JP2003304551A - Projection type display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projection type display apparatus capable of displaying an image in a substantial color tone without being affected by color components of an environmental light reflected in a projection face and a reflection characteristic of the projection face. <P>SOLUTION: The projection type display apparatus includes: a plurality of image forming means 19, 20 for respectively controlling the transmissivity of a light of each color from a light source on the basis of an applied color signal; a projection means 21 for projecting a color image formed by the image forming means onto the projection face; color information detection means 12, 22 for detecting color information of a reflected light from the projection face; and a color correction means 18 for correcting the color signal applied to the image forming means in response to the color information detected by the color information detection means. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection display device such as a liquid crystal projector and a DLP projector.

[0002]

2. Description of the Related Art A projection display device forms an image by passing light emitted from a light source through an image forming element (light valve), and projects the formed image on a projection surface (screen) through a projection lens. It is a device and has an advantage that it can be easily displayed on a large screen.

[0003]

However, the projection type display device has an aspect that the hue of the projected image is greatly affected by the ambient light at the place where the device is used and the reflection characteristic of the screen. This will be specifically described with reference to FIGS. 8 and 9.

In FIG. 8, the projection light 7 from the projection display device 6 is reflected by the screen 2 and travels toward the viewer 5 as image light 8. On the other hand, the illumination light 3 emitted from the illumination device 1 for ambient illumination is incident on the screen 2, and the reflected light is directed to the viewer 5 as the ambient light 4. Therefore, when the viewer 5 sees the image projected on the screen 2, the viewer 5 sees the image light 8 on which the ambient light 4 is superimposed. for that reason,
When the illuminating device 1 emits yellow illumination light, the ambient light 4 is also yellow, and the image viewed by the viewer 5 becomes yellowish.

Also, when the reflectance of the screen 2 depends on the wavelength of light, that is, when the screen 2 has a wavelength selection characteristic, the hue of the image viewed by the viewer 5 is different from the original one. For example, when the projection light of the projection display device 6 is projected on the yellow wall, the image viewed by the viewer becomes yellowish. This is because the reflectance of the yellow wall in the blue region is lower than that of the green region and the red region.

As shown in FIG. 9, in order to allow the viewer 5 to see an image as close to the original color as possible, the projection display device 6 is provided with a color sensor 9, and the illumination light emitted by the illumination device 1 is emitted. It is also known to detect the color information of 10 and perform color correction of the projection light 7 based on the detected color information.

However, in the configuration of FIG. 9, the color correction of the projection light 7 is performed based on the color information of the illumination light 10 coming directly from the illumination device 1, and the influence of the ambient light 4 reflected by the screen 2 is influenced. It cannot be removed sufficiently, and appropriate color correction cannot be expected especially when the projection surface has wavelength selection characteristics.

The present invention has been made in view of the above problems, and an image having an original color tone can be displayed without being affected by the color components of ambient light reflected on the projection surface and the reflection characteristics of the projection surface. It is an object to provide a projection display device.

[0009]

[Means for Solving the Problems] In order to achieve the above object,
According to the invention described in claim 1, an image forming unit for forming a color image by controlling the transmittance of light of each color from the light source based on the applied color signal, and the formation of the image forming unit. The projection means for projecting the color image on the projection surface, the color information detecting means for detecting the color information of the reflected light from the projection surface, and the image forming means according to the color information detected by the color information detecting means. There is provided a projection display device including: a color correction unit that corrects an applied color signal.

According to a second aspect of the invention, in the first aspect of the invention, an image of a specific color is projected from the projection means at the time of start-up, and based on the color information detected by the color information detection means at that time. And a means for automatically executing a sequence for determining the degree of correction of the color signal by the color correction means.

According to a third aspect of the present invention, in the first or second aspect of the invention, it is detected whether the color information detected by the color information detecting means is within a predetermined range. It further comprises means, and if the color information is not included in the range, the color signal is not corrected.

The invention according to claim 4 is the invention according to claims 1 to 3.
In the invention according to any one of the items 1 to 3), a part of the reflected light from the projection surface is selected so that the color information detection means detects color information about a part of the image on the projection surface. Is further included.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. The first embodiment of the present invention will be described with reference to FIGS. In FIG. 1A, 11 is a projection display device of the present invention, 1
4 is a projection surface, 15 is a viewer, 13 is an incandescent lamp for illumination, 1
Reference numeral 7 denotes image light projected from the projection display device 11 through the projection lens 21 and reflected by the projection surface 14, and reference numeral 16 denotes ambient light emitted by the incandescent lamp 13 and reflected by the projection surface 14. The projection display device 11 has a color sensor 12 built therein. The color sensor 12 is for detecting the chromaticity of ambient light,
The tristimulus value X (λ) Y (λ) Z (λ) value can be detected.

FIG. 1B shows the structure of the projection display device 11 in the vicinity of the color sensor 12 and the projection lens 21. In the figure, 20 is an amplifier for amplifying R, G, B signals respectively,
Reference numeral 18 is a control circuit for controlling the gain of the amplifier 20 according to the color information from the color sensor 12, and 19 is R from the amplifier 20,
A liquid crystal panel that forms an image from light from a light source (not shown) according to G and B signals, and 22 is a condenser lens that collects the ambient light 16 and the image light 17 reflected by the projection surface 14 on the light receiving surface of the color sensor 12. . The operation of the projection display device 11 will be described below.

The color sensor 12 detects the color component of the light condensed on its light receiving surface, and the result is used as color information in the control circuit 1.
Send to 8. Based on this color information, the control circuit 18 uses R,
The gain of each amplifier 20 for G and B signals is adjusted. This corrects the color deviation of the image on the projection surface.

In this embodiment, the incandescent lamp 13 that emits light with a large amount of yellow component is used, and the color sensor 12 controls the color information indicating that the light condensed by the condenser lens 22 has a large amount of yellow component. Send to 18. The control circuit 18 adjusts the gain of the amplifier 20 according to the color information so that the liquid crystal panel 19 forms an image with less yellow component. Specifically, as shown in the graph of FIG. 2, the slope of the straight line representing the input-output characteristic of the amplifier 20 is made smaller for the R signal and the G signal than for the B signal. As a result, the yellow component of the image formed by the liquid crystal panel 19 is reduced, but the yellow component of the ambient light is added accordingly, so that the viewer 15 can see the image of the original correct tone.

When ambient light is not white and has a large amount of a specific color component, for example, a yellow component, conventionally, even when a white image is projected, the yellow component is superimposed and a yellowish image is displayed. However, according to the first embodiment, since the bias of the color components is corrected, the viewer can see the white image which is the original color. Similarly, even if the ambient light is white light, if the projection surface has a color selection characteristic, for example, if it is a yellow wall, a large amount of yellow component is conventionally reflected even when a white image is projected, and a yellowish color is produced. I was seeing an image with a
According to the first embodiment, even in this case, the bias of the color components is corrected, and the viewer can see the original white image.

Embodiment 2. Embodiment 1 described above
Is configured to detect color deviation and correct it while using the projection display device, that is, while projecting an image.However, when the projection display device is started, the color correction amount is automatically adjusted. It may be calculated and the input-output characteristics of the amplifier may be corrected.

In this case, for example, a 100% white image is projected when the projection display device 11 is started up, the control circuit 18 calculates the color correction amount based on the detection result of the color sensor 12 at that time, and the calculation result is obtained. The control circuit 18 has a function of automatically executing a sequence for correcting the input-output characteristic of the amplifier based on the above equation. Instead of projecting a 100% white image at startup, R, G, and B images may be sequentially projected, and the color correction amounts may be calculated and adjusted individually.

Embodiment 3. If the ambient light contains a large amount of a specific color component and the ambient light is significantly different from white, or if the projection surface has a remarkable wavelength selection characteristic, there is no effect even if correction is performed, and the color reproducibility is broken. Will result. Therefore, in the third embodiment, the color correction is performed only when the detection result of the color component by the color sensor 12 is within a certain range, and the color correction is not performed outside the range. The specific operation will be described below.

When the projection display apparatus 11 is started up, the control circuit 18 determines the ratio R / G of the red component to the green component and the blue to the green component based on the information from the color sensor 12 before performing the color correction. The ratio B / G of the components is calculated, and it is checked whether or not the points having those values as coordinates are within the predetermined area A of the map shown in FIG. If it is within the area A, it is determined that color reproduction is possible by color correction,
The sequence shifts to the color correction sequence described in the second embodiment. If the point is outside the area A, it is determined that color correction will result in over-correction, and failure will occur in terms of color reproducibility, and color correction will not be performed. The shape and size of the area A are not limited to those shown in FIG.
It can be set arbitrarily according to the situation.

Fourth Embodiment In some cases, the illumination light is not evenly applied to the projection surface. 4 (a) and 4 (b),
The irradiation intensity of the incandescent lamp 13 on the projection surface 14 is strong above the projection surface 14, and therefore, the upper part of the projection surface 14 is more yellowish than the lower part. In such a situation, projection type display device 23 according to Embodiment 4 of the present invention enables the user to select a position (color detection range) to be a reference for color correction from the projection surface. Have. The configuration will be specifically described below.

As shown in FIG. 5A, in the projection display device 23 of the fourth embodiment, the color detection device 25 is arranged at the position where the image of the projection surface 14 is formed. Figure 5 (b)
As shown in FIG. 3, the color detection device 25 includes a plurality of color detection elements 26 arranged in a lattice so that the light reflected from the entire projection surface 14 can be captured as a surface, and the control circuit 18 can be operated by the user. An element used for color detection is electrically selected from the plurality of elements in accordance with an instruction from.

For example, when only the upper portion of the projection surface 14 is affected by ambient light, color reproducibility at the central portion of the screen is deteriorated if color correction is performed according to that portion. However, according to the present embodiment. In such a case, the user can perform color correction according to the central portion of the screen.

Location to be used as a reference for color correction (color detection range)
6 may be used instead of the configuration shown in FIG. 5 as a configuration that enables selection from the projection plane. In FIG. 6, reference numeral 23 denotes a variable magnification system lens for forming an image of the reflected light from the projection surface as color information on the color sensor 12, and by moving the whole or part of the variable magnification system lens 23 along the optical axis. The range of the projection plane where an image is formed on the color sensor 12 can be changed.

Further, as shown in FIG. 7, the color sensor 12 and the condenser lens 22 may be integrally formed so as to be rotatable about an axis perpendicular to the optical axis. By changing the rotation angle, the user can image the light from any part of the projection surface on the color sensor 12. still,
It is also possible to combine the configurations of FIGS.

[0027]

According to the first aspect of the present invention, the projection capable of displaying an image with an original color tone is not affected by the color components of the ambient light reflected on the projection surface and the reflection characteristics of the projection surface. A mold display device is provided.

According to the second aspect of the present invention, it is possible to automatically calculate the color correction amount at the time of starting the projection display device and correct the input-output characteristic of the amplifier.

According to the third aspect of the invention, if the color correction is performed excessively, and if there is a possibility of failure in terms of color reproducibility, it is possible not to perform the color correction. it can.

According to the invention described in claim 4, when the illumination light is not uniformly applied to the projection surface, the user can select a portion (color detection range) to be a reference for color correction from the projection surface. it can.

[Brief description of drawings]

1A is an explanatory view of a usage state of a projection display apparatus according to a first embodiment of the present invention, and FIG. 1B is a diagram showing a part of a configuration of the projection display apparatus according to the first embodiment. Is.

FIG. 2 is an explanatory diagram of an input-output characteristic setting operation of the color signal amplifier.

FIG. 3 is a diagram showing a map used for color correction only in a case where a color component detection result is within a certain range in the projection display apparatus according to the third embodiment of the present invention.

FIG. 4A is an explanatory diagram of a usage state of a projection display apparatus according to a third embodiment of the present invention, and FIG. 4B is an explanatory diagram of a state in which illumination light is nonuniformly applied to a projection surface.

5A is an explanatory diagram of a configuration that enables selection of a color detection range included in the projection display apparatus according to Embodiment 4 of the present invention, and FIG. 5B is a description of a color detection device used in the configuration. It is a figure.

FIG. 6 is an explanatory diagram of another configuration that enables selection of a color detection range.

FIG. 7 is an explanatory diagram of yet another configuration that enables selection of a color detection range.

FIG. 8 is an explanatory diagram of a usage state of a conventional projection display device.

FIG. 9 is an explanatory diagram of a usage state of a projection type display device including a conventional color sensor.

[Explanation of symbols]

1 illumination device, 2 screen, 3 illumination light, 4
Ambient light, 5 viewers, 6 projection display device, 7
Projection light, 8 image light, 9 color sensor, 10 illumination light, 11 projection display device, 12 color sensor, 1
3 lighting devices, 14 screens, 15 viewers,
16 ambient light, 17 image light, 18 control circuit,
19 liquid crystal panel, 20 amplifier, 21 projection lens, 22 condensing lens, 23 projection display device, 2
5 color detection device, 26 color detection element.

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Claims (4)

[Claims] 1. An image forming unit for forming a color image by controlling the transmittance of light of each color from a light source on the basis of an applied color signal, and a color image formed by the image forming unit on a projection surface. A projection means for projecting onto the projection surface, a color information detecting means for detecting color information of the reflected light from the projection surface, and a color signal applied to the image forming means according to the color information detected by the color information detecting means. A projection display device comprising: a color correction unit that performs correction. 2. An image of a specific color is projected from the projection means at the time of startup, and the degree of correction of the color signal of the color correction means is determined based on the color information detected by the color information detection means at that time. The projection display device according to claim 1, further comprising means for automatically executing the sequence. 3. Further comprising means for detecting whether or not the color information detected by said color information detecting means is within a predetermined range, and if the color information is not within said range, The projection display device according to claim 1, wherein the color signal is not corrected. 4. The color information detecting means further includes means for selecting a part of light reflected from the projection surface so that the color information detecting means detects color information about a part of an image on the projection surface. The projection display device according to claim 1, wherein the projection display device is a display device.