JP6566717B2 - Multi-screen display device and multi-screen display method - Google Patents

Description

  The present technology relates to a multi-screen display device and a multi-screen display method that combine a plurality of video display device screens to form one screen (multi-screen).

  There is a multi-screen display device as a device for displaying an image on a large screen. A multi-screen display device is a device that displays video by composing one large-scale screen by combining the screens of a plurality of video display devices. Some video contents to be displayed on the multi-screen display device include, for example, camera color or TV video where full color reproducibility is regarded as important. Some of them are based on primary colors and color reproducibility is not so important.

  As a plurality of video display devices constituting the multi-screen display device, for example, there is a projection video display device. A projection display apparatus is an apparatus that displays an image on a screen by irradiating light from a light source onto the image display device and projecting the image from the back of the screen. As light sources, light emitting diodes (LEDs) have been widely used in recent years due to the increasing demand for lower power consumption of devices and longer life of light sources. For example, light from a light source device composed of three LEDs each emitting light of three primary colors of red (Red: abbreviation R), green (Green: abbreviation G), and blue (Blue: abbreviation B) is used as a dichroic mirror or dichroic prism. The image is modulated into image light by an image display device such as a digital micromirror device (DMD), and a color image is projected.

  Since the LEDs used as the light source have different characteristics, the brightness of the screen and the screen between a plurality of projection display apparatuses at the beginning of use (at the start of use) or as the use time elapses. Variations in chromaticity may occur. In a multi-screen display device, the screens of a plurality of projection-type video display devices are combined to form one screen (hereinafter sometimes referred to as “multi-screen”). If there is, the luminance difference between the screens and the chromaticity difference between the screens become conspicuous. If it does so, the sense of unity of a multi-screen will be spoiled. For this reason, it is necessary to constantly adjust each projection image display device so that the difference in screen brightness and the difference in chromaticity of the screens displayed between the projection image display devices are reduced.

  In an example of a conventional multi-screen display device, after installing the multi-screen display device, the display color of each projection display device is measured using a sensor in the projection display device, and the obtained colorimetric value is obtained. There is a method of correcting to a desired luminance and a desired chromaticity based on the above. At this time, the chromaticity of white (White: abbreviation W) of the multi-screen is adjusted so as to be substantially constant from the beginning of use (see, for example, Patent Document 1).

  Also, when installing a multi-screen display device, the target luminance value and target chromaticity value are automatically obtained from the luminance data and chromaticity data stored in the memory of each projection display device, and adjustment by humans is required. Some of them automatically adjust the luminance and chromaticity between multiple screens (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 10-90645 Japanese Patent No. 4823660

  The LEDs of R, G, and B have different lifetimes, that is, the rate at which the luminance decreases as the usage time elapses, depending on the color due to the difference in the structure or constituent material of the light emitting portion. Furthermore, the lifetime of the LED is easily affected by the environment in which it is used, particularly the ambient temperature environment, and the lifetime of the LED is shortened even if the ambient temperature used is increased. Further, when the LED is driven by the pulse width modulation method, the life of the LED is shortened even if the duty ratio, that is, the ratio of the lighting time to the blinking period is increased.

  As described above, the lifetimes of the LEDs used as the light source of the projection display apparatus are individually different. Therefore, for example, as disclosed in Patent Document 1, the method of adjusting the chromaticity of W of the multi-screen so as to be kept substantially constant while the projection display apparatus is in use, the brightness of R, G and B In order to maintain the balance, it is necessary to balance the luminance of R, G, and B by lowering the video signal gain of other colors in accordance with the color with the lowest luminance. For this reason, the brightness of the multi-screen may be greatly reduced.

  The present technology is intended to solve the above-described problems, and relates to a multi-screen display device and a multi-screen display method that can be adjusted while suppressing a decrease in luminance when displaying video on a multi-screen. It is.

A multi-screen display device according to an aspect of the present technology is a multi-screen display device that configures one multi-screen by combining screens of a plurality of video display devices, and each of the video display devices displays a video on the screen. A light emitting diode for emitting light, a green light emitting diode and a blue light emitting diode, and a sensor for measuring a luminance value of each light emitted from the red light emitting diode, the green light emitting diode and the blue light emitting diode, the multi-screen display device, based on each said luminance value measured at each of said sensors, target brightness the brightness of each light emitted from each of said red light emitting diodes, each of the green light emitting diode and each said blue light emitting diode comprising a brightness controller for controlling the said target luminance is prestored in each of the video display device A luminance calculated from the common color gamut based on the color reproduction characteristic is, the brightness control unit, of the red light emitting diode, is a ratio of said measured intensity values to the luminance value at the start of use The brightness maintenance ratio is calculated, the lowest brightness maintenance ratio among them is set as the red minimum maintenance ratio, and the brightness control unit calculates the brightness maintenance ratio of each green light emitting diode, and the lowest brightness maintenance ratio among them is calculated. The green color minimum maintenance rate is set, and the luminance control unit calculates the luminance maintenance rate of each blue light emitting diode, the lowest luminance maintenance rate among them is set as the blue minimum maintenance rate, and the luminance control unit is configured to start the use. the red minimum maintenance rate which varies with time from said calculating new said target luminance based on the green lowest retention ratio and the blue minimum maintenance rate, the target that has been newly calculated Based on the time, each of said red light emitting diode, for controlling the brightness of each light emitted from each said green light emitting diode and each said blue light emitting diode.

A multi-screen display method according to an aspect of the present technology is a multi-screen display method for displaying video on a single multi-screen combining a plurality of video display devices, and each of the video display devices displays a video on the screen. A red light emitting diode, a green light emitting diode, and a blue light emitting diode that emit light for display; and a sensor that measures a luminance value of each light emitted from the red light emitting diode, the green light emitting diode, and the blue light emitting diode. Each of the red light emitting diodes, calculating a luminance maintenance ratio that is a ratio of the measured luminance value to a luminance value at the start of use, and using the lowest luminance maintenance ratio as a minimum red maintenance ratio, The brightness maintenance rate of the diode is calculated, and the lowest brightness maintenance rate among them is set as the green minimum maintenance rate. Calculates the luminance maintenance rate of Ord, the lowest and the brightness maintenance ratio of the blue minimum maintenance rate, the red minimum maintenance rate which varies with time from the time of the start of use, the green minimum maintenance rate and A new target luminance is calculated based on the blue minimum maintenance ratio, and each of the red light emitting diodes, the green light emitting diodes, and the blue light emitting diodes emits light based on the newly calculated target luminance. The luminance of light is controlled, and the target luminance is a luminance calculated from a common color reproduction range based on color reproduction characteristics stored in advance in each of the video display devices .

A multi-screen display device according to an aspect of the present technology is a multi-screen display device that configures one multi-screen by combining screens of a plurality of video display devices, and each of the video display devices displays a video on the screen. A light emitting diode for emitting light, a green light emitting diode and a blue light emitting diode, and a sensor for measuring a luminance value of each light emitted from the red light emitting diode, the green light emitting diode and the blue light emitting diode, the multi-screen display device, based on each said luminance value measured at each of said sensors, target brightness the brightness of each light emitted from each of said red light emitting diodes, each of the green light emitting diode and each said blue light emitting diode comprising a brightness controller for controlling the said target luminance is prestored in each of the video display device A luminance calculated from the common color gamut based on the color reproduction characteristic is, the brightness control unit, of the red light emitting diode, is a ratio of said measured intensity values to the luminance value at the start of use The brightness maintenance ratio is calculated, the lowest brightness maintenance ratio among them is set as the red minimum maintenance ratio, and the brightness control unit calculates the brightness maintenance ratio of each green light emitting diode, and the lowest brightness maintenance ratio among them is calculated. The green color minimum maintenance rate is set, and the luminance control unit calculates the luminance maintenance rate of each blue light emitting diode, the lowest luminance maintenance rate among them is set as the blue minimum maintenance rate, and the luminance control unit is configured to start the use. the red minimum maintenance rate which varies with time from said calculating new said target luminance based on the green lowest retention ratio and the blue minimum maintenance rate, the target that has been newly calculated Based on the time, each of said red light emitting diode, for controlling the brightness of each light emitted from each said green light emitting diode and each said blue light emitting diode.

  According to such a configuration, instead of maintaining the luminance balance of R, G, and B, luminance control can be performed so as to use as much luminance as possible for each color of R, G, and B. When displaying an image on the screen, adjustment can be performed while suppressing a decrease in luminance.

A multi-screen display method according to an aspect of the present technology is a multi-screen display method for displaying video on a single multi-screen combining a plurality of video display devices, and each of the video display devices displays a video on the screen. A red light emitting diode, a green light emitting diode, and a blue light emitting diode that emit light for display; and a sensor that measures a luminance value of each light emitted from the red light emitting diode, the green light emitting diode, and the blue light emitting diode. Each of the red light emitting diodes, calculating a luminance maintenance ratio that is a ratio of the measured luminance value to a luminance value at the start of use, and using the lowest luminance maintenance ratio as a minimum red maintenance ratio, The brightness maintenance rate of the diode is calculated, and the lowest brightness maintenance rate among them is set as the green minimum maintenance rate. Calculates the luminance maintenance rate of Ord, the lowest and the brightness maintenance ratio of the blue minimum maintenance rate, the red minimum maintenance rate which varies with time from the time of the start of use, the green minimum maintenance rate and A new target luminance is calculated based on the blue minimum maintenance ratio, and each of the red light emitting diodes, the green light emitting diodes, and the blue light emitting diodes emits light based on the newly calculated target luminance. The luminance of light is controlled, and the target luminance is a luminance calculated from a common color reproduction range based on color reproduction characteristics stored in advance in each of the video display devices .

  According to such a configuration, instead of maintaining the luminance balance of R, G, and B, luminance control can be performed so as to use as much luminance as possible for each color of R, G, and B. When displaying an image on the screen, adjustment can be performed while suppressing a decrease in luminance.

  The objectives, features, aspects and advantages of the present technology will become more apparent from the detailed description and the accompanying drawings provided below.

It is a figure which shows typically the structure of the multi-screen display apparatus regarding embodiment. FIG. 2 is a diagram schematically showing a hardware configuration when the multi-screen display device shown in FIG. 1 is actually operated. FIG. 2 is a diagram schematically showing a hardware configuration when the multi-screen display device shown in FIG. 1 is actually operated. It is a flowchart which shows the procedure of the correction | amendment calculation in a master projection type display apparatus and a slave projection type display apparatus regarding embodiment. It is a figure which shows an example of two mutually different color reproduction ranges. It is the schematic which shows an example of the lifetime curve of LED when the same magnitude | size electric current is sent through all the LEDs. It is the schematic which shows the other example of the lifetime curve of LED when the same magnitude | size electric current is sent through all the LEDs. It is a flowchart which shows the procedure of the correction | amendment calculation in a master projection type display apparatus and a slave projection type display apparatus regarding embodiment.

  Embodiments will be described below with reference to the accompanying drawings. Note that the drawings are schematically shown, and the mutual relationship between the sizes and positions of the images shown in different drawings is not necessarily described accurately, and can be changed as appropriate. Moreover, in the description shown below, the same code | symbol is attached | subjected and shown in the same component, and it is the same also about those names and functions. Therefore, the detailed description about them may be omitted.

<First Embodiment>
Hereinafter, a multi-screen display device and a multi-screen display method according to this embodiment will be described.

  FIG. 1 is a diagram schematically illustrating a configuration of a multi-screen display device according to the present embodiment. As illustrated in FIG. 1, the multi-screen display device is configured by combining the screens of two projection video display devices to form a larger display screen.

  As illustrated in FIG. 1, the multi-screen display device includes an LED light source 3 mr that emits R, an LED light source 3 mg that emits G, an LED light source 3 mb that emits B, a screen 9 m, and a three-primary-color light sensor 10 m. And a luminance control unit 111m.

  2 and 3 are diagrams schematically showing a hardware configuration when the multi-screen display device shown in FIG. 1 is actually operated. As illustrated in FIGS. 2 and 3, the multi-screen display device is configured by combining the screens of two projection video display devices to form a larger display screen.

  In FIG. 2, one projection display device is a master projection display device 2m. The other projection display device is a slave projection display device 2s. The master projection display device 2m and the slave projection display device 2s generally have the same configuration. In the following description, the master projection display device 2m may be simply referred to as “master device”, and the slave projection display device 2s may be simply referred to as “slave device”.

  In FIG. 3, one projection display device is a master projection display device 202m. The other projection display device is a slave projection display device 202s. The master projection display device 202m and the slave projection display device 202s generally have the same configuration.

  In FIG. 2, a master projection display device 2m and a slave projection display device 2s are shown as hardware configurations for realizing the multi-screen display device in FIG.

  The master projection display device 2m includes an LED light source 3mr that emits R, an LED light source 3mg that emits G, an LED light source 3mb that emits B, a dichroic mirror 4m that selectively transmits and reflects light, and a relay. A lens 5m, a total internal reflection (TIR) prism 6m, a DMD 7m as an image display device, a projection lens 8m, a screen 9m, a three primary color light sensor 10m, a processing circuit 11m, a storage device 12m, and a processing circuit 13m With.

  The slave projection display device 2s includes an LED light source 3sr that emits R, an LED light source 3sg that emits G, an LED light source 3sb that emits B, and a dichroic mirror 4s that selectively transmits and reflects light. A relay lens 5s, a TIR prism 6s, a DMD 7s as an image display device, a projection lens 8s, a screen 9s, a three primary color light sensor 10s, a processing circuit 11s, and a storage device 12s.

  In FIG. 3, a master projection display device 202m and a slave projection display device 202s are shown as hardware configurations for realizing the multi-screen display device in FIG.

  The master projection display device 202m includes an LED light source 3mr that emits R, an LED light source 3mg that emits G, an LED light source 3mb that emits B, a dichroic mirror 4m that selectively transmits and reflects light, and a relay. A lens 5m, a TIR prism 6m, a DMD 7m as an image display device, a projection lens 8m, a screen 9m, a three primary color light sensor 10m, a processing circuit 211m, and a processing circuit 13m are provided.

  The slave projection display device 2s includes an LED light source 3sr that emits R, an LED light source 3sg that emits G, an LED light source 3sb that emits B, and a dichroic mirror 4s that selectively transmits and reflects light. A relay lens 5s, a TIR prism 6s, a DMD 7s as an image display device, a projection lens 8s, a screen 9s, a three primary color light sensor 10s, and a processing circuit 211s.

  The storage device 12m and the storage device 12s include, for example, a hard disk (hard disk drive, i.e., HDD), random access memory (i.e., RAM), read-only memory (i.e., ROM), flash memory, and erasable programmable. Memory (memory) including volatile or non-volatile semiconductor memory, magnetic disk, flexible disk, optical disk, compact disk, mini disk, DVD, etc., such as read only memory (EPROM) and electrically erasable programmable read-only memory (EEPROM) Medium) Configured by a memory (storage medium) including

  The processing circuit 11m may execute a program stored in the storage device 12m. That is, for example, it may be a central processing unit (CPU), a microprocessor, a microcomputer, or a digital signal processor (DSP). The processing circuit 11s may execute a program stored in the storage device 12s.

  When the processing circuit 11m executes a program stored in the storage device 12m, the luminance control unit 111m is realized by software, firmware, or a combination of software and firmware. Note that the function of the luminance control unit 111m may be realized, for example, by cooperation of a plurality of processing circuits. When the processing circuit 11s executes a program stored in the storage device 12s, the brightness control unit 111s is realized by software, firmware, or a combination of software and firmware.

  Software and firmware are described as programs and stored in the storage device 12m and the storage device 12s. The processing circuit 11m implements the above functions by reading and executing a program stored in the storage device 12m. That is, the storage device 12m stores a program that results in the above functions being executed by the processing circuit 11m. The processing circuit 11s implements the above functions by reading and executing a program stored in the storage device 12s.

  Further, the processing circuit 211m may be dedicated hardware. That is, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an integrated circuit (ASIC), a field-programmable gate array (FPGA), or a combination thereof It may be. The processing circuit 211s may be dedicated hardware.

  When the processing circuit 211m is dedicated hardware, the luminance control unit 111m is realized by the processing circuit 211m operating. Note that the function of the processing circuit 211m may be realized by a separate circuit or a single circuit. When the processing circuit 211s is dedicated hardware, the luminance control unit 111s is realized by the processing circuit 211s operating.

  The function of the luminance control unit 111m is realized in the processing circuit 11m that partially executes a program stored in the storage device 12m, and partly realized in the processing circuit 211m that is dedicated hardware. May be. The functions of the luminance control unit 111s are realized in the processing circuit 11s that partially executes a program stored in the storage device 12s, and partly realized in the processing circuit 211s that is dedicated hardware. May be.

  Hereinafter, a description will be given with reference to FIG.

  In the master projection display device 2m, the light emitted from the LED light source 3mr, the LED light source 3mg, and the LED light source 3mb is combined by the dichroic mirror 4m. Then, the synthesized light passes through the relay lens 5m and the TIR prism 6m having a total reflection surface, and is irradiated to the DMD 7m. In DMD7m, the inclination of the micromirror changes according to the video signal, and the combined light of R, G, and B is modulated into ON light and OFF light for each of R, G, and B colors in a time division manner. The on-light is output to the projection lens 8m, and an image is projected onto the screen 9m.

  Three primary color light sensors 10m are arranged on the optical path of the off light. Since the off-light from the DMD 7m is synchronized with the cycle in which the LED light source 3mr, the LED light source 3mg, and the LED light source 3mb are lit in a time-sharing manner, the off-light is incident on the three primary color light sensor 10m. While the display device 2m is in use, the luminance change and chromaticity change of each color component of the LED light source 3mr, the LED light source 3mg, and the LED light source 3mb can be monitored.

  Since the three primary color light sensor 10m takes off light from the DMD 7m, it does not interfere with an image projected on the screen 9m during use. Further, since the three primary color light sensor 10m takes off light from the DMD 7m, it is not easily affected by the surrounding environment such as outside light. It is assumed that the three primary color light sensor 10m can output tristimulus value XYZ data for each of R, G, and B colors.

  The modulation of light in the DMD 7m is controlled by the processing circuit 11m. The processing circuit 11m in the master projection display device 2m and the processing circuit 11s in the slave projection display device 2s are connected by a communication cable 16 such as RS232C.

  The operation in the master projection display device 2m is generally realized in the same manner in the slave projection display device 2s.

  When the master projection display device 2m is manufactured, tristimulus XYZ data SCRm is measured at the factory when the R, G, and B images are displayed on the screen 9m by a measuring instrument such as a color analyzer. The tristimulus value XYZ data SCRm is stored in the storage device 12m as display characteristic storage means inside the master projection display device 2m. In addition, in the slave projection display device 2s, tristimulus XYZ data SCRs when R, G, and B images are displayed on the screen 9s by a measuring instrument such as a color analyzer is measured at the factory at the time of manufacture. . The tristimulus value XYZ data SCRs is stored in the storage device 12s as display characteristic storage means inside the slave projection display device 2s.

  That is, the tristimulus value XYZ data SCRm of the master projection display device 2m is stored in the storage device 12m of the master projection display device 2m, and the slave projection display device is stored in the storage device 12s of the slave projection display device 2s. 2s tristimulus value XYZ data SCRs are stored.

  FIG. 4 is a flowchart showing a correction calculation procedure in the master projection display device 2m and the slave projection display device 2s. Hereinafter, the procedure of the correction calculation will be described with reference to FIG.

  First, as described above, in the master projection display device 2m, the tristimulus value XYZ data SCRm when the R, G, and B images are displayed on the screen 9m is measured (see step ST1). Then, the tristimulus value XYZ data SCRm is stored in the storage device 12m inside the master projection display device 2m. In the slave projection display device 2s, tristimulus values XYZ data SCRs when each of the R, G, and B images is displayed on the screen 9s are measured (see step ST2). Then, the tristimulus values XYZ data SCRs are stored in the storage device 12s inside the slave projection display device 2s.

  Next, the processing circuit 13m is based on the tristimulus value XYZ data SCRm stored in the storage device 12m and the tristimulus value XYZ data SCRs stored in the storage device 12s supplied through the communication cable 16. The common color reproduction range is calculated. Then, the target luminance and target chromaticity Ct of the entire multi-screen are calculated (see step ST3).

  For the calculation method of the target luminance and target chromaticity Ct set at the beginning of use of the master projection display device 2m and the slave projection display device 2s, for example, refer to the method described in Patent Document 2. Can do.

  FIG. 5 is a diagram illustrating an example of two different color reproduction ranges. Specifically, FIG. 5 is a diagram illustrating u′v ′ chromaticity. In FIG. 5, the vertical axis represents v ′ chromaticity and the horizontal axis represents u ′ chromaticity.

  As a method of calculating the target luminance and the target chromaticity Ct, first, as illustrated in FIG. 5, the target luminance and the target chromaticity Ct are calculated from the tristimulus value XYZ data SCRm of the master projection display device 2m on the u′v ′ chromaticity diagram. Plot u'v 'coordinates. Similarly, the u′v ′ coordinates calculated from the tristimulus value XYZ data SCRs of the slave projection display device 2s are plotted. Here, a triangle (a figure indicated by a solid line in FIG. 5) on which u′v ′ coordinates calculated from the tristimulus value XYZ data SCRm are plotted is defined as a triangle RmGmBm. In addition, a triangle (a figure indicated by a dotted line in FIG. 5) on which u′v ′ coordinates calculated from the tristimulus value XYZ data SCRs are plotted is referred to as a triangle RsGsBs.

  A triangle RmGmBm indicates the color reproduction range of the master projection display device 2m. A triangle RsGsBs indicates the color reproduction range of the slave projection display device 2s. The coordinate value of the common area triangle RtGtBt is calculated from the coordinate value of the triangle RmGmBm and the coordinate value of the triangle RsGsBs.

  Then, the common area triangle RtGtBt represents a color range that can be reproduced (displayed) in both the master projection display device 2m and the slave projection display device 2s.

  The processing circuit 13m converts the u′v ′ coordinate value of the common area triangle RtGtBt into the tristimulus value XYZ, and uses this as data representing the target luminance and the target chromaticity, that is, the target luminance and the target chromaticity Ct. As for the luminance, the lowest luminance data included in the tristimulus value XYZ data SCRm and the tristimulus value XYZ data SCRs is set as the target luminance data.

  The processing circuit 11m of the master projection display device 2m calculates the correction coefficient CSCm for generating the target luminance and the target chromaticity Ct based on the target luminance and the target chromaticity Ct and the tristimulus value XYZ data SCRm. Calculation is performed (see step ST4 in FIG. 4).

  The calculated correction coefficient CSCm is stored in the storage device 12m of the master projection display device 2m. Further, the processing circuit 11m of the master projection display device 2m performs luminance correction and chromaticity correction on the video signal based on the calculated correction coefficient CSCm, and outputs the corrected video signal.

  Here, the target luminance and target chromaticity Ct and the tristimulus value XYZ data SCRm in the master projection display device 2m are all tristimulus value XYZ data for each of R, G, and B colors, and have nine elements. Can be represented by a matrix of 3 rows and 3 columns. Further, the correction coefficient CSCm represents the strength of each component of the tristimulus value XYZ data for each color of R, G, and B, and is similarly composed of nine elements. It can be represented by a three-column matrix. Therefore, a simplified notation using symbols is shown as follows.

  Here, “x” in the equation represents a matrix product. The same applies to the following formulas.

  The processing circuit 11s of the slave projection display device 2s receives the target luminance and target chromaticity Ct transmitted from the master projection display device 2m through the communication cable 16, and receives the target luminance and target chromaticity Ct and the tristimulus value XYZ data SCRs. Based on the above, the correction coefficient CSCs for generating the target luminance and the target chromaticity Ct is calculated in the slave projection display device 2s (see step ST5 in FIG. 4).

  The calculated correction coefficient CSCs is stored in the storage device 12s of the slave projection display device 2s. In addition, the processing circuit 11s of the slave projection display device 2s performs luminance correction and chromaticity correction on the video signal based on the calculated correction coefficient CSCs, and outputs the corrected video signal.

  Here, similarly to the case shown in the formula (1) in the master projection display device 2m, the target luminance and the target chromaticity Ct in the slave projection display device 2s are simply expressed using symbols as follows. .

  In the master projection display device 2m, the corrected video signal output from the processing circuit 11m is supplied to the DMD 7m. In the slave projection display device 2s, the corrected video signal output from the processing circuit 11s is supplied to the DMD 7s. By supplying to, control is performed such that the luminance and chromaticity at the beginning of use of the projection display apparatus constituting the multi-screen approach the target luminance and target chromaticity Ct.

  At this time, the processing circuit 11m of the master projection display device 2m is based on the tristimulus value XYZ data DSTm output from the three primary color light sensors 10m and the correction coefficient CSCm stored in the storage device 12m. The initial sensor brightness and sensor chromaticity Ftm are calculated as sensor data calculation values at the beginning of use of the display device 2m (see step ST6 in FIG. 4). The calculated initial sensor brightness and sensor chromaticity Ftm are stored in the storage device 12m of the master projection display device 2m.

  Here, the initial sensor brightness, sensor chromaticity Ftm, and tristimulus value XYZ data DSTm in the master projection display device 2m are all tristimulus value XYZ data for each of R, G, and B colors. Can be represented by a matrix of 3 rows and 3 columns. Therefore, a simplified notation using symbols is shown as follows.

  Similarly, in the case of the slave projection display device 2s, the initial sensor luminance and sensor chromaticity Fts are calculated (see step ST7 in FIG. 4). In the case of the slave projection display device 2s, the master projection display device using the tristimulus value XYZ data DSTs output from the three primary color light sensors 10s at the beginning of use and the correction coefficient CSCs stored in the storage device 12s. Similarly to the case represented by the expression (3) at 2 m, the following is abbreviated using symbols.

  The calculated initial sensor brightness and sensor chromaticity Fts are stored in the storage device 12s of the slave projection display device 2s.

  As the usage time of the master projection display device 2m and the slave projection display device 2s elapses, the LED light source deteriorates over time, so that the brightness and chromaticity of the multi-screen gradually change from the beginning of use. That is, the luminance and chromaticity of the image displayed on the screen 9m of the master projection display device 2m gradually change from the target luminance and target chromaticity Ct adjusted at the beginning of use. The luminance and chromaticity of the image displayed on the screen 9s of the slave projection display device 2s also gradually change from the target luminance and target chromaticity Ct adjusted at the beginning of use.

  In a multi-screen display device, it is necessary to constantly adjust each projection-type video display device so that the luminance difference and chromaticity difference between screens are reduced. Therefore, in the master projection display device 2m, control is performed so as to reduce the difference in luminance and chromaticity between the screens based on the tristimulus value XYZ data DSTm output from the three primary color light sensors 10m. In the slave projection display device 2s, control is performed so as to reduce the difference in luminance and chromaticity between the screens based on the tristimulus value XYZ data DSTs output from the three primary color light sensors 10s.

  As mentioned above, the lifetimes of R, G and B LEDs are individually different. Therefore, for example, the life curve of the LED light source 3mr that emits R used in the master projection display device 2m (the transition of the luminance maintenance rate with the lapse of usage time) and the life curve of the LED light source 3mg that emits G FIG. 6 shows a lifetime curve of the LED light source 3mb that emits B and B. The life curve of the LED light source 3sr that emits R used in the slave projection display device 2s, the life curve of the LED light source 3sg that emits G, and the life curve of the LED light source 3sb that emits B are shown in FIG. 7 shows.

  FIG. 6 and FIG. 7 are schematic diagrams showing the lifetime curves of LEDs when the same current flows through all LEDs. 6 and 7, the vertical axis represents the luminance maintenance rate [%], and the horizontal axis represents the usage time [hour]. 6 and 7, DC indicates the duty ratio, and Tj indicates the junction temperature (the temperature of the light emitting layer of the LED chip). 6 and 7, the life curve of the R LED is indicated by a solid line, the life curve of the G LED is indicated by a dotted line, and the life curve of the R LED is indicated by a one-dot chain line.

  The junction temperature Tj differs between the case shown in FIG. 6 and the case shown in FIG. In the case of an LED light source often used in a projection display apparatus, the life of the R LED is generally shorter than the life of the G LED and the life of the B LED. Moreover, since this lifetime curve shows the transition of the luminance maintenance rate with the elapsed time of use of each LED light source, of the tristimulus value XYZ data obtained when each of the R, G, and B LED light sources is turned on Is equivalent to the rate of change of the value of Y. Further, in the tristimulus value XYZ data, the change rate of the X value and the change rate of the Z value with respect to the change rate of the Y value corresponding to the luminance are substantially the same for each of the R, G, and B colors. . This is because the relative ratios of the tristimulus values X, Y, and Z for each color of R, G, and B are substantially the same regardless of the elapsed time of use. The degree change is small.

  The processing circuit 11m of the master projection display device 2m includes tristimulus value XYZ data DSTmi output from the three primary color light sensors 10m when the i time has elapsed from the start of use, and the correction coefficient CSCm stored in the storage device 12m. Based on the above, the sensor brightness and the sensor chromaticity Fmi after elapse of i time are calculated as sensor data calculation values when i time has elapsed from the start of use of the master projection display device 2m (see step ST8 in FIG. 4). ).

  Here, the sensor brightness and sensor chromaticity Fmi and tristimulus value XYZ data DSTmi after the e-hour elapse in the master projection display device 2m are all tristimulus value XYZ data for each of R, G, and B colors. Since it is composed of two elements, each can be represented by a matrix of 3 rows and 3 columns. Therefore, a simplified notation using symbols is shown as follows.

  That is, the sensor brightness and the sensor chromaticity in the master projection display device 2m are obtained from the initial sensor brightness and the sensor chromaticity Ftm expressed by the formula (3) by the elapse of i hours from the start of use. The values of the sensor luminance and the sensor chromaticity Fmi after the e time indicated by are changed.

  Similarly, in the case of the slave projection display device 2s, the sensor luminance and the sensor chromaticity Fsi after i time elapse are calculated (see step ST9 in FIG. 4). In the case of the slave projection display device 2s, when i time has elapsed since the start of use, the tristimulus value XYZ data output from the three primary color light sensors 10s is represented by DSTsi and the correction coefficient CSCs stored in the storage device 12s. In the same manner as in the case represented by the expression (5) in the master projection display device 2m, the following is simply expressed using symbols.

  That is, the sensor brightness and the sensor chromaticity in the slave projection display device 2s are obtained from the initial sensor brightness and the sensor chromaticity Fts shown in the formula (4) by the elapse of i hours from the start of use, as shown in the formula (6). The values of the sensor luminance and the sensor chromaticity Fsi after the i time elapse are changed.

  In order to control the luminance and chromaticity of the image displayed on the screen 9m of the master projection display device 2m when i time has elapsed from the start of use so as to approach the desired luminance and chromaticity, i time has elapsed. Correction may be performed so that the later sensor brightness and sensor chromaticity Fmi become the new target sensor brightness and target sensor chromaticity Ftmi.

  Therefore, the processing circuit 11m of the master projection display device 2m performs master projection display based on the tristimulus value XYZ data DSTmi output from the three primary color light sensors 10m and the correction coefficient CSCm stored in the storage device 12m. In the apparatus 2m, the correction coefficient CCGmi for generating the new target sensor brightness and target sensor chromaticity Ftmi is calculated. Further, the processing circuit 11m of the master projection display device 2m corrects the luminance and chromaticity of the video signal based on the calculated correction coefficient CCGmi, and outputs the corrected video signal.

  Here, the new target sensor luminance and target sensor chromaticity Ftmi and tristimulus value XYZ data DSTmi after e time has elapsed in the master projection display device 2m are all tristimulus values XYZ for R, G, and B colors. Since it is data and is composed of nine elements, each can be represented by a matrix of 3 rows and 3 columns. Further, the correction coefficient CCGmi represents the strength of each component of the tristimulus value XYZ data for each of R, G, and B colors. It can be expressed as a matrix of Therefore, it will be shown as follows when it is simply expressed using symbols.

  In the case of the slave projection display device 2s, when i time elapses from the start of use, the new target sensor luminance and target sensor chromaticity are set to Ftsi, and the correction for generating the target sensor luminance and target sensor chromaticity Ftsi is performed. Assuming that the coefficient is CCGsi, the slave projection display device 2s is simply expressed using the following symbols as in the case represented by the equation (7) in the master projection display device 2m.

  In order to reduce the luminance difference and chromaticity difference between the screens of the master projection display device 2m and the slave projection display device 2s even when i time has elapsed from the start of use, the master projection display device 2m The master projection display device 2m is based on the initial sensor brightness and sensor chromaticity Ftm calculated to bring the multi-screen close to the target brightness and target chromaticity Ct at the beginning of use of the master projection display device 2m. New target sensor brightness and target sensor chromaticity Ftmi may be set. In the slave projection display device 2s, the initial sensor luminance and sensor chromaticity Fts calculated to bring the multi-screen closer to the target luminance and target chromaticity Ct at the beginning of use of the slave projection display device 2s are set. The new target sensor brightness and target sensor chromaticity Ftsi of the slave projection display device 2s may be set as a reference.

  Therefore, new target sensor brightness and target sensor chromaticity Ftmi of the master projection display apparatus 2m are calculated by multiplying the initial sensor brightness and sensor chromaticity Ftm of the master projection display apparatus 2m by the coefficient δti. Further, by multiplying the initial sensor brightness and sensor chromaticity Fts of the slave projection display apparatus 2s by the coefficient δti, new target sensor brightness and target sensor chromaticity Ftsi of the slave projection display apparatus 2s are calculated.

  The common coefficient δti is set so that the luminance for each of R, G, and B colors is utilized as much as possible between the master projection display device 2m and the slave projection display device 2s. Specifically, a luminance maintenance factor for each of R, G, and B colors is calculated between the master projection display device 2m and the slave projection display device 2s, and for each of R, G, and B colors, Select the one with the lower luminance maintenance rate. Further, the coefficient δti is a Y value corresponding to each of the R, G, and B luminance values included in the tristimulus value XYZ data DSTmi output from the three primary color light sensor 10m, and the three primary color light sensor 10s. Intensity of each component of the tristimulus value XYZ data calculated for each color of R, G, and B, calculated from the Y value corresponding to the R, G, and B luminance values included in the stimulus value XYZ data DSTsi It is assumed that it is composed of 9 elements and is represented by a 3 × 3 matrix.

  The processing circuit 13m of the master projection display device 2m supplies tristimulus value XYZ data DSTmi output from the three primary color light sensors 10m of the master projection display device 2m through the communication cable 16 when i time has elapsed from the start of use. The coefficient δti is calculated based on the tristimulus value XYZ data DSTsi output from the three primary color light sensors 10s of the slave projection display device 2s (see step ST10 in FIG. 4).

  Here, even when i time has elapsed from the start of use, control is performed so as to reduce the luminance difference and chromaticity difference between the screen of the master projection display device 2m and the screen of the slave projection display device 2s. In this case, the equation (7) for calculating the new target sensor luminance and the target sensor chromaticity Ftmi after e lapse of time in the master projection display device 2m can be replaced with the equation (9).

  The processing circuit 11m of the master projection display device 2m corrects the luminance and chromaticity of the video signal based on the calculated correction coefficient CCGmi (see step ST11 in FIG. 4), and outputs the corrected video signal. To do.

  The processing circuit 11s of the slave projection display device 2s receives the coefficient δti transmitted from the master projection display device 2m through the communication cable 16, and obtains the new target sensor brightness and target sensor chromaticity Ftsi after the e-hour has elapsed. calculate.

  Here, even when i time has elapsed from the start of use, control is performed so as to reduce the luminance difference and chromaticity difference between the screen of the master projection display device 2m and the screen of the slave projection display device 2s. In this case, the equation (8) for calculating the new target sensor brightness and the target sensor chromaticity Ftsi after the e time has elapsed in the slave projection display device 2s can be replaced with the equation (10).

  The processing circuit 11s of the slave projection display device 2s corrects the luminance and chromaticity of the video signal based on the calculated correction coefficient CCGsi (see step ST12 in FIG. 4), and outputs the corrected video signal. To do.

  In the master projection display device 2m, the corrected video signal output from the processing circuit 11m is supplied to the DMD 7m, whereby the luminance and color after i hours have elapsed from the start of use of the projection display device constituting the multi-screen. Control is performed so that the degree approaches the target luminance and chromaticity.

  Further, in the slave projection display device 2s, the corrected video signal output from the processing circuit 11s is supplied to the DMD 7s, whereby the luminance after the lapse of i hours from the start of use of the projection video display device constituting the multi-screen. Control is performed so as to bring the chromaticity closer to the target luminance and chromaticity.

  The luminance and chromaticity Ctmi of the image displayed on the screen 9m of the master projection display device 2m at this time can be calculated from the correction coefficient CSCm and the correction coefficient CCGmi (see step ST13 in FIG. 4).

  When i time has elapsed from the start of use, R and G displayed on the screen 9m when a full-bit video signal (uncorrected video signal) is supplied to the DMD 7m from the processing circuit 11m of the master projection display device 2m When the luminance and chromaticity of each image of B and B are expressed by tristimulus value XYZ data SCRmi, the above luminance and chromaticity Ctmi and tristimulus value XYZ data SCRmi are all three for each of R, G, and B colors. Stimulus value XYZ data, which is composed of nine elements and can be represented by a 3 × 3 matrix. Therefore, in the formula (7), the tristimulus value XYZ data DSTmi output from the three primary color light sensor 10m can be replaced by the above tristimulus value XYZ data SCRmi, and can be expressed by the formula (11).

  In the case of the slave projection display device 2s, when i time has elapsed from the start of use, the brightness and chromaticity of the image displayed on the screen 9s is Ctsi, and a full-bit video signal (uncorrected video signal) is generated. When the luminance and chromaticity of each of the R, G, and B images displayed on the screen 9s when supplied to the DMD 7s are tristimulus values XYZ data SCRsi, the equation (11) is expressed in the master projection display device 2m. As in the case, in the slave projection display device 2s, the following simple symbols are used (see step ST14 in FIG. 4).

  As the usage time elapses, in the master projection display device 2m, the tristimulus value XYZ data SCRmi and the tristimulus value XYZ data DSTmi output from the three primary color light sensors 10m are values corresponding to the respective constituent elements. Are changing at approximately the same rate. Further, in the slave projection display device 2s, the tristimulus value XYZ data DSTsi output from the tristimulus value XYZ data SCRsi and the three primary color light sensors 10s change corresponding values of the constituent elements at substantially the same rate. doing.

  Therefore, the luminance and chromaticity Ctmi of the image displayed on the screen 9m of the master projection display device 2m and the luminance and chromaticity Ctsi of the image displayed on the screen 9s of the slave projection display device 2s are substantially the same values. Become. That is, even when i time has elapsed from the start of use, the brightness difference and chromaticity difference between the screen of the master projection display device 2m and the screen of the slave projection display device 2s are adjusted to be small. Yes.

  Hereinafter, the calculation of the coefficient δti in the processing circuit 13m of the master projection display device 2m and the calculation of the correction coefficient CCGmi in the processing circuit 11m will be described in detail. The calculation of the correction coefficient CCGsi in the processing circuit 11s of the slave projection display device 2s is performed in the same manner as the calculation of the correction coefficient CCGmi in the processing circuit 11m. In the following calculation, a projection display device in which additive color mixture is established is assumed.

  Expression (1) for calculating the target luminance and the target chromaticity Ct at the beginning of use of the master projection display device 2m can be expressed as Expression (13).

  In Equation (13), the components Xtr, Ytr, Ztr, Xtg, Ytg, Ztg, Xtb, Ytb, and Ztb of the matrix on the left side are the target luminance and target chromaticity Ct at the beginning of use of the master projection display device 2m. is there. Also, Ctr (Xtr, Ytr, Ztr) is equal to the tristimulus value when R is displayed, Ctg (Xtg, Ytg, Ztg) is equal to the tristimulus value when G is displayed, and Ctb (Xtb, Ytb, Ztb) is equal to the tristimulus value when B is displayed.

  In Expression (13), the components Xmr, Ymr, Zmr, Xmg, Ymg, Zmg, Xmb, Ymb, and Zmb of the first matrix on the right side are stored in the storage device 12m of the master projection display device 2m. The tristimulus value XYZ data SCRm when the R, G, and B images are displayed on the screen 9m. SCRmr (Xmr, Ymr, Zmr) is equal to the tristimulus value when R is displayed, SCRmg (Xmg, Ymg, Zmg) is equal to the tristimulus value when G is displayed, and SCRmb (Xmb, Ymb, Zmb) is equal to the tristimulus value when B is displayed.

  Further, in the equation (13), the components RRm, RGm, RBm, GRm, GGm, GBm, BRm, BGm, and BBm of the second matrix on the right side are the target luminance and the initial value of the master projection display device 2m. This is a correction coefficient CSCm for adjusting to the target chromaticity Ct. Each component indicates the strength of each of the R, G, and B components, RRm indicates the strength of an R monochromatic component when R is displayed, and RGm is a G component that is mixed when R is displayed RBm indicates the strength of the B component that is mixed when R is displayed, GRm indicates the strength of the R component that is mixed when G is displayed, and GGm indicates the strength when G is displayed G indicates the intensity of the monochrome component, GBm indicates the intensity of the B component that is mixed when G is displayed, BRm indicates the intensity of the R component that is mixed when B is displayed, and BGm indicates B The intensity of the G component that is mixed when displayed is shown, and BBm is the intensity of the component of B single color when B is displayed.

  When the strength of each of the R, G, and B components can take a value in the range of 0 to 1 (when the maximum value of the output of each of the R, G, and B components is 1), the configuration of the correction coefficient CSCm The element is

  It is necessary to satisfy. When the equations (14) to (16) are not satisfied, the R, G, and B tristimulus values XYZ data Ctr, Ctg and the target luminance and the target chromaticity Ct at the beginning of use of the master projection display device 2m Tristimulus value XYZ data Ctw (Xtw, Ytw, Ztw) when displaying W obtained by simply mixing colors of Ctb is not correctly reflected on the multi-screen.

  In this initial stage of use, equation (3) for calculating the initial sensor brightness and sensor chromaticity Ftm of the master projection display device 2m can be expressed as equation (17).

  In Expression (17), the components Xftmr, Yftmr, Zftmr, Xftmg, Yftmg, Zftmg, Xftmb, Yftmb, and Zftmb of the left-hand side matrix are the sensor brightness and sensor chromaticity Ftm at the start of use in the master projection display device 2m. is there. Further, Ftmr (Xftmr, Yftmr, Zftmr) is equal to the tristimulus value when R is displayed, Ftmg (Xftmg, Yftmg, Zftmg) is equal to the tristimulus value when G is displayed, and Ftmb (Xftmb, Yftmb, Zftmb) is equal to the tristimulus value when B is displayed.

  In Equation (17), the components Xdmr, Ydmr, Zdmr, Xdmg, Ydmg, Zdmg, Xdmb, Ydmb, and Zdmb of the first matrix on the right side are the three primary color lights at the beginning of use in the master projection display device 2m. This is tristimulus value XYZ data DSTm output from the sensor 10m. Further, DSTmr (Xdmr, Ydmr, Zdmr) is equal to the tristimulus value when R is displayed, DSTmg (Xdmg, Ydmg, Zdmg) is equal to the tristimulus value when G is displayed, and DSTmb (Xdmb, Ydmb, Zdmb) is equal to the tristimulus value when B is displayed.

  The sensor brightness and the sensor chromaticity in the master projection display device 2m are the sensor brightness and the sensor chromaticity Fmi after i hours have elapsed from the sensor brightness and the sensor chromaticity Ftm at the beginning of use when i time has passed since the start of use. The value changes. Equation (5) for calculating the sensor brightness and sensor chromaticity Fmi after the e-hour has elapsed can be expressed as equation (18).

  In Expression (18), the components Xfmri, Yfmri, Zfmri, Xfmgi, Yfmgi, Zfmgi, Xfmbi, Yfmbi, and Zfmbi of the matrix on the left side are sensor luminances when i time has elapsed from the start of use in the master projection display device 2m. And sensor chromaticity Fmi. Fmri (Xfmri, Yfmri, Zfmri) is equal to the tristimulus value when R is displayed, Fmgi (Xfmgi, Yfmgi, Zfmgi) is equal to the tristimulus value when G is displayed, and Fmbi (Xfmbi, Yfmbi, Zfmbi) is equal to the tristimulus value when B is displayed.

  In the equation (18), the component Xdmri, Ydmri, Zdmri, Xdmgi, Ydmgi, Zdmgi, Xdmbi, Ydmbi, and Zdmbi of the first matrix on the right side of the master projection display device 2m are expressed in i time from the start of use. This is tristimulus value XYZ data DSTmi output from the three primary color light sensor 10m when it has elapsed. Further, DSTmri (Xdmri, Ydmri, Zdmri) is equal to the tristimulus value when R is displayed, DSTmgi (Xdmgi, Ydmgi, Zdmgi) is equal to the tristimulus value when G is displayed, and DSTmbi (Xdmbi, Ydmbi, Zdmbi) is equal to the tristimulus value when B is displayed.

  When i time has elapsed from the start of use, the difference in luminance and chromaticity between the screen of the master projection display device 2m and the screen of the slave projection display device 2s is reduced, and R, G, and B In the master projection display device 2m, the sensor brightness and sensor chromaticity Fmi when i time has elapsed from the start of use are set to the new target sensor brightness and target sensor color so that the brightness for each color is utilized to the maximum. Control is performed to bring the degree Ftmi closer.

  As shown in Expression (9), in calculating a new target sensor luminance and target sensor chromaticity Ftmi, the coefficient δti is calculated first.

  In the master projection display device 2m, the luminance maintenance factors when i hours have elapsed from the start of use of the LED light source 3mr, LED light source 3mg, and LED light source 3mb that respectively emit R, G, and B are δmri, δmgi, and δmbi, respectively. In the slave projection display device 2s, the luminance maintenance rates when i hours have elapsed from the start of use of the LED light source 3sr, LED light source 3sg, and LED light source 3sb that emit R, G, and B, respectively, are δsri, δsgi, and δsbi, respectively. Then, each luminance maintenance rate is obtained by Expression (19) to Expression (24).

  Ydmr, Ydmg, and Ydmb are R, G, and B included in the tristimulus value XYZ data DSTm output from the three primary color light sensors 10m of the master projection display device 2m at the beginning of use, as shown in Expression (17). Is the data corresponding to the luminance value when. Ydmri, Ydmgi, and Ydmbi are tristimulus XYZ data DSTmi output from the three primary color light sensors 10m of the master projection display device 2m when i time has elapsed from the start of use, as shown in Expression (18). Is data corresponding to the luminance value when R, G, and B included in are displayed.

  Similarly, Ydsr, Ydsg, and Ydsb are luminance values when R, G, and B included in the tristimulus value XYZ data DSTs output from the three primary color light sensors 10s of the slave projection display device 2s at the beginning of use are displayed. Is data corresponding to. Ydsri, Ydsgi, and Ydsbi display R, G, and B included in the tristimulus value XYZ data DSTsi output from the three primary color light sensors 10s of the slave projection display device 2s when i time has elapsed from the start of use. It is data corresponding to the luminance value at the time.

  Further, when δmri and δsri are compared, the smaller value is the red minimum retention rate δtri, when δmgi and δsgi are compared, the smaller value is the green minimum retention rate δtgi, and smaller when δmbi and δsbi are compared. Let the value be the blue minimum retention rate δtbi.

  In the master projection display device 2m, Expression (9) for calculating a new target sensor luminance and target sensor chromaticity Ftmi when i time has elapsed from the start of use can be expressed as Expression (25).

  In Expression (25), the second matrix on the left side is the coefficient δti. In Expression (25), the components ααmi, αβmi, αγmi, βαmi, ββmi, βγmi, γαmi, γβmi, and γγmi of the third matrix on the right side are expressed as sensor brightness and This is a correction coefficient CCGmi for bringing the sensor chromaticity Fmi closer to the new target sensor luminance and the target sensor chromaticity Ftmi.

  Expression (26) for calculating the correction coefficient CCGmi can be obtained by modifying Expression (25).

  Expression (11) for calculating the luminance and chromaticity Ctmi of the image displayed on the screen 9m of the master projection display device 2m when i time has elapsed from the start of use, using the correction coefficient CCGmi calculated in Expression (26). ) Can be expressed as in equation (27).

  In Expression (27), the components Xtmri, Ytmri, Ztmri, Xtmgi, Ytmgi, Ztmgi, Xtmbi, Ytmbi, and Ztmbi of the matrix on the left side are the screens of the master projection display device 2m when i time has elapsed since the start of use. It is the brightness | luminance and chromaticity Ctmi of the image | video displayed on 9m. Also, Ctmri (Xtmri, Ytmri, Ztmri) is equal to the tristimulus value when R is displayed, Ctmgi (Xtmgi, Ytmgi, Ztmgi) is equal to the tristimulus value when G is displayed, and Ctmbi (Xtmbi, Ytmbi, Ztmbi) is equal to the tristimulus value when B is displayed.

  In Expression (27), the component Xmri, Ymri, Zmri, Xmgi, Ymgi, Zmgi, Xmbi, Ymbi, and Zmbi of the first matrix on the right side is the master projection type when i time elapses from the start of use. Three representing the luminance and chromaticity of each of the R, G and B images displayed on the screen 9m when a full-bit video signal (uncorrected video signal) is supplied to the DMD 7m from the processing circuit 11m of the display device 2m. Stimulus value XYZ data SCRmi. SCRmri (Xmri, Ymri, Zmri) is equal to the tristimulus value when R is displayed, SCRmgi (Xmgi, Ymgi, Zmgi) is equal to the tristimulus value when G is displayed, and SCRmbi (Xmbi, Ymbi, Zmbi) is equal to the tristimulus value when B is displayed.

  As described above, the luminance and chromaticity Ctmi of the image displayed on the screen 9m of the master projection display device 2m when i time has elapsed from the start of use are finally obtained from the equation (27) through a series of calculations. The slave projection display device 2s also obtains the luminance and chromaticity Ctsi of the image displayed on the screen 9s by the same calculation, and obtains the values of the luminance and chromaticity Ctmi and the values of the luminance and chromaticity Ctsi. Are approximately the same value.

  As described above, the difference in luminance and chromaticity between the screen of the master projection display device 2m and the screen of the slave projection display device 2s is reduced regardless of the elapsed time of use, and R, G, and B The correction calculation method for controlling so as to use the luminance for each color as much as possible has been described, but what effect is obtained after the master projection display device 2m and the slave projection display device 2s have been used for a long time. Whether it can be obtained will be described using specific numerical examples.

  In the initial stage of use, the equation (1) for calculating the target luminance and the target chromaticity Ct of the image displayed on the screen 9m of the master projection display device 2m is expressed by the equation (13) as the equation (28). Expression (2) for calculating the target luminance and target chromaticity Ct of the image displayed on the screen 9s of the projection display device 2s is assumed to be expressed by Expression (13) as Expression (29).

  In (28) and Equation (29), the matrix on the left side is the target luminance and target chromaticity Ct adjusted at the beginning of use. From the values of the components of this matrix, the target luminance and target chromaticity Ct are

  Is calculated. In Expressions (28) and (29), the conditions of Expressions (14) to (16) are also satisfied for the correction coefficient CSCm and the correction coefficient CSCs shown in the second matrix on the right side of each expression. ing.

  Equations for calculating initial sensor brightness and sensor chromaticity Ftm in the master projection display device 2m at the beginning of use by using the correction factor CSCm shown in Equation (28) and the correction factor CSCs shown in Equation (29). (3) is calculated from the equation (17) according to the equation (17), the equation (4) for calculating the initial sensor luminance and the sensor chromaticity Fts in the slave projection display device 2s is expressed by the equation (17). 31).

  The screen 9s of the slave projection display device 2s is adjusted in order to adjust the change in luminance and chromaticity of the image displayed on the screen 9m of the master projection display device 2m as the usage time elapses. In order to adjust the changes in the luminance and chromaticity of the video displayed on the screen, for example, the luminance and chromaticity correction calculation is performed when 60,000 hours have elapsed since the start of use.

  With the passage of 60,000 hours from the start of use, the tristimulus value XYZ data DSTmi output from the three primary color light sensor 10m of the master projection display device 2m is also output from the three primary color light sensor 10s of the slave projection display device 2s. The value of the tristimulus value XYZ data DSTsi to be changed also changes.

  The equation (5) for calculating the sensor luminance and the sensor chromaticity Fmi after 60,000 hours has elapsed in the master projection display device 2m is expressed by the equation (18) in the slave projection display device 2s as shown in the equation (32). The equation (6) for calculating the sensor luminance and the sensor chromaticity Fsi after 60,000 hours has been expressed by the equation (18) as the equation (33).

  The difference in luminance and chromaticity between the screen of the master projection display device 2m and the screen of the slave projection display device 2s when 60,000 hours have elapsed from the start of use is reduced, and R, G, and A new target sensor brightness and target sensor chromaticity Ftmi and target sensor brightness and target sensor chromaticity Ftsi that use the maximum brightness for each color of B are calculated. Therefore, the luminance for each color of the LED light sources of the master projection display device 2m and the slave projection display device 2s for obtaining the components δtri, δtgi and δtbi of the coefficient δti shown in the equations (9) and (10) The maintenance rate is calculated as in Expression (34) to Expression (39) from Expression (19) to Expression (24).

  From the values calculated from Equation (34) to Equation (39), the component of the coefficient δti is

  It becomes.

  As described above, the lifetime curve of the LED light source used in the master projection display device 2m is shown in FIG. 6, and the lifetime curve of the LED light source used in the slave projection display device 2s is shown in FIG. Then, the luminance maintenance rate of each LED light source that can be read from FIG. 6 and FIG. 7 and the three primary color light sensors 10m of the master projection display device 2m shown by the equations (34) to (39) are output. The tristimulus output from the tri-primary light sensor 10s of the slave projection display device 2s shown by the equations (34) to (39), and the luminance maintenance rate of each LED light source calculated from the values of the stimulus value XYZ data DSTmi It can be seen that each of the LED light source luminance maintenance rates calculated from the value XYZ data DSTsi is a close value.

  When 60,000 hours have elapsed from the start of use, the correction coefficient CCGmi for generating new target sensor brightness and target sensor chromaticity Ftmi in the master projection display device 2m is expressed by Expression (40) according to Expression (26). As described above, the correction coefficient CCGsi for generating new target sensor brightness and target sensor chromaticity Ftsi in the slave projection display device 2s is calculated as shown in Expression (41) by Expression (26).

  Here, in Expression (25) for calculating the target sensor luminance and the target sensor chromaticity Ftmi when 60,000 hours have elapsed from the start of use of the master projection display device 2m, the second matrix on the right side (initial use start) When the product of the third correction coefficient CSCm) and the third matrix (correction coefficient CCGmi when 60,000 hours have elapsed since use) is calculated, Equation (42) is obtained.

  As can be seen from the equation (25), the value calculated by the equation (42) indicates that the master projection display device 2m after the start of use has a new target sensor luminance and target sensor chromaticity Ftmi. R, G, and B components based on the tristimulus value XYZ data DSTmi output from the three primary color light sensor 10m of the master projection display device 2m, which is the first matrix on the right side of Expression (25). This is a new correction coefficient for determining the strength of the.

  Therefore, as in the case where the correction coefficient CSCm calculated at the beginning of use is expressed by the equations (14) to (16), values of R, G, and B components in the range of 0 to 1 are used. When possible (when the maximum value of the output of each R, G and B component is 1), the sum of the component outputs for each color of R, G and B should not exceed 1 (ie normalize) )There is a need.

  For example, in equation (42), the total output of the R components is

  R, G, and B are simply mixed in the new target sensor brightness and target sensor chromaticity Ftmi after 60,000 hours of the master projection display device 2m calculated by Expression (25). The brightness and chromaticity of W obtained in this way are not correctly reflected on the multi-screen.

  Therefore, based on the equation (26), the correction coefficient CCGmi of the master projection display apparatus 2m calculated by the expression (40) calculates ααmi + βαmi + γαmi, αβmi + ββmi +, and αγmi + βγmi + γγmi from each component of the correction coefficient CCGmi. Further, in the correction coefficient CCGsi of the slave projection display device 2s calculated by the equation (41), ααsi + βαsi + γαsi, αβsi + ββsi + γβsi, and αγsi + βγsi + γγsi are calculated from each component of the correction coefficient CCGsi.

  Further, assuming that the maximum value among these six calculated values is MAXαβγ, the correction coefficient CCGmi of the master projection display device 2m is expressed by ααmI, αβmI, αγmI expressed by the equations (43) to (51), By replacing βαmI, ββmI, βγmI, γαmI, γβmI, and γγmI with new correction coefficients CCGmI as components, R, G, and R at the new target sensor luminance and target sensor chromaticity Ftmi after 60,000 hours have elapsed. The brightness and chromaticity of W obtained by simply mixing B can be correctly reflected on the multi-screen.

  In the slave projection display device 2s, the same calculation is performed, and the correction coefficient CCGsi is replaced with a new correction coefficient CCGsI having ααsI, αβsI, αγsI, βαsI, ββsI, βγsI, γαsI, γβsI, and γγsI as components. With the new target sensor luminance and target sensor chromaticity Ftsi after the elapse of 60,000 hours, the W luminance and chromaticity can be correctly reflected on the multi-screen.

  The luminance and chromaticity of the multi-screen when 60,000 hours have elapsed from the start of use, based on the correction coefficient CCGmI of the master projection display device 2m and the correction coefficient CCGsI of the slave projection display device 2s obtained from the above calculation. Expression (27) for calculating Ctmi can be expressed as shown in Expression (52) in the master projection display apparatus 2m and as shown in Expression (53) in the slave projection display apparatus 2s.

  The image displayed on the screen 9m of the master projection display device 2m when 60,000 hours have elapsed from the start of use due to the component of the matrix on the left side of Expression (52) is

  Is calculated. Also, the image displayed on the screen 9 s of the slave projection display device 2 s when 60,000 hours have elapsed since the start of use is given by the component of the matrix on the left side of Expression (53):

  Is calculated. As described above, the luminance difference and chromaticity difference between the screen of the master projection display device 2m and the screen of the slave projection display device 2s are small when any of R, G, B, and W is displayed. It turns out that it is adjusted so that.

  On the other hand, in order to compare with the result of the above correction calculation, as an example of a conventional multi-screen display device as described in Patent Document 1, for example, an image displayed on the screen 9m of the master projection display device 2m, Further, in the image displayed on the screen 9s of the slave projection display device 2s, the correction of the master projection display device 2m for adjusting the chromaticity of W so as to be substantially constant regardless of the usage time. The coefficient CCGmI and the correction coefficient CCGsI of the slave projection display device 2s are calculated.

  In the master projection display device 2m, the correction coefficient is set so that the sensor luminance and the sensor chromaticity Fmi when 60,000 hours have elapsed from the start of use approach the target sensor luminance and the target sensor chromaticity Ftm at the beginning of use. CCGmi is calculated. For that purpose, in the equation (40), the constituent elements δtri, δtgi and δtbi of the coefficient δti for obtaining the new target sensor luminance and target sensor chromaticity Ftmi after 60,000 hours may be set to the same ratio ( Since the strengths of the R, G, and B components need only be equalized, for example, all of them are set to 1 and the equation (40) for calculating the correction coefficient CCGmi is replaced by the equation (54).

  Similarly, in the slave projection display device 2s, in the equation (41), the components δtri, δtgi, and δtbi of the coefficient δti for obtaining a new target sensor luminance and target sensor chromaticity Ftsi after 60,000 hours are calculated. Since the ratios may be the same (since the R, G, and B components have the same strength), for example, all of them are set to 1 and Equation (41) for calculating the correction coefficient CCGsi is expressed by Equation (55). Replaced.

  The correction coefficient CCGmi of the master projection display apparatus 2m and the correction coefficient CCGsi of the slave projection display apparatus 2s calculated by the expressions (54) and (55) are replaced with new correction coefficients CCGmI and CCGsI, respectively. The calculation method is the same as described above. The formula (52) for calculating the luminance and chromaticity Ctmi of the multi-screen when 60,000 hours have elapsed from the start of use is the slave projection display as shown in the formula (56) in the master projection display device 2m. In the apparatus 2s, it can be expressed as shown in Expression (57).

  The image displayed on the screen 9m of the master projection display device 2m when 60,000 hours have elapsed from the start of use due to the component of the matrix on the left side of the equation (56) is

  Is calculated. Also, the image displayed on the screen 9 s of the slave projection display device 2 s when 60,000 hours have elapsed since the start of use due to the component of the matrix on the left side of Expression (57) is:

  Is calculated. As described above, the luminance difference and chromaticity difference between the screen of the master projection display device 2m and the screen of the slave projection display device 2s are small when any of R, G, B, and W is displayed. It turns out that it is adjusted so that.

  In summary, in the brightness and chromaticity of W of the multi-screen, the initial values adjusted at the beginning of use are the master projection display device 2m and the slave projection display device 2s according to the equations (28) and (29). Both

  However, in the calculation method for correcting the luminance for each color of R, G and B according to the present embodiment to the maximum, the master projection type is used when 60,000 hours have passed since the start of use. In the display device 2m, according to the equation (52),

  In the slave projection display device 2s, according to the equation (53),

  It becomes.

  That is, as compared with the initial value, it can be seen that although the chromaticity of W causes a change of duv = 0.027, the luminance is maintained at about 70%.

  On the other hand, in the conventional calculation method for correcting the chromaticity of W of the multi-screen so that it is always substantially constant regardless of the passage of time from the start of use, when 60,000 hours have passed since the start of use, the master projection display device At 2 m, according to equation (56)

  In the slave projection display device 2s, according to the equation (57),

  It becomes.

  That is, compared with the initial value, the chromaticity of W is substantially constant with only a change of duv = 0.003, but the luminance is only about 42%, and the luminance of W is greatly reduced. I understand that.

  As shown in FIG. 6 and FIG. 7, in the R, G, and B LED light sources used for the master projection display device 2m and the slave projection display device 2s, the lifespan of the R LED is changed to other G and B. Compared to R, which has the lowest luminance in order to maintain the luminance balance of R, G, and B, if the W chromaticity of the multi-screen is to be kept substantially constant, the luminance is shorter and the luminance of R is faster than that. This is because it is necessary to lower the other G and B video signal gains.

  On the other hand, as in this embodiment, instead of maintaining the luminance balance of R, G, and B, the target chromaticity of W is used for the usage time so as to use as much luminance as possible for each color of R, G, and B. If the setting is sequentially reset as time passes, the chromaticity of W gradually changes with time, but the rate of lowering the G and B video signal gains can be reduced, so that the brightness as a multi-screen The maintenance rate can be increased. In any of the calculation methods, the change in chromaticity of R, G, and B is small and substantially constant regardless of the elapsed time of use.

  When displaying video content that is based on the primary colors and does not place much importance on full-color color reproducibility on multiple screens, such as a communication system diagram or an operation system diagram, use the calculation method of this embodiment. It is possible to adjust so that the difference in luminance and the difference in chromaticity between the screens of each projection display apparatus with the passage of time are automatically reduced. Further, the time during which the brightness of the multi-screen is lowered, for example, the time until the brightness is reduced by half with respect to the initial use start time can be extended.

  Therefore, it is possible to reduce the frequency of replacing only the projection display device or the light source device, and to reduce the cost for maintenance of the multi-screen display device.

  In the above embodiment, the multi-screen display device is configured by two projection video display devices, but the multi-screen display device may be configured by three or more projection video display devices. In this case, for example, the first calculation is performed between the arbitrarily selected first and second projection display apparatuses, and then the same calculation is performed between the calculation result and the third projection display apparatus. Thereafter, the same result can be obtained by repeating these processes. That is, by obtaining the lowest red maintenance ratio δtri, green minimum maintenance ratio δtgi, and blue minimum maintenance ratio δtbi, which is the lowest among the plurality of projection display devices, the same result as described above can be obtained.

Second Embodiment
A multi-screen display device and a multi-screen display method according to this embodiment will be described. In the following, the same components as those described in the above embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted as appropriate.

  In the first embodiment, the tristimulus value XYZ data of the image displayed on the screen 9m of the master projection display device 2m and the tristimulus value XYZ of the image displayed on the screen 9s of the slave projection display device 2s. Between the data and the tristimulus value XYZ data output from the three primary color light sensor 10m and the three primary color light sensor 10s, the values of the corresponding component elements change with the passage of time of use. In this example, the ratio of values between R, G, and B and the ratio of values between X, Y, and Z are different.

  That is, the R, G, and B chromaticity values calculated from the respective tristimulus values XYZ data or the luminance ratio between R, G, and B are different, so that the master projection display device 2m at the initial stage of use is used. And tristimulus value XYZ data output from the three primary color light sensor 10m and the three primary color light sensor 10s are used for the calculation as they are when calculating the target luminance and target chromaticity Ct common to the slave projection display device 2s. Can not.

  On the other hand, when a high-precision three-primary-color light sensor is used for the three-primary-color light sensor 10m and the three-primary-color light sensor 10s, the tristimulus value XYZ data output from the three-primary-color light sensor 10m and the three-primary-color light sensor 10s are used for calculation. It is possible to calculate the target luminance and target chromaticity Ct at the beginning of use.

  The high-accuracy three-primary-color light sensors mentioned above are three tristimulus values XYZ data of images displayed on the screen 9m of the master projection display device 2m and three images of images displayed on the screen 9s of the slave projection display device 2s. With respect to the stimulus value XYZ data, the rate of change when the value of each corresponding component changes with the passage of time of use is substantially equal, and the ratio of the values among R, G and B, and X , Y and Z are three primary color light sensors capable of outputting tristimulus value XYZ data having substantially the same ratio of values. That is, the R, G, and B chromaticity values calculated from each tristimulus value XYZ data, or the luminance ratio among R, G, and B are substantially the same.

  The configuration of the multi-screen display device of this embodiment is as shown in FIGS. 1, 2 and 3 as in the first embodiment. Further, a correction coefficient or a target luminance and target chromaticity calculation method performed by the processing circuit 11m of the master projection display device 2m, the processing circuit 11s of the slave projection display device 2s, or the processing circuit 13m of the master projection display device 2m. Is generally the same as the first embodiment.

  However, at the time of manufacturing the master projection display device 2m, it is necessary to measure tristimulus values XYZ data SCRm when the R, G, and B images are displayed on the screen 9m by a measuring instrument such as a color analyzer in the factory. Absent. Further, at the time of manufacturing the slave projection display device 2s, tristimulus XYZ data SCRs when R, G, and B images are displayed on each screen 9s are measured by a measuring instrument such as a color analyzer in a factory. There is no need. For this reason, the operations of the equations (1) and (2) in the first embodiment are not required in the present embodiment.

  FIG. 8 is a flowchart showing a correction calculation procedure in the master projection display device 2m and the slave projection display device 2s. Hereinafter, the procedure of the correction calculation will be described with reference to FIG.

  The target luminance and target chromaticity Ct at the beginning of use are the tristimulus XYZ data DSTm (see step ST101) output from the three primary color light sensors 10m of the master projection display device 2m, and the slave projection display device 2s. It is calculated from tristimulus value XYZ data DSTs (see step ST102) output from the three primary color light sensors 10s (see step ST103).

  In the first embodiment, the equation (3) for calculating the sensor brightness and the sensor chromaticity Ftm at the beginning of use of the master projection display device 2m is expressed by the equation (58) (see step ST104). By replacing equation (4) for calculating the sensor luminance and sensor chromaticity Fts at the beginning of use of the projection display device 2s as shown in equation (59) (see step ST105), the target luminance in this embodiment and A target chromaticity Ct is calculated.

  That is, the initial sensor brightness and sensor chromaticity Ftsm of the master projection display device 2m are equal to the initial sensor brightness and sensor chromaticity Fts of the slave projection display device 2s, and the master projection display at the start of use is the same. The target luminance and target chromaticity Ct common to the device 2m and the slave projection display device 2s are represented.

  When i time has elapsed from the start of use, the luminance and chromaticity Ctmi of the image displayed on the screen 9m of the master projection display device 2m (see step ST106, step ST108, step ST109 and step ST111), and slave projection The calculation method of the luminance and chromaticity Ctsi (see step ST107, step ST108, step ST110, and step ST112) of the image displayed on the screen 9s of the mold display device 2s is based on the equation (5) in the first embodiment. It is the same as Expression (12).

  That is, the three primary color light sensors 10m of the master projection display device 2m output tristimulus value XYZ data equivalent to the tristimulus value XYZ data of the image displayed on the screen 9m of the master projection display device 2m. If this is possible, the same effects as in the first embodiment can be obtained in the present embodiment. The tri-primary color light sensor 10s of the slave projection display device 2s outputs tristimulus value XYZ data equivalent to the tristimulus value XYZ data of the image displayed on the screen 9s of the slave projection display device 2s. If this is possible, the same effects as in the first embodiment can be obtained in the present embodiment.

  In the first embodiment, the tristimulus value XYZ data SCRm and the tristimulus value XYZ data SCRs measured at the factory at the time of manufacturing the master projection display device 2m and the slave projection display device 2s, The target brightness and target chromaticity Ct at the beginning of use after installation are calculated.

  For this reason, when the environmental temperature at the time of manufacture and the environmental temperature of the place where it is actually installed (especially the junction temperature Tj of the LED) are significantly different, the emission intensity of the LED light source also differs. There may be a difference in luminance and chromaticity between the screen of the projection display device 2m and the screen of the slave projection display device 2s.

  On the other hand, in this embodiment, the target luminance and target chromaticity Ct at the beginning of use of the master projection display device 2m are determined by the tristimulus value XYZ data DSTm output from the three primary color light sensor 10m in the actually installed environment. Since it is calculated, it is not affected by the difference in environmental temperature as described above. Further, since the target luminance and target chromaticity Ct at the beginning of use of the slave projection display device 2s are calculated from the tristimulus value XYZ data DSTs output from the three primary color light sensors 10s in the actually installed environment, It is not affected by the difference in environmental temperature.

<Effect>
Below, the effect by said embodiment is illustrated.

  According to the above embodiment, the multi-screen display device is a combination of the screens of a plurality of video display devices, that is, the screen 9m of the master projection display device 2m and the screen 9s of the slave projection display device 2s. Configure multiple screens.

  The master projection display device 2m includes an LED light source 3mr that emits light for displaying an image on the screen 9m, an LED light source 3mg, an LED light source 3mb, and a primary color light sensor 10m.

  The three primary color light sensor 10m measures the luminance value of each light emitted from the LED light source 3mr, the LED light source 3mg, and the LED light source 3mb.

  The slave projection display device 2s includes an LED light source 3sr, an LED light source 3sg and an LED light source 3sb that emit light for displaying an image on the screen 9s, and a three-primary-color light sensor 10s.

  The three primary color light sensor 10s measures the luminance value of each light emitted from the LED light source 3sr, the LED light source 3sg, and the LED light source 3sb.

  In addition, the multi-screen display device includes a luminance control unit 111m that controls the luminance of each light emitted from the LED light source 3mr, the LED light source 3mg, and the LED light source 3mb based on each luminance value measured by the three primary color light sensors 10m. Prepare.

  In addition, the multi-screen display device includes a luminance control unit 111s that controls the luminance of each light emitted from the LED light source 3sr, the LED light source 3sg, and the LED light source 3sb based on each luminance value measured by the three primary color light sensors 10s. Prepare.

  Then, the luminance control unit 111m calculates a luminance maintenance ratio that is a ratio of the measured luminance value to the luminance value at the start of use of the LED light source 3mr, and sets the lowest luminance maintenance ratio as the red minimum maintenance ratio δtri. To do.

  Then, the luminance control unit 111m calculates a luminance maintenance rate that is a ratio of the measured luminance value to the luminance value at the start of use of the LED light source 3mr, and the luminance control unit 111s maintains the luminance of the LED light source 3sr. The rate is calculated, and the lowest luminance maintenance rate is set as the red minimum maintenance rate δtri.

  In addition, the luminance control unit 111m calculates a luminance maintenance rate that is a ratio of the measured luminance value to the luminance value at the start of use of the LED light source 3mg, and the luminance control unit 111s maintains the luminance of the LED light source 3sg. The rate is calculated, and the lowest luminance maintenance rate among them is defined as the green minimum maintenance rate δtgi.

  In addition, the luminance control unit 111m calculates a luminance maintenance rate that is a ratio of the measured luminance value to the luminance value at the start of use of the LED light source 3mb, and the luminance control unit 111s maintains the luminance of the LED light source 3sb. The rate is calculated, and the lowest luminance maintenance rate is set as the blue minimum maintenance rate δtbi.

  In addition, the luminance control unit 111m controls the luminance of each light emitted from the LED light source 3mr, the LED light source 3mg, and the LED light source 3mb based on the red minimum maintenance rate δtri, the green minimum maintenance rate δtgi, and the blue minimum maintenance rate δtbi. To do.

  In addition, the luminance control unit 111s controls the luminance of each light emitted from the LED light source 3sr, the LED light source 3sg, and the LED light source 3sb based on the minimum red maintenance rate δtri, the minimum green maintenance rate δtgi, and the minimum blue maintenance rate δtbi. To do.

  According to the above embodiment, the multi-screen display device combines the screens of a plurality of video display devices, that is, the screen 9m of the master projection display device 2m and the screen 9s of the slave projection display device 2s. One multi-screen is configured.

  The master projection display device 2m includes an LED light source 3mr that emits light for displaying an image on the screen 9m, an LED light source 3mg, an LED light source 3mb, and a primary color light sensor 10m.

  The three primary color light sensor 10m measures the luminance value of each light emitted from the LED light source 3mr, the LED light source 3mg, and the LED light source 3mb.

  The slave projection display device 2s includes an LED light source 3sr, an LED light source 3sg and an LED light source 3sb that emit light for displaying an image on the screen 9s, and a three-primary-color light sensor 10s.

  The three primary color light sensor 10s measures the luminance value of each light emitted from the LED light source 3sr, the LED light source 3sg, and the LED light source 3sb.

  The multi-screen display device includes a processing circuit 11m that executes a program and a storage device 12m that stores the program.

  The multi-screen display device includes a processing circuit 11s that executes a program and a storage device 12s that stores the program.

  And the following operation | movement is implement | achieved when the processing circuit 11m runs a program.

  That is, the brightness of each light emitted from the LED light source 3mr, the LED light source 3mg, and the LED light source 3mb is controlled based on each brightness value measured by the three primary color light sensors 10m.

  Here, the luminance maintenance rate, which is the ratio of the measured luminance value to the luminance value at the start of use of the LED light source 3mr, is calculated, the luminance maintenance rate of the LED light source 3sr is calculated, and the lowest luminance maintenance rate among them is calculated. Let red minimum maintenance rate δtri.

  Moreover, the luminance maintenance rate which is the ratio of the measured luminance value to the luminance value at the start of use of the LED light source 3 mg is calculated, the luminance maintenance rate of the LED light source 3 sg is calculated, and the lowest luminance maintenance rate among them is green. The minimum maintenance rate is δtgi.

  Moreover, the luminance maintenance rate which is the ratio of the measured luminance value to the luminance value at the start of use of the LED light source 3mb is calculated, the luminance maintenance rate of the LED light source 3sb is calculated, and the lowest luminance maintenance rate among them is blue. The minimum maintenance rate is δtbi.

  The brightness of each light emitted from the LED light source 3 mr, the LED light source 3 mg, and the LED light source 3 mb is controlled based on the minimum red maintenance rate δtri, the minimum green maintenance rate δtgi, and the minimum blue maintenance rate δtbi.

  Further, the processing circuit 11s executes the program, thereby realizing the following operation.

  That is, the luminance of each light emitted from the LED light source 3sr, the LED light source 3sg, and the LED light source 3sb is controlled based on each luminance value measured by the three primary color light sensors 10s.

  The brightness of each light emitted from the LED light source 3sr, the LED light source 3sg, and the LED light source 3sb is controlled based on the minimum red maintenance rate δtri, the minimum green maintenance rate δtgi, and the minimum blue maintenance rate δtbi.

  According to the above embodiment, the multi-screen display device combines the screens of a plurality of video display devices, that is, the screen 9m of the master projection display device 2m and the screen 9s of the slave projection display device 2s. One multi-screen is configured.

  The master projection display device 2m includes an LED light source 3mr that emits light for displaying an image on the screen 9m, an LED light source 3mg, an LED light source 3mb, and a primary color light sensor 10m.

  The three primary color light sensor 10m measures the luminance value of each light emitted from the LED light source 3mr, the LED light source 3mg, and the LED light source 3mb.

  The slave projection display device 2s includes an LED light source 3sr, an LED light source 3sg and an LED light source 3sb that emit light for displaying an image on the screen 9s, and a three-primary-color light sensor 10s.

  The three primary color light sensor 10s measures the luminance value of each light emitted from the LED light source 3sr, the LED light source 3sg, and the LED light source 3sb.

  In addition, the multi-screen display device includes a processing circuit 211m. The multi-screen display device includes a processing circuit 211s.

  Then, the processing circuit 211m performs the following operation.

  That is, the processing circuit 211m controls the luminance of each light emitted from the LED light source 3mr, the LED light source 3mg, and the LED light source 3mb based on the luminance values measured by the three primary color light sensors 10m.

  Here, the luminance maintenance rate, which is the ratio of the measured luminance value to the luminance value at the start of use of the LED light source 3mr, is calculated, the luminance maintenance rate of the LED light source 3sr is calculated, and the lowest luminance maintenance rate among them is calculated. Let red minimum maintenance rate δtri.

  Moreover, the luminance maintenance rate which is the ratio of the measured luminance value to the luminance value at the start of use of the LED light source 3 mg is calculated, the luminance maintenance rate of the LED light source 3 sg is calculated, and the lowest luminance maintenance rate among them is green. The minimum maintenance rate is δtgi.

  Moreover, the luminance maintenance rate which is the ratio of the measured luminance value to the luminance value at the start of use of the LED light source 3mb is calculated, the luminance maintenance rate of the LED light source 3sb is calculated, and the lowest luminance maintenance rate among them is blue. The minimum maintenance rate is δtbi.

  Then, the processing circuit 211m controls the luminance of each light emitted from the LED light source 3mr, the LED light source 3mg, and the LED light source 3mb based on the minimum red maintenance rate δtri, the minimum green maintenance rate δtgi, and the minimum blue maintenance rate δtbi. .

  The processing circuit 211s performs the following operation.

  That is, the processing circuit 211s controls the luminance of each light emitted from the LED light source 3sr, the LED light source 3sg, and the LED light source 3sb based on each luminance value measured by the three primary color light sensors 10s.

  Then, the processing circuit 211s controls the luminance of each light emitted from the LED light source 3sr, the LED light source 3sg, and the LED light source 3sb based on the minimum red maintenance rate δtri, the minimum green maintenance rate δtgi, and the minimum blue maintenance rate δtbi. .

  According to such a configuration, instead of maintaining the luminance balance of R, G, and B, luminance control can be performed so as to use as much luminance as possible for each color of R, G, and B. When displaying an image on the screen, adjustment can be performed while suppressing a decrease in luminance.

  In particular, when displaying video content based on primary colors and not giving much importance to full-color color reproducibility on a multi-screen, such as a communication system diagram or an operation system diagram, by using the calculation method of this embodiment, Thus, it is possible to adjust so that the difference in luminance and the difference in chromaticity between the screens of the respective projection display devices as the usage time elapses are automatically reduced.

  In addition, since the luminance is controlled within a range that can be commonly reproduced in a plurality of video display devices, it is possible to reduce the luminance difference and chromaticity difference between the screens of the video display devices.

  In addition, by suppressing the decrease in luminance, for example, it is possible to extend the usage time until the luminance is halved with respect to the initial use start. Therefore, since the frequency of replacing the video display device itself or the LED light source can be reduced, the cost for maintenance of the multi-screen display device can be suppressed.

  In addition, since the rate of lowering the video signal gain can be reduced, many gradations of the video displayed on the multi-screen can be maintained, and the number of colors that can be expressed increases.

  Note that configurations other than these configurations can be omitted as appropriate, but the above-described effects can be produced even when at least one of the other configurations shown in this specification is added as appropriate.

  Further, according to the above embodiment, the luminance control unit 111m normalizes the red minimum maintenance rate δtri, the green minimum maintenance rate δtgi, and the blue minimum maintenance rate δtbi, and normalizes the red minimum maintenance rate δtri and the green minimum maintenance. Based on the rate δtgi and the blue minimum maintenance rate δtbi, the brightness of each light emitted from the LED light source 3mr, the LED light source 3mg, and the LED light source 3mb is controlled. In addition, the luminance control unit 111s normalizes the red minimum maintenance rate δtri, the green minimum maintenance rate δtgi, and the blue minimum maintenance rate δtbi, and normalizes the red minimum maintenance rate δtri, the green minimum maintenance rate δtgi, and the blue minimum maintenance rate δtbi. The brightness of each light emitted from the LED light source 3sr, the LED light source 3sg, and the LED light source 3sb is controlled based on the above.

  According to such a configuration, by normalization, the brightness and chromaticity of W obtained by simply mixing the colors of R, G, and B are within the range in which the multi-screen is correctly reflected from each light emitting diode. The luminance of the emitted light can be controlled.

  Further, according to the above embodiment, the master projection display device 2m includes the DMD 7m that modulates each light emitted from the LED light source 3mr, the LED light source 3mg, and the LED light source 3mb into on-light and off-light.

  Then, the three primary color light sensor 10m measures each light modulated into the off-light among the light emitted from the LED light source 3mr, the LED light source 3mg, and the LED light source 3mb.

  The slave projection display device 2s includes a DMD 7s that modulates each light emitted from the LED light source 3sr, the LED light source 3sg, and the LED light source 3sb into ON light and OFF light.

  Then, the three primary color light sensor 10s measures each light modulated into the off-light among the light emitted from the LED light source 3sr, the LED light source 3sg, and the LED light source 3sb.

  According to such a configuration, the three primary color light sensors do not interfere with the image projected on the screen. Therefore, the brightness and chromaticity change of the LED light source can be monitored appropriately at all times during use of the multi-screen display device.

  Moreover, according to said embodiment, a luminance value is tristimulus value XYZ data.

  Further, according to the above embodiment, in the multi-screen display method, the screens of a plurality of video display devices, that is, the screen 9m of the master projection display device 2m and the screen 9s of the slave projection display device 2s are combined. Display video on one multi-screen.

  The master projection display device 2m includes an LED light source 3mr that emits light for displaying an image on the screen 9m, an LED light source 3mg, an LED light source 3mb, and a primary color light sensor 10m.

  The three primary color light sensor 10m measures the luminance value of each light emitted from the LED light source 3mr, the LED light source 3mg, and the LED light source 3mb.

  The slave projection display device 2s includes an LED light source 3sr, an LED light source 3sg and an LED light source 3sb that emit light for displaying an image on the screen 9s, and a three-primary-color light sensor 10s.

  The three primary color light sensor 10s measures the luminance value of each light emitted from the LED light source 3sr, the LED light source 3sg, and the LED light source 3sb.

  Then, a luminance maintenance rate that is a ratio of the measured luminance value to a luminance value at the start of use of the LED light source 3mr is calculated, a luminance maintenance rate of the LED light source 3sr is calculated, and the lowest luminance maintenance rate among them is red. The minimum maintenance rate is δtri.

  Moreover, the luminance maintenance rate which is the ratio of the measured luminance value to the luminance value at the start of use of the LED light source 3 mg is calculated, the luminance maintenance rate of the LED light source 3 sg is calculated, and the lowest luminance maintenance rate among them is green. The minimum maintenance rate is δtgi.

  Moreover, the luminance maintenance rate which is the ratio of the measured luminance value to the luminance value at the start of use of the LED light source 3mb is calculated, the luminance maintenance rate of the LED light source 3sb is calculated, and the lowest luminance maintenance rate among them is blue. The minimum maintenance rate is δtbi.

  Further, the brightness of each light emitted from the LED light source 3 mr, the LED light source 3 mg, and the LED light source 3 mb is controlled based on the minimum red maintenance rate δtri, the green minimum maintenance rate δtgi, and the blue minimum maintenance rate δtbi.

  Further, the brightness of each light emitted from the LED light source 3sr, the LED light source 3sg, and the LED light source 3sb is controlled based on the minimum red maintenance rate δtri, the minimum green maintenance rate δtgi, and the minimum blue maintenance rate δtbi.

  According to such a configuration, instead of maintaining the luminance balance of R, G, and B, luminance control can be performed so as to use as much luminance as possible for each color of R, G, and B. When displaying an image on the screen, adjustment can be performed while suppressing a decrease in luminance.

  Note that configurations other than these configurations can be omitted as appropriate, but the above-described effects can be produced even when at least one of the other configurations shown in this specification is added as appropriate.

<Modification>
In the above-described embodiment, the material, material, size, shape, relative arrangement relationship, implementation condition, and the like of each component may be described. It is not limited to what is described in the book. Therefore, innumerable modifications not illustrated are assumed within the scope of the present technology. For example, the case where at least one component is modified, added or omitted, and further, the case where at least one component in at least one embodiment is extracted and combined with the components of other embodiments are included. It is.

  In addition, as long as no contradiction arises, “one or more” components described as being provided with “one” in the above-described embodiment may be provided. Furthermore, each component is a conceptual unit, and one component consists of a plurality of structures, one component corresponds to a part of the structure, and a plurality of components. And the case where the component is provided in one structure. Each component includes a structure having another structure or shape as long as the same function is exhibited.

  Also, the descriptions in this specification are referred to for all purposes related to the present technology, and none of them is admitted to be prior art.

  Further, in the above embodiment, when a material name or the like is described without being particularly specified, the material includes other additives, for example, an alloy or the like unless a contradiction arises. .

  In addition, each component described in the above embodiment is assumed to be software or firmware, or hardware corresponding thereto, and in both concepts, each component is a “unit” or “processing circuit” or the like. Called.

  The present technology may be a case where each component is distributed and provided in a plurality of devices (that is, a system-like aspect).

  2 m, 202 m Master projection display device, 2 s, 202 s Slave projection display device, 3 mb, 3 mg, 3 mr, 3 sb, 3 sg, 3 sr LED light source, 4 m, 4 s dichroic mirror, 5 m, 5 s relay lens, 6 m, 6 s TIR prism, 7m, 7s DMD, 8m, 8s projection lens, 9m, 9s screen, 10m, 10s three primary color light sensors, 11m, 11s, 13m, 211m, 211s processing circuit, 12m, 12s storage device, 16 communication cable, 111m, 111s brightness control Part, CCGmi, CCGsi, CSCm, CSCs correction coefficient, Ct target luminance and chromaticity, Ctmi, Ctsi luminance and chromaticity, DSTm, DSTs, SCRm, SCRs Tristimulus value XYZ data, Ftm, Fts, Fmi, Fsi Sir luminance and sensor chromaticity, Tj junction temperature, ti coefficient.

Claims (5)

A multi-screen display device that composes one multi-screen by combining the screens of a plurality of video display devices,
Each of the video display devices
A red light emitting diode, a green light emitting diode, and a blue light emitting diode that emit light for displaying an image on the screen;
A sensor for measuring a luminance value of each light emitted from the red light emitting diode, the green light emitting diode, and the blue light emitting diode;
The multi-screen display device
A luminance control unit that controls the luminance of each light emitted from each of the red light emitting diodes, each of the green light emitting diodes, and each of the blue light emitting diodes to a target luminance based on each of the luminance values measured in each of the sensors; Prepared,
The target luminance is a luminance calculated from a common color reproduction range based on color reproduction characteristics stored in advance in each of the video display devices,
The luminance control unit calculates a luminance maintenance ratio that is a ratio of the measured luminance value to a luminance value at the start of use of each red light emitting diode, and sets the lowest luminance maintenance ratio among them as a red minimum maintenance ratio. ,
The luminance control unit calculates the luminance maintenance rate of each green light-emitting diode, the lowest luminance maintenance rate among them as the green minimum maintenance rate,
The luminance control unit calculates the luminance maintenance rate of each blue light-emitting diode, the lowest luminance maintenance rate among them as the blue minimum maintenance rate,
The brightness control unit, the red minimum maintenance rate which varies with time from the time of the start of use, calculates a new said target luminance based on the green lowest retention ratio and the blue minimum maintenance rate, new Based on the calculated target luminance, control the luminance of each light emitted from each of the red light emitting diodes, each of the green light emitting diodes and each of the blue light emitting diodes,
Multi-screen display device. Each of the video display devices
A DMD that modulates each light emitted from the red light emitting diode, the green light emitting diode, and the blue light emitting diode into on-light and off-light;
The sensor measures each light modulated to the off-light among the light emitted from the red light emitting diode, the green light emitting diode, and the blue light emitting diode,
The multi-screen display device according to claim 1 . The luminance value is tristimulus value XYZ data.
The multi-screen display device according to claim 1 or 2 . A multi-screen display method for displaying video on a single multi-screen combining screens of a plurality of video display devices,
Each of the video display devices
A red light emitting diode, a green light emitting diode, and a blue light emitting diode that emit light for displaying an image on the screen;
A sensor for measuring a luminance value of each light emitted from the red light emitting diode, the green light emitting diode, and the blue light emitting diode;
For each red light emitting diode, calculate the luminance maintenance rate that is the ratio of the measured luminance value to the luminance value at the start of use, the lowest luminance maintenance rate among them as the red minimum maintenance rate,
The brightness maintenance rate of each green light emitting diode is calculated, and the lowest brightness maintenance rate among them is set as the green minimum maintenance rate,
Calculate the luminance maintenance rate of each blue light emitting diode, the lowest luminance maintenance rate among them is the blue minimum maintenance rate,
A new target brightness is calculated based on the minimum red maintenance ratio, the minimum green maintenance ratio, and the minimum blue maintenance ratio that change with the passage of time from the start of use , and the newly calculated target brightness is calculated. Based on the control of the brightness of each light emitted from each of the red light emitting diodes, each of the green light emitting diodes and each of the blue light emitting diodes ,
The target luminance is a luminance calculated from a common color reproduction range based on color reproduction characteristics stored in advance in each of the video display devices.
Multi-screen display method. The luminance value is tristimulus value XYZ data.
The multi-screen display method according to claim 4 .

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