JPH10117358A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct convergence deviation by moving the display positions of 1st and 2nd adjustment patterns in a prescribed direction to minimize the difference of output signals provided, when these adjustment patterns are selectively alternately outputted. SOLUTION: For a 1st adjustment pattern P1 , its luminance level becomes a peak at a point (a), and its luminance lowers gradually from a point a1 to a point (b) and becomes a '0' level at the point (b). A 2nd adjustment pattern P2 has change characteristics in reverse to the 1st adjustment pattern P1 , its luminance level is gradually increased from the point (a) and its luminance reaches a peak at the point (b) and becomes a '0' level later. Then, the 1st and 2nd adjustment patterns P1 and P2 are alternately displayed, while being switched at prescribed timing, the luminance level between the points (a) and (b) is detected by a photodetection part. The respective adjustment patterns P1 and P2 are moved so that the luminance level difference between the respective adjustment patterns P1 and P2 can become a minimum value. Namely, by changing the luminance level, the convergence deviation can be corrected.

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]

Since each color light output from each projection tube has a different incident angle with respect to the screen, convergence adjustment is performed to adjust the color shift and 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. So, to correct this convergence gap,
For example, a convergence deviation correction system disclosed in Japanese Patent Application Laid-Open No. H8-9399 and a display device using the same are known.

In this conventional example, as a method of detecting a convergence deviation, for example, a luminance received at a predetermined position on an outer peripheral portion of a transmission screen (comprised of a Fresnel lens, a lenticular lens, etc.) of a rear projection type projector device is used. A photodetector for detecting the level is provided. Then, the maximum output voltage when the adjustment pattern of constant brightness for adjusting the convergence deviation projected by the projection tube is incident on the photodetector and the minimum output voltage when the adjustment pattern is not incident on the photodetector are set in advance. Detected and stored, comparing these voltage values with the voltage values currently detected from the photodetector, to determine whether the specific position of the adjustment pattern and the position of the photodetector have a fixed positional relationship. Is to be detected.

However, in the above conventional example, it is necessary to detect and store the maximum voltage value and the minimum voltage value in advance, and it takes time and effort for adjustment. Further, since the maximum voltage value and the minimum voltage value are once subjected to A / D conversion and then compared as digital data, A / D conversion means having a wide dynamic range is required. In addition, since the comparison is made with the previously stored maximum / minimum voltage value, an error occurs if the measurement condition changes due to the influence of external light or the like during the adjustment.
Further, an expensive photodetector having a large light receiving area is required to detect how much the adjustment pattern is incident on the photodetector. Further, when the light receiving portion is widened, the photodetector may be located in the screen, and the image may be significantly reduced, and the number of scanning lines crossing the light receiving portion may change depending on the adjustment state. Since an error occurs, there is a problem that it is necessary to perform a coarse adjustment in advance.

[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. In a display device capable of forming a first adjustment pattern, a first adjustment pattern whose luminance changes along a predetermined direction and a second adjustment pattern having characteristics opposite to those of the first adjustment pattern are generated. An adjustment pattern generating means, arranged at a position where the first and second adjustment patterns can be input in the vicinity of the screen and / or the outer periphery of the screen, and measures the luminance of a predetermined portion of the first and second adjustment patterns Light detecting means, a deflection waveform generating means for moving the display positions of the first and second adjustment patterns, and a deflection waveform generating means for selectively outputting the first and second adjustment patterns. A display device comprising control means for controlling the movement of the display position of the first and second adjustment patterns in a predetermined direction such that the difference between the output signals of the light detection means is minimized or maximized. I do.

According to the present invention, each color image can be aligned by comparing the outputs of the light detecting means when the first adjustment pattern and the second adjustment pattern are displayed alternately. Is performed on the image of each color of RGB, so that the convergence deviation can be corrected. Therefore, during the measurement by the light detection unit, even if the measurement conditions change due to, for example, external light or light reflected from the screen, it is possible to suppress the occurrence of an error,
Further, since the influence of the reflected light from the screen or the like is small, the adjustment can be performed with high accuracy during the display of the video signal.

[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, in the present invention, the video processor 2 is provided with the adjustment pattern generator 3.

As will be described later, the adjustment pattern generating section 3 is configured to generate and output first and second adjustment patterns which are alternately displayed in the convergence deviation adjustment mode. In the adjustment mode, control is performed so that a pattern signal for displaying an adjustment pattern is selected and output instead of the input signal selected by the switch SW. Also, since the first and second adjustment patterns may be incident on the light detection unit described later, the first and second adjustment patterns are generated only in the overscan area that is not the effective image area, and the first and second adjustment patterns are generated in the effective image area. A normal image selected by the switch SW may be output. 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, so that, for example, a Fresnel lens,
Screen 6 composed of lenticular lenses, etc.
Image can be projected on the screen. That is, the image for each color formed on the tube surface of each of the projection tubes 4 (R, G, and B) is combined directly on the screen 6 after being reflected through the optical system or by the reflection means, and is combined with the color image. 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. The output of the light detector 8 (a, b, c, d) is converted to a voltage level by the current / voltage converter 9, further converted to digital data by the A / D converter 10, and supplied to the controller 11. .

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 further apply the correction of 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 selects a video signal in response 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 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,
The deflection waveform generator 12 based on the measurement value detected in d)
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).

In the present invention, the memory 14 is constituted as a storage means for temporarily storing the measured values during the adjustment mode, for example, as a work area for correcting the convergence deviation by comparing the measured values at predetermined intervals. Used.
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.
Are specific photodetectors 8 (a, b,
FIGS. 2A and 2B are diagrams schematically showing a change portion of the luminance level of the adjustment pattern corresponding to the positions of c and d. FIG. 2A is a first adjustment pattern, and FIG. 2B is a first adjustment pattern. And the second adjustment pattern in which the changing brightness level is reversed.

The first adjustment pattern P ₁ shown in FIG.
Is a part of one horizontal period for correcting the convergence in the horizontal direction, for example, where the luminance level peaks at point a, and gradually decreases from point a _{1 to} point b ₁ and becomes zero at point b. Is shown. Also,
Figure 2 a second adjustment pattern P ₂ shown in (b) has a first adjustment pattern P ₁ and the inverse of the change characteristics, gradually luminance level is increased from _a point a, peak b ₁ point Shows a part of one horizontal period in which the signal reaches the 0 level after the threshold value has been reached. Then, the first adjustment pattern P ₁ and the second adjustment pattern P ₂
Are switched and displayed alternately at a predetermined timing. For example, the light detection unit 8c (8d) detects the brightness level between the points a and b, and sets the brightness level difference between the adjustment patterns to the minimum value. The convergence deviation can be corrected by moving the adjustment pattern.

[0018] In FIG. 2 (a) (b), but up to b ₁ point from _a point a showed a pattern that varies in opposite directions gradually luminance level, steps between b ₁ point from _a point a It is also possible to form an adjustment pattern in which the luminance changes.

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 brightness levels of the adjustment patterns P ₃ and P ₄ for adjusting the convergence deviation in the vertical direction. FIGS. 3A, 3 B, ₃ C, and 3 D show the adjustment patterns P ₃ , schematic diagram showing stepwise changes in the brightness level of one horizontal line of the P _4, FIG. 3 (e) is FIG 3 (a) (b)
Is a diagram showing the luminance level D _1, D ₂ which are detected from the adjustment pattern shown in (c) (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 P ₃ and P _4. The luminance levels of the horizontal lines are changed as needed.

As shown in FIGS. 3 (a), 3 (b), 3 (c) and 3 (d), the adjustment pattern P ₃ is a horizontal line extending from point a _{2 to} point b ₂ as shown by a solid line. Each time, the luminance level is gradually reduced. Further, b adjustment pattern P ₄ from a _2-point as indicated by a broken line
_The luminance 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 P ₃ (solid line) and the adjustment pattern P ₄ (dashed line) are switched at a predetermined timing and alternately displayed, and, for example, the light detection unit 8a (8b) changes the brightness level between points a _{2 and} b _2. Detect
The convergence deviation can be corrected by moving each adjustment pattern such that the luminance level difference between each adjustment pattern becomes the minimum value, that is, changing the luminance level for each horizontal line.

[0021] Incidentally, a plurality of an example is shown in which the luminance level changes, continuous between e.g. a _2-point ~b ₂ points per each horizontal line between FIG 3 (e) in a _2-point ~b ₂ points May be set as the same luminance level, and this 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 P ₁ and P ₂ or the adjustment patterns P ₃ and P ₄ described with reference to FIGS. ) Or the positions corresponding to the light detection units 8 (c, d) are alternately displayed, and the patterns to be displayed are schematically shown in FIGS. 4 (a) to 4 (d). become. Adjustment pattern P ₁ and the adjustment pattern P ₂ to modify the horizontal convergence displacement, the light detector 8
a position corresponding to c and / or the light detection unit 8d, for example, as shown in FIG. 4 (a) (b), alternately as an adjustment pattern of varying intensity in the horizontal direction toward the b ₁ point from _a point a Is displayed. The adjustment pattern P ₃ and adjustment pattern P ₄ to correct the vertical convergence deviation, the position corresponding to the light detecting portion 8a and / or the light detection unit 8b, for example as shown in FIG. 4 (c) (d) Then, an adjustment pattern in which the luminance changes in the vertical direction from point a _{2 to} point b ₂ is alternately displayed.

Although not shown in FIG. 1, for example, photodetectors are provided at the four corners of the bezel 7, and at positions corresponding to these photodetectors, that is, at corners where an image is formed, for example, as shown in FIG. e) the adjustment pattern P ₅ shown in (f),
P ₆ , the adjustment patterns P ₇ and P ₈ shown in FIGS.
Are alternately displayed, so that position detection in the horizontal direction and the vertical direction can be performed. FIG. 4 (e) (f)
Adjustment pattern P _5, P ₆ shown in is a pattern displayed alternately, for example, the upper left corner and / or lower right corner portion of the bezel 7, b ₁ point from the left oblique direction (a ₁ point, and a ₂ is formed so that the brightness level changes toward the b ₂ points) from the point. Further, FIG. 4 (g) (h) to indicate adjustment pattern P _7, P _8, is a pattern displayed alternately, for example, the upper right corner and / or lower left corner portion of the bezel 7, the right oblique direction (a ₁ point b ₁ point, and toward the b ₂ points) from a _2-point is formed so that the brightness level changes from.

Since these adjustment patterns P _{5 to} P ₈ are formed so that the luminance level changes in the horizontal direction and the vertical direction from the corners, when correcting the convergence deviation in the horizontal direction, for example, after first modified horizontal horizontal convergence displacement by detecting the brightness level while moving (from a ₁ point b ₁ point direction), is then moved (from a _2-point b ₂ points direction) perpendicular to the However, by detecting the luminance level for each horizontal line, the convergence deviation can be corrected.

The adjustment pattern P ₅ and the adjustment pattern P
₆ , the adjustment pattern P ₇ and the adjustment pattern P ₈ may be displayed alternately in pairs. The adjustment patterns P ₅ and P ₆ may be displayed in the upper right corner and / or the upper left corner of the image, and the adjustment pattern P ₇ , it may be displayed to P ₈ in the upper left corner and / or the upper right corner of the image. FIG.
Each of the adjustment patterns shown in (a) to (h) is displayed at a position corresponding to the light detection unit 8 (a, b, c, d) arranged on the bezel 7, so that the user can It is not displayed for.

Next, an example in which the convergence deviation is corrected by the adjustment pattern will be described. FIGS. 5A and 5B
FIG. 3 is a schematic diagram showing an example in which a convergence deviation is actually corrected by the first and second adjustment patterns P _{1 and} P ₂ shown in FIGS. In this figure, a case will be described as an example in which the convergence deviation in the horizontal direction is corrected by using the light detection units 8c and 8d provided on the left and right of the bezel 7 shown in FIG. Also, the measured value D ₁
Is an adjustment pattern P ₁ input to the light detection unit 8c (8d).
And the measured value D ₂ indicate the level of the adjustment pattern P ₂ input to the photodetector 8 c (8 d), and these measured values indicate the current / voltage converter 9 and the A / D converter 10. This is supplied to the control unit 11 via the control unit 11. Further, in this figure shows for convenience the second adjustment pattern P ₂ by a broken line.

For example, as shown in FIG.
If on the basis of the intersection C, and a boundary the point of intersection C, and the measured value D ₁ greater than the measured value D ₂ in the arrow L side, the arrow R
The measurement value D ₂ is larger than the measured value D ₁ is the side. That in FIG. 5 (a), the light detecting unit 8c (8d) will be measured located in the arrow L side from the intersection C as a position of the reference to correct the convergence, measurements D _1> D ₂
Becomes In this case, the controller 11 receives the measurement result of the light detector 8c and controls the deflection waveform generator 12 to move the display positions of the adjustment patterns P ₁ and P _{2 in} the direction of the arrow L. Then, each time the adjustment patterns P ₁ and P ₂ are moved, the measured values D ₁ and D ₂ are compared, and the display position is moved in the direction of the arrow L until the difference becomes, for example, a minimum.

As shown in FIG. 5B,
If the light detecting unit 8c (8d) makes a measurement by the arrow R side of the intersection point C, the measurement result is D ₁ <D _2. In this case, the controller 11 receives the measurement result of the light detector 8c and controls the deflection waveform generator 12 to move the display positions of the adjustment patterns P ₁ and P _{2 in} the direction of the arrow R. Each time the adjustment patterns P ₁ , P ₂ are moved, the measured values D ₁ ,
Compared to D _2, or the difference is minimized for example, or FIG. 5 as shown (c), the to move the display position in the direction of arrow R until the measured value D ₁ = D ₂ To

[0029] Thus, for example, the light detecting unit 8c, by measuring the luminance difference adjustment patterns P _1, P ₂ by 8d, which position adjustment pattern P _1, P ₂ is the optical detection unit 8c, relative to 8d Can be detected. Further, in accordance with the detection result, the deflection waveform generator 12
, And the adjustment patterns P ₁ and P ₂ can be displayed at the position where the difference between the measured values D ₁ and D ₂ is minimized. By performing this adjustment repeatedly for each of the RGB colors, the convergence is achieved. The deviation can be corrected.

Correction of vertical convergence deviation
Adjustment pattern P_Three , P _Four Display and
The same measurement as that of the light detection units 8c and 8d is performed by the output units 8a and 8b.
You just need to make a decision. In this case, as shown in FIGS.
The change characteristics of the luminance level between the point a and the point b
For each adjustment, for example, the adjustment pattern P_Three In case of shine for each line
The video signal increases in degree, and the adjustment pattern P_Four in the case of
Are formed such that the luminance decreases for each line. Soshi
And the measurement by the light detectors 8a and 8b over the line
Value D₁ , D_Two Adjustment patterns so that the difference between
You will move your body up and down.

In the following, according to the flowchart shown in FIG. 6, the light detecting section 8 (any of 8a, 8b, 8c, 8d)
The process of the control unit 11 when correcting the convergence deviation in the horizontal direction by using is described. In this flowchart, the position of the G color is adjusted first, and then the R color is adjusted.
An example of shifting to the color B and the color B is given.

First, the process shifts to an adjustment mode for correcting a convergence deviation (S001). After entering the adjustment mode,
For example the adjustment pattern P ₁ for G color adjusting adjustment pattern P
₂ will be displayed alternately. Therefore, at the timing adjustment pattern P ₁ is displayed by the projection tube 4 (S002), the measurement value D ₁ of the particular optical detector 8 memory 14
(S003). Then, by switching the display of the projection tube 4 from the adjustment pattern P ₁ in the adjustment pattern P ₂ (S004), stores the measurement value D ₂ of the light detector 8 in the memory 14 (S00
Five). Then, the measured value D stored in the memory 14
₁ compares the D _2, to determine any one value is larger (the magnitude of the luminance difference) (S006).

If it is determined in step S006 that D ₁ <D ₂ , the process proceeds to step S007, where the adjustment patterns P ₁ , P
₂ is moved in the direction of arrow R (shown in FIG. 5B). If it is determined in step S006 that D ₁ <D ₂ , the process proceeds to step S008, where the adjustment patterns P ₁ , P ₂
Is moved in the direction of arrow L (shown in FIG. 5A). Then, similarly to the case of steps S003 and S005, the measured values D ₁ and D ₂ after the movement are stored in the memory 14 (S009), and step S0
It is determined whether the magnitudes of the measured values D ₁ and D ₂ stored in 09 have been reversed (S010). Here, if the magnitudes of the measurement values D ₁ and D ₂ are not reversed, the process returns to step S006, and the measurement values D ₁ and D ₂
Moving the adjustment pattern according to the magnitude of D _2. Also,
If it is determined that the magnitudes of the measured values D _{1 and} D ₂ have been reversed after steps S006 to S009, the adjustment of the G color is ended at that timing (S011).

When the adjustment of the G color is completed, next, for example, an adjustment pattern for the R color is displayed to perform the alignment of the R color and the G color (S012, S013). May be performed in the same manner as steps S001 to S011 described in the case of G color.

In step S006, for example, FIG.
As described in (c), the measured value D ₁ and the measured value D
_{If 2} is determined to be equal (for example, intersection C), the process proceeds to step S011 on the spot as indicated by a broken line, and G
The color registration may be terminated. Also, since the measured values D ₁ and D ₂ after the movement are stored in step S009, the difference between these measured values (= D
_{If 1−} D ₂ ) is held, it can be compared with the level difference of the difference (= D ₁ −D ₂ ) of the measured value measured in the next routine, and if this level difference is monitored, the adjustment pattern can be obtained. Can be determined.

Further, for example, when correcting the convergence deviation in the torsional direction, the difference between the measured values D _{1 and} D ₂ of the respective light detectors 8a and 8b is calculated by simultaneously using the light detectors 8a and 8b. By calculating the difference between these detection results as a detection result, it is possible to detect a positional shift in the torsion direction. By controlling the deflection waveform generator 12 in accordance with the difference, it is possible to perform alignment in the twist direction. Furthermore, by using the light detection units 8c and 8d together with the light detection units 8a and 8b, it is possible to detect positional deviation in the twist direction at four locations around the screen 6.

Further, even when the convergence deviation is corrected using the adjustment patterns P ₉ and P ₁₀ as shown in FIG. 7, for example, the luminance difference H is provided at a position apart from the intersection C of each pattern to adjust the adjustment position. Can be prevented from losing sight of the direction in which the adjustment pattern is moved (adjustment direction) even when the deviation is large.

Further, as the adjustment pattern is shown in FIG. 8, for example, an adjustment pattern P ₁₁ which luminance has a peak at a given point, adjustments have this adjustment pattern P ₁₁ and opposite characteristics using the pattern P _12, by the light detecting section 8 (a, b, c, d) is point I, i.e. luminance difference is detected to measure the portion to be the maximum point, so that it is possible to correct the convergence deviation become.

In the above embodiment, the light detection unit 8
(A, b, c, d) a bezel 7 supporting the screen 6
Although the example of disposing them has been described above, they may be disposed on the screen 6.

[0040]

As described above, according to the present invention, a plurality of adjustment patterns having the opposite characteristics are displayed alternately, and at this time, the displacement of the position adjustment pattern is determined from the measured value by the light detecting means. That is, the convergence deviation can be adjusted. As a result, it is not necessary to prepare in advance for detecting and storing a reference set value as in the related art, and the adjustment can be performed quickly. In addition, even if the measurement conditions change due to, for example, external light or reflected light from a screen during the measurement, it is possible to suppress the occurrence of an error and to reduce the influence of the reflected light from the screen or the like. Automatic adjustment can be performed with high accuracy during display. Further, since the light detection means only needs to detect the luminance at a predetermined point, there is an advantage that the size can be reduced and the cost can be reduced.

[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 showing a state when an adjustment pattern is displayed.

FIG. 5 is a diagram illustrating an example in which convergence deviation is corrected using the first and second adjustment patterns shown in FIG. 2;

FIG. 6 is a flowchart illustrating a process performed by a control unit when correcting a convergence deviation;

FIG. 7 is a schematic diagram illustrating an example of another adjustment pattern.

FIG. 8 is a schematic diagram illustrating an example of another adjustment pattern.

[Explanation of symbols]

2 video processor, 3 adjustment pattern generator, 4
Projection tube, 5 deflection yoke, 6 screen, 7 bezel, 8a, 8b, 8c, 8d photodetector, 9 current / voltage converter, 10 A / D converter, 11 controller, 12
Deflection waveform generator, 13 DY drive, 14 memory,
RC remote commander, P ₁ to P ₁₂ adjustment pattern

Claims (7)

[Claims] 1. A display device capable of projecting an image by a projection tube of each of RGB colors and forming a color image by synthesizing the image of each color on a screen, wherein a luminance changes along a predetermined direction. An adjustment pattern, an adjustment pattern generating means for generating a second adjustment pattern having a characteristic opposite to that of the first adjustment pattern, and the first and the second in the vicinity of the screen and / or the outer periphery of the screen. A light detecting unit that is arranged at a position where an adjustment pattern of the first and second adjustment patterns can be input, and that measures a luminance of a predetermined portion of the first and second adjustment patterns; and a deflection unit that moves a display position of the first and second adjustment patterns. The waveform generation means, and the first and second adjustment patterns are selectively output alternately, and the difference between the output signals of the light detection means, which is obtained, is minimized or maximized. The display device, characterized in that the display position of the second adjustment pattern and control means for performing control to move in a predetermined direction. 2. The display device according to claim 1, wherein the first and second adjustment patterns are formed such that the luminance gradually changes in a horizontal direction and / or a vertical direction. 3. The display device according to claim 1, wherein the first and second adjustment patterns are formed such that luminance changes stepwise in a horizontal direction and / or a vertical direction. 4. The display device according to claim 1, wherein said light detecting means comprises a photodiode. 5. The display device according to claim 1, wherein said light detecting means comprises a phototransistor. 6. The light detecting means according to claim 1, wherein said light detecting means is made of amorphous silicon.
The display device according to claim 1. 7. The display device according to claim 1, wherein said light detecting means is made of cadmium sulfide.