JPH10276445A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the measurement precision of an adjustment pattern which corrects convergence deviation. SOLUTION: This device is provided with an adjustment pattern generating means which generates an adjustment pattern, a light detecting part 8 which is provided with a light receiving part 21 that is arranged at a position where the adjustment pattern can be inputted near the periphery of a screen 6 and inputs an adjustment pattern that is projected from a projection tube and a hood part 23 which partially or entirely interrupts external incident light GL that is made incident through the screen 6 against the part 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 capable of projecting an image by a projection tube of each color of RGB and synthesizing the image of each color on a screen to form a color image.

[0002]

2. Description of the Related Art For example, a CRT (Ca
Thode Ray Tube), using a projection tube composed of a projection lens, etc., and projecting each color image output from each projection tube onto, for example, a wall-mounted screen or a transmission screen, etc., to synthesize each color image on the screen. 2. Description of the Related Art A projector device is known as a display device that forms a color image by using a projector.

[0003]

By the way, convergence adjustment is performed on the production line so that each color light outputted from each of the projection tubes is correctly matched on the screen to obtain a good image. However, when the projector device is placed or installed in a home or a hall after the convergence adjustment, for example, a convergence deviation may occur due to the influence of geomagnetism at that position. In order to correct the convergence shift, there is known a convergence shift correction system disclosed in, for example, JP-A-8-9399, and a display device using the same.

In this conventional example, as a method of detecting the convergence deviation, for example, the luminance received at a predetermined position on the outer peripheral portion of a transmissive screen (comprised of a Fresnel lens, a lenticular lens, etc.) of a rear projection type projector device. Light detecting means for detecting the level is provided. The adjustment pattern of constant brightness for adjusting the convergence deviation projected by the projection tube has a maximum output voltage when the light detection means is input and a minimum output voltage when the adjustment pattern is not input to the light detection means. Are detected and stored in advance, and these voltage values are compared with the voltage values currently detected from the light detecting means to determine whether the specific position of the adjustment pattern and the position of the light detecting means have a fixed positional relationship. No is detected. Each voltage value is compared as A / D converted digital data.

In some cases, the light detecting means detects and outputs a voltage other than the detection voltage of the adjustment pattern, which may lead to a measurement error. For example,
The dark current or the like of the light detecting means itself can be canceled by applying a predetermined bias in advance, and only the measured value can be output. In addition, if external incident light that enters the housing of the display device via the transmission screen during the measurement is input to the light detection unit, the measurement result of the adjustment pattern is affected. For example, it is possible to cancel if the external incident light that is incident during the measurement is at a certain level, but a higher voltage value is output than when only the adjustment pattern is detected. The A / D converter for converting to data cannot be used in the full range, and the measurement accuracy decreases. Further, when the luminance level of the external incident light changes during the measurement, the adjustment pattern may be canceled due to the change in the luminance, and there has been a problem that the reliability of the measured value is reduced.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an image is projected by a projection tube of each color of RGB, and an image of each color is synthesized on a screen to form a color image. A display device capable of forming an adjustment pattern, comprising: an adjustment pattern generation unit that generates an adjustment pattern; and a light receiving unit that is arranged near the outer periphery of the screen at a position where the adjustment pattern can be input, and that measures the luminance of the adjustment pattern. And a light blocking means for blocking part or all of the externally incident light that enters through the screen from the light receiving unit.

According to the present invention, part or all of the externally incident light can be cut off to the light receiving portion of the light detecting means, so that the influence of the externally incident light is reduced and the measurement accuracy of the adjustment pattern is improved. Can be done. As a result, it is possible to obtain a good image without convergence deviation.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the display device according to the present invention will be described. FIG. 1 is a block diagram showing a main part of the projector device of the present embodiment. The tuner 1 is configured to select, for example, a terrestrial broadcast, a satellite broadcast, or the like received by the antenna A. The received signal selected here is selected by the switch SW and supplied to the video processor 2.
Although not shown, an external signal supplied from, for example, a video deck provided as an external input device is selected by a switch SW via an external input terminal t and supplied to the video processor 2. The video processor 2 performs various kinds of signal processing on the reception signal selected by the switch SW or the external input signal as needed, and outputs a video signal of each color of RGB.

Further, the video processor 2 is provided with an adjustment pattern generator 3. As will be described later, the adjustment pattern generation unit 3 is configured to generate and output first and second adjustment patterns that are alternately displayed in the convergence deviation adjustment mode, and to output the first and second adjustment patterns in the adjustment mode. , Not the input signal selected by the switch SW, but the pattern signal for displaying the adjustment pattern is selected and output. Also, since the first and second adjustment patterns may be input to a light detection unit described later,
The first and second adjustment patterns may be generated only in the overscan area that is not the effective image area, and a normal image selected by the switch SW may be output in the effective image area. In this case, the convergence deviation can be corrected while monitoring a normal image on the screen.

[0010] RGB output from the video processor 2
The video signal of each color is provided for each color, for example, CR
Projection tube 4R, 4G, 4B composed of T, projection lens, etc.
Supplied to The projection tube 4 (R, G, B) deflects the input video signal at a predetermined timing by the deflection yokes 5R, 5G, 5B, for example, by using a Fresnel lens,
Screen 6 composed of lenticular lenses, etc.
To be able to project an image. That is, the image for each color formed on the tube surface of each of the projection tubes 4 (R, G, B) is combined directly on the screen 6 after being reflected via the optical system or directly by the reflection means, and a color image is formed. It is formed.

The screen 6 is supported by a bezel 7 disposed around the screen 6 and attached to a housing of a projector device (not shown). In the case of this embodiment, the photodetectors 8a and 8b (for example, for correcting vertical convergence deviation) which are constituted by, for example, a photodiode, a phototransistor, etc. And photodetectors 8c and 8d
(For example, for correcting horizontal convergence deviation), which receives (receives) an adjustment pattern in the adjustment mode and outputs an input level, that is, a measured value as a current level. The light receiving unit of the light detecting unit 8 (a, b, c, d) may be configured to be light-sensitive with a material such as amorphous silicon or cadmium sulfide. Further, as will be described in detail later, the light detection unit 8 (a, b, c,
In (d), an eave portion serving as a light blocking unit is provided so that a part or all of the external incident light that enters through the screen 6 can be blocked from the light receiving unit. The output of the light detection unit 8 (a, b, c, d) is converted to a voltage level by a current / voltage conversion unit 9, further converted to digital data by an A / D conversion unit 10, and
Supplied to

When correcting the convergence deviation in the vertical direction (horizontal direction), for example, the correction can be performed only by the light detection unit 8a (light detection unit 8c).
By providing the (light detection unit 8d), the adjustment accuracy can be improved, and the light detection units 8a and 8b (the light detection unit 8d) can be adjusted.
Both c and 8d) can be used to correct the convergence deviation in the twist direction. That is, when the adjustment is performed only in the vertical and horizontal directions, the light detection unit 8a or 8
b, at least two of the photodetectors 8c or 8d may be provided. Further, by arranging the light detection units at the four corners of the screen 6, it is possible to apply the correction to the convergence deviation around the screen.

The control unit 11 turns on / off the power of the projector itself, selects a channel of the tuner 1, and responds to a command input from the remote commander RC via the command receiving unit 12 by a user's input operation. Various controls such as image quality adjustment by the video processor 2 and switching of the switch SW are performed. Further, for example, by turning on the power while holding down a predetermined operation key of the remote commander RC, it is possible to shift to a service mode in which various maintenances can be performed. In this case, a normal image display is performed. A menu screen or the like on which a specific maintenance operation can be performed without performing the operation is displayed. At this time, it is possible to shift to the adjustment mode for correcting the convergence deviation. Note that the adjustment mode does not necessarily need to be provided as one of the service modes, and may be selectable by a normal menu operation or the like.

When the operation mode is shifted to the adjustment mode, the control unit 11 controls the adjustment pattern generation unit 3 to display the adjustment pattern, and also converts the digital data inputted from the A / D conversion unit 10 into the light detection unit 8 ( a, b, c,
Based on the measured value (voltage value) of d), the deflection waveform generator 12
Control. As a result, the displayed adjustment pattern can be moved in the horizontal direction, the vertical direction, and the like. Then, the generated deflection waveform is supplied to the DY drive 13, and a deflection current for correcting the convergence deviation is supplied from the DY drive 13 to the deflection yoke 5 (R, G, B).

The memory 14 is configured as a storage means for temporarily storing the measured values in the adjustment mode, for example, and is used as a work area when correcting the convergence deviation by comparing the measured values at predetermined intervals. The memory 14 is also used as a work area or the like when performing various kinds of signal processing other than in the adjustment mode, and is also used as a means for storing set values and the like after adjustment.

Next, the adjustment pattern output from the adjustment pattern generator 3 in the adjustment mode will be described. FIG.
FIG. 2A is a diagram schematically showing a change portion of the luminance level of the horizontal adjustment pattern corresponding to the positions of the light detection units 8c and 8d provided on the bezel 7, and FIG. FIG. 2B shows a second adjustment pattern in which the changing brightness level is reversed from the first adjustment pattern.

The first adjustment pattern P1 shown in FIG.
For example, the luminance level is peaked at point a1,
The luminance gradually decreases from point a1 to point b1, and a part of one horizontal period at which point b1 becomes 0 level is shown. Further, the second adjustment pattern P shown in FIG.
2 has a change characteristic opposite to that of the first adjustment pattern P1, and indicates a part of one horizontal period in which the luminance level gradually increases from the point a1 and reaches the 0 level after reaching the peak at the point b1. ing. To correct convergence deviation,
The first adjustment pattern P1 and the second adjustment pattern P2 are switched and displayed alternately at a predetermined timing, and, for example, the luminance level between points a1 and b1 is detected by the light detection unit 8c (and / or 8d). . Then, the convergence deviation can be corrected by moving each adjustment pattern so that the luminance level difference of each adjustment pattern becomes the minimum value.

In FIGS. 2A and 2B, a pattern in which the luminance level gradually changes in the opposite direction from the point a1 to the point b1 is shown, but the luminance is stepwise changed from the point a1 to the point b1. A changing adjustment pattern may be formed.

The convergence deviation in the vertical direction is
The correction is performed using an adjustment pattern having a different luminance level for each horizontal line. FIG. 3 is a diagram schematically showing the luminance levels of the adjustment patterns P3 and P4 for adjusting the convergence deviation in the vertical direction. FIGS. 3A, 3B, 3C and 3D show one of the adjustment patterns P3 and P4. FIG. 3E is a schematic diagram showing the change in the luminance level of the horizontal line in a stepwise manner.
It is a figure which shows the brightness level D1, D2 detected from the adjustment pattern shown to (c) and (d). FIG. 3 (a)
In (b), (c), and (d), four patterns of luminance levels are shown as one set of horizontal lines that form the adjustment patterns P3 and P4. The luminance levels of the corresponding number of horizontal lines are changed.

As shown in FIGS. 3 (a), 3 (b), 3 (c) and 3 (d), the adjustment pattern P3 gradually changes from point a2 to point b2 for each horizontal line as shown by the solid line. Is a pattern in which the luminance level becomes low. Further, the adjustment pattern P4 is moved from the point a2 to the point b as shown by the broken line.
The brightness level is gradually increased for each horizontal line toward two points. In other words, FIG.
FIG. 3E shows a change in luminance level corresponding to FIGS. 3A and 3B.

Then, the adjustment pattern P3 and the adjustment pattern P4 are switched and displayed alternately at a predetermined timing, and, for example, the light detector 8a (8b) detects the luminance level between the points a2 and b2, and The convergence deviation can be corrected by moving each adjustment pattern so that the luminance level difference becomes the minimum value, that is, by changing the luminance level for each horizontal line.

FIG. 3E shows an example in which the luminance level changes for each horizontal line between points a2 and b2. For example, a plurality of continuous horizontal lines between points a2 and b2 are displayed. As the same luminance level, the luminance level may be changed stepwise for each of a plurality of lines.
In this case, for example, video signals of a plurality of horizontal lines having the same luminance level are simultaneously input to the light detection unit 8a (8b).

When actually correcting the convergence deviation, the adjustment patterns P1, P2 or the adjustment patterns P3, P4 described with reference to FIGS. The display is performed alternately at the positions corresponding to 8a and 8b, and the optical path in this case is, for example, as shown in FIG. 4 as an example.

FIG. 4 is a schematic diagram for explaining an optical path when the adjustment patterns P3 and P4 in the vertical direction are input to the light detection units 8a and 8b. ing. In addition, the projection tube 4 (R,
G and B) are arranged side by side, but only one is shown in this figure. The image light projected from the projection tubes 4 (R, G, B) is reflected forward by a mirror M arranged in the housing 20 and reaches the screen 6. Here, the optical path indicated by the solid line is the image light L forming an effective screen, and an image is formed by transmitting through the screen 6. The optical path indicated by a broken line is outside the effective screen, that is, the overscanned image light PL that does not appear on the screen 6, and the adjustment patterns P3 and P4 described with reference to FIG. 3 are output. Thereby, the projection tube 4
Adjustment pattern P output from (R, G, B)
3, P4 are input to the light receiving sections of the photodetectors 8a, 8b.

Although not shown, when viewed from above the projector device, for example, the horizontal adjustment patterns P1 and P2 which are the overscanned image light PL are:
Similarly, after being reflected by the mirror M, the light is input to the light detection units 8c and 8d.

As described above, the light detecting section 8 (a, b,
By inputting the adjustment pattern P (1, 2, 3, 4) to c and d), the convergence deviation can be corrected. However, as shown in FIG. 5, for example, when external incident light GL is incident from the outside of the housing 20 via the screen 6 and the mirror M, depending on the incident angle, the light detection units 8a and 8b (8c and 8d). Will be entered. In this case, an error occurs in the measurement of the adjustment pattern and the measurement accuracy is reduced. Therefore, according to the present invention, as described with reference to FIG. 6, the light detection unit 8 (a, b, c, d) blocks light. An eave portion is provided as a means so that part or all of the external incident light GL can be blocked from the light receiving portion. Note that at least the adjustment pattern P
It is formed so that the external incident light GL can be blocked to such an extent that an error does not occur in the measurement of (1, 2, 3, 4) and the measurement accuracy is reduced.

Hereinafter, the configuration of the light detecting section 8 will be described in detail. FIG. 6 is an enlarged view showing the vicinity of the light detection unit 8b shown in FIGS. 4 and 5, and the image light L and PL output from the light detection unit 8b and the projection tube 4 (not shown) and the screen. 6, optical paths of external incident lights GL1 to GL3 input through a mirror M (not shown) are schematically shown.

As described above, the light detecting section 8b is attached to the bezel 7 supporting the screen 6,
Together with the housing 20. The light detection unit 8b supports a light receiving unit 21 for actually inputting light and allows the light receiving unit 21 to be disposed on the bezel 7, and a light receiving unit 21 from the upper end portion of the holder 22. For example, it is constituted by an eaves portion 23 which covers the portion and can block external incident light GL1 to GL3. Note that the image light L forming the effective screen reaches the screen 6 and forms an image on the screen 6.

By providing the eaves portion 23 as described above, for example, the externally incident light GL1 to GL3
Can be shut off. For this reason, the light receiving unit 21 can detect the adjustment pattern P serving as the image light PL in a state where the influence of the external incident lights GL1 to GL3 is reduced. Therefore, since the detection output can be set to a low level, the A / D converter 10 can be used in a full range. This makes it possible to improve the measurement accuracy of correcting the convergence deviation due to the adjustment pattern P. Further, even when the amount of the external incident light GL changes during the measurement, the influence on the light receiving unit 21 can be reduced, so that it is possible to prevent an error in the measurement result due to the external incident light GL.

Although FIG. 6 shows only the light detecting section 8b as an example, the light detecting section 8a and the horizontal light detecting sections 8c and 8d have the same configuration.
External incident light GL to the light receiving unit can be blocked.

Further, in the present embodiment, an example has been described in which the eaves portion 23 is formed as a part of the light detection portion 8, but the eaves portion 23 may be formed on the bezel 7 to which the light detection portion 8 is attached. . Further, by forming the eaves portion 23 in black, it is possible to minimize the reflection of the external incident light GL on the eaves portion 23, and to improve the measurement accuracy.

Further, in this embodiment, an example has been described in which the eaves 23 are provided as the light blocking means. However, the shape of the light blocking means is not limited to this, and the external incident light G
It is only necessary that L be formed in a shape that can block a part or all of L.

[0033]

As described above, according to the present invention, when the convergence is adjusted by using the adjustment pattern that is used as the overscanned image light, the external incident light incident from the outside of the housing via the screen is adjusted. Since part or all of the light receiving unit can be blocked, the output of the light receiving unit can be stabilized without being affected by external incident light, and the measurement accuracy can be improved. become. In addition, by forming the light blocking means integrally with the holder section holding the light receiving section, low cost can be realized. Further, by forming the light blocking means in black, reflection at the eaves can be minimized, and internal reflection of the housing can be reduced to improve measurement accuracy. As described above, according to the present invention, the convergence deviation can be corrected with high accuracy, so that a good image can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a main part of a display device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing luminance levels of first and second adjustment patterns (horizontal direction) in the present embodiment.

FIG. 3 is a schematic diagram showing a luminance level of a vertical adjustment pattern in the present embodiment.

FIG. 4 is a schematic diagram illustrating an example of an optical path when an adjustment pattern is output.

FIG. 5 is a schematic diagram illustrating an example of an optical path of external incident light.

FIG. 6 is a schematic diagram illustrating an example in which an optical path of external incident light is blocked by an eave portion.

[Explanation of symbols]

3 adjustment pattern generator, 6 screen, 7 bezel, 8a, 8b, 8c, 8d photodetector, 20 housing,
21 light receiving section, 22 holder section, 23 eave section, GL1,
GL2, GL3 External incident light, L video light, P1 to P4
Adjustment pattern

Claims (3)

[Claims] 1. A display device capable of projecting an image by a projection tube of each color of RGB and forming a color image by synthesizing the image of each color on a screen, comprising: an adjustment pattern generating means for generating an adjustment pattern; A light detection unit that is arranged at a position where the adjustment pattern can be input near the outer periphery of the screen and includes a light receiving unit that measures the luminance of the adjustment pattern, and a part or all of the external incident light that enters through the screen. A light blocking unit for blocking the light receiving unit. 2. The display device according to claim 1, wherein the light blocking unit is formed integrally with the light detecting unit. 3. The display device according to claim 1, wherein the light blocking unit is formed in black.