifying the completion (step T4/NO), the control unit 150A waits until the signal is received.

Further, when the control unit 150A receives a signal notifying the completion from the projector 100B (step T4/YES), the control unit 150A transmits a calculated tristimulus value acquisition request to the projector 100B (step T5). The control unit 150A determines whether or not the tristimulus value is received from the projector 100B (step T6). When the tristimulus value is not received from the projector 100B (step T6/NO), the control unit 150A waits until the tristimulus value is received.

Further, when the control unit 150A receives the tristimulus value from the projector 100B, the control unit 150A stores the received tristimulus value in the storage unit 160A. Next, the control unit 150A sets a target value for color matching (step T7). The control unit 150A compares the tristimulus value received from the projector 100B with the tristimulus value generated by the control unit 150A, and identifies the panel coordinate with the lowest brightness. For example, the control unit 150A may compare Y values having luminance information among the three stimulus values and specify the panel coordinates associated with the Y value having the smallest value. Further, when there are a plurality of panel coordinates having the lowest brightness, the panel coordinates having the lowest brightness may be specified by comparing other stimulus values such as an X value and a Z value.

When the control unit 150A specifies the panel coordinate with the lowest brightness, the control unit 150A sets the tristimulus value of the specified panel coordinate with the lowest brightness as the target value. The control unit 150A calculates the correction parameter for correcting the tristimulus values of the other panel coordinates by using the above-described equation (11) with the set target value as Target_XYZ (step T8). Further, the control unit 150A similarly generates a correction parameter by the equation (11) for the tristimulus value received from the projector 100B and associated with each panel coordinate of the projector 100B (step T8). Step T8 corresponds to an example of the “generation step” of the present invention.

The control unit 150A generates a correction parameter for each panel coordinate of the projector 100A and stores the generated correction parameter in the storage unit 160A (step T9). The correction parameter generated here corresponds to an example of the “first correction parameter” of the present invention. The control unit 150A also generates a correction parameter for each panel coordinate of the projector 100B and transmits the generated correction parameter to the projector 100B (step T10). The correction parameter generated here corresponds to an example of the “second correction parameter” of the present invention.

After that, when the supply of the image signal from the image supply device 200 is started, the control unit 150A causes the image processing unit 143A to correct the image data by the generated correction parameter (step T11). Then, the control unit 150A causes the projection unit 110A to project image light based on the corrected image data on the screen SC. As a result, an image based on the image data whose color tone has been corrected by the correction parameter is displayed on the screen SC (step T12).

FIG. 9 is a flowchart showing the operation of the projector 100B.
The operation of the projector 100B will be described with reference to the flowchart shown in FIG.
The control unit 150B determines whether or not a signal instructing the calculation of the tristimulus value has been received from the projector 100A (step U1). When the control unit 150B has not received the signal instructing the calculation (step U1/NO), the control unit 150B waits for the start of the process until the signal is received.

When the control unit 150B receives a signal instructing the calculation of tristimulus values from the projector 100A (step U1/YES), the control unit 150B executes the processes of steps S2 to S16 shown in FIG. A tristimulus value is calculated by coordinates (step U2). When the calculation of the tristimulus value is completed, the control unit 150B transmits a signal notifying the completion of the calculation to the projector 100A (step U3). The step U2 includes the “second determination step”, the “second projection step” and the “second acquisition step” of the present invention.

Next, the control unit 150B determines whether or not a tristimulus value acquisition request has been received from the projector 100A (step U4). When the acquisition request for the tristimulus values has not been received (step U4/NO), the control unit 150B waits until the acquisition request is received.

When the control unit 150B receives the tristimulus value acquisition request (step U4/YES), the control unit 150B transmits the tristimulus value calculated for each panel coordinate to the projector 100A (step U5). After that, the control unit 150B determines whether or not the correction parameter is received from the projector 100A (step U6). When the correction parameter is not received (step U6/NO), the control unit 150B waits until the correction parameter is received.

Upon receiving the correction parameter from the projector 100A (step U6), the control unit 150B stores the received correction parameter in the storage unit 160B (step U7). After that, when the supply of the image signal from the image supply device 200 is started, the control unit 150B causes the image processing unit 143B to correct the image data by the generated correction parameter (step U8). Then, the control unit 150B causes the projection unit 110B to project the image light based on the corrected image data on the screen SC. As a result, an image based on the image data whose color tone has been corrected by the correction parameter is displayed on the screen SC (step U9).

As described above, the display system 1 of the second embodiment includes the projector 100A and the projector 100B.
The projector 100A includes a projection unit 110A, a spectral imaging unit 137A, a control unit 150A, a storage unit 160A, and an estimated value calculation unit 175A.
The projection unit 110A projects the image light on the screen SC to display the adjustment image on the screen SC.
The spectral image capturing unit 137A includes an image sensor 303A and a spectral element 302A, captures an adjustment image, and outputs spectral image data.
The control unit 150A determines the color and gradation of the adjustment image to be projected by the projection unit 110A, and causes the projection unit 110A to project the adjustment image corresponding to the determined color and gradation. In addition, the control unit 150A sets the measurement condition determined based on the determined color of the adjustment image in the spectral image pickup unit 137A, and causes the spectral image pickup unit 137A to image the adjustment image projected by the projection unit 110A to perform spectral analysis. Acquire imaging data.

The projector 100B includes a projection unit 110B, a spectral imaging unit 137B, a control unit 150B, a storage unit 160B, and an estimated value calculation unit 175B.
The projection unit 110B projects the image light on the screen SC to display the adjustment image on the screen SC.
The spectral image capturing unit 137B includes an image sensor 303B and a spectral element 302B, captures an adjustment image, and outputs spectral image data.
The control unit 150B determines the color and gradation of the adjustment image to be projected by the projection unit 110B, and causes the projection unit 110B to project the adjustment image corresponding to the determined color and gradation. In addition, the control unit 150B sets the measurement condition determined based on the determined color of the adjustment image in the spectral image capturing unit 137B, causes the spectral image capturing unit 137B to capture the adjustment image projected by the projection unit 110B, and performs spectral analysis. Acquire imaging data.

Therefore, in the present embodiment, color measurement of the adjustment image projected by the projector 100A and color measurement of the adjustment image projected by the projector 100B can be accurately performed. Further, it is possible to accurately perform color matching between the image displayed by the projector 100A and the image displayed by the projector 100B based on the color measurement result of the adjustment image. In addition, the projector 100A and the projector 100B can calculate the tristimulus values by the spectral imaging unit 137A and the spectral imaging unit 137B, respectively, and the image displayed by the projector 100A and the image displayed by the projector 100B can be displayed without transmitting/receiving the correction parameter. It is possible to accurately match the color with.

The above-described embodiment is a preferred embodiment of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the scope of the present invention.
For example, in the above-described embodiment, the case where a single-color image of each color of R, G, and B is displayed as the adjustment image has been described as an example. However, in one adjustment image, the R region, G The area of B and the area of B may be included.

Further, in the above-described embodiment, as the light modulation device 113 that modulates the light emitted from the light source, a configuration using three transmissive liquid crystal panels corresponding to RGB colors has been described as an example. The invention is not limited to this. For example, a configuration using three reflective liquid crystal panels may be used, or a system in which one liquid crystal panel and a color wheel are combined may be used. Alternatively, a system using three digital mirror devices (DMD), a DMD system combining one digital mirror device and a color wheel, or the like may be used. When only one liquid crystal panel or DMD is used as the light modulator, a member corresponding to a synthetic optical system such as a cross dichroic prism is unnecessary. In addition to the liquid crystal panel and the DMD, an optical modulator that can modulate the light emitted from the light source can be used without any problem.

Further, the processing units of the flowcharts shown in FIGS. 4, 8 and 9 are divided according to the main processing contents in order to facilitate understanding of the processing, and depending on the division method or name of the processing unit, The invention is not limited. Depending on the processing content, it may be divided into more processing units, or one processing unit may be divided into more processing units. Further, the order of the processing may be appropriately changed within a range that does not interfere with the gist of the present invention.

Further, each functional unit shown in FIG. 1 shows a functional configuration, and a specific mounting form is not particularly limited. In other words, it is not always necessary to individually implement hardware corresponding to each functional unit, and it is of course possible to implement a function of a plurality of functional units by executing a program by one processor. Further, in the above-described embodiment, some of the functions realized by software may be hardware, or some of the functions realized by hardware may be realized by software. Further, the specific detailed configuration of each of the other parts of the projector 100 can be arbitrarily changed without departing from the spirit of the present invention.

Further, when the projector control method and the image correction method of the present invention are implemented by a computer, the program executed by the computer may be configured as a recording medium or a transmission medium that transmits the program. A magnetic or optical recording medium or a semiconductor memory device can be used as the recording medium. Specifically, the recording medium is a flexible disk, an HDD (Hard Disk Drive), a CD-ROM (Compact Disk Read Only Memory), a DVD (Digital Versatile Disk), a Blu-ray (registered trademark) Disc, a magneto-optical disk. Are listed. Further, as the recording medium, a portable recording medium such as a flash memory or a card type recording medium or a fixed recording medium can be cited. The recording medium may be a non-volatile storage device such as a RAM (Random Access Memory), a ROM (Read Only Memory), or an HDD, which is an internal storage device included in the display device.

3... Cable, 10, 20... Projection area, 100, 100A, 100B... Projector, 101... Bus, 110, 110A, 110B... Projection part, 111... Light source, 113... Light modulator, 115, 115A, 115B... Liquid crystal panel Reference numeral 117... Optical unit, 120, 120A, 120B... Driving unit, 121, 121A, 121B... Light source driving circuit, 123, 123A, 123B... Light modulation device driving circuit, 131, 131A, 131B... Operation panel 133, 133A, 133B... Remote control light receiving section, 135, 135A, 135B... Input interface, 137, 137A, 137B... Spectral imaging section, 139, 139A, 139B... Communication section, 141, 141A, 141B... Image interface, 143, 143A, 143B... Image Processing unit, 145, 145A, 145B... Frame memory, 150, 150A, 150B... Control unit, 160, 160A, 160B... Storage unit, 161,... Control program, 162... Adjustment image data, 163... Pattern image data, 164... Setting data, 165... Parameter, 167... Calibration data, 167a... Correction data, 167b... Projection transformation matrix, M... Estimation matrix, 170... Processor, 171... Projection control unit, 173... Imaging control unit, 175... Estimated value calculation unit Reference numeral 177... Generation unit, 200... Image supply device, 301... Incident optical system, 302... Spectroscopic element, 303... Imaging element, 304... Reflective film, 305... Reflective film, 306... Gap changing unit.

One aspect for solving the above problem includes a projection unit, a spectroscopic imaging unit including an imaging element and a spectroscopic element, a projection unit, and a control unit that controls the spectroscopic imaging unit, and the control unit is A color and gradation of an image projected by the projection unit are set to a first color and a first gradation, and a first image corresponding to the set first color and the first gradation is projected onto the projection unit. Then, the first measurement condition corresponding to the first color is set in the spectral image capturing unit, the first image projected by the projection unit is captured by the spectral image capturing unit, and first captured image information is acquired, The color and gradation of the image projected by the projection unit are set to the first color and the second gradation, and the second image corresponding to the set first color and the second gradation is projected on the projection unit. Then, the first measurement condition corresponding to the first color is set in the spectral imaging unit, and the second image projected by the projection unit is caused to image by the spectral imaging unit to acquire second captured image information. , Setting the color and gradation of the image projected by the projection unit to the second color and the third gradation, and projecting the third image corresponding to the set second color and the third gradation to the projection unit Then, the second measurement condition corresponding to the second color is set in the spectral image capturing unit, the third image projected by the projection unit is captured by the spectral image capturing unit, and third captured image information is acquired, The color and gradation of the image projected by the projection unit are set to the second color and the fourth gradation, and the fourth image corresponding to the set second color and the fourth gradation is projected on the projection unit. Then, the second measurement condition corresponding to the second color is set in the spectral image capturing unit, and the spectral image capturing unit captures the fourth image projected by the projection unit to obtain fourth captured image information. , Is a projector.

Another aspect for solving the above problem is a control method of a projector including a projection unit and a spectral imaging unit including an imaging element and a spectral element, wherein a color and gradation of an image projected by the projection unit are set. A first image corresponding to the set first color and the first gradation is set, and a first image corresponding to the set first color and the first gradation is projected on the projection unit to set a first measurement condition corresponding to the first color. The first image projected by the projection unit is set to the spectral imaging unit, the spectral imaging unit captures the first captured image information, and the color and gradation of the image projected by the projection unit are set to the first image. One color and a second gradation are set, a second image corresponding to the set first color and the second gradation is projected on the projection unit, and the first measurement condition corresponding to the first color is set. The second image is set in the spectral imaging unit, the spectral imaging unit captures the second image projected by the projection unit to acquire second captured image information, and the color and gradation of the image projected by the projection unit Two colors and a third gradation are set, a third image corresponding to the set second color and the third gradation is projected on the projection unit, and the second measurement condition corresponding to the second color is set. The third image is set in the spectral imaging unit, the third image projected by the projection unit is imaged by the spectral imaging unit to acquire third captured image information, and the color and gradation of the image projected by the projection unit are set to the second. The color and the fourth gradation are set, and the fourth image corresponding to the set second color and the fourth gradation is projected on the projection unit, and the second measurement condition corresponding to the second color is set. A method of controlling a projector, which is set in a spectral imaging section, and causes the spectral imaging section to capture the fourth image projected by the projection section to acquire fourth captured image information.

FIG. 8 is a flowchart showing the operation of the projector 100A.
The operation of the projector 100A will be described with reference to the flowchart shown in FIG.
The control unit 150A determines whether or not an operation for selecting color matching has been received (step T1). The control unit 150A determines whether or not an operation for selecting color matching has been received based on an operation signal input from the input interface 135A (step T1 ). When the operation of selecting the color matching is not accepted (step T1 /NO), the control unit 150A waits for the operation to start until the operation is accepted. Further, when the control unit 150A receives an operation instructing execution of another process, the control unit 150A executes an operation corresponding to the received operation and returns to the determination of step S1.

Upon receiving the correction parameter from the projector 100A (step U6 /YES ), the control unit 150B stores the received correction parameter in the storage unit 160B (step U7). After that, when the supply of the image signal from the image supply device 200 is started, the control unit 150B causes the image processing unit 143B to correct the image data by the generated correction parameter (step U8). Then, the control unit 150B causes the projection unit 110B to project the image light based on the corrected image data on the screen SC. As a result, an image based on the image data whose color tone has been corrected by the correction parameter is displayed on the screen SC (step U9).

Claims (14)

A projection unit,
A spectral imaging unit including an imaging element and a spectroscopic element;
A control unit that controls the projection unit and the spectral imaging unit;
The control unit sets the color and gradation of the image projected by the projection unit to a first color and a first gradation, and sets the first image corresponding to the set first color and the first gradation to the first image. Let the projection unit project
A first measurement condition corresponding to the first color is set in the spectral image capturing unit, the first image projected by the projection unit is captured by the spectral image capturing unit, and first captured image information is acquired,
The color and gradation of the image projected by the projection unit are set to the first color and the second gradation, and the second image corresponding to the set first color and the second gradation is projected on the projection unit. Let
The first measurement condition corresponding to the first color is set in the spectral image capturing unit, the second image projected by the projection unit is captured by the spectral image capturing unit, and second captured image information is acquired,
The color and gradation of the image projected by the projection unit are set to the second color and the third gradation, and the third image corresponding to the set second color and the third gradation is projected on the projection unit. ,
A second measurement condition corresponding to the second color is set in the spectral image capturing unit, the third image projected by the projection unit is captured by the spectral image capturing unit, and third captured image information is acquired,
The color and gradation of the image projected by the projection unit are set to the second color and the fourth gradation, and the fourth image corresponding to the set second color and the second gradation is projected on the projection unit. Let
A projector in which the second measurement condition corresponding to the second color is set in the spectral image capturing unit, and the fourth image projected by the projection unit is captured by the spectral image capturing unit to acquire fourth captured image information. .. The control unit, based on the acquired first captured image information, the second captured image information, the third captured image information, and the fourth captured image information, image data which is a source of an image projected by the projection unit. The projector according to claim 1, which generates a correction parameter for correcting the. The control unit sets the wavelength range corresponding to the first color as an imaging range as the first measurement condition, and performs imaging on the spectral imaging unit while changing the spectral wavelength of the spectroscopic element for each first wavelength interval. Then, the intensity of light corresponding to the spectral wavelength is acquired as the first captured image information and the second captured image information,
As the second measurement condition, a wavelength range corresponding to the second color is set as an imaging range, and the spectral imaging unit executes imaging while changing the spectral wavelength of the spectroscopic element for each of the first wavelength intervals, The projector according to claim 1, wherein the intensity of light corresponding to a wavelength is acquired as the third captured image information and the fourth captured image information. The control unit estimates the intensity and spectrum of light for each of the first wavelength intervals acquired as the first captured image information, the second captured image information, the third captured image information, and the fourth captured image information. The projector according to claim 3, wherein an estimated value of a spectrum for each second wavelength interval having a shorter interval than the first wavelength interval is calculated based on the estimation matrix used for. The estimation matrix is calculated based on the first captured image information, the second captured image information, the third captured image information, and the fourth captured image information output by the spectral imaging unit. Projector. The estimation matrix includes measurement data obtained by measuring the first image, the second image, the third image, and the fourth image for each second wavelength interval by a dedicated measuring device, and the estimated value. The projector according to claim 5, which is a determinant that minimizes the square error of The spectroscopic element includes a pair of reflecting films facing each other, and a gap changing unit that changes a distance between the pair of reflecting films,
The projector according to claim 3, wherein the control unit changes the distance between the pair of reflective films to the gap changing unit to change the spectral wavelength of the spectroscopic element. The control unit is
The color and gradation of the image projected by the projection unit are set to the third color and the fifth gradation, and the fifth image corresponding to the set third color and the fifth gradation is projected on the projection unit. ,
A third measurement condition corresponding to the third color is set in the spectral imaging unit, the fifth image projected by the projection unit is captured by the spectral imaging unit, and fifth captured image information is acquired,
The color and gradation of the image projected by the projection unit are set to the third color and sixth gradation, and the sixth image corresponding to the set third color and sixth gradation is projected onto the projection unit. Let
The sixth measurement condition corresponding to the third color is set in the spectral image capturing unit, and the sixth image projected by the projection unit is captured by the spectral image capturing unit to acquire sixth captured image information. Item 1. The projector according to item 1. The first color is red, the first gradation has a gradation value lower than that of the second gradation,
The second color is green, the third gradation has a lower gradation value than the fourth gradation,
The third color is blue, the fifth gradation has a lower gradation value than the sixth gradation,
The first measurement condition is a wavelength range corresponding to red,
The second measurement condition is a wavelength range corresponding to green,
The projector according to claim 8, wherein the third measurement condition is a wavelength range corresponding to blue. The gradation values of the first gradation, the third gradation and the fifth gradation are equal,
The projector according to claim 8, wherein the second gradation, the fourth gradation, and the sixth gradation have the same gradation value. The control unit is
The colors and gradations of the image projected by the projection unit are set to the first color and the seventh gradation, and the seventh image corresponding to the set first color and the seventh gradation is projected on the projection unit. ,
The first measurement condition corresponding to the first color is set in the spectral image capturing unit, the spectral image capturing unit captures the seventh image projected by the projection unit, and seventh captured image information is acquired.
The color and gradation of the image projected by the projection unit are set to the second color and the eighth gradation, and the eighth image corresponding to the set second color and the eighth gradation is projected on the projection unit. Let
The second measurement condition corresponding to the second color is set in the spectral image capturing unit, and the spectral image capturing unit captures the eighth image projected by the projection unit to obtain eighth captured image information,
The color and gradation of the image projected by the projection unit are set to the third color and the ninth gradation, and the ninth image corresponding to the set third color and the ninth gradation is projected on the projection unit. Let
The third measurement condition corresponding to the third color is set in the spectral image capturing unit, the ninth image projected by the projection unit is captured by the spectral image capturing unit, and ninth captured image information is acquired,
The seventh gradation is a gradation between the first gradation and the second gradation,
The eighth gradation is a gradation between the third gradation and the fourth gradation,
The projector according to claim 8, wherein the ninth gradation is a gradation between the fifth gradation and the sixth gradation. A display system comprising a first projector and a second projector,
The first projector is
A first projection unit,
A first spectral imaging unit including a first imaging element and a first spectral element;
A color and gradation of an image to be projected on the first projection unit are determined, an image corresponding to the determined color and gradation is projected on the first projection unit, and measurement is determined based on the determined color of the image. A first control unit that sets a condition in the first spectral imaging unit and causes the first spectral imaging unit to capture the image projected by the first projection unit to acquire first captured image information. ,
The second projector is
A second projection unit,
A second spectral imaging unit including a second imaging element and a second spectral element;
A color and gradation of an image to be projected on the second projection unit are determined, an image corresponding to the determined color and gradation is projected on the second projection unit, and measurement is determined based on the determined color of the image. A second control unit configured to set a condition in the second spectral imaging unit, cause the second spectral imaging unit to capture the image projected by the second projection unit, and acquire second captured image information. ,
The first control unit changes at least one of a color and a gradation of an image projected by the first projection unit a plurality of times to obtain a plurality of first captured image information output by the first spectral imaging unit,
The second control unit changes at least one of a color and a gradation of an image to be projected by the second projection unit a plurality of times to obtain a plurality of second captured image information output by the second spectral imaging unit,
The first controller corrects an image projected by the first projector based on the acquired first captured image information and a plurality of the second captured image information received from the second controller. A display system for generating a first correction parameter and a second correction parameter for correcting an image projected by the second projector. A method of controlling a projector, comprising: a projection unit; and a spectral imaging unit including an image sensor and a spectral element,
The color and gradation of the image projected by the projection unit are set to the first color and the first gradation, and the first image corresponding to the set first color and the first gradation is projected on the projection unit. ,
A first measurement condition corresponding to the first color is set in the spectral image capturing unit, the first image projected by the projection unit is captured by the spectral image capturing unit, and first captured image information is acquired,
The color and gradation of the image projected by the projection unit are set to the first color and the second gradation, and the second image corresponding to the set first color and the second gradation is projected on the projection unit. ,
The first measurement condition corresponding to the first color is set in the spectral image capturing unit, the second image projected by the projection unit is captured by the spectral image capturing unit, and second captured image information is acquired,
The color and gradation of the image projected by the projection unit are set to the second color and the first gradation, and the third image corresponding to the set second color and the first gradation is projected on the projection unit. ,
A second measurement condition corresponding to the second color is set in the spectral image capturing unit, the third image projected by the projection unit is captured by the spectral image capturing unit, and third captured image information is acquired,
The color and gradation of the image projected by the projection unit are set to the second color and the second gradation, and the fourth image corresponding to the set second color and the second gradation is projected on the projection unit. ,
A projector in which the second measurement condition corresponding to the second color is set in the spectral image capturing unit, and the fourth image projected by the projection unit is captured by the spectral image capturing unit to acquire fourth captured image information. Control method. A first projector including a first projection unit, a first spectral imaging unit including a first image sensor and a first spectral element, a second projection unit, and a second projector including a second image sensor and a second spectral element. An image correction method in a display system including a second projector including a spectral imaging unit,
In the first projector,
A first determining step of determining a color and gradation of an image to be projected on the first projection unit;
A first projection step of projecting an image corresponding to the determined color and gradation on the first projection unit;
A measurement condition determined based on the determined color of the image is set in the first spectral imaging unit, and the image projected by the first projection unit is caused to image by the first spectral imaging unit, and a first captured image A first acquisition step of acquiring information,
In the second projector,
A second determining step of determining the color and gradation of the image to be projected by the second projection unit;
A second projection step of projecting an image corresponding to the determined color and gradation on the second projection unit;
A measurement condition determined based on the determined color of the image is set in the second spectral imaging unit, and the image projected by the second projection unit is caused to be captured by the second spectral imaging unit so that a second captured image is obtained. A second acquisition step of acquiring information,
In the first projector, at least one of the color and the gradation of the image projected by the first projection unit is changed in the first determining step, and the image in which at least one of the color and the gradation is changed is the first image. The projection step causes the first projection section to project, and the first projection step causes the first spectral imaging section to capture the image projected by the first projection section to acquire a plurality of the first captured image information.
In the second projector, at least one of the color and the gradation of the image projected by the second projection unit is changed by the second determining step, and the image in which at least one of the color and the gradation is changed is the second image. The projection step causes the second projection section to project, and the second projection step causes the second spectral imaging section to capture the image projected by the second projection section to acquire a plurality of the second captured image information.
In the first projector, a first correction that corrects an image projected by the first projector based on the plurality of acquired first captured image information and the plurality of second captured image information received from the second projector. An image correction method comprising: a generation step of generating a parameter and a second correction parameter for correcting an image projected by the second projector.

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