JP2005275078A - Method for controlling color temperature by using color wheel, and image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily control color temperature by suppressing the reduction of brightness at the time of controlling the color temperature in a method for controlling the color temperature of a display image displayed on an image display device by using a color wheel. <P>SOLUTION: The color wheel capable of changing the rates of respective colors occupying a circumference in accordance with distances from the center 9 of the color wheel is used. The color temperature of a display image displayed on the image display device using the color wheel can be controlled by changing the position of an optical spot 8 with which the color wheel is irradiated and a distance from the center 9 of the color wheel, therefore by changing the relative display time of respective colors. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a color temperature adjustment method in an image display device using a spatial light modulator (SLM) and a color wheel.

An image display device using a spatial light modulator (SLM) provides an image by selectively providing light. The digital micromirror device (DMD) is a type of SLM, and has thin-film square mirrors (micromirrors) regularly formed on a semiconductor address circuit chip at a level of several hundred thousand or more. Each mirror is suspended in space by one or more hinges, and these mirrors are selectively tilted by electrostatic attraction generated on the control circuit. Micromirrors usually tilt in the diagonal direction to +10 degrees or -10 degrees to achieve an electrical and mechanical stable state, and either tilt angle is switched at high speed. By incorporating DMD into a suitable light source and optical system equipment, an image display device that sequentially provides light at each pixel in the screen is formed.
In an image display device equipped with a DMD, the light emitted from the light source to the DMD is selectively reflected to the image plane by a micromirror that is selectively tilted based on the image data loaded in the memory cell of the DMD. Or reflected to deflect from the image plane. At this time, each mirror projects light corresponding to one pixel of the image. Normally, the irradiation light from the light source is incident on the DMD at an angle of 20 degrees, and if the micromirror is on, the light is irradiated toward the projection lens, and the pixels in the display image are displayed brightly. On the contrary, if the micromirror is in the off state, the irradiation light is reflected at an angle of −40 degrees, so that the projection lens is not irradiated and the pixels in the display image are displayed darkly. An image display device including an SLM including a DMD provides a display image by sequentially irradiating light for each pixel.
In an image display device equipped with an SLM, as one method for obtaining a color image, the color light filtered by the color wheel divided into red (R), green (G), and blue (B) segments is displayed in a time-sharing manner. There is a method for obtaining a color image. When the image data in one frame of the display image is displayed, the light from the light source irradiated to the SLM is filtered by the segment color of the color wheel, and sequentially becomes R, G, B color light to the SLM. Irradiated. The color light sequentially irradiated to the SLM is selectively reflected on the image plane by the image data, and displays R, G, and B colors on each pixel. At this time, different colors of R, G, and B are sequentially displayed in each pixel so that an appropriate color can be recognized.
In an image display device equipped with an SLM, as a method of obtaining color light having only a specific wavelength from light emitted from a light source when obtaining a color image, the light source is irradiated from a light source in addition to the transmission type color wheel. A method of sequentially obtaining two or more types of colored light by having two or more types of segments that reflect only a specific wavelength with respect to the light that is emitted from a light source by using a cylindrical type color wheel instead of a disc type There is also a method of obtaining two or more kinds of colored light by filtering or reflecting the reflected light. In recent years, there is also a method called “SCR (Sequential Color Recapture)”, which allows the SLM to irradiate three colors of color light simultaneously by making the arrangement of R, G, B of the color wheel spiral. In the embodiment of the present invention, an image display device having an SLM using a transmissive and disc type color wheel is mainly taken up. According to the true object of the present invention, a method of obtaining colored light from light from a light source Can be applied in any of the above methods.
The color gradation in each pixel can be obtained by accurately time-division displaying each color light of R, G, B displayed on the screen. That is, each pixel can perform 256-level luminance display including no display time (0) of each color corresponding to black display in each color, and full color display can be achieved by combining color lights of a plurality of luminance levels.
As a method for changing the color tone in an image display apparatus (such as a DLP projector) using a color wheel, mainly a color temperature adjustment method, there is “Japanese Patent Laid-Open No. 9-12743”. This color temperature adjustment method adjusts the relative display time for each color displayed sequentially to adjust the color temperature in the image, and the following two methods are mentioned as this color temperature adjustment method. Note that the standard color wheel in the following has three segments R, G, and B, and each segment has a 120-degree arc.
a) The color temperature is adjusted by relatively increasing the display time of other colors by reducing the display time of one or more colors by black display.
b) Increasing the percentage of a color on the circumference of a standard color wheel (and consequently reducing the percentage of other colors on the circumference) The color temperature is adjusted by reducing the color display time.
In addition, in the image display technology for the image display device using the color wheel, Nobuo Nishida Responsible Editing "Advanced Display Technology (Volume 7) Large Screen Display" Kyoritsu Publishing, May 25, 2002, p.62-72 etc. By reference, it is believed that it will help a deeper understanding of the present invention.

Japanese Patent Laid-Open No. 9-127436 (column 8, lines 20 to 35 and FIG. 3) Japanese Patent Laid-Open No. 9-127436 (column 3, lines 2 to 20 and FIG. 2) Nobuo Nishida Responsible Editing “Advanced Display Technology (Volume 7) Large Screen Display” Kyoritsu Shuppan, May 25, 2002, p.62-72

The above color temperature adjustment method has the following problems. In a), since the display time of a certain color is reduced by black display, as a result, the brightness of the entire screen is reduced when the color temperature is adjusted.
In b), the color temperature is physically adjusted by increasing or decreasing the arcs of the segments in the color wheel in order to customize the color temperature for different markets. However, after creating an image display device equipped with a color wheel with each segment size increased or decreased, when adjusting the color temperature without reducing the brightness, it is equipped with a color wheel with a different segment size for each color. The color wheel must be replaced, and the replacement work requires time and dedicated equipment, which imposes a heavy burden on the user.

An object of the digital display device is to allow the user to easily adjust the color temperature to a favorite color by using the same color wheel to suppress a decrease in luminance of the entire screen as much as possible. That means
In color temperature adjustment technology for digital display using color wheel
i) a color wheel in which the ratio of the circumference of each color in the circumferential direction (rotation direction) to the circumference is continuously changed according to the distance from the center;
ii) a color wheel central axis moving device for changing the distance of the light spot formed on the color wheel from the center of the color wheel or an optical system device for moving the irradiation position of the light spot formed on the color wheel;
iii) Equipped with a device that continuously increases or decreases the display time according to the ratio of the light spot formed on the color wheel to the circumference of each color that continuously changes depending on the distance from the center of the color wheel. And a color temperature adjusting method and an image display device using the color temperature adjusting method. That is, in an image display device that performs digital display using a color wheel, the center of the color wheel having the characteristics of i) is translated in the direction perpendicular to the light beam that forms the light spot by the device described in ii). The position of the light spot is moved outward (or inward) on the color wheel. As a result, the color temperature is adjusted by increasing or decreasing the relative display time of each color according to the ratio of each color to the circumference. Further, not only the center position of the color wheel is moved, but also the light spot irradiation position optically formed on the color wheel is moved so that the center axis of the color wheel is moved in the same manner as in the method of moving the center axis of the color wheel. The color temperature is adjusted by changing the relative display time. At this time, a device iii) for increasing / decreasing the display time of each color of the pixel data with respect to the input image in accordance with the display time in the unit time of each color, which varies depending on the ratio of each color to the circumference, which varies depending on the distance from the center, is necessary. It is.
It should be noted that the shape and size of the segment for changing the ratio of each color in the circumferential direction in i) is not limited.

In the color temperature adjustment in the digital display using the color wheel, the color temperature can be continuously adjusted using the same color wheel without inserting the black display time. Therefore, it is possible to suppress a decrease in luminance of the entire image at the time of color temperature adjustment as seen in the above color temperature adjustment method a), and color wheel replacement work necessary when performing color temperature adjustment without reducing the luminance as in b). Can reduce the burden on users.

Hereinafter, embodiments of the present invention will be described with reference to the drawings and tables.
[Example 1]
FIG. 1 is a conceptual diagram of the entire image display apparatus, and FIG. 2 shows an example of a color wheel that enables color temperature adjustment introduced in the present invention.
The light emitted from the light source 1 in FIG. 1 is collected and forms a light spot 3 in a color wheel 2 equipped with a motor. The light irradiated on the color wheel 2 is filtered by each segment in the color wheel 2 and becomes color light, which is irradiated on the image conversion device (DMD) 5. At this time, the color wheel 2 is rotated by a motor, and the color lights R, G, and B corresponding to each segment are sequentially irradiated to the image conversion device 5. The color light applied to the image conversion device 5 is adaptively reflected (or transmitted) by the image conversion device 5 with respect to each pixel of the input image, and sequentially projected onto the screen 7 through the projection lens 6 appropriately. .
The installation position of the color wheel 2 in the image display device can be installed behind the image conversion device 5. That is, the light emitted from the light source is applied to the image conversion device, and the light adaptively reflected by the image conversion device passes through the color wheel and is sequentially projected on the screen as color light.
Image data / signals are input to the signal interface 10. The image data / signal input to the signal interface 10 is subjected to appropriate processing such as A / D conversion and Y / C separation depending on the type of signal, such as analog video signal and digital graphic data, and the image data processor Sent to 11.
The image data sent to the image data processor 11 is processed by the image data processor 11 so that the image is properly displayed on the image display device. That is, tasks such as color space conversion for converting luminance / color difference signal YUV to RGB data, linear conversion for gamma correction, and line generation to interpolate interlaced data into one image are performed.
The display memory 12 appropriately provides 1-bit information for each pixel of the image conversion device 5 in the image data received from the image data processor 11. The display memory 12 has a built-in buffer memory and can own image data for at least two display frames. By so-called “ping-pong” in which the two buffers are controlled, the image data is continuously sent to the image conversion device 5, the motor built in the color wheel 2, and the light source 1. At this time, the image conversion device 5, the color wheel 2, and the light source 1 are controlled by the master 14 so as not to cause a phase shift in color display in each pixel in each image data. That is, the information for each pixel in each frame is associated with each color light emitted to the image conversion device 5, and the image conversion device 5 is switched ON / OFF (ON indicates the state of irradiation on the screen, and OFF indicates the screen. By controlling the rotation speed of the color wheel 2, the R, G, and B color lights are sequentially displayed on the screen as appropriate based on the image information. The viewer recognizes it as a desired color and recognizes it as a color image.
Various devices are controlled by the master 14 through the color temperature conversion device 13 so that the image on the image display device is displayed at the color temperature set by the user. When the color temperature setting of the display image is changed by the user, the color wheel 2 is moved parallel to the order of several degrees with respect to the light emitted from the light source 1 by the light spot moving device 15 and formed on the color wheel 2. The distance from the center of the light spot 3 and the color wheel 2 changes, or the distance from the center of the light spot 3 and the color wheel 2 changes optically by the light spot moving device 15, and the color temperature adjustment direction in the present invention Thus, the color temperature of the display image is adjusted.

Αb, βb, and γb in the color wheel shown in FIG. 2 indicate the segment B's circumferential arc as viewed from the center of the color wheel, which changes depending on the distance from the center of the color wheel, of the segment B that transmits blue light in the color wheel. Represents an angle. Similarly, αr, βr, and γr are the angles of the circumferential arc of segment R as seen from the center of the color wheel, which changes depending on the distance from the center of the color wheel of segment R that transmits red light, and αg, βg, and γg are green Represents the angle of the circumferential arc of the segment G as viewed from the center of the color wheel, which varies depending on the distance from the center of the color wheel of the segment G that transmits the light. Also, here, the diameter of this color wheel is 13 cm, the distance from the center of the color wheel of the circumferential arc corresponding to the circumference αb, αr, αg is 3 cm, the circumference corresponding to the circumference βb, βr, βg It is assumed that the distance from the color wheel center of the arc is 4 cm, and the distance from the color wheel center of the circumferential arc corresponding to the circumferences γb, γr, and γg is 5 cm.
The transmission characteristics of each segment in the color wheel of FIG. 2 are as follows: if the ratio of the display time of transmitted light in each segment is 1: 1: 1 for R, G, and B, the color characteristics of the displayed image Shall be consistent with the sRGB standard. That is, if the ratio of R, G, and B display times of the display device in FIG. 1 is 1: 1: 1, the color temperature of the color wheel introduced here has a display characteristic of 6500K. Therefore, the conversion formula from RGB to XYZ color space at this time is as follows.

  The chromaticity coordinates on the xy chromaticity diagram of each color in the image display device using the color wheel can be obtained by the following equation.

x = X / (X + Y + Z)
y = Y / (X + Y + Z) ・ ・ ・ ・ ・ Formula 2
Further, the angle of the circumferential arc in FIG. 2 in each segment of the color wheel shown in FIG. 2 is as follows.

αb = αr = αg = 120 ° ・ ・ ・ ・ ・ 1.1
βb = 140 °, βr = βg = 110 ° ・ ・ ・ ・ ・ 1.2
γb = 160 °, γr = γg = 100 ° ・ ・ ・ ・ ・ 1.3

Here, assuming that the angles of the circumferential arcs in the R, G, and B segments of the color wheel shown in FIG. 2 are φr, φg, and φb, respectively, and that the color wheel rotates T per second, the color wheel is 1 The time it takes to rotate is 1 / T second, and the displayable time of each color light that can be displayed per second is as follows.

Tr = (φr / 360) x (1 / T) x T (seconds)
Tg = (φg / 360) x (1 / T) x T (seconds)
Tb = (φb / 360) x (1 / T) x T (seconds)

(Tr, Tg, and Tb are the displayable times per second of colored light corresponding to the R, G, and B segments of the color wheel, respectively.)

That is,
Tr = (φr / 360) (seconds)
Tg = (φg / 360) (seconds) ・ ・ ・ ・ ・ Formula 3
Tb = (φb / 360) (seconds)
And become.
In the display device shown in FIG. 1, it is assumed that the light spot irradiated on the color wheel is irradiated on the circumferential arcs of αb, αr, and αg on the color wheel of FIG. At this time, according to 1.1 and Equation 3, the relative display time of each color light R, G, B when displaying all white is 1: 1: 1. From the light transmission characteristics of the color wheel, the displayed image The color temperature is 6500K.
Next, consider the case where the position of the light spot on the color wheel is moved on the circular arc of βb, βr, and βg on the color wheel of FIG. At this time, the relative display time of each color light of R, G and B at the time of all white display is 1.2: 11:11:14 according to Equation 3. Here, the relative values of X, Y, and Z are obtained from Equation 1, and the chromaticity coordinate at the white point is obtained from Equation 2, and the color temperature is derived to be 8000K. Similarly, when the light spot is moved on the circular wheel of γb, γr, and γg on the color wheel in FIG. 2, the relative light of each color of R, G, and B when displaying all white from 1.3 and Equation 3 above. The display time is 10:10:16, and the color temperature is 11000K. In addition, the color temperature with respect to the angle of the circumferential arc that changes depending on the distance from the circumference of each segment including the above three types, and the x and y coordinates at the white point on the xy chromaticity diagram are as follows: Become.

The color wheel described in FIG. 2 has each segment satisfying Table 1 above.

There are two methods for changing the distance of the light spot irradiated to the color wheel from the center of the color wheel.
1) The distance of the light spot formed on the color wheel from the center of the color wheel is changed by translating the central axis of the color wheel in a direction perpendicular to the light beam forming the light spot.
2) Optically move the irradiation position of the light spot formed on the color wheel to change the distance of the light spot from the center of the color wheel.

First, consider the case where the position of the light spot irradiated on the color wheel is moved by the method 1). That is, the color temperature in the image display device is adjusted as follows.
It is assumed that an image having a color temperature of 6500K is projected on the image display device provided with the color wheel (the color temperature is set to 6500K). At this time, if the color wheel central axis is moved by 1 cm in the direction perpendicular to the light beam forming the light spot and in the direction opposite to the light spot, the distance between the color wheel central axis and the light spot is 4 cm. Become. Therefore, an image having a color temperature of 8000K is obtained according to Table 1 above. Similarly, when the color wheel central axis is moved and the distance between the color wheel central axis and the light spot is changed to 5 cm and 6 cm, images having color temperatures of 11000K and 18000K are obtained from Table 1, respectively. It is done. Conversely, if the distance between the color wheel and the light spot is 2 cm, an image with a color temperature of 5400K can be obtained.
When the position of the light spot irradiated on the color wheel is optically moved by the method of 2), the distance from the light spot to the central axis of the color wheel is 2 cm, 3 cm, 4 cm, 5 cm, 6 cm as in 1). When the position of the light spot is moved so that the following can be obtained, images having color temperatures of 5400K, 6500K, 8000K, 11000K, and 18000K can be obtained from Table 1 above.
In the image display device provided with the color temperature adjusting method, each color light filtered by the color wheel is sequentially irradiated onto a screen or the like through the image conversion device, so that the viewer recognizes it as an image. At this time, by the color temperature adjustment method, the image conversion device is controlled in accordance with the relative irradiation time of the color light that changes according to the color temperature to the image conversion device, thereby corresponding to each pixel data in the image. It is necessary to control the irradiation time of each color light to the screen or the like.
Here is a simple example. In the image display device provided with the color temperature adjusting method, it is assumed that the color temperature is set to 6500K, and the image display device performs blue display. Assuming that the color wheel rotates T per second, the time for which the color wheel rotates once is 1 / T. At this time, when the color wheel makes one rotation from Table 1 and Formula 3, the time tb (65) during which the blue color light is applied to the image conversion device is:
tb (65) = (120/360) x (1 / T) ... 1.4
And become. Further, when the color temperature is set to 11000K in the image display device, the time tb (110) during which the blue color light is irradiated to the image conversion device when the color wheel rotates once from Table 1 and Equation 3 is as follows. ,
tb (110) = (160/360) x (1 / T) ...... 1.5
And become.
It is assumed that the number of gradations of each color displayed in the image display device is 8-bit 256 gradations, and the gradations of each color change at equal intervals. When the image display device performs blue display with the highest saturation (blue gradation in the image display device is 255), the image conversion device is irradiated during one rotation of the color wheel at color temperatures of 6500K and 11000K. The time tb (65,255) and tb (110,255) at which the reflected (or transmitted) blue color light is projected on the screen are calculated from 1.4 and 1.5, respectively.
tb (65,255) = (120/360) x (1 / T) x (255/255) ... 1.6
tb (110,255) = (160/360) x (1 / T) x (255/255) ... 1.7

And become. In addition, when projecting blue with intermediate saturation in the image display device (blue gradation in the image display device is 128) on the screen, the color wheel rotates once at a color temperature of 6500K and 11000K. The time tb (65,255) and tb (110,255) at which the blue color light irradiated and reflected (or transmitted) on the image conversion device is projected on the screen are calculated from 1.4 and 1.5, respectively.
tb (65,128) = (120/360) x (1 / T) x (128/255) ...... 1.8
tb (110,128) = (160/360) x (1 / T) x (128/255) ...... 1.9

And become.
From 1.6, 1.7 and 1.8, 1.9, even in the blue display of the same gradation in the image display device, if the color temperature is different, blue color light is irradiated on the screen during one rotation of the color wheel. The time required is different. Similarly, in the red display and the green display, if the color temperature is different even when the display has the same gradation, the time during which the color light is irradiated on the screen during one rotation of the color wheel is different. .
The image display device according to the present invention performs image conversion for controlling ON / OFF of the image conversion device corresponding to image data / signal according to a desired color temperature in order to set a projection image to a desired color temperature. It has a device control device.
In an image display device comprising a light spot position moving device using either the color wheel or the light spot position moving method, by reducing the display time of one or more colors by black display, There is no need to adjust the color temperature by increasing the display time of other colors. Therefore, it is possible to adjust the color temperature from 5400K to 18000K without reducing the brightness of the entire image as much as possible and without having to replace the color wheel. Note that the color wheel and the light spot moving method described here are examples for realizing the present invention and are not specified.

[Example 2]
The color temperature adjusting method according to the present invention is also applied to the SCR method, which is one type of image display using SLM. SCR technology is a method of improving the efficiency of using light emitted from a light source among image display technologies using SLM. Sequential Color Recapture and Dynamic Filtering: A Method of Scrolling Color (D. Scott Dewald, Steven M. Penn, and Michael Davis). SCR is a system that allows multiple colors of light to be applied to the SLM simultaneously by making the RGB arrangement of the color wheel spiral. Hereinafter, a brief description of the SCR method will be given.
The light emitted from the light source enters a device called an “integrator rod”. The integrator rod is a cylindrical or cylindrical device with a mirror inside, and the light exit surface of the integrator rod is equipped with a color wheel with an arrangement of spiral R, G, B color segments. . Only the light incident surface and the light exit surface of the integrator rod are open, and only the light that matches the R, G, and B surfaces of the color wheel can travel forward. Other light is repeatedly reflected in the integrator rod until the color matches. The color wheel rotates and the color light obtained by filtering by each color segment is irradiated to the SLM while changing the vertical (or left and right) position one after another, and selectively projected based on the image data By being reflected toward the lens, it is projected on the screen and recognized as an image. The integrator rod used in the SCR system can be replaced with any shape glass rod having the same internal reflection action.

FIG. 3 shows a simple conceptual diagram of an image display apparatus provided with an SCR system that can implement the color temperature adjusting method according to the present invention. The light emitted from the light source 16 enters the integrator rod 18 through the light incident surface 17. The light exit surface 19 of the integrator rod 18 is provided with a color wheel 20 having color segments of R, G, and B colors in which the proportion of the color in the circumference varies depending on the distance from the center. Of the incident light, only the light that matches the R, G, and B surfaces of the color wheel 20 travels forward. Other light is repeatedly reflected in the integrator rod 18 until the colors match. The color wheel 20 or the integrator rod 18 is provided with a moving device, and the moving device continuously changes the distance from the center of the color wheel 20 to the light emitting surface 19 of the integrator rod 18. Acts on the rod 18. The color wheel 20 rotates and the color light filtered by each color segment is irradiated to the image conversion device 22 while changing the position one after another, and is selected based on the image data / signal and the set color temperature. Are reflected and projected onto a screen to be recognized as an image.

FIG. 4 shows a color wheel 20 ′ in which the color temperature adjustment method according to the present invention can be carried out in the image display apparatus using the SCR system shown in FIG. The ratio of two or more kinds of colors in the color wheel 20 ′ to the circumference continuously changes depending on the distance from the center 25 of the color wheel 20 ′. Here, the color wheel 20 'satisfies the ratios of the circumferences of the R, G, and B colors on the circumferences 26, 27, and 28, respectively, 1: 1: 1, 11:11:14, and 10:10:16. It has color segments that draw a simple curve. In the color wheel 20 ′, the distance from the center 25 and the ratio of each color to the circumference satisfy Table 1 described in the first embodiment.
The dashed curve described along the curve forming the color segment in the color wheel 20 ′ and the curve forming the B segment in the clockwise direction as viewed from the B segment in the color wheel 20 ′ are The circumference at an arbitrary distance from the center 25 in the color wheel 20 ′ is equally divided. That is, when the color segments in the color wheel 20 ′ are formed by the broken curve and the curve in the clockwise direction as viewed from the B segment, the color lights R and G irradiated to the image conversion device 22 in FIG. The ratio of the irradiation time of B is always 1: 1: 1, and it is necessary to adjust the ratio of the irradiation time of R, G, B by black display when converting the color temperature of the display image.
As the transmission characteristics of each segment in the color wheel 20 ′, if the ratio of the display time of transmitted light in each segment is 1: 1: 1 in the same manner as the color wheel shown in FIG. Assume that the color characteristics of the image to be matched with the sRGB standard. That is, if the ratio of the display times of R, G, and B of the image display device in FIG. 3 is 1: 1: 1, the color temperature is assumed to be 6500K.
Assuming that the center of the light exit surface 29 of the integrator rod is provided on the circumference 27, the relative display time of R, G, and B at the time of all white projection in the image display device of FIG. 3 is 1: 1: 1. The color temperature of the displayed image becomes 6500K. In addition, when the center of the light exit surface 29 of the integrator rod on the circumference 28 is provided, the relative display time of R, G, B when displaying all white is 11:11:14, and the color temperature of the display image is 8000K. Become. When the center of the light exit surface 29 of the integrator rod is placed on the circumference 28, the relative display time of R, G, B when displaying all white is 10:10:16, and the color temperature of the display image is 11000K . Thereafter, as in the first embodiment, the color temperature in the display image can be changed by sequentially changing the distance from the center of the color wheel 20 ′ to the center of the light exit surface 29 of the integrator rod. Therefore, it is not necessary to adjust the ratio of the display time of each color light by inserting a black display in a certain color light, so that the color temperature in the display image can be adjusted without reducing the overall luminance.
In the second embodiment, an example in which a color wheel having three color segments of R, G, and B is used in the SCR system has been introduced. The invention is applicable.

In the first and second embodiments, the disk type transmission type color wheel is used to describe the embodiment of the present invention. However, if the true meaning of the present invention is understood, the color temperature adjusting method of the present invention is a disk. It will be understood that the present invention can be applied not only to the transmissive color wheel of the type but also to the image display device using the SLM having the transmissive color wheel of the cylindrical type.

[Example 3]
In the color light generating means for generating a plurality of types of color light from the light emitted from the light source, the color temperature shown in the present invention is not limited to that using a transmission type color wheel but also using a reflection type color wheel. Adjustment methods are applied. The reflection type color wheel has a plurality of types of color segments that reflect only a specific wavelength in the light emitted from the light source, thereby generating a plurality of color lights from the light emitted from the light source.
In the image display device provided with the reflection type color wheel having two or more kinds of color segments and the SLM, the proportion of each color in the circumference of the color segments provided on the reflection surface of the color wheel is the color wheel. By using a color wheel that changes depending on the distance from the center, it is possible to adjust the color temperature without reducing the luminance as in the image display device using the transmission type color wheel described in the first and second embodiments. An image display device can be obtained. The shape of the color wheel at this time is the same as that of the transmissive color wheel shown in FIG. 2, and each color segment may have a reflection characteristic, or other shapes may be used. A process similar to that described in the first and second embodiments is performed after the generation of the colored light until the image is generated.

In the embodiment of the color temperature adjustment method of the image display device using the color wheel for sequential color display in the present invention, an example using DMD which is a reflection type image conversion device as an image conversion device is taken up. The present invention can also be applied to an image display device using a color wheel having an SLM of another type such as a reflective liquid crystal or a transmissive liquid crystal. Further, the color temperature adjustment method in the present invention is not limited to the image display device based on SLM. In the image display device including the color light generation device that generates a plurality of types of color light from the light emitted from the light source, The present invention can be applied to an image display device provided with a color light generating device that accompanies rotation.

The schematic diagram showing the outline | summary of the whole apparatus showing the Example of this invention An example of a color wheel according to an embodiment of the present invention Schematic diagram showing the outline of the entire apparatus representing an embodiment of the present invention in the SCR system An example of a color wheel according to an embodiment of the present invention in the SCR system

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Light source, 2 ... Color wheel, 3 ... Light spot, 4 ... Lens, 5 ... Image converter (DMD), 6 ... Projection lens, 7 ... Screen, 8 ... light spot, 9 ... color wheel center, 10 ... signal interface, 11 ... pixel data processor, 12 ... display memory, 13 ... color temperature control device, 14 ... Master (timing device) 15 ... Light spot moving device 16 ... Light source 17 ... Light incident surface 18 ... Integrator rod 19 ... Light exit surface 20 ... Color wheel, 21 ... lens, 22 ... image conversion device (DMD), 23 ... projection lens, 24 ... screen, 25 ... center, 26 ... circumference, 27 ...・ Circle, 28 ... Circle, 29 ... Integre Position of light rod light exit surface, 30 ... signal interface, 31 ... pixel data processor, 32 ... display memory, 33 ... color temperature control device, 34 ... master (timing device), 35 ... Integrator rod light exit surface moving device

Claims (4)

Color light generating means for generating a plurality of types of color light from light emitted from a light source, wherein the ratio of the color light per unit time is continuously variable by changing a portion to which the emitted light is irradiated . 2. The color light generating means according to claim 1, further comprising a rotating disk in which the ratio of each color filter in the circumferential direction is continuously different depending on the distance from the center of rotation. 2. The color light generating means according to claim 1, further comprising a rotating cylinder in which the ratio of each of the plurality of color filters in the circumferential direction is continuously different in a direction parallel to the rotation axis. An image display device using the color light generating means according to claim 1.

Images