JP2012003213A - Projection type display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projection type display capable of excellently adjusting display element modulation timing and color wheel rotation timing.SOLUTION: A projector comprises: a color wheel 21; a motor 22 for rotating the color wheel 21; a position sensor 23 for detecting a rotation reference position of the color wheel 21 and outputting an index signal; a motor control circuit 108 for controlling the motor 22 on the basis of the index signal; a DMD 50 for modulating the light of each color separated by the color wheel 21; a video signal processing circuit 105 for generating a DMD control signal; a color sensor 70 for outputting a light receiving signal corresponding to chromaticity of the light emitted from the DMD 50; and a CPU 110 for adjusting the output timing of the index signal on the basis of the light receiving signal so that the timing of each light irradiated to the DMD 50 synchronizes with the output timing of the DMD control signal corresponding to each light.

Description

  The present invention relates to a projection display apparatus that modulates light from a light source by a display element and enlarges and projects the light on a projection surface, and in particular, color-separates light from the light source by a color wheel, It is suitable for use in a projection display device that modulates.

  Conventionally, only one display element such as a DMD (Digital Micro-mirror Device) is used as one type of projection display device (hereinafter referred to as “projector”) that enlarges and projects an image on a projection surface (screen or the like). A so-called single-plate projector is known.

  In this type of projector, a color wheel is disposed between the light source and the display element. The color wheel has, for example, a configuration in which a plurality of segments (transmission regions) that transmit only light in a specific wavelength region (light of red, green, blue, etc.) are arranged in the rotation direction, and are driven to rotate by a motor. Is done. Light from the light source is separated into red, green, blue, and other color lights by a color wheel, and each color light is irradiated onto the display element in a time-sharing manner. The display element performs modulation according to each color light, and the modulated light (hereinafter referred to as “image light”) is sequentially projected on the projection surface. At this time, since the switching of each color light is performed at high speed, the image of each light on the projection surface is synthesized and displayed as one image to the user's eyes.

  In such a projector, when each color light separated in each segment is irradiated on the display element, output of a control signal for causing the display element to perform the modulation operation so that the modulation operation corresponding to the color light is performed. It is necessary to synchronize the timing and the rotation timing of the color wheel.

  For this reason, the color wheel is provided with a marker and a position sensor for detecting the marker position (rotation reference position) in order to detect the rotation position. From the position sensor, a position detection signal (hereinafter referred to as “index signal”) serving as an index of rotation is output. The control signal to the display element is output in synchronization with the vertical synchronization signal included in the video signal input from the outside, and this vertical synchronization signal and a certain timing (for example, simultaneously with the vertical synchronization signal or for a predetermined time) The rotation of the color wheel is controlled so that the index signal is output with a delayed timing. Thereby, the output timing of the control signal to the display element is synchronized with the rotation timing of the color wheel.

  However, manufacturing errors may occur at the attachment positions of the markers and position sensors. As a result, there is a possibility that a deviation occurs in the detection of the rotation reference position. In this case, the output timing of the control signal to the display element and the rotation timing of the color wheel cannot be properly synchronized, and the image quality of the projected image may be degraded.

  For this reason, when manufacturing the projector, it is necessary to perform an operation of adjusting the output timing of the index signal in accordance with the positional deviation of the marker and the position sensor. In this case, for example, as an adjustment method, a color light detection device that receives video light emitted from the projector is connected to the projector so that a proper output can be obtained from the color light detection device in a state where a test image is projected. A method may be employed in which the output timing of the index signal is adjusted (see Patent Document 1).

JP 2004-347645 A

  However, in the above adjustment method, since it is necessary to connect a light detection device provided separately from the projector to the projector, the adjustment work can be performed only for one projector at a time. Further, the adjustment work can be performed only at the time of manufacture, and the adjustment work cannot be performed when the user replaces the color wheel himself. Therefore, when the color wheel is replaced by the user himself, there is a possibility that the output timing of the control signal to the display element and the rotation timing of the color wheel cannot be properly synchronized.

  SUMMARY An advantage of some aspects of the invention is that it provides a projection display apparatus capable of satisfactorily adjusting the timing of a modulation operation by a display element and the rotation timing of a color wheel.

  In the projection display device of the present invention, a plurality of segments having different colors are arranged in the rotation direction, and the color wheel for separating the white light from the light source into a plurality of colors in a time-sharing manner by these segments, and the color wheel are rotated. A position detection unit that detects a rotation reference position provided in the color wheel and outputs a position detection signal, a motor control unit that controls the motor based on the position detection signal, and the color A display element that modulates light of each color separated by a wheel, a signal processing unit that generates a control signal for causing the display element to perform a modulation operation according to the light of each color, and emitted from the display element A color detection unit that outputs a color detection signal corresponding to the chromaticity of the light; a timing at which the light of each color is applied to the display element; and the control signal corresponding to the light of each color. So it and the timing output from the signal processing unit is synchronized, based on the color detection signal, and an adjusting unit that adjusts the output timing of the position detection signal.

  For example, the adjustment unit acquires the color detection signal from the color detection unit in a state where video light based on a single-color test image is emitted from the display element, and based on the acquired color detection signal, the test The output timing of the position detection signal may be adjusted so that the color purity of the image is maximized.

  Further, for example, the signal processing unit may be configured to output the control signal in synchronization with a vertical synchronization signal. In this case, a signal delay unit that delays the vertical synchronization signal by a set delay time and outputs the delayed signal to the motor control unit is provided. Further, the adjustment unit is configured to set the delay time based on the color detection signal so that the color purity of the test image is maximized. Further, the motor control unit is configured to control the motor so that the position detection signal is synchronized with the delayed vertical synchronization signal.

  According to the projection display device of the present invention, even if the rotation reference position is shifted due to a manufacturing error, the rotation timing of the color wheel and the timing of the modulation operation by the display element can be properly synchronized.

  Moreover, since the output timing of the position detection signal is adjusted using the color detection unit provided in the projection display device main body, it is adjusted not only at the time of manufacture but also when the user replaces the color wheel by himself / herself. Work can be performed, and synchronization between the rotation timing of the color wheel and the timing of the modulation operation by the display element can be optimized.

The projection display device of the present invention acquires the color detection signal from the color detection unit in a state where video light based on a monochromatic test image is emitted from the display element, and based on the acquired color detection signal, The color purity of the test image may be acquired, and a determination unit that determines the suitability of the color wheel based on the acquired color purity may be further provided.

  In this case, the adjustment unit may be configured not to adjust the output timing of the position detection signal when the determination unit determines that the color wheel is not appropriate. Or you may arrange | position the alerting | reporting part which alert | reports that a color wheel is not appropriate.

  According to such a configuration, adjustment of the output timing of the position detection signal with respect to an inappropriate color wheel can be avoided. In addition, the user can be informed that the color wheel is not appropriate.

  In the projection display device of the present invention, the display element may be a DMD (digital micromirror device). In this case, the color detection unit may be configured to be irradiated with off-light from the DMD.

  With such a configuration, the color detection unit does not interfere with the image light projected on the screen during normal operation.

  As described above, according to the present invention, it is possible to provide a projection display device that can satisfactorily adjust the timing of the modulation operation by the display element and the rotation timing of the color wheel.

  The effects and significance of the present invention will become more apparent from the following description of embodiments. However, the following embodiment is merely an example when the present invention is implemented, and the present invention is not limited to what is described in the following embodiment.

It is a figure which shows the structure of the projector which concerns on embodiment. It is a figure which shows the structure of the circuit system of the projector which concerns on embodiment. It is a figure which shows the drive timing of the color wheel unit which concerns on embodiment, and DMD. It is a flowchart which shows the control action which concerns on the index adjustment process which concerns on embodiment. It is a figure for demonstrating the operation | movement for calculating | requiring the optimal index value which concerns on embodiment. It is a figure for demonstrating the effect of embodiment. It is a flowchart which shows the control action which concerns on the 1st identification process which concerns on embodiment. It is a figure which shows the change characteristic of chromaticity with respect to an index value when the red raster pattern which concerns on embodiment is projected. It is a figure which shows the change characteristic of chromaticity with respect to an index value when the red raster pattern which concerns on embodiment is projected. It is a flowchart which shows the control action which concerns on the 2nd identification process which concerns on embodiment. It is a figure which shows the change characteristic of the chromaticity with respect to the index value when the red raster pattern, green raster pattern, and blue raster pattern which concern on embodiment are projected. It is a figure which shows the change characteristic of the once differential value of chromaticity with respect to the index value when the red raster pattern, green raster pattern, and blue raster pattern which concern on embodiment are projected.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram showing a configuration of a projector 1 according to the present embodiment. FIG. 1A shows the configuration of the optical system, and FIG. 1B shows the configuration of the color wheel unit 20.

  As shown in FIG. 1A, the projector 1 includes a light source lamp 10, a color wheel unit 20, a rod integrator 30, a relay optical system 40, a DMD 50, a projection optical system 60, and a color sensor 70. I have.

  The light source lamp 10 includes an arc tube 11 and a reflector 12. For the arc tube 11, a metal halide lamp, an ultra-high pressure mercury lamp, a xenon lamp or the like is used. The reflector 12 is formed in an elliptical shape. White light emitted from the arc tube 11 is reflected by the reflector 12 and travels forward while converging.

  White light emitted from the light source lamp 10 passes through the color wheel unit 20 and is collected on the incident surface of the rod integrator 30.

  The color wheel unit 20 is arranged so that the color wheel 21 is positioned near the condensing point of the white light emitted from the light source lamp 10. The color wheel unit 20 is easily attached and detached so that the user can replace the color wheel unit 20 by, for example, being fitted and fixed to a holding unit (not shown).

  The color wheel unit 20 includes a color wheel 21, a motor 22, and a position sensor 23. As shown in FIG. 1B, the color wheel 21 has a ring shape and is arranged in six rotation segments 21W, 21C, 21B, and 21G of white, cyan, blue, green, yellow, and red. , 21Y, 21R.

  The white segment 21W has an optical characteristic of transmitting visible light as it is. That is, the white segment 21W is a transparent region, and white light (hereinafter referred to as “W light”) is transmitted as it is. The C segment 21C has an optical characteristic of transmitting only light in the cyan wavelength band (hereinafter referred to as “C light”). The B segment 21B has an optical characteristic of transmitting only light in the blue wavelength band (hereinafter referred to as “B light”). The G segment 21G has an optical characteristic of transmitting only light in the green wavelength band (hereinafter referred to as “G light”). The Y segment 21Y has an optical characteristic of transmitting only light in the yellow wavelength band (hereinafter referred to as “Y light”). The R segment 21R has an optical characteristic of transmitting only light in the red wavelength band (hereinafter referred to as “R light”).

  In the present embodiment, the angles of the three segments 21R, 21G, and 21B of R, G, and B are substantially equal, and the angles of the two segments 21Y and 21C of Y and C are the three segments 21R, The angle is about one third of the angle of 21G and 21B. In addition, the angle of the W segment 21W is set to about one half of the angle of the three segments 21R, 21G, and 21B.

  A rotating plate 22 a that is rotated by a motor 22 is fixed to an opening formed in the center of the color wheel 21. When the motor 22 is driven, the rotating plate 22a rotates and the color wheel 21 rotates.

  The position sensor 23 is for detecting the rotational position of the color wheel 21. The color wheel 21 is provided with a marker 21a serving as a rotation reference position, and a position sensor 23 is provided at a predetermined position on the rotation trajectory of the marker 21a. Each time the color wheel 21 rotates once, the marker 21a is detected by the position sensor 23, and an index signal serving as a rotation index is output. For example, the position sensor 23 is composed of a light emitting element and a light receiving element, and the marker 21a is composed of a reflecting member. In this case, the marker 21a can be detected by receiving light emitted from the light emitting element and reflected by the marker 21a with the light receiving element. In the present embodiment, the marker 21a is arranged at the boundary position between the C segment 21C and the B segment 21B.

  When the color wheel 21 rotates, light sequentially enters each segment 21W, 21C, 21B, 21G, 21Y, 21R, and passes through each segment 21W, 21C, 21B, 21G, 21Y, 21R, W light, C light, B Light, G light, Y light, and R light are emitted from the color wheel 21 in a time-sharing manner.

  The light transmitted through the color wheel 21 enters the rod integrator 30. The rod integrator is made of a glass material and has a quadrangular prism shape. The light incident on the rod integrator 30 is repeatedly reflected on the inner wall surface when propagating through the rod, and the illuminance distribution is made uniform and emitted from the emission surface.

  The light emitted from the rod integrator 30 is guided by the three relay lenses 41, 42, 43 and the mirror 44 constituting the relay optical system 40, and is irradiated to the DMD 50.

  The DMD 50 is sequentially irradiated with W light, C light, B light, G light, Y light, and R light in a time-sharing manner. The DMD 50 includes micromirrors arranged in a matrix, and the micromirrors are driven on and off based on a drive signal corresponding to each incident light to modulate each light. One micromirror constitutes one pixel. The light reflected by the micromirror when the micromirror is turned on (on light) travels toward the projection optical system 60, and the light reflected by the micromirror when the micromirror is turned off (off light) deviates from the projection optical system 60. Head to the predetermined position.

  The image light generated by the modulation operation of the DMD 50 enters the projection optical system 60 and is projected on the screen by the projection optical system 60.

  Since the color wheel 21 rotates at a very high speed, the switching between the segments 21W, 21C, 21B, 21G, 21Y, and 21R is performed at a very high speed. For this reason, the image | video by each light sequentially projected on the screen is projected on a user's eyes as one image | video.

  The color sensor 70 is arranged on the optical path of the off light from the DMD 50. Off light from the DMD 50 is incident on the color sensor 70. The color sensor 70 includes three photodiodes each having sensitivity to R light, G light, and B light, and a light reception signal corresponding to the chromaticity of incident light is output from each photodiode.

  FIG. 2 is a diagram showing a configuration of a circuit system of projector 1 according to the present embodiment.

  The input switching circuit 101 is a circuit that switches an input terminal to be connected from among a plurality of input terminals. A video signal is input from an input terminal connected by the input switching circuit 101. When the input video signal is an analog signal, it is converted into a digital signal by the A / D converter 102 and input to the correction circuit 103. When the input video signal is a digital signal, it is passed through the A / D converter 102. Without being input to the correction circuit 103.

  The correction circuit 103 performs various correction processes such as scaling correction (correction of the number of pixels) and gamma correction. The video signal output from the correction circuit 103 is input to the synchronization circuit 104 and also input to the video signal processing circuit 105.

  The synchronization circuit 104 extracts a vertical synchronization signal (Vsync) from the video signal and outputs it to the video signal processing circuit 105 and the delay circuit 107.

  The video signal processing circuit 105 generates a DMD control signal for each pixel (micromirror) of the DMD 50 to perform a modulation operation from the input video signal, and outputs the DMD control signal to the DMD driver 106. The DMD driver 106 drives the DMD 50 according to the DMD control signal. The DMD control signal is a signal in which the gradation is determined for each pixel of the DMD 50, and is configured by a control signal that matches the segment configuration of the color wheel 21, for example, the WCBGYR segment.

  The delay circuit 107 delays the input vertical synchronization signal according to the set index value, and outputs a delayed vertical synchronization signal (Delay VSync) (hereinafter referred to as “delay synchronization signal”) to the motor control circuit 108.

  An index signal is input from the position sensor 23 to the motor control circuit 108. The motor control circuit 108 generates a motor control signal based on the index signal so that the index signal is synchronized with the delay synchronization signal, and outputs the motor control signal to the motor driver 109. The motor driver 109 drives the motor 22 according to the motor control signal.

  As a method for controlling the rotation of the motor 22, for example, PWM control is used. The motor driver 109 is provided with a rotation sensor that detects that the motor 22 has rotated by a certain rotation angle, and a detection signal from the rotation sensor is input to the motor control circuit 108 as a rotation speed signal. The motor control circuit 108 adjusts the amount of current applied to the motor 22 so that the rotation speed obtained from the rotation speed signal becomes a desired rotation speed.

  The CPU 110 controls the delay circuit 107 and the video signal processing circuit 105, and executes an index adjustment process described later. Further, the CPU 110 acquires light reception signals from the three photodiodes of the color sensor 70 in the index adjustment process, and the color purity of light incident on the color sensor 70 from the acquired light reception signals, for example, chromaticity (x value, y Value). Then, the index value is adjusted using the obtained chromaticity, and the index value obtained by the adjustment is set in the delay circuit 107.

  FIG. 3 is a diagram showing the drive timing of the color wheel unit 20 and the DMD 50. As shown in FIG.

  As shown in FIG. 3, in the present embodiment, DMD control corresponding to W light, C light, B light, G light, Y light and R light from the video signal processing circuit 105 in synchronization with the vertical synchronization signal. Signals are output sequentially. In the present embodiment, one frame of DMD control signal is output twice during one period of the vertical synchronization signal. In accordance with this, the rotation speed of the color wheel 21 is set so that the color wheel 21 rotates twice during one cycle of the vertical synchronization signal.

The length (output time) of the DMD control signal corresponding to each color light is set according to the angle of the corresponding segment 21W, 21C, 21B, 21G, 21Y, 21R, and the color wheel 21 is set to the set rotation. When rotating at a speed, white light from the light source lamp 10 passes through the segments 21W, 21C, 21B, 21G, 21Y, and 21R only to the segments 21W, 21C, 21B, 21G, 21Y, and 21R. A corresponding DMD control signal is output.

  The delay synchronization signal (Delay VSync) is output at a timing delayed by a certain delay time from the vertical synchronization signal (VSync), and the color wheel 21 rotates so that the index signal is synchronized with the delay synchronization signal.

  The delay time is set such that when the index signal is synchronized with the delay synchronization signal, the rotational position of each segment 21W, 21C, 21B, 21G, 21Y, 21R is synchronized with the corresponding DMD control signal. . The delay time has a one-to-one correspondence with the index value set in the delay circuit 107, and is set to a time corresponding to the index value. The delay time can be adjusted in the range of 0 to a predetermined time (for example, the time required for the color wheel 21 to rotate 180 ° at the set rotation speed), and the index value is also a predetermined range corresponding thereto. (For example, 0 to 360) can be adjusted.

  Since the relationship between the index signal and the rotation position of each segment is determined by the mounting position of the marker 21a and the position sensor 23 in the color wheel unit 20, the delay time (index value) is also determined thereby. However, manufacturing errors may occur in the attachment positions of the marker 21a and the position sensor 23. As a result, there is a possibility that the relationship between the index signal and the rotational position of each segment is shifted. Therefore, when the delay time is fixed, the rotation timing of the color wheel 21 and the output timing of the DMD control signal to the DMD 50 may not be properly synchronized.

  Therefore, in the present embodiment, an index adjustment process for adjusting the index value, that is, the delay time to an appropriate value, is executed under the control of the CPU 110. Hereinafter, the index adjustment process will be described in detail.

  FIG. 4 is a flowchart showing a control operation related to the index adjustment process. FIG. 5 is a diagram for explaining an operation for obtaining an optimum index value.

  The index adjustment process is executed when a predetermined operation is performed using the operation buttons. For example, the index adjustment process can be executed by an operator's operation when a projector is manufactured in a factory. Further, when the user replaces the color wheel unit 20 by himself / herself, the operation can also be executed by the user's operation.

  Referring to FIG. 4, CPU 110 causes video signal processing circuit 105 to generate a raster pattern (test image) composed of a single red color and project it onto the screen (S101). In this case, only the DMD control signal (hereinafter referred to as “R signal”) corresponding to the R light is output from the video signal processing circuit 105 at the output timing of the R signal. Note that data relating to the raster pattern is stored in advance in a memory (not shown).

  If the index value is not appropriate, light other than the R light is irradiated onto the DMD 50 during the period in which the R signal is output, so that the raster pattern does not become pure red and its color purity is low. In the case of a red raster pattern, the x value in the chromaticity (x value, y value) increases as the color purity increases. As the index value approaches an appropriate value, the amount of R light emitted to the DMD 50 increases during the period in which the R signal is output, and the color purity increases accordingly. Is getting bigger. When the index value reaches an optimum value, only the R light is irradiated onto the DMD 50 during the period in which the R signal is output, so that the raster pattern becomes pure red. At this time, the color purity of the raster pattern reaches a peak, and the x value becomes the largest. As shown in FIGS. 5A to 5C, when the index value is changed within the adjustment range, a peak of color purity, that is, a peak of x value appears.

  The CPU 110 performs the following steps S102 to S106 to obtain an index value at which the color purity reaches a peak for the red raster pattern.

  First, as shown in FIG. 5A, the CPU 110 equally divides the adjustment range of the index value into four, and the five points (P1 to P5) of the minimum point, the maximum point of the index value, and points on the three dividing lines. ) Are sequentially set in the delay circuit 107. At each point, three light reception signals from the color sensor 70 are acquired, and chromaticity (x value, y value) is obtained based on these light reception signals (S102). For example, a predetermined arithmetic expression or a look-up table can be used to obtain chromaticity from the received light signal.

  When the image sensor (ON light) based on the raster pattern projected onto the screen is detected by the color sensor 70, the x value increases as the color purity of the raster pattern increases. However, in the present embodiment, the color sensor 70 receives off-light from the DMD 50 when the raster pattern is projected. For this reason, the higher the x value of the raster pattern on the screen, the smaller the off light x value obtained from the light reception signal of the color sensor 70.

  The CPU 110 extracts, from among the five index values, an index value that maximizes the x value of the raster pattern, that is, minimizes the off light x value (S103). And as shown in FIG.5 (b), in the point before and behind the extracted index value (P3), and two points (P6, P7) of the half interval of the measurement points (P2, P4) before and behind the last time. Similarly to step S102, chromaticity (x value, y value) is obtained (S104).

  Next, the CPU 110 extracts from the three index values (P6, P3, P7) an index value that maximizes the x value of the raster pattern (minimizes the x value of off-light) (S105). .

  Next, the CPU 110 determines whether or not the resolution of the index value is minimized (S106). For example, when the index value is set in increments of 1, the three index values are consecutive integers, and it is determined that the resolution is minimized when the next two points before and after cannot be taken.

  If the CPU 110 determines that the resolution is not minimum (S106: NO), the CPU 110 returns to the process of step S104, and again, as shown in FIG. 5C, again two points before and after the extracted index value (P3) (P8, In P9), chromaticity (x value, y value) is obtained (S104).

  In this way, the processing of steps S104 to S106 is repeated until it is determined in step S106 that the resolution of the index value is minimized. As a result, the raster pattern approaches the index value at which the color purity of the raster pattern reaches a peak. Eventually, as shown in FIG. 5 (d), when the three index values become continuous integers and the resolution of the index values becomes minimum (S106: YES), the CPU 110 calculates the index value (Pn) extracted last. An index value at which the color purity reaches a peak, that is, an optimum index value is set in the delay circuit 107 (S107). Then, the projection of the raster pattern is stopped by the video signal processing circuit 105 (S108), and the process is terminated.

  FIG. 6 is a diagram for explaining the effect of the present embodiment.

According to the present embodiment, the index value (delay time) is adjusted by the index adjustment process. For example, as shown in FIG. 6A, when the position of the marker 21a is shifted to the C segment side from the boundary position between the C segment and the B segment, which is the design position, the index value (delay time) becomes the value of the design position. A value (short time) T1 smaller than (time) T0 is set. Further, as shown in FIG. 6B, when the position of the marker 21a is shifted from the design position to the B segment side, the index value (delay time) is larger than the design position value (time) T0 (long time). ) Set to T2. As a result, a manufacturing error occurs in the attachment position of the marker 21a and the position sensor 23, and even if the relationship between the index signal and the rotation position of each segment is shifted, the rotation timing of the color wheel 21 and the DMD to the DMD 50 are detected. The output timing of the control signal can be properly synchronized. Therefore, it is possible to maintain good image quality.

  Further, according to the present embodiment, the index adjustment process is performed using the color sensor 70 built in the projector main body. Therefore, unlike the configuration in which the color sensor is separately connected to the projector during adjustment, the index value is adjusted not only when the projector 1 is manufactured, but also when the user replaces the color wheel unit 20 himself. It can be carried out. Therefore, synchronization between the rotation timing of the color wheel 21 and the output timing of the DMD control signal to the DMD 50 can be more appropriately optimized.

  Further, in the present embodiment, the color sensor 70 is arranged on the optical path of the off light from the DMD 50, so that the index adjustment process is performed using the off light that is the reverse characteristic of the on light. During normal operation, the color sensor 70 does not hinder the image light (ON light) projected on the screen.

  Although the present embodiment has been described above, in the same way as the above embodiment, by detecting the peak of the color purity of the raster pattern, not only the adjustment of the index value but also the genuine color wheel unit 20 is mounted. It is also possible to identify whether or not it is present. If the CPU 110 identifies that the color wheel unit 20 is not a genuine product, for example, the CPU 110 stops the control for adjusting the index value.

  Hereinafter, the first identification process and the second identification process will be described.

  First, the first identification process will be described. In the first identification process, whether or not the color wheel unit 20 is a genuine product is identified by determining whether or not the angles of the R, G, and B segments 21R, 21G, and 21B are appropriate.

  FIG. 7 is a flowchart showing a control operation related to the first identification process. 8 and 9 are diagrams showing chromaticity change characteristics with respect to index values when a red raster pattern is projected. FIG. 8A shows a change characteristic when the color wheel unit 20 is a genuine product, and FIG. 8B shows a change characteristic when the angle of the R segment 21R is smaller than the genuine product. FIG. 8C shows the relationship between the R segment 21R and the R signal when the color purity peak occurs when the angle of the R segment 21R is smaller than the genuine product. FIG. 9A shows the change characteristics when the color wheel unit 20 is a genuine product, and FIG. 9B shows the change characteristics when the angle of the R segment 21R is larger than the genuine product. FIG. 9C shows the relationship between the R segment 21R and the R signal when the color purity peak occurs when the angle of the R segment 21R is larger than the genuine product.

Referring to FIG. 7, CPU 110 causes video signal processing circuit 105 to generate a raster pattern (test image) composed of a single red color and project it onto the screen (S201). Next, the CPU 110 detects the peak of the color purity of the raster pattern (S202). In step S202, processing similar to that in steps S102 to S106 in the index adjustment processing of FIG. 4 is executed. As will be described later, when color purity peaks are continuous, the x values of the three points may be the same in the same processing as S105. In this case, the index value of the center point is extracted as the index value having the maximum x value.

  Here, when the color wheel unit 20 mounted on the projector is not a genuine product and the angle of the R segment 21R is smaller than the genuine product, as shown in FIG. Even if the output timing of the DMD control signal is properly synchronized, light other than the R light is emitted to the DMD 50 during the output period of the R signal. For this reason, the color purity of the raster pattern is low, and as shown in FIG. 8B, the x value when the color purity is a peak is smaller than that of the genuine product shown in FIG.

  As described above, the x value obtained from the light reception signal of the color sensor 70 by the CPU 110 is the off-light value. For this reason, when the angle of the segment 21R is smaller than the genuine product, the value of the chromaticity x is larger in the off-light value than in the genuine product.

  The CPU 110 determines whether or not the peak value of color purity is comparable to that of a genuine product by comparing the x value of the off light with a predetermined threshold (S203). Here, since the x value when the color purity is a peak differs depending on the angle of the R segment 21R of the genuine color wheel unit 20 and the spectral characteristics of the segment, the threshold is set in consideration of these conditions. The When the x value of the off light is larger than the threshold value, it can be determined that the peak value of the color purity is not the same level as that of the genuine product.

  If the angle of the R segment 21R is smaller than the genuine product and the CPU 110 determines that the peak value of the color purity is not the same as that of the genuine product (S203: YES), an OSD display indicating that the color wheel unit 20 is not a genuine product. The notification is made by voice (S205). On the other hand, when the angle of the R segment 21R is appropriate and the CPU 110 determines that the peak value of the color purity is comparable to that of the genuine product (S203: NO), it is determined whether or not the peak of the color purity is continuous. Is determined (S204).

  When the color wheel unit 20 mounted on the projector is not a genuine product and the angle of the R segment 21R is larger than the genuine product, as shown in FIG. Since the R light is irradiated onto the DMD 50 over the entire output period of the R signal, as shown in FIG. 9B, the color purity peaks are continuous, that is, there are a plurality of maximum x values. (In the case of the x value of off-light, there are a plurality of minimum values).

  If the angle of the R segment 21R is larger than the genuine product, and the CPU 110 determines that the peak of color purity is continuous (S204: YES), the OSD display or voice alerts that the color wheel unit 20 is not a genuine product. (S205).

  On the other hand, if the CPU 110 determines that the peak of the color purity is not continuous because the angle of the R segment 21R is appropriate (S204: NO), the CPU 110 returns to step S201 and processes the raster pattern composed of a single green color as a video signal process. It is generated by the circuit 105 and projected onto the screen. In this case, only the DMD control signal corresponding to the G light is output from the video signal processing circuit 105 at the output timing of this DMD control signal.

  Next, the CPU 110 performs the processing of steps S202 to S204 as in the case of the red raster pattern. If the angle of the G segment G21 is different from that of the genuine product, the CPU 110 determines that the peak value of the color purity of the raster pattern is not the same as that of the genuine product, or if the peak of the color purity is determined to be continuous. The color wheel unit 20 is notified by OSD display or voice that the color wheel unit 20 is not genuine (S205).

  In the case of a green raster pattern, the y value in the chromaticity (x value, y value) becomes maximum when the color purity of the raster pattern reaches a peak. In this case, the y value of the off-light is minimum. Therefore, in step S203, if the y value of the off-light is larger than the corresponding threshold value, it is determined that the peak value of color purity is not the same as that of the genuine product. In step S204, if there are a plurality of minimum values of the y value of the off-light, it is determined that the peak of color purity is continuous.

  If the angle of the G segment 21G is appropriate, the CPU 110 returns to step S201 again, causes the video signal processing circuit 105 to generate a raster pattern composed of a single blue color, and projects it onto the screen. In this case, only the DMD control signal corresponding to the B light is output from the video signal processing circuit 105 at the output timing of this DMD control signal.

  The CPU 110 performs the processing from step S202 to S204 as in the case of the red and green raster patterns. If the angle of the B segment B21 is different from that of the genuine product, the CPU 110 determines that the peak value of the color purity of the raster pattern is not the same as that of the genuine product, or if the peak of the color purity is determined to be continuous. The color wheel unit 20 is notified by OSD display or voice that the color wheel unit 20 is not genuine (S205).

  In the case of a blue raster pattern, the x value or y value in the chromaticity (x value, y value) becomes minimum when the color purity of the raster pattern reaches a peak. In this case, the x value or y value of the off light is maximized. Therefore, in step S203, for example, if the y value for off-light is smaller than the corresponding threshold value, it is determined that the peak value of color purity is not comparable to that of a genuine product. Further, in step S204, for example, if there are a plurality of maximum off-light y values, it is determined that the peak of color purity is continuous.

  In this way, when the angle of the B segment 21B is appropriate and projection of all raster patterns of red, green, and blue is finished (S206: YES), the process ends.

  If the three RGB segments 21R, 21G, and 21B are appropriate and the main segments are appropriate, the color wheel unit 20 is considered to have a high probability of being a genuine product. However, if it is desired to further improve the identification accuracy when there are other color segments of RGB, it may be further determined whether or not the angles of the other color segments are appropriate.

  Next, the second identification process will be described. In the second identification process, whether the color wheel unit 20 is a genuine product is identified by detecting the number of segments.

  FIG. 10 is a flowchart illustrating a control operation according to the second identification process. FIGS. 11A, 11B, and 11C are diagrams illustrating chromaticity change characteristics with respect to index values when a red raster pattern, a green raster pattern, and a blue raster pattern are projected, respectively. is there. FIGS. 12A, 12B, and 12C show change characteristics of the once-differential value of chromaticity with respect to the index value when a red raster pattern, a green raster pattern, and a blue raster pattern are projected, respectively. FIG. 11 and 12 show a case where a color wheel unit having four RGBW segments is mounted.

Referring to FIG. 10, CPU 110 first causes video signal processing circuit 105 to project a red raster pattern (S301). Then, while changing the index value, the chromaticity (x value, y value) of the raster pattern at each index value (actually, the chromaticity of the off-light) is obtained (S302). Similarly, the chromaticity of the raster pattern at each index value is determined for the green raster pattern and the blue raster pattern (S301, S302). When the chromaticity measurement is completed for all the red, green, and blue raster patterns (S303: YE)
S) The CPU 110 counts the number of color purity peaks based on the chromaticity at all index values (S304).

  When a red raster pattern is projected, the DMD 50 is irradiated not only with R light but also with other segments adjacent to the R segment 21R during the output period of the R signal by changing the index value. The For example, as shown in FIG. 11A, when the DM light 50 is irradiated with G light or W light, not only the red color purity peak (Q2) but also the green color purity peak (Q1) or white color. The peak of purity (Q3) can be detected by the CPU 110.

  Similarly, when a green raster pattern is projected, not only the green color purity peak (Q5) but also the blue color purity peak (Q4) and the red color purity as shown in FIG. 11B. The peak (Q6) can be detected by the CPU 110. Furthermore, when a blue raster pattern is projected, the CPU 110 detects not only the blue color purity peak (Q7) but also the green color purity peak (Q8) as shown in FIG. 11C. obtain.

  In these color purity peaks, peaks appear at least in both the x value and the y value. When the change curves of the x value and the y value shown in FIG. 11 are differentiated once, the x value and the y value have peaks in the change curves of the single differentiation shown in FIGS. 12 (a), 12 (b), and 12 (c). The index value is “0”.

  In step S304, the following processing is performed. That is, the CPU 110 first extracts an index value having a value of “0” in the change curve of the first derivative. In the example shown in FIGS. 11 and 12, index values of eight peaks Q1 to Q8 are extracted.

  Next, the CPU 110 extracts index values having the same x value and y value from the extracted index values. For example, if the difference between the x value and the y value is within a range of ± 0.025, the x value and the y value are regarded as the same value. In the examples shown in FIG. 11 and FIG. 12, the peak values of Q1 and Q5, the peaks of Q2 and Q6, and the peak values of Q4 and Q7 are considered to be the same. The CPU 110 counts the peaks having the same x value and y value as one, and calculates the number of peaks. In the example shown in FIGS. 11 and 12, the number of color purity peaks is four. Thus, the CPU 110 determines that the number of segments of the color wheel unit 20 currently mounted on the projector is four.

  Next, the CPU 110 determines whether or not the obtained peak number of color purity, that is, the number of segments is the same as the number of segments of genuine products (S305). Since the wheel unit 20 is considered to be a genuine product, the processing is terminated as it is. On the other hand, if they are not the same (S305: NO), the CPU 110 notifies that the color wheel unit 20 is not a genuine product by OSD display or voice (S306).

  In this way, if the first identification process and the second identification process are performed, it is possible to identify whether or not the genuine color wheel unit 20 is mounted on the projector. Thereby, it is possible to prevent an inappropriate color wheel unit 20 from being used, and to maintain an appropriate image quality.

  Although the present embodiment has been described above, the present invention is not limited to the above embodiment, and the embodiment of the present invention can be variously modified in addition to the above embodiment. is there.

For example, in the above embodiment, the peak of color purity is narrowed down from the entire adjustment range of the index value. However, it is considered that the possibility that the marker 21a and the position sensor 23 are greatly deviated from the design position is low. For this reason, if priority is given to shortening the adjustment time, narrowing down of the peak of color purity is started from a range close to an index value when the marker 21a and the position sensor 23 are attached to the design position. Anyway.

  In the above embodiment, index adjustment processing is performed using a raster pattern of a single red color. However, the present invention is not limited to a single red raster pattern, and a single green raster pattern or a single blue raster pattern may be used. In this case, when the color purity of the green raster pattern reaches a peak, the y value in the chromaticity (x value, y value) is maximized. Therefore, when the green raster pattern is used, the y value of the raster pattern is used. It is preferable to detect an index value at which the color purity reaches a peak depending on whether or not is the maximum (the y value of the off-light is minimum). Further, when the color purity of the blue raster pattern reaches a peak, the x value or the y value in the chromaticity (x value, y value) is minimized, so that when the blue raster pattern is used, the raster pattern The index value at which the color purity reaches a peak may be detected based on whether the x value or y value is minimum (the x value or y value of off light is maximum).

  Further, in the above embodiment, the color sensor 70 is arranged on the optical path of the off light from the DMD 50. However, the present invention is not limited to this, and a light-shielding shutter that opens and closes the optical path of the image light is provided between the exit side of the projection optical system 60 and between the DMD 50 and the projection optical system 50, so The color sensor 70 may be arranged. In this case, when the index adjustment process is performed, the light shielding shutter is closed, and the color sensor 70 is arranged on the optical path of the image light. In this way, during normal operation, the color sensor 70 does not hinder the image light, and the chromaticity (x value, y value) of the image light based on the raster pattern is actually determined by the color sensor. 70 can be detected.

  Furthermore, in the above embodiment, the color wheel unit 20 composed of six RGBWYC segments is used. However, the color wheel unit 20 is not limited to this, and for example, a color composed of four RGBW segments or three RGB segments. A wheel unit 20 may be used.

  Furthermore, although DMD50 is used as a display element in the said embodiment, it is not restricted to this, For example, a reflective liquid crystal panel may be used.

  Furthermore, the present invention can be applied to a projector other than a projector including one light source lamp and a color wheel unit. For example, the present invention can be applied to a projector having a configuration in which two color wheel units are arranged in each optical path from two light source lamps. Also, the present invention can be applied to a projector having a configuration in which two color wheel units are arranged in the front-rear direction in the optical path from the light source lamp.

  In addition, various modifications can be made as appropriate within the scope of the technical idea shown in the claims.

20 Color wheel unit 21 Color wheel 21 W W segment 21 C C segment 21 B B segment 21 G G segment 21 Y Y segment 21 R R segment 22 Motor 23 Position sensor (position detection unit)
50 DMD (display element)
70 Color sensor (color detector)
105 Video signal processing circuit (signal processing unit)
107 delay circuit (signal delay unit)
108 Motor control circuit (motor control unit)
110 CPU (adjustment unit)

Claims (6)

In a projection display device,
A plurality of segments of different colors are arranged in the rotation direction, and by these segments, the color wheel that separates the white light from the light source into a plurality of colors in a time-sharing manner,
A motor for rotating the color wheel;
A position detection unit that detects a rotation reference position provided in the color wheel and outputs a position detection signal;
A motor control unit for controlling the motor based on the position detection signal;
A display element for modulating light of each color separated by the color wheel;
A signal processing unit that generates a control signal for causing the display element to perform a modulation operation according to the light of each color;
A color detection unit that outputs a color detection signal corresponding to the chromaticity of the light emitted from the display element;
Based on the color detection signal, the timing at which the light of each color is irradiated on the display element and the timing at which the control signal corresponding to the light of each color is output from the signal processing unit are synchronized. An adjustment unit for adjusting the output timing of the position detection signal;
A projection-type display device comprising: The projection display device according to claim 1,
The adjustment unit acquires the color detection signal from the color detection unit in a state where video light based on a single-color test image is emitted from the display element, and based on the acquired color detection signal, the test image Adjusting the output timing of the position detection signal so that the color purity is maximized;
A projection display device characterized by that. The projection display device according to claim 2,
The signal processing unit outputs the control signal in synchronization with a vertical synchronization signal,
Furthermore, a signal delay unit that delays the vertical synchronization signal by a set delay time and outputs the delayed signal to the motor control unit,
The adjustment unit sets the delay time based on the color detection signal so that the color purity of the test image is maximized,
The motor control unit controls the motor so that the position detection signal is synchronized with the delayed vertical synchronization signal;
A projection display device characterized by that. The projection display device according to any one of claims 1 to 3,
In a state where image light based on a single color test image is emitted from the display element, the color detection signal is acquired from the color detection unit, and the color purity of the test image is acquired based on the acquired color detection signal. A determination unit for determining the suitability of the color wheel based on the acquired color purity;
A projection display device characterized by that. The projection display device according to claim 4,
The adjustment unit does not adjust the output timing of the position detection signal when the determination unit determines that the color wheel is not appropriate.
A projection display device characterized by that. The projection display device according to any one of claims 1 to 5,
The display element is a DMD (digital micromirror device),
The color detection unit is irradiated with off-light from the DMD.
A projection display device characterized by that.

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