JP2001045327A - Picture display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device for reducing deterioration of the display fidelity of a video projected on a display screen even when regions whose levels of burning are different are generated on the display screens of cathode ray tubes due to the difference of the aspect rates of the pictures of video signals. SOLUTION: This picture display device is provided with cathode ray tubes 2R, 2G, and 2B as picture outputting means equipped with fluorescent faces KR, KG, and KB as picture outputting faces for outputting images having plural regions Ka, Kb and Kc whose luminance performances are different, luminance sensors 11a-11d as luminance detecting means for detecting the luminance of the image outputted from each region Ka, Kb, and Kc of the image outputted from the cathode ray tubes 2R, 2G, and 2B, a luminance adjusting circuit 22 as a luminance adjusting means for adjusting the luminance of the images out putted from each area Ka, Kb, and Kc based on the luminance detected by the luminance sensors 11a-11b, and a drive circuit 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device for displaying a video signal, and more particularly to a display device in which luminance unevenness due to screen burn-in is reduced.

[0002]

2. Description of the Related Art For example, in a display device such as a television device using a cathode ray tube, as the use of the cathode ray tube progresses, so-called phosphor screen burn-in causes a reduction in screen brightness. The baking is caused by irradiating the phosphor layer provided on the inner surface of the panel glass of the cathode ray tube with an electron beam from an electron gun, thereby deteriorating the materials constituting the phosphor layer and the panel glass.

[0003]

The display of an image on the screen of a cathode ray tube is performed by horizontal scanning and vertical scanning of an electron beam emitted from an electron gun of the cathode ray tube toward a fluorescent screen of the cathode ray tube. Will be The aspect ratio of the screen (frame) formed by this scanning
Has been standardized, and 4: 3 has been the mainstream in the past, but recently, the aspect ratio has been changed to 16: 3 so as to be included in the format of a video signal for digital television.
The video signals constituting the nine images have also increased. There are several methods for displaying an image having an aspect ratio of 16: 9 on a cathode ray tube having a display screen (fluorescent screen) having an aspect ratio of 4: 3. For example, the image is displayed on the display screen of the cathode ray tube. There is a method of reducing only the vertical size without changing the horizontal size of the image. In this method, for example, as shown in FIG. 11, the area Ra where the image having the aspect ratio of 16: 9 is displayed on the display screen S having the aspect ratio of 4: 3 is not the entire display screen S but the display screen S. The image is not displayed in the upper region Rb and the lower region Rc of the display screen S. When an image having an aspect ratio of 16: 9 is displayed on a display screen S having an aspect ratio of 4: 3 shown in FIG. 11 for a long time, a burn-in of a region Ra in which an image having an aspect ratio of 16: 9 is displayed is caused. , The luminance of the screen in the region Ra relatively decreases. Therefore, for example, when an image having an aspect ratio of 4: 3 is displayed on the entire display screen S, the luminance of the image in the region Ra becomes relatively low, and the boundary line M between the region Ra and the regions Rb and Rc in the image. Is displayed, and the display quality is impaired.

[0004] The problem of burn-in of the display screen also occurs in the case of a cathode ray tube alone, but is particularly remarkable in the case of a projection display device (projector). For example, FIG.
Shows an example of the configuration of the rear projector. FIG.
2A is a side view, and FIG. 12B is a front view. As shown in FIG.
Are three cathode ray tubes 102R, 102G, 102 that emit monochromatic images of red (R), green (G), and blue (B), respectively.
B are arranged in a line, and each cathode ray tube 102R, 102G,
This is an apparatus for enlarging an image projected on a display screen 102s of 102B with a projection lens 103, reflecting the image with a reflecting mirror 104, and projecting the image on the back of a screen 105. In the rear projector 101, the projection optical system and the observation position are on opposite sides of the screen, and the screen 105 is a transmissive screen, and diffuses the projected light.
Each cathode ray tube 102R projected on the screen 105,
By superimposing the images of 102G and 102B,
A color image is projected in front of the screen 105.

For example, cathode ray tubes 102R, 102G,
The aspect ratio of each display screen 102s of 102B is 4: 3
When an image having an aspect ratio of 16: 9 is displayed on each of these display screens 102s, the cathode ray tubes 102
The above-described burn-in problem occurs on the display screens 102s R, 102G, and 102B, and the screen 105 displays the image of the display screen 102s on which the burn-in has occurred as it is. In a projection display device such as the rear projector 101, in order to increase the brightness of the screen S, the output of each of the cathode ray tubes 102R, 102G, 102B is increased, and each of the cathode ray tubes 102R, 102G, 102
Burning of the display screen 102s of B easily proceeds.

The present invention has been made in view of the above-described problems. For example, regions having different degrees of burn-in occur on a display screen of a cathode ray tube due to a difference in aspect ratio of an image of a video signal. In particular, it is an object of the present invention to provide a display device capable of suppressing deterioration of image quality of an image projected on a display screen.

[0007]

According to the present invention, there is provided an image display apparatus comprising: an image output unit having an image output surface for outputting an image having a plurality of regions having different luminance performances; A luminance detecting means for detecting the luminance of the image output from each area; and a luminance between the respective areas by adjusting the luminance of the image output from each area based on the luminance detected by the luminance detecting means. Brightness adjustment means for correcting the difference.

[0008] The image display device of the present invention further comprises display means having a display surface for displaying an image output from the image output means, and wherein the luminance detecting means comprises a luminance of the image displayed on the display surface. Is detected.

The brightness adjusting means adjusts the brightness so that the brightness output of the relatively high brightness area of the image output surface matches the brightness output of the relatively low brightness area.

[0010] The brightness detecting means is provided at a position corresponding to a vicinity of a boundary of each area of the image output surface on the display surface so as to be able to detect the brightness of an image output from each area. It is possible.

Further, the image display device of the present invention further comprises a luminance boundary detecting means for detecting a boundary of a region having a luminance difference on the image output surface based on a luminance distribution of the image displayed on the display surface. A configuration is also possible.

[0012] The brightness detecting means may be provided so as to be able to detect a brightness distribution of the display surface in a predetermined direction.

[0013] The luminance detecting means and the luminance boundary detecting means include an image pickup means for picking up an image output from the image output means, and an image output surface based on the picked-up image. It can be configured by image processing means for detecting the boundary and the brightness of each area.

A portable image output device having at least one cathode ray tube having the image output surface, a projection lens for enlarging and projecting an image output from the cathode ray tube, and a projection lens from the cathode ray tube on a screen. And an imaging camera that captures an image that is enlarged and projected.

The image display device according to the present invention comprises: at least one cathode ray tube having the image output surface; a projection lens for enlarging and projecting an image output from the cathode ray tube; and an image projected through the projection lens from the back. The transmissive screen includes a transmissive screen that transmits the transmissive screen toward the front, and luminance sensors provided on both sides of the rear surface of the transmissive screen at respective positions where a luminance difference in a vertical direction of the transmissive screen occurs.

An image display device according to the present invention comprises: at least one cathode ray tube having the image output surface; a projection lens for enlarging and projecting an image output from the cathode ray tube; and an image projected through the projection lens from the back. The transmission screen includes a transmission screen that transmits the transmission screen toward the front, and a luminance sensor that is linearly provided on both sides on the rear surface of the transmission screen.

An image display device according to the present invention comprises: at least one cathode ray tube having the image output surface; a projection lens for enlarging and projecting an image output from the cathode ray tube; and an image projected through the projection lens on a front surface. Screen and
A luminance sensor is provided on each side of the front surface of the screen at each position where a luminance difference in the vertical direction of the transmissive screen occurs.

An image display apparatus according to the present invention comprises: at least one cathode ray tube having the image output surface; a projection lens for enlarging and projecting an image output from the cathode ray tube; and an image projected through the projection lens from the front. And a brightness sensor linearly provided on both sides of the front surface of the transmission screen.

According to the present invention, the luminance of an image from an image output surface is detected, and the luminance of an image output from each region of the image output surface is adjusted based on the detected luminance to obtain a luminance difference between the respective regions. Is corrected, even if the luminance performance of a part of the image output surface is deteriorated due to the burning of the image output surface, the problem of the occurrence of the boundary line due to the luminance difference on the displayed image is eliminated.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. First Embodiment FIG. 1 is a perspective view from the side of a rear projector as one embodiment of the display device of the present invention, and FIG. 2 is a perspective view from the front side of the display device shown in FIG. The rear projector 1 shown in FIGS. 1 and 2 includes a screen 5 provided on the front side of the apparatus, a reflecting mirror 4 provided behind the screen 5 and separated from the screen 5 and inclined in a predetermined direction, Three cathode ray tubes 2R, 2G, 2B fixed to
And brightness sensors 11a to 11d provided at predetermined positions on an outer frame 6 extending vertically on both sides of the screen 5. A projection lens 3 is provided in each of the cathode ray tubes 2R, 2G and 2B.

The screen 5 projects an image emitted from each of the cathode ray tubes 2R, 2G and 2B from the back, and transmits and diffuses the image. The screen 5 has an aspect ratio (horizontal-vertical ratio) of 4: 3. The reflecting mirror 4 reflects an image emitted from each of the cathode ray tubes 2R, 2G, and 2B toward the back of the screen 5.

The cathode ray tube 2R emits a red (R) monochromatic image, and this monochromatic image is enlarged through the projection lens 3,
The light is reflected by the reflecting mirror 4 and projected on the screen 5. The cathode ray tube 2G emits a green (G) monochromatic image, and the monochromatic image is magnified through the projection lens 3, reflected by the reflecting mirror 4, and projected on the screen 5. The cathode ray tube 2B is blue (B)
Is emitted through the projection lens 3, reflected by the reflecting mirror 4, and projected on the screen 5. Each of the cathode ray tubes 2R, 2G, and 2B has, for example, 4:
It has a fluorescent screen which is an image output plane having an aspect ratio of 3.

The brightness sensors 11a to 11d are provided on the back side of the screen 5 of the outer frame 6 provided on the outer periphery of the screen 5. The brightness sensors 11a to 11d provided on the outer frame 6 extending on both sides of the screen 5 in the vertical direction are used when displaying an image having an aspect ratio of 16: 9 on the screen 5 at the upper end of the image having the aspect ratio of 16: 9. And on the horizontal lines M1 and M2 located at the lower end. Each of the luminance sensors 11a to 11d has a horizontal line M
2 and an area Ra on which an image having an aspect ratio of 16: 9 on the screen 5 shown in FIG.
The luminance difference between the areas Rb and Rc where the image with the aspect ratio of 16: 9 above is not displayed is detected.

FIG. 3 is a configuration diagram including the circuit configuration of the rear projector 1 shown in FIG. 1 and FIG. As shown in FIG. 3, the rear projector 1 according to the present embodiment
Has a drive circuit 21 for driving each of the cathode ray tubes 2R, 2G, and 2B, and a brightness adjustment circuit 22 to which detection values 11sa to 11sd detected by the brightness sensors 11a to 11d are input.

The drive circuit 21 is a circuit for outputting an image corresponding to the contents of the video signal G to the fluorescent screen which is the image output surface of each of the cathode ray tubes 2R, 2G and 2B based on the input video signal G. . Specifically, the drive circuit 21 controls the emission and acceleration of the electrons from the electron guns provided in the cathode ray tubes 2R, 2G and 2B, and drives the deflection coils of the cathode ray tubes 2R, 2G and 2B. Control for scanning the electron beam on the phosphor screen is performed.

The brightness adjustment circuit 22 is provided for each brightness sensor 11a.
Based on the detected values 11sa to 11sd of the cathode ray tubes 2R, 2G, and 2B, the image output from the region where the luminance performance of the fluorescent screen of the cathode ray tubes 2R, 2G, and 2B is relatively deteriorated and the region where the luminance performance is not deteriorated are This is a circuit for adjusting the luminance output.

FIG. 4 is a diagram showing the structure of the fluorescent screen of each of the cathode ray tubes 2R, 2G and 2B. As shown in FIG. 4, each of the cathode ray tubes 2R, 2G and 2B is, for example,
It has fluorescent screens KR, KG, and KB having an aspect ratio of 4: 3. The area NR on the outer periphery of the phosphor screens KR, KG, KB
Is a non-effective area where the output image is not displayed on the screen 5, and the image output from the non-effective area NR is displayed in the outer frame 6 on the outer periphery of the screen 5. From the fluorescent screens KR, KG, KB of the cathode ray tubes 2R, 2G, and 2B,
For example, if the image having the aspect ratio of 16: 9 is continuously output, the luminance performance of the area Ka for outputting the image having the aspect ratio of 16: 9 of each of the phosphor screens KR, KG, and KB is changed to the other area Kb. , Kc. The region Ka and the regions Kb and Kc correspond to the regions Ra, Rb and Rc of the screen 5, respectively. Each cathode ray tube 2 having a region Ka whose luminance performance is relatively deteriorated
When, for example, a 4: 3 image is output from the R, 2G, and 2B phosphor screens KR, KG, and KB, the brightness of the image in the area Ra of the screen 5 shown in FIG. Regions Rb and Rc are relatively high.
Therefore, horizontal lines M1 and M2 on the screen 5 have a boundary line of an image having a luminance difference, and the display quality of the screen 5 is reduced.

The brightness adjustment circuit 22 according to the present embodiment includes detection values 11sa to 1 detected by the brightness sensors 11a to 11d.
On the basis of the luminance difference between the area Ra of the screen 5 and the areas Rb and Rc of the screen 5 which is 1 sd, the area Ka for outputting an image having a 16: 9 aspect ratio of the fluorescent screen of each of the cathode ray tubes 2R, 2G and 2B and Other areas Kb,
A luminance adjustment signal 22 s for adjusting the luminance output of the image to be output from Kc is output to the drive circuit 21.

The drive circuit 21 outputs the luminance adjustment signal 22s
, The brightness of each of the cathode ray tubes 2R, 2G and 2B is adjusted. That is, each of the cathode ray tubes 2R, 2G and 2B
The amount of electrons when the electron beam is scanned over the region Ka of the phosphor screen and the amount of electrons when the electron beam is scanned over the regions Kb and Kc are adjusted, and the region Ra and the regions Rb and Rc of the screen 5 are adjusted. Is corrected.

Hereinafter, an example of a procedure for adjusting the brightness of the rear projector 1 having the above configuration will be described with reference to a flowchart shown in FIG. First, a monochromatic image of uniform luminance is output from the entire phosphor screens KR, KG, and KB of each of the cathode ray tubes 2R, 2G, and 2B or only the non-effective area NR of the phosphor screens KR, KG, and KB (step S1). ). When a monochromatic image with uniform luminance was output from the phosphor screens KR, KG, and KB, it was displayed on the screen 5 that the luminance performance of the area Ka of each phosphor screen KR, KG, and Kb was relatively deteriorated. As for the luminance of the image, the luminance of the region Ra becomes relatively low with the horizontal lines M1 and M2 shown in FIG.
And Rc have relatively high luminance. Also, the fluorescent screen K
The image output from the non-effective area NR of R, KG, KB is displayed on the outer frame 6 of the screen 5, and the luminance on the outer frame 6 extending in the vertical direction on both sides of the screen 5 is also set with the horizontal lines M1 and M2 as boundaries. The luminance of the region Ra is relatively low, and the luminance of the regions Rb and Rc is relatively high. There is no particular limitation on when to perform the operation of outputting a monochromatic image of uniform luminance from the entirety of the phosphor screens KR, KG, and KB, or only the non-effective area NR of the phosphor screens KR, KG, and KB. For example, this is performed every time the rear projector 1 is started.

In this state, the brightness sensors 11a to 11a provided on the outer frame 6 extending in the vertical direction on both sides of the screen 5 are provided.
11d, a luminance difference between the region Ra and the regions Rb and Rc is detected (step S2). Each brightness sensor 11a
11d to 11sd are input to the luminance adjustment circuit 22.

In the brightness adjustment circuit 22, each brightness sensor 11
Based on the detection signals 11sa to 11sd of a to 11d,
A phosphor screen K for preventing a luminance difference from occurring between images displayed in the region Ra of the screen 5 and the regions Rb and Rc.
The luminance output from each of the regions Ka, Kb, and Kc of R, KG, and KB is calculated (step S3). Area R of screen 5
The luminance output from each of the areas Ka, Kb, and Kc of the phosphor screens KR, KG, and KB for preventing a luminance difference from occurring between the images displayed in the area a and the areas Rb and Rc is, for example, relative to the luminance performance. Regions Kb of high phosphor screens KR, KG, KB,
The luminance output of Kc is reduced, and calculation is performed so as to match the luminance output of the area Ka having relatively low luminance performance. By calculating in this way, it is possible to suppress the power consumption of each of the cathode ray tubes 2R, 2G, and 2B.

The luminance adjustment circuit 22 calculates the calculated phosphor screen K
The luminance output corresponding to each of the regions Ka, Kb, and Kc of R, KG, and KB is output to the drive circuit (step S4). When a video signal G for displaying an image having an aspect ratio of 4: 3 is displayed on the screen 5 by the drive circuit 21 (step S).
5) The luminance difference between the region Ra of the screen 5 and the regions Rb and Rc is corrected, and the boundary line due to the luminance difference does not occur at the positions of the horizontal lines M1 and M2 of the screen 5 shown in FIG.

As described above, according to the present embodiment, the brightness sensor 11a is located near the boundary between the region Ra and the regions Rb and Rc on the screen 5 where a brightness difference is assumed to occur in advance.
11d, the brightness of the image displayed on the screen 5 is detected, and based on the detected value, each of the cathode ray tubes 2R, 2R,
G, 2B phosphor screens KR, KG, KB regions Ka, K
By correcting the luminance output from b and Kc, it is possible to prevent the occurrence of a boundary line due to a luminance difference when an image having an aspect ratio of 4: 3 is displayed on the screen 5. Also, in the present embodiment, the brightness sensors 11a to 11a-1
By providing 1d on the outer frame 6 on the back side of the screen 5,
The phosphor screens KR, K of the cathode ray tubes 11R, 11G, 11B
Since the brightness of the image output from the non-effective areas NR of G and KB can be detected, and the brightness sensors 11a to 11d are invisible to the observer when the screen 5 is viewed from the front, the rear projector 1 This is advantageous in terms of design. In the above-described embodiment, the deterioration of the display quality of the screen 5 due to the burning caused by outputting the image having the aspect ratio of 16: 9 to the phosphor screens KR, KG, and KB having the aspect ratio of 4: 3 is suppressed. However, the present invention is not limited to this,
For example, the image of the Vista size is converted to the fluorescent screens KR, KG, K
The output to B can be dealt with by installing the brightness sensors 11a to 11d at positions corresponding to the size of the image.

Second Embodiment FIG. 6 is a configuration diagram including a circuit of a rear projector according to a second embodiment of the display device of the present invention. The difference between the rear projector 61 shown in FIG. 6 and the above-described rear projector 1 is that the luminance sensors 31 provided on both sides of the screen 5 of the rear projector 61 can detect the luminance distribution in the vertical direction of the screen 5. The processing content of the brightness adjustment circuit 35 of the rear projector 61 is different depending on the difference of the brightness sensor, and other components are the same as those of the rear projector 1 according to the above-described embodiment.

As shown in FIG. 6, the brightness sensors 31 are linearly provided on both sides of the rear surface of the screen 5 of the rear projector 61. These brightness sensors 31
Are capable of detecting, for example, the luminance of each position corresponding to a scanning line constituting an image displayed on the screen 5, for example, 525 lines. The brightness sensor 31
The luminance signal 31s detected by the screen 5 is output to the luminance adjustment circuit 35, respectively.

FIG. 7 is a diagram showing an example of the configuration of the luminance adjustment circuit 35. As shown in FIG.
Has A / D conversion circuits 36 and 37, luminance detection value memories 38 and 39, a luminance boundary detection circuit 40, and a luminance correction circuit 41.

The A / D conversion circuits 36 and 37 generate a luminance signal 31s composed of an analog signal detected by each luminance sensor 31.
Are converted into digital signals, and these are output to the luminance detection value memories 38 and 39, respectively. The luminance detection value memories 38 and 39 hold quantized luminance values of, for example, 525 points in the vertical direction on the screen 5 detected by each luminance sensor 31.

The luminance boundary detection circuit 40 calculates a boundary position H at which the vertical luminance of the screen 5 changes from the vertical luminance distribution of the screen 5 obtained from the luminance values stored in the luminance detection value memories 38 and 39. Is detected, and a boundary position signal 35sb for specifying the boundary position H is output to the luminance detection circuit 4.
1 and to the drive circuit 21. Specifically, for example, as shown in FIG. 3, when an image having an aspect ratio of 4: 3 is displayed on the entire screen 5 as shown in FIG. The positions of M1 and M2, which are boundaries between the regions Rb and Rc, which are relatively high, are detected.

The luminance correction circuit 41 includes a luminance boundary detection circuit 4
The fluorescent screens KR, K of the cathode ray tubes 2R, 2G, 2B for correcting the luminance difference in the image displayed on the screen 5 based on the boundary position signal 35sb input from 0.
The luminance output of an image to be output from each of the areas Ka, Kb, and Kc of G and KB is calculated, and a luminance correction signal 35sa for specifying the calculated luminance output value is output to the drive circuit 21.

Based on the boundary position signal 35sb and the luminance correction signal 35sa output from the luminance boundary detection circuit 40 and the luminance detection circuit 41, the driving circuit 21 generates the fluorescent screen KR of each of the cathode ray tubes 2R, 2G and 2B. , KG,
The amount of electrons when the electron beam is scanned over the region Ka of KB and the amount of electrons when the electron beam is scanned over the regions Kb and Kc are adjusted, and the region Ra of the screen 5 and the regions Rb and Rc are adjusted. Correct the brightness difference.

In the rear projector 61 having the above configuration, the range of the area Ra, the areas Rb and Rc of the screen 5, that is, the positions of the boundaries M1 and M2 on the screen 5 are not specified in advance, or And the position of M2 changes, the screen 5
The positions of the boundary lines M1 and M2 can be specified from the luminance distribution detected by the luminance sensors 31 linearly provided on both sides of. For this reason, in each of the phosphor screens KR, KG, and KB of each of the cathode ray tubes 2R, 2G, and 2B, a region in which the luminance performance deteriorates relatively gradually changes, or, for example, an aspect ratio of 4: 3. Phosphor screen KR, K
When a plurality of images having different sizes in the vertical direction (vertical direction) are output, such as an image having a 16: 9 aspect ratio or an image having a Vista size for G and KB, thereby causing deterioration in luminance performance in a specific area. For example, it is possible to easily detect a boundary position where a luminance difference occurs.

Third Embodiment FIG. 8 is a block diagram showing an example of a front projector. The front projector 71 shown in FIG. 8 includes, for example, a plurality (three) of cathode ray tubes 74R, 74G, and 74B that output monochromatic images of red (R), green (G), and blue (B), respectively. An image output device 73 for enlarging and projecting each image from the tubes 74R, 74G, 74B, and an image output device 73
72 on which the image output from the projector is projected on the front
And The front projector 71 displays an image displayed on the front of the screen 72 on the screen 72.
Observe from the front side of.

In the front projector 71, when images having different aspect ratios are output from the fluorescent screens KR, KG, and KB of the cathode ray tubes 74R, 74G, and 74B, similarly to the above-described embodiment, the fluorescent screens KR, KG, and KB are output. Deterioration of the luminance performance of the specific area is relatively advanced, and there is a problem that the deterioration of the luminance performance of the specific area causes a boundary line to be generated on the image displayed on the screen 72 due to a luminance difference, thereby deteriorating display quality. are doing. In a front projector, for example, a screen and an image output device that are always fixed at a fixed position and used (installed type),
Some screens and image output devices are portable, and their relative positions are not fixed (portable type).

In the installation type front projector, for example, as shown in FIG. 9, a brightness sensor is provided on both sides of the front surface of a screen 72 in the same manner as in the case of the rear projector 61 according to the above-described second embodiment. 76 may be provided linearly. By processing the detection signal of the luminance sensor 76 using the same circuit as that of the rear projector 61 according to the above-described second embodiment, deterioration of the display quality of the screen 72 due to deterioration of the luminance performance of the specific area is avoided. be able to.

Fourth Embodiment FIG. 10 is a diagram showing a configuration of a front projector 81 as a display device according to a fourth embodiment of the present invention.
The front projector 81 according to the present embodiment is a portable front projector in which a screen 72 and an image output device 73 can be carried. As shown in FIG. 10, the image output device 73 includes a CCD camera 75 as an imaging unit having a visual field capable of imaging the entire front surface of the screen 72. Also, the front projector 8
1 includes an image processing circuit 82 for performing predetermined processing on image data captured by the CCD camera 75, and a drive circuit 83 for driving each of the cathode ray tubes 74R, 74G, and 74B included in the image output device 73.

The image processing circuit 82 processes the image data of the screen 72 captured by the CCD camera 75, and extracts a relatively high-luminance area and a relatively low-luminance area on the screen 72. Specify the boundary position of. In addition, each cathode ray tube 74R, 74G, 74B corresponding to each region having a luminance difference whose boundary position is specified.
The luminance output of the image output from each area of the phosphor screen is calculated. The image processing circuit 82 outputs to the drive circuit 83 a signal 82sa for specifying the boundary position of the region having the luminance difference and a signal 82sb for specifying the luminance output of each region of the phosphor screen. The drive circuit 83 outputs these signals 82sa and 82sa.
Based on the sb, the brightness of the fluorescent screen of each of the cathode ray tubes 74R, 74G, 74B is adjusted, and the brightness difference existing in the image displayed on the screen 72 is corrected. With such a configuration, each of the cathode ray tubes 74R, 74G, provided in the image output device 73 of the portable type front projector 81,
It is possible to prevent the display quality of the screen 72 from deteriorating due to the luminance deterioration of a specific area of the fluorescent screen 74B.

Note that, as in this embodiment, the screen 7
2 is captured by the CCD camera 75, a predetermined process is performed on the image data, a luminance distribution in the image is specified, and a region having a luminance difference is extracted.
For example, it is possible to cope with a case where a region where the luminance is reduced exists in a specific region inside the screen 72 and a boundary between regions having a luminance difference on both sides of the screen 72 cannot be detected.

[0049]

According to the present invention, even if a region having a different degree of printing occurs on the image output surface of the cathode ray tube due to a difference in the aspect ratio of the image of the video signal, the image is output from the image output surface. It is possible to suppress the deterioration of the display quality of the video projected on the display surface on which the image is displayed.

[Brief description of the drawings]

FIG. 1 is a side view of a rear projector according to an embodiment of the present invention.

FIG. 2 is a front view of the rear projector shown in FIG.

FIG. 3 is a configuration diagram including a circuit configuration of the rear projector shown in FIGS. 1 and 2;

FIG. 4 is a diagram for explaining a configuration of each phosphor screen of a cathode ray tube provided in the rear projector shown in FIG.

FIG. 5 is a flowchart illustrating an example of a luminance adjustment procedure of the rear projector 1.

FIG. 6 is a configuration diagram of another embodiment of the display device of the present invention.

7 is a circuit configuration diagram 9 illustrating an example of a configuration of a luminance adjustment circuit of the rear projector 61 in FIG.

FIG. 8 is a diagram illustrating an example of a configuration of a front projector.

FIG. 9 is a diagram illustrating a configuration of a screen of a display device according to a third embodiment of the present invention.

FIG. 10 is a diagram illustrating a configuration of a display device according to a fourth embodiment of the present invention.

FIG. 11 is a diagram for explaining a state of a display screen on which images having different aspect ratios are displayed.

FIG. 12 is a diagram illustrating an example of a configuration of a rear projector.

[Explanation of symbols]

1 ... rear projector, 2R, 2G, 2B ... cathode ray tube,
3: Projection lens, 4: Reflecting mirror, 5: Screen, 11a
11d: brightness sensor, 21: drive circuit, 22: brightness adjustment circuit, KR, KG, KB: fluorescent screen.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hideki Okada 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation F-term (reference) 5C021 PA17 PA53 PA66 PA78 RB01 SA11 XA02 XA35 5C058 AA01 BA06 BB11 5C082 AA02 AA21 BA34 BA35 BA41 BD01 CA81 CA84 CA85 CB01 DA51 MM03 MM10

Claims (12)

[Claims] 1. An image output means having an image output surface for outputting an image having a plurality of areas having different luminance performances, and detecting the luminance of an image output from each area of the image output from the image output means. Brightness detecting means, based on the brightness detected by the brightness detecting means,
An image display device comprising: a brightness adjustment unit configured to adjust a brightness of an image output from each of the regions to correct a brightness difference between the respective regions. 2. The image processing apparatus according to claim 1, further comprising a display unit having a display surface for displaying an image output from the image output unit, wherein the luminance detection unit detects the luminance of the image displayed on the display surface. An image display device according to claim 1. 3. The image display according to claim 1, further comprising: a luminance boundary detecting means for detecting a boundary of a region having a luminance difference on the image output surface based on a luminance distribution of the image displayed on the display surface. apparatus. 4. The image processing apparatus according to claim 1, wherein said luminance detecting means is provided at a position corresponding to a vicinity of a boundary of each region of said image output surface on said display surface so as to be able to detect luminance of an image outputted from each of said regions. Item 3. The image display device according to Item 2. 5. The image display device according to claim 3, wherein said luminance detecting means is provided so as to detect a luminance distribution in a predetermined direction on said display surface. 6. An image pickup means for picking up an image output from said image output means, and detecting, based on the picked-up image, a boundary between regions having a luminance difference on the image output surface and a luminance of each region. The image display device according to claim 1, further comprising an image processing unit. 7. An at least one cathode ray tube having the image output surface, a projection lens for enlarging and projecting an image output from the cathode ray tube, and an image passing through the projection lens is projected from the back, and this is projected on the front. The image display device according to claim 4, further comprising: a transmission screen that transmits light toward the transmission screen; and brightness sensors provided on both sides of a rear surface of the transmission screen at respective positions where a luminance difference in a vertical direction of the transmission screen occurs. 8. At least one cathode ray tube having the image output surface, a projection lens for enlarging and projecting an image output from the cathode ray tube, and an image passing through the projection lens is projected from the back, and this is projected on the front. The image display device according to claim 5, further comprising: a transmission screen that transmits light toward the screen; and brightness sensors that are linearly provided on both sides on a rear surface of the transmission screen. 9. A cathode ray tube having the image output surface, a projection lens for enlarging and projecting an image output from the cathode ray tube, a screen on which an image passed through the projection lens is projected on the front side, The image display device according to claim 4, further comprising a luminance sensor provided on each side of the front surface of the screen at each position where a luminance difference in a vertical direction of the transmission screen occurs. 10. A cathode ray tube having the image output surface, a projection lens for enlarging and projecting an image output from the cathode ray tube, a screen on which an image passed through the projection lens is projected from the front, The image display device according to claim 5, further comprising: a luminance sensor linearly provided on each side of a front surface of the transmission screen. 11. The brightness adjusting device according to claim 1, wherein said brightness adjusting means adjusts the brightness output of a relatively high brightness area of the image output surface so as to match the brightness output of a relatively low brightness area. Image display device. 12. A portable image output device having at least one cathode ray tube having the image output surface, a projection lens for enlarging and projecting an image output from the cathode ray tube, and a projection lens from the cathode ray tube through a projection lens. The image display device according to claim 5, further comprising: an imaging camera configured to capture an image enlarged and projected on a screen.