JP3352468B2 - Automatic convergence adjustment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic convergence adjusting device for automatically adjusting a geometric distortion and a convergence of a CRT video projector.

[0002]

2. Description of the Related Art Conventionally, in geometric distortion adjustment and convergence adjustment, an R, G, B image is formed into a rectangle while watching an image of a convergence adjustment signal (cross hatch signal or dot signal) projected on a screen. , And R, G,
The adjustment was manually performed so that B overlapped, but it took tens of minutes to several hours to complete a series of adjustments. In addition, there are a number of adjustment items for performing these adjustments, and there are dozens of adjustment volumes. As a result, skill is required for the adjustment, and a general projector user can easily perform the geometric adjustment. Distortion adjustment and convergence adjustment could not be performed. Further, in the front projection type projector, when the set is moved, it is necessary to perform the geometric distortion adjustment, the convergence adjustment and the focus adjustment each time, and this is an obstacle to simplifying the use of the projector.

Next, a conventional method for adjusting geometric distortion will be described. The geometric distortion occurs due to the influence of the installation angle (elevation angle, concentration angle) of the CRT with respect to the projection lens and the screen. This correction is performed by receiving a crosshatch signal, adjusting the raster of G so that it is rectangular on the screen, adjusting horizontal and vertical trapezoidal distortion (keystone adjustment),
It performs pincushion distortion adjustment (PCC adjustment) and linearity adjustment. The adjustment of each geometric distortion is performed by the adjuster so that a correct raster shape can be obtained by visual observation while viewing the adjustment image (cross hatch) projected on the screen. Therefore, skill is required for the adjustment, and a general projector user cannot perform the geometric distortion adjustment.

Next, a convergence adjustment method will be described. The convergence adjustment is an adjustment for making each of the R, G, and B single-color images overlap on the screen to become a color image. The R and B images are converted to the G images based on the G projection position. Overlap. This adjustment is performed such that the vertical and horizontal lines of R and B overlap the vertical and horizontal lines of G while projecting the crosshatch signal on the screen and watching the crosshatch signal.
In the adjustment procedure, first, convergence adjustment for superimposing the R and G images is performed. At this time, the adjustment is performed without taking the image of B. This is because the convergence adjustment between R and G can be easily performed by erasing the B image.

When this adjustment is completed, a convergence adjustment for superimposing the B image on the G image is performed. At this time, the image of R is erased, and the image of B is adjusted to two colors of G and B. The adjustment procedure for superimposing the R or B video on the G video has some differences depending on the convergence correction method (analog convergence, point convergence), but here the analog procedure mainly used in the conventional projector is used. A convergence adjustment procedure using the convergence method will be described.

FIG. 11 shows main adjustment points on the screen at the time of convergence adjustment. In the figure, 51 is a screen, 57 is a raster projected on the screen, 52 is an X axis, 53 is a Y axis, 54 is a focus point of static convergence adjustment at the center of the screen, 55, 5
Reference numeral 6 denotes a horizontal and vertical width and linearity adjustment attention points on the X and Y axes, respectively. Also, the video patterns (vertical lines, horizontal lines, intersections of the vertical lines and horizontal lines) of the portions other than the above 54 to 56 become all the convergence adjustment points in the area where the detailed convergence adjustment is performed when performing the detailed convergence adjustment. .

Hereinafter, the procedure of the convergence adjustment will be described. The convergence adjustment includes an adjustment for overlapping R on G and an adjustment for overlapping B on G. The adjustment of R and B may be performed from either. Note that the adjustment procedure is the same. Hereinafter, the adjustment method will be described. First, paying attention to the static convergence adjustment attention point 54 at the center of the screen, the control is superimposed on the G adjustment attention point by adjusting the horizontal and vertical static convergence adjustment volumes. Note that static convergence is convergence correction in which the entire screen is DC-driven in the horizontal direction (horizontal static convergence) or the vertical direction (vertical static convergence).

When the screen center portion overlaps G, the horizontal and vertical axes of the screen center and horizontal axis (X axis) and the vertical axis (Y axis) of the screen overlap the central horizontal axis and central vertical axis of G, respectively. SKE
Superimposed on G by W adjustment and BOW adjustment. This is X
This is convergence correction for adjusting the inclination of the axis and the Y axis.

Next, the horizontal width and the horizontal linearity are adjusted. The H-WIDE and H-LIN are adjusted so that the horizontal width and the linearity adjustment attention point 55 all overlap the G horizontal width and the linearity adjustment attention point 55. Adjust the adjustment volume. At this time, R-H-S is used for adjusting the horizontal width and horizontal linearity of only the left and right sides of the screen.
There is also a convergence circuit having IDE, LH-SIDE adjustment volumes, and if these adjustment volumes are present, these adjustment volumes are also adjusted here.

Subsequently, the vertical width and vertical linearity are adjusted. This is the point of interest 56 for the vertical width and linearity adjustment.
The volume adjustment of V-WIDE and V-LIN is performed so that all the points overlap the vertical width and linearity adjustment attention point 56 of G. Thus, the rough adjustment of the convergence adjustment of the entire screen is completed. The reason for the rough adjustment is that in the convergence adjustment so far, only the images on the X axis and the Y axis overlap the G in the screen, and the portions of the screen other than the X and Y axes do not completely overlap. Therefore, it is necessary to adjust the convergence of that part. Therefore, the convergence detailed adjustment (X,
(Convergence adjustment for parts other than the Y axis).

[0011] The detailed adjustment is sometimes referred to as "zone adjustment". The entire screen is divided into several small zones, and the vertical and horizontal lines of R and B in each zone are replaced with the vertical line of G. And convergence adjustment to overlap the horizontal line. In the low-cost convergence circuit, four-division zone adjustment is common, and is also called “four-division keystone adjustment”. Also, in each zone,
Horizontal and vertical convergence adjustment volumes are provided. In addition, in order to increase the convergence adjustment accuracy, the number of zones is increased, and 9 zones, 16 zones,
Some convergence circuits have 25 zones, and even more.

In the adjustment method, in each zone, the horizontal and vertical convergence volumes are adjusted so that the vertical and horizontal lines in the selected zone completely overlap the vertical and horizontal lines of G. . Therefore, although the adjustment accuracy improves as the number of zones increases, a longer adjustment time is required because the number of adjustment volumes increases.

As described above, the convergence adjustment procedure for R and B is exactly the same. To adjust the convergence of one video projector, the above adjustment procedure is performed for R and B. The adjustment procedure is performed twice in total. When all the above adjustments are completed, the convergence adjustment is completed. However, the number of volumes to be adjusted by the convergence adjustment is about 40 to 50 (in the case of a four-divided zone), a long adjustment time is required, and the number of adjustment procedures is large. However, skill is required due to difficulty. The conventional convergence adjustment procedure described above is shown in FIG.

Next, the convergence circuit will be described. Conventional convergence circuits include an analog convergence circuit and a digital convergence circuit. In the former, a convergence correction signal is created in an analog manner, and convergence adjustment is performed using tens of correction level adjustment volumes. There are roughly three types of convergence circuits in the latter. The first digital convergence circuit creates a convergence correction signal in an analog manner as in the analog convergence circuit, and a convergence correction level adjustment volume is digitally controlled by an electronic volume or the like. The correction level is adjusted.

The second digital convergence circuit generates a basic waveform signal of the convergence correction signal by digital operation, digitally adjusts the level of each signal, and combines them to obtain a convergence correction signal. .

The third digital convergence circuit calculates a convergence correction signal from the horizontal and vertical deviation data of G and R and B and G at adjustment points of several tens to several hundreds on the screen. There is a point convergence method to be created.

Of the above convergence circuits, the analog convergence circuit and the first and second digital convergence circuits perform convergence adjustment in accordance with the convergence adjustment procedure described in the adjustment procedure.
In addition, the third digital method (point convergence)
In this method, the convergence correction is performed by inputting the data of the amount of deviation of R and B from G at each adjustment point in the horizontal and vertical directions. A large amount of data needs to be input, so analog convergence and other digital It takes longer to input data than the convergence circuit, and the adjustment time is longer.

Further, as a system for automating the convergence adjustment of R and B, R and B projected on a screen are adjusted.
By detecting the projection position of the adjustment points of G and B on the screen,
The amount of deviation between the R and G adjustment points and the B and G adjustment points is detected,
In some cases, a convergence correction signal is created so that these overlap exactly. FIG. 13 is a block circuit diagram showing the configuration of this conventional convergence adjusting device. In the figure, 9 is a pattern signal generating unit, 11 is an adjustment point position detecting unit, 12 is a convergence circuit unit, 13 is an image processing unit, 20 is a video projector body, and a monochrome CCD camera for detecting an image projected on a screen. Is used to detect the projection positions of all the adjustment points on the screen for each of R, G, and B single colors, to detect convergence errors at the R, G, and B and G adjustment points, and to calculate the convergence error from the convergence errors. Convergence adjustment is performed by creating a correction signal. In position detection, luminance data in a small area having an adjustment point of data detected for each adjustment point is cut out using a low-frequency repetitive video pattern, and the center position of the adjustment point is obtained by an approximate expression. The detection accuracy is 0.3 × scan line accuracy.

The convergence correction signal obtained here is a correction signal for superimposing on the R and B G images.
No correction signal is created for G. Therefore, if geometric distortion such as keystone distortion or PCC distortion remains in the G image, the geometric distortion remains in the image after the convergence adjustment. To prevent this, before adjusting the convergence of R and B, keystone or PC
C adjustment (geometric distortion adjustment) is performed by manual visual adjustment,
It is necessary to eliminate the geometric distortion. It should be noted that the visual adjustment requires skill and requires an adjustment time, so that it is difficult for a general user of the video projector to perform the adjustment.

In a video projector, if the set is used for a long time, a drift occurs, and the drift causes a convergence deviation at the time of turning on the power and several hours later. This is because the set body rises in temperature by generating heat during operation of the projector body.
Therefore, when the set is used for a long time, the color shift of R, G, and B gradually occurs, and the viewer of the projector perceives the color shift and eventually deteriorates the image quality.

[0021]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and the adjuster automatically and simply gives a command for starting geometric distortion and convergence adjustment. An object of the present invention is to provide an automatic convergence adjusting device capable of performing highly accurate geometric distortion and convergence adjustment in a short time.

[0022]

An automatic convergence adjusting apparatus according to the present invention projects an image pattern signal for position detection on a screen in a time-division manner for each of R, G, and B single colors on a screen, and detects the monochromatic position detection image pattern. Are sequentially read by the imaging means, and the center of the screen of the projected G image is adjusted.
Set the alignment point as the normal position of the adjustment point of the screen center, and
G image based on the normal position of the adjustment point of the screen center
Calculate the normal position of each adjustment point of (or the projected G
The center position between the adjustment points at the left and right ends of the screen
G image projected as the X coordinate of the normal position of the adjustment point
Adjust the center position between the adjustment points at the top and bottom of the screen
The Y coordinate of the regular position of the set point
G image based on the normal position of the adjusted point of the screen center
Of each adjustment point), and for each adjustment point, first, the amount of deviation of the G from the normal position in the horizontal and vertical directions is detected, and the position of each adjustment point of the G image is corrected. R,
The horizontal and vertical shift amounts of the respective adjustment points with respect to the corrected G of B are detected to correct the positions of the respective adjustment points of the R and B images .

[0023]

The convergence correction signal in the present invention is:
Based on the horizontal and vertical position coordinates detected by the position detection operation of each of the R, G, and B adjustment points projected on the screen, a rectangular G is obtained by performing geometric distortion adjustment of G. The normal position coordinates of each adjustment point are calculated, the horizontal and vertical directions are corrected, and R and G are adjusted for each adjustment point.
, The horizontal and vertical shift amounts between the B and G normal positions are calculated, and based on the shift amount data, R and B horizontal and vertical convergence correction signals are created by a digital convergence circuit. , B convergence correction is performed.

[0024]

[Embodiment 1] Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block circuit diagram showing a configuration of the first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes an imaging unit that reads a position detection pattern projected on a screen, 2 denotes a position detection unit that detects a position of an adjustment point from an output signal of the imaging unit 1, and 3 stores an output signal of the imaging unit 1. 4 is a shift amount detecting unit for detecting a shift amount of R and B with respect to the G adjustment point, 5 is a unit for calculating the coordinates of the normal position of G, and 6 is an R, B
A digital convergence circuit for generating G and B horizontal and vertical convergence correction signals, 7 is a convergence output circuit for amplifying the output correction signal of the digital convergence circuit 6, and 8 is R, G and B respectively installed at the neck of the CRT. Horizontal and vertical convergence coils, 9 is a pattern signal generation unit for generating a position detection pattern, 10 is a control unit for controlling geometric distortion and convergence adjustment, and 11 is a position detection of an adjustment point among the constituent blocks. Is a convergence circuit for performing convergence correction.

In order to automatically perform the geometric distortion adjustment and the convergence adjustment, it is necessary to set many adjustment points on a screen and detect the projection position of each adjustment point. Further, it is necessary to detect the correction amount. In the first embodiment, the correction amount is detected as a deviation amount from the reference position.

FIG. 2 shows an example of setting adjustment points on the screen 51, which is a total of 35 adjustment points 58 of 7 horizontal points and 5 vertical points.
4 shows the adjustment point position when the symbol is provided. An image pattern 59 for position detection is displayed at the position of each of the adjustment points 58, and the horizontal and vertical coordinates of all the R, G, and B adjustment points are detected.

The image pattern 59 for position detection is shown in FIG.
As shown in FIG. 7, a circular pattern in which the luminance distribution is given by a sine wave signal in both the horizontal and vertical directions is used. FIG.
(B) shows the horizontal signal waveform of the vertical center axis,
(C) shows a signal waveform in the vertical direction of the center axis in the left-right direction. Since this signal waveform is a sine wave signal, the frequency component of the signal is not high, it is hardly affected by the frequency characteristics of the video circuit, the position can be detected as surface data, and the center position of the circular pattern can be detected. Has the characteristic that the luminance distribution becomes symmetrical left and right and up and down with respect to this peak position as a center point, and the position of the adjustment point 58 on the screen 51 is detected with an accuracy equal to or less than the pixel of the imaging means. It is suitable for automatic position detection. Further, as the installation position conditions of the adjustment points, it is necessary that the adjustment points exist on the X and Y axes and that the intervals between the adjustment points in the horizontal and vertical directions are constant.

At the time of position detection, one position detection pattern 59 is displayed at the position of each adjustment point 58 on the screen 51, and the position detection patterns 59 are displayed on the entire screen 51 by the number of adjustment points 58. At this time, the position detection video pattern 59 is displayed in such a way that only a single color of each of R, G, and B is displayed on the screen, and the position of each adjustment point of each of R, G, and B is detected in a time-division manner. . In the video projector, the luminance of the image at the periphery of the screen projected on the screen 51 is lower than the luminance at the center of the screen. This is due to the effect of the angle of view of the projection lens. Therefore, in order to compensate for this, the luminance level of the position detection video pattern 59 in the peripheral portion of the screen is set higher in advance than that of the position detection video pattern 59 in the screen center portion. As a result, the detection accuracy can be ensured even in the position detection of the peripheral portion of the screen.

Next, a position detecting method will be described. The entire screen is read at once by the imaging means 1 such as a CCD camera, and the position coordinates (X, Y coordinates) of each position detection image pattern 59 on the screen 51 are calculated. Ask by. The method of obtaining the position coordinates is as follows.
Since the detection signal of No. 9 is a sine wave signal, a sine wave signal is also obtained as the output signal of the imaging means 1 if there is no influence of noise. This output signal is stored in the frame memory 3, and the data in the vicinity of the adjustment point for performing the position detection is subsequently converted in the horizontal direction when obtaining the X coordinate (horizontal coordinate), and in the Y direction (vertical coordinate).
Is calculated by extracting data in the vertical direction. The data cutout area is the range shown in FIGS. 3B and 3C. The luminance distribution of the above cut-out area is expressed by Equation 1.
The constants a, b, and c are obtained by approximation using the quadratic expression f (x) shown in FIG. The approximation calculation is performed using the least squares method so that the error is as small as possible. f (x) = ax ² + bx + c Equation 1

Next, the X coordinate which gives the peak of the approximate quadratic equation f (x) of Equation 1 is calculated. Equation 1 · f (x) is
To become a convex parabola on the position detection image pattern 59, X-coordinate x _MAX giving a peak of approximate expression f (x) is determined by Equation 2 shown below. x _MAX = −b / 2a Equation 2 X-coordinate x giving peak calculated as above
_MAX is the position of the adjustment point 58 on the screen 51. Similarly, when the position is detected also in the vertical direction, the X and Y coordinates of the adjustment point on the screen 51 are obtained. Subsequently, for the other adjustment points 58, similarly, X,
The Y coordinate can be calculated. Also, the X and Y coordinates can be calculated for the adjustment points of the three colors R, G and B in the same manner.

Next, a method of determining the normal position coordinates of G will be described. As for the projection positions of the adjustment points on the screen 51 of G, unless the geometric distortion is adjusted, the respective adjustment points of G are not arranged in a grid pattern. In other words, even if a circular pattern is projected, the projected circular pattern is not projected on the screen 51 and becomes a distorted circular pattern. Therefore, the normal position coordinates of each of the G adjustment points 58 are determined so that each of the G adjustment points is arranged in a grid pattern, and the G convergence adjustment allows each of the G adjustment points 58 to have the correct grid shape on the screen 51. To be arranged in

However, if the normal position coordinates of each of the G adjustment points 58 are determined unilaterally, the G image is displayed on the phosphor screen edge of the CRT phosphor screen and a part of the image is missing (neck). Shadow). In order to prevent this symptom, the normal position coordinates of each G adjustment point 58 are determined using some position coordinate data of the G adjustment points 58 projected on the screen 51. Therefore, first, the projection position of the G adjustment point 58 on the screen is detected by the method described above. However, at this time, it is not necessary to detect the position coordinates of all the G adjustment points 58.

In order to determine the normal position coordinates of the G adjustment point 58, first, the adjustment point of the G screen center 54,
A total of 5 adjustment points 5 including adjustment points 55 and 56 at both ends of the X and Y axes
8 detects the projection position coordinates on the screen 51. FIG. 6 shows these adjustment points. Also, for explanation,
The detected X, Y coordinates of each adjustment point are represented by lower case letters (x, y), the normal position coordinates are represented by upper case letters (X, Y), and
To represent the coordinates of the point, the center (C), the left and right (L, R) of the X-axis end, and the upper and lower (T, B) subscripts of the Y-axis end are added. Note that all the adjustment points on the screen are a total of 35 points, 7 horizontal points and 5 vertical points.

The normal position coordinates X _C of the adjustment point of the screen center,
For Y _C, the detected x _C and y _C are used as they are. Next, X,
The normal position coordinates X _L , X _R , Y _L , and Y _R of the adjustment point at the Y-axis end are
Detected coordinates x _L of the X-axis at both ends, x _R, y _L, it is determined by the formula 3.1 to 3.3 below the y _{R. X L = X C - (x} R -x L) / 2 ····· formula _{3.1 X R = X C + (} x R -x L) / 2 ····· formula 3.2 Y _L = Y _R = y _C ························································································································································· The normal position coordinates having a rectangular shape are determined by making the Y coordinate equal to the Y coordinate of the center adjustment point.

Next, the normal position coordinates of the adjustment points at both ends of the Y axis are determined. This can be determined in the same manner as described above for both ends of the X-axis, and is shown in Equations 4.1 to 4.3. Y _T = Y _C − (y _B −y _T ) / 2 Equation 4.1 Y _B = Y _C + (y _B −y _T ) / 2 Equation 4.2 X _T = X _B = x _C ····· Equation 4.3

Next, the normal position coordinates of the adjustment points at the four corners are determined. Normal position coordinates of the upper left corner of the screen adjustment point, the X-coordinate and X _L, Y coordinates may be set to Y _T. Similarly, the X and Y coordinates of the lower left adjustment point are X _L and Y _B , and the upper right adjustment point is X
_R, Y _T, the adjustment point of the lower right X _R, may be set to Y _B. Thus, four corners and eight adjustment points at both ends of the X and Y axes become rectangular.

The normal position coordinates of the remaining G adjustment points are obtained by equally dividing the normal position coordinates of the four corner adjustment points determined above. Now, horizontal 7 points, because of the adjustment point of the vertical five points, the horizontal adjustment point interval is obtained by 6 equally divided adjustment point interval of the right and left ends, six equal parts point adjusting point X _L to X _R Let the X coordinate be the X coordinate of the normal coordinate of each adjustment point. Similarly, regarding the Y coordinate, the Y coordinate of the quadrant of the adjustment points Y _{T to} Y _{B is set} as the Y coordinate of each adjustment point. Thus, the normal position coordinates of all the adjustment points of G are determined.

Next, the actual projection position coordinates of all the adjustment points of G projected on the screen are detected. this is,
This is to create a correction signal for adjusting the geometric distortion of G. The detection method can be performed by the position detection method described above. Next, the horizontal and vertical shift amounts of the normal position coordinates of each adjustment point determined previously and the actual projection position coordinates (detection coordinates) of the adjustment point are calculated for each adjustment point, and G as the shift amount data is calculated. Used to create horizontal and vertical convergence correction signals.

Next, a method of creating the G horizontal and vertical convergence correction signals will be described. First, creation of a horizontal convergence correction signal will be described. Now, it is assumed that there are seven horizontal adjustment points and five vertical adjustment points. Also, three adjustment points are provided as interpolation points during the horizontal retrace period and one point during the vertical retrace period. It is also assumed that the signal received by the video projector is an NTSC signal. At this time, the deviation amount data of the G adjustment point with respect to the normal position includes seven deviation amount data at 1H and five deviation amount data at 1V, but there are ten deviation amount data at 1H due to interpolation of the retrace period. At 1 V, there are six shift amount data, and a horizontal convergence correction signal is created from these data.

However, among the convergence correction signals in the horizontal direction, the correction signals of six lines, which are the lines on which the adjustment points exist, can be directly created from the deviation amount data, but the remaining 519 lines of correction signals are directly derived from the deviation amount data. I can't get it. Therefore, in order to generate a horizontal convergence correction signal for all lines, the deviation amount data for 519 lines is obtained by performing interpolation processing. In the interpolation processing, interpolation data is created by filtering from the deviation amount data of each adjustment point on the line where the adjustment point exists. Through the above processing, the deviation amount data of each line for generating the horizontal convergence correction signal for all 525 lines is obtained.

By the above-described interpolation processing, ten pieces of shift amount data are obtained for all of the 525 lines, and the horizontal convergence correction signal of each line can be obtained by approximation using an approximate expression up to the ninth order. . But,
Since the actual convergence can be substantially corrected by the correction up to the fourth-order distortion, a convergence correction signal is created by a fourth-order approximation formula. An output signal based on the approximate expression is subjected to a low-order low-pass filter, current-amplified by an output circuit 7, and passed to a horizontal convergence coil 8 provided at the neck of the CRT to perform horizontal convergence correction.

On the other hand, the vertical convergence correction signal is 1
Although there are six pieces of shift amount data in V, a high-order approximation formula is calculated in the same manner as in the case of horizontal, and this is used as a vertical convergence correction signal. The vertical convergence correction signal also uses a fourth-order approximation formula as in the case of the horizontal. The output signal based on the approximate expression is current-amplified in the output circuit 7 and is passed through the vertical convergence coil 8 installed at the neck of the CRT in the same manner as the horizontal convergence correction to perform vertical convergence correction.

Thus, the geometric distortion adjustment of G is completed, and the G image projected on the screen has a shape having a correct aspect ratio. Geometric distortion may remain because the axis is shifted or the winding of each coil is shifted from an arrangement for creating an ideal deflection magnetic field. Therefore, in order to increase the accuracy of the geometric distortion correction adjustment, the projection position coordinates of each of the G adjustment points on the screen are detected again, the amount of deviation from the normal position coordinates is detected again, and the G horizontal position is again detected. , Create a vertical correction signal, and create the first horizontal,
A new horizontal and vertical correction signal of G is obtained in addition to the vertical correction signal, and the correction signal is supplied to the convergence coil 8 of G to increase the correction accuracy of the geometric distortion correction of G.

Subsequently, the procedure for the convergence correction of R and B is started. Here, the projection position coordinates on the screen of the R, G and B adjustment points are detected again. The detection method is exactly the same as the detection of the position of the G adjustment point. Note that R, G, B
The detection of the positions of the three color adjustment points is performed for each of the single colors.
Position detection is performed by time division in the order of G and B. When the detection of the position of each of the three color adjustment points is completed, G is generated for each of the R and B adjustment points in order to create R and B convergence correction signals.
Of the horizontal and vertical directions with respect to the coordinates of the projection position.

Now, the horizontal position coordinates of each detected adjustment point of R, G, B are x _RH , x _GH , x _BH , and the vertical position coordinates are x _RV ,
If x _GV and x _BV are ず れ X _RH , △ X _BH , △ X _RV , and △ X _BV , respectively, the horizontal and vertical shift amounts of R and B with respect to G are:
These can be represented by the following equations 5.1 to 5.4. ΔX _RH = x _RH −x _GH ... Equation 5.1 ΔX _BH = x _BH −x _GH ... Equation 5.2 ΔX _RV = x _RV −x _GV. Equation 5.3 ΔX _BV = x _BV −x _GV ··· Equation 5.4 By calculating these for all adjustment points, the G of R and B is obtained at all adjustment points on the screen. Are detected in the horizontal and vertical directions.

Next, R and B horizontal and vertical convergence correction signals are created by calculation from the deviation amount data of each adjustment point. The creation method is exactly the same as the method described in the explanation of the creation of the horizontal and vertical convergence correction signals for G. The created R and B horizontal and vertical convergence correction signals are respectively amplified by the output circuit 7 and passed to the R and B convergence coils 8 installed on the R and B CRTs to thereby correct the R and B convergence. The images of the three colors R, G, and B overlap exactly on the screen.

However, as described for the G correction signal, the R and B images may not be exactly overlapped with the G image due to variations in the R and B convergence coils 8. In order to increase the convergence adjustment accuracy, the projection positions of the R, G, and B adjustment points on the screen are detected again. Here, the G projection position is also detected again by reducing the time difference between the projection position data of the R, G, and B adjustment points used when creating the convergence correction signal. To escape the effects. The created convergence re-correction signal is added to the initially calculated convergence correction signal, and a new convergence correction signal is obtained and supplied to the R and B convergence coils 8 to complete the convergence adjustment. The convergence correction signal for R and B and the convergence correction signal for geometric distortion correction of G are stored in the convergence correction signal memory provided in the digital convergence circuit 6 by storing the convergence correction signal data. And can be read at any time. Therefore, if the projector body is not moved, the convergence correction is performed by reading the correction signal data from the convergence correction signal memory.

The convergence adjustment is programmed in the control means 10 so that the convergence adjustment is started at the time of turning on the power of the video projector, and the convergence adjustment is performed at predetermined intervals to correct the convergence deviation due to the drift. It is possible to do. Although the convergence adjustment is automatically performed, it can be appropriately performed by a manual operation.

Embodiment 2 FIG. In the first embodiment, the case where five points of the screen center and the four corner adjustment points are used to determine the normal position coordinates of the G adjustment point has been described.
The normal position coordinates of all the adjustment points of G can be determined only by detecting the position coordinates of the four adjustment points at both ends of the axis.
FIG. 7 shows adjustment point positions at which position detection is performed. In the second embodiment, a method of determining the normal position coordinates of the G adjustment point when four detection adjustment points are provided at both ends of the X and Y axes will be described.

In this case, the normal position coordinates X _C and Y _C of the center adjustment point are determined by the following equations 6.1 and 6.2. X _C = (x _L + x _R ) / 2 Equation 6.1 Y _C = (y _T + y _B ) / 2 Equation 6.2 This is the adjustment of both ends of the X and Y axes. The middle point of the X and Y coordinates of the point is set as the normal position of the adjustment point of the screen center. In addition,
The normal position coordinates of the other adjustment points are determined by the same method as the procedure described in the first embodiment. Also, the method of adjusting the convergence of the correction signal for the geometric distortion of G and the convergence of R and B are the same as in the first embodiment, and the same effects as in the first embodiment can be obtained.

Embodiment 3 FIG. In the second embodiment, the case where the four adjustment points at both ends of the X and Y axes are used to determine the normal position coordinates of the G adjustment point has been described, but the four adjustment points of the four screen corners are used. Can also determine the normal position coordinates of G. FIG. 8 shows the positions of the adjustment points for performing the position detection.
Hereinafter, a method of determining the normal position coordinates in this case will be described.

Now, the X and Y coordinates at which the adjustment points of the screen 4 corners are detected are _assigned the subscripts _TL , _TR , _BL and _BR to x and y in the order of the upper left, upper right, lower left and lower right adjustment points, respectively. Show with attached. First, the normal position coordinates of the X coordinate at both ends of the X axis and the Y coordinate of both ends of the Y axis are determined as temporary normal position coordinates by equations 7.1 to 7.4. x _L = (x _TL + x _BL ) / 2 Equation 7.1 x _R = (x _TR + x _BR ) / 2 Equation 7.2 y _T = (y _TL + y _TR ) / 2 ····· Equation 7.3 y _B = (y _BL + y _BR ) / 2 ····· Equation 7.4

Next, the coordinates of the normal position of the adjustment point of the screen center are calculated by the coordinates x _L , x _R , y _T , calculated by the above equations 7.1 to 7.4.
X _C and Y _{C are} calculated from y _{B according} to equations 6.1 and 6.2. Next, the normal position coordinates of the adjustment points at both ends of the X and Y axes are calculated as X _C and Y _C
Is determined by the equations 3.1 to 3.3. Hereinafter, the normal position coordinates of the other adjustment points are determined by the procedure described in the first embodiment, and the convergence correction signal is created in the same procedure as in the first embodiment.

Embodiment 4 FIG. In the second and third embodiments, the case where four adjustment points are used to determine the normal position coordinates of the G adjustment point has been described. However, even if the number of detection adjustment points is two,
The normal position coordinates of the G adjustment point can be determined. In the fourth embodiment, a method of determining the normal position coordinates of the G adjustment point when two detection adjustment points are provided at both ends of the X axis will be described. FIG. 9 shows the positions of the adjustment points for performing the position detection. In addition,
In this case, the positions of the adjustment points on the screen need to be arranged at equal intervals in the horizontal and vertical directions. As a matter of course, the position detection pattern in this case is a signal having a correct aspect ratio, and is created such that a part of the rectangular position detection pattern is not missing. Hereinafter, a description will be given assuming that position detection is performed using a position detection pattern satisfying this condition.

The X coordinate of the adjustment point of the screen center is set to the midpoint coordinate of the X coordinates of the two detected points. In addition, since there are seven adjustment points in the horizontal direction, the X coordinate of each adjustment point is an X coordinate value that divides the X coordinate of the two adjustment points whose position has been detected into six equal parts. Note that the interval between adjustment points in the horizontal direction is A. on the other hand,
The Y-coordinate, the average value of the Y coordinate of the second adjusting point was detected position and normal coordinates Y _C of the screen center adjustment point. Since there is a condition of the position detection signal that the vertical adjustment point interval is equal to the horizontal adjustment point interval, the Y coordinate of each adjustment point is Y _C + A, Y _C −A, Y _C + 2A, Y _C −2A. , ...
Is determined. In the following, correction is performed by creating R, G, and B correction signals in the same manner as in the above embodiments.

Embodiment 5 FIG. Fourth Embodiment In the fourth embodiment, the case where two adjustment points at both ends of the X axis are used to determine the normal position coordinates of G has been described. However, the adjustment of G can be performed by using two adjustment points at both ends of the Y axis. The normal position coordinates of the point can be determined. FIG. 10 shows the positions of the adjustment points for performing the position detection in this case. The method of determining the normal position coordinates of the other adjustment points can be obtained by exactly the same procedure simply by exchanging the X axis and the Y axis and the X coordinate and the Y coordinate in the fourth embodiment.

Embodiment 6 FIG. In each of the above embodiments, R, G, B
A video projector integrating a projection position detection unit and a convergence correction signal generation unit was described, and the explanation was given.However, the adjustment point position detection unit 11 was made independent to form a single unit of the automatic geometric distortion adjustment device, Further, a configuration may be provided in which an interface circuit with the convergence circuit unit 12 is provided, and the convergence correction signal is generated by receiving the output deviation amount data of the automatic geometric distortion adjustment device in the video projector body. In this case, since the adjustment point position detection unit 11 is not included in the video projector main unit, the price of the video projector main unit can be reduced, and the same automatic adjustment as in the above embodiments can be performed by adding the adjustment point position detection unit. There is an effect that can be.

Embodiment 7 FIG. In each of the above embodiments, 3CRT3
I explained the lens type video projector,
Even a 3CRT1 lens type video projector requires geometric distortion adjustment, and by applying the present invention, a 3CRT
Automatic geometric distortion adjustment can be performed even with a one-lens type video projector, and the adjustment can be easily performed.

Embodiment 8 FIG. Note that the operation of determining the G normal position coordinates by appropriately selecting the G normal position coordinate determination method described in the first to sixth embodiments can be performed by software. An apparatus capable of changing the number of detection adjustment points of G for determining coordinates can be configured.

[0060]

As described above, according to the present invention, it is possible to obtain an apparatus capable of performing high-accuracy adjustment automatically and in a short time for geometric distortion adjustment and convergence adjustment of a video projector. There is.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating positions of adjustment points according to the first embodiment.

FIG. 3 is a waveform diagram of a position detection image pattern and a position detection signal according to the first embodiment.

FIG. 4 is a diagram illustrating a shape of distortion to be corrected by geometric distortion adjustment.

FIG. 5 is a flowchart illustrating an adjustment procedure of automatic geometric distortion / convergence adjustment according to the first embodiment.

FIG. 6 is a diagram illustrating an example of an adjustment point for performing position detection in order to determine a G normal position coordinate according to the first embodiment.

FIG. 7 is a diagram illustrating an example of an adjustment point for performing position detection in order to determine a G normal position coordinate according to the second embodiment of the present invention.

FIG. 8 is a diagram illustrating an example of an adjustment point for performing position detection to determine a G normal position coordinate according to the third embodiment of the present invention.

FIG. 9 is a diagram illustrating an example of an adjustment point for performing position detection to determine a G normal position coordinate according to the fourth embodiment of the present invention.

FIG. 10 is a diagram illustrating an example of an adjustment point for performing position detection to determine a G normal position coordinate according to the fifth embodiment of the present invention.

FIG. 11 is a diagram showing adjustment points of interest at the time of conventional convergence adjustment.

FIG. 12 is a diagram showing a procedure of a conventional convergence adjustment.

FIG. 13 is a block circuit diagram showing a configuration of a conventional automatic convergence adjustment device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 imaging means 2 position detection unit 3 frame memory 4 shift amount detection unit 5 G normal position coordinate calculation unit 6 digital convergence circuit 7 convergence output circuit 8 convergence coil 9 position detection signal generation unit 10 control unit 11 adjustment point position detection unit 12 Convergence circuit part 51 Screen 57 Raster 58 Geometric distortion automatic adjustment point 59 Position detection image pattern

Claims (5)

(57) [Claims] A means for generating R, G, and B image pattern signals for position detection indicating positions of a plurality of adjustment points set on a raster; and inputting the image pattern signals to a CRT video projector. means for detecting R, G, and means for sequentially project images of B, R issued movies in the screen, G, the position of each adjusting point of the image of B on the screen Te, the movies out the G The adjustment point of the screen center of the
The normal position of the screen center adjustment point
Screen center of G image based on the normal position of the adjustment point
Means for calculating the normal position of each adjustment point other than G, and the detected G with respect to the normal position of each adjustment point of the G image.
Detects the amount of deviation of each adjustment point of the G video and generates correction signals in the horizontal and vertical directions to correct the position of each adjustment point of the G video so that each adjustment point of the G video overlaps the normal position Means for detecting a shift amount of each adjustment point of the R and B images with respect to each adjustment point of the corrected G image to generate a correction signal in the horizontal and vertical directions to generate a correction signal in the horizontal and vertical directions. R and B so that each adjustment point overlaps with each adjustment point of the corrected G image .
An automatic convergence adjusting device comprising: means for correcting the position of each adjustment point of an image; and means for controlling each of the means in accordance with a predetermined sequence. 2. A means for generating R, G, B image pattern signals for position detection indicating positions of a plurality of adjustment points set on a raster, and inputting the image pattern signals to a CRT video projector. means for detecting R, G, and means for sequentially project images of B, R issued movies in the screen, G, the position of each adjusting point of the image of B on the screen Te, the movies out the G In the adjustment points at the left and right ends of the screen
The intermediate position is defined as the X coordinate of the normal position of the adjustment point of the screen center,
In the adjustment points at the upper and lower ends of the screen of the projected G image
The intermediate position is defined as the Y coordinate of the normal position of the adjustment point of the screen center,
The normal position of the adjustment point of the screen center obtained in this way
Each adjustment point of the screen center other than G image the location as a reference
Means for calculating a normal position ; and the detected G with respect to the normal position of each adjustment point of the G image.
Detects the amount of deviation of each adjustment point of the G video and generates correction signals in the horizontal and vertical directions to correct the position of each adjustment point of the G video so that each adjustment point of the G video overlaps the normal position Means for detecting a shift amount of each adjustment point of the R and B images with respect to each adjustment point of the corrected G image to generate a correction signal in the horizontal and vertical directions to generate a correction signal in the horizontal and vertical directions. R and B so that each adjustment point overlaps with each adjustment point of the corrected G image .
Convergence apparatus for automatically adjusting includes means for correcting the position of each adjusting point of the image, and means for controlling the upper Symbol respective means in accordance with a predetermined sequence. 3. The convergence function according to claim 2,
In the dynamic adjustment device, the adjustment points at the left and right ends and the adjustment points at the upper and lower ends are
Calculated based on the adjustment points of the four corners of the screen of G video
Automatic convergence adjustment device. 4. The method according to claim 1, wherein
In the convergence automatic adjustment device described above, The number and positions of the adjustment points for the R, G, and B images are set in advance.
Equipped with a means to switch to a defined pattern, Means for controlling each of the above means according to a predetermined sequence
Predicts the number and position of the adjustment points for the R, G, and B images.
Means to switch to the set pattern
Automatic convergence adjustment device that controls according to the impedance. 5. The method according to claim 1, wherein
In the convergence automatic adjustment device described above, By means for correcting the position of each adjustment point of the G image,
The detected G with respect to the normal position of each adjustment point of the G image
The amount of deviation of each adjustment point of the video
Generates a correction signal in the direct direction so that each adjustment point of the G image is normal
The position of each adjustment point of the G image is corrected so that it overlaps the position.
After the adjustment, the position of each adjustment point of the G image is corrected.
The step is to the normal position of each adjustment point of the corrected G image.
The amount of deviation of each adjustment point of the detected G image is detected and water is detected.
Horizontal and vertical correction signals Of the G video
Each adjustment point of the G image so that each adjustment point overlaps the normal position
Automatic convergence adjustment device that corrects the position of the camera.