JPH0646437A - Convergence corrector - Google Patents

Abstract

PURPOSE:To attain the multi-scan automatic convergence using an optical sensor and to facilitate the control of the screen position by changing simultaneously plural pieces of correction point data at each fixed rate by making use of the characteristic of an LPF. CONSTITUTION:A control instruction is inputted through a keyboard 100 for the position of a screen, and a CPU selects a position on a screen and controls this position. Meanwhile a pattern generator 80 produces a control reference pattern and a cursor pattern showing the selected position and displays both patterns on the screen. When the screen position is selected and controlled, not only just a single piece of correction data but a fact how each correction data is changed at each specific rate is stored in a coefficient memory 60 as a coefficient. Then all correction points set on the same scanning line are simultaneously changed at each fixed rate based on the stored coefficient. Thus it is possible to deal with each display mode of a multi-scan display device by changing the contents of the memory 60.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital convergence correction device for a display device such as a color TV and a display terminal using a CRT, and more particularly to a digital convergence correction device for the multi-scan type display device.

[0002]

2. Description of the Related Art In the case of supporting a multi-scan type display device, the same correction data is read out after adjusting in one display mode in the conventional digital convergence as described in, for example, JP-A-63-59191. There is a method that corresponds by changing the.

[0003]

SUMMARY OF THE INVENTION In the above conventional example,
Sufficient correction is performed in the display mode adjusted as a reference, but sufficient correction accuracy may not be obtained in other display modes corresponding to different read addresses. In this case, in order to obtain sufficient accuracy in each display mode,
Some readjustment is required. Here, the most effective means is auto-convergence. For example, as described in Japanese Patent Laid-Open No. 3-52490, a dummy screen in which an optical sensor is arranged is used. However, if the display mode changes, the display rate, aspect ratio, etc. will change, and the adjustment point position or adjustment display pattern managed by time will not match the position of the optical sensor, and adjustment may not be successful as it is. There is.

Of course, manual adjustment can be considered,
For example, as disclosed in Japanese Patent Laid-Open No. 3132286, there is a method in which an adjustment reference pattern is provided on a screen and an adjustment display pattern is aligned with it in order to satisfy both color misregistration correction and graphic distortion correction. . Even in this case, when the display mode is changed, the adjustment point position or the adjustment display pattern does not match the adjustment reference pattern. It is inconvenient to switch the reference pattern on the screen for each display mode, and adjustment is troublesome. After all, I want to share one reference pattern.

In any of the conventional examples, the relationship between the multi-scan and the adjustment in each display mode has not been taken into consideration.

An object of the present invention is that in a multi-scan display device, the adjustment point or the adjustment display pattern is always at the same position on the screen regardless of the display mode, and the adjustment can be performed by the same photosensor position or the same adjustment reference pattern. It is to provide a possible digital convergence correction device. Another object is to provide a convergence correction device that can be easily adjusted.

[0007]

Normally, the vertical position and the vertical interval of the adjustment point or the adjustment display pattern can be set finely because there are many scanning lines. Therefore, if the display mode changes, the vertical position and the vertical interval are changed accordingly. Also, the horizontal position and horizontal interval of the adjustment display pattern are adjusted to the position of the optical sensor or the adjustment display pattern by controlling the timing and interval.

On the other hand, the horizontal position and horizontal interval of the adjustment points are
Utilizing the fact that the correction points are arranged in order in time, a small number of correction points (in this case, the adjustment points are representative points of the correction points) are arranged at equal intervals, and discrete correction data read out in series from there Is used after being smoothed by LPF (Low Pass Filter). This is an effective means for reducing the memory capacity. Since the number of correction points is small, it is not possible to freely adjust arbitrary points as they are. Therefore, the CY current at a desired position is adjusted by utilizing the characteristics of the LPF and simultaneously changing a plurality of correction point data at a constant rate.

[0009]

As described above, the adjustment display pattern and the adjustment reference pattern can be matched without any problem.

Next, at the adjustment point, due to the action of the LPF, one correction data affects the CY current in a certain range in the vicinity. In other words, the CY current at an arbitrary position is affected by the plurality of correction point data. Here, it is possible to change the combination of the correction data that affects an arbitrary point so that the position of the point on the screen does not change (the CY current at the point does not change). Therefore, it is possible to selectively adjust a certain point by simultaneously changing a plurality of correction point data at a constant rate, and to prevent another arbitrarily set point from moving on the screen. Therefore, even if the display mode changes, the adjustment point position can be set at an arbitrary position.

[0011]

EXAMPLES Examples of the present invention will be described below.

FIG. 1 is a block diagram showing a first embodiment of the present invention. In the figure, 10 is an address counter for supplying an address according to the scanning timing of the screen to the frame memory 20, 20 is a frame memory for storing correction data, 30
Is a DAC (Digital-Analog Converte) that converts the correction data read from the frame memory into an analog signal.
r), 40 is an LPF for smoothing the analog signal output from the DAC 30, 50 is a CY amplifier that converts the analog voltage signal output from the LPF 40 into a current flowing through CY (Convergence Yoke), 60 is a coefficient memory, and 70 is A CPU for controlling the convergence system, 80 a pattern generator for generating an adjustment display signal, 91 CY, 92 a video circuit of a display device, and 100 a keyboard for adjustment. Frame memory 20, pattern generator 8
0 is provided independently corresponding to each display mode of multi-scan.

First, in normal times, the correction data is read from the frame memory 20 in correspondence with the address output from the address counter 10 in synchronization with the screen scanning, and D
It is converted into an analog signal by AC30. The signal is passed to LPF4
After smoothing at 0, it is input to the CY amplifier 50 and converted into a CY current for correction.

On the other hand, at the time of adjustment, a command is input using the keyboard 100, and the CPU selects a position on the screen and adjusts the selected position. At this time, the pattern generator 80 generates a reference pattern for adjustment and a cursor pattern indicating the selection position and displays it on the screen. Here, in the present invention, when selecting and adjusting the screen position, not only one correction data is changed, but at what ratio each correction data is changed is stored as a coefficient in the coefficient memory 60, and according to that, All the correction points on the same scanning line are simultaneously changed at a constant rate. This coefficient memory 60
By changing the contents of, it is possible to correspond to each display mode of the multi-scan display device. After the adjustment is completed for each adjustment point, it is necessary to perform interpolation calculation in the vertical direction to determine the correction data of all the correction points.

FIG. 2 is a relationship diagram showing the relationship between the correction points and the adjustment points in the two display modes. The grid is a display pattern for adjustment, and the grid points are the adjustment points. Moreover, the x mark represents a correction point. Depending on the display mode, the adjustment point is not always the representative point of the correction points.

The display mode 1 is a reference display mode in which the adjustment points coincide with the correction points. On the other hand, in display mode 2, the adjustment points do not match the correction points. Therefore, if the correction data of a plurality of correction points is changed once at a constant rate, it is possible to move only the adjustment points selected as the composite waveform on the screen and prevent the remaining adjustment points from moving. .

FIG. 3 is a principle view showing the principle of preventing mutual interference between adjustment points in the present invention. As shown in (a), if finite correction data other than 0 is given to only one correction point on the same scanning line and the correction data of the remaining correction points is set to 0, the CY current as shown in (b) is obtained. can get. Correction data d
1 not only affects the CY current i1 at the corresponding point, but also d
It also affects the CY currents i0 and i2 corresponding to 0 and d2. Conversely, the CY current i1 corresponding to d1 is affected by d0, d1 and d2. Therefore, at the ratio shown in (C), d
By setting 0 to d4 (actually all correction data on the same scanning line), i0, i2, i3 can be set to 0 and only i1 can be changed. By changing the ratio of d0 to d4, it is possible to prevent interference with the CY current at any position. However, the adjustment point interval cannot be made too large or small due to the time constant of the LPF. Since the degree of freedom does not increase, the number of adjustment points cannot be set more than the number of correction points.

An example of how to obtain the coefficient memory will be shown here.

First, one adjustment point or correction point is selected from the state of certain correction data, and the correction data is changed. It is better to move it vertically. At that time, other adjustment point positions are also affected, and if a horizontal line is displayed on the scanning line, the position moves as shown in FIG. 3 (b). After that, when the correction point data on the same scanning line is changed so as to restore the movement of each unselected adjustment point, the display finally becomes as shown in FIG. 3 (d). Here, when the change amount of each correction data is calculated, the ratio of each correction data on the same scanning line which is adjusted at one time can be calculated. It is easiest to do it completely unadjusted or fully adjusted.

Alternatively, the CY current can be directly checked and obtained without returning to the original adjustment points on the screen.

FIG. 4 is a block diagram showing a second embodiment of the present invention. The difference from the first embodiment is that the keyboard 100 is replaced by the optical sensor 110. Since the optical sensor is arranged at the grid point position in FIG. 2 and the CPU 70 only performs the adjustment that the human is doing, the other operations are the same as those in the first embodiment, and the description thereof will be omitted.

[0022]

As described above, according to the present invention, since the adjustment points on the screen can be freely set, the adjustment points or the display patterns for adjustment are always in the same position on the screen in the multi-scan display device regardless of the display mode. Therefore, it is possible to provide a digital convergence correction device capable of adjustment using the same optical sensor position or the same adjustment reference pattern. Therefore, multi-scan auto-convergence using an optical sensor becomes possible. Moreover, since mutual interference between the adjustment points can be prevented, adjustment is easy.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a relationship diagram showing a relationship between correction points and adjustment points in two display modes.

FIG. 3 is a principle diagram showing a principle of preventing mutual interference between adjustment points in the present invention.

FIG. 4 is a configuration diagram showing a second embodiment of the present invention.

[Explanation of symbols]

10 ... Address counter, 20 ... Frame memory, 30
... DAC, 40 ... LPF, 50 ... CY amplifier, 60 ... Coefficient memory, 70 ... CPU, 80 ... Pattern generator, 91
... CY, 92 ... video circuit, 100 ... keyboard, 11
0 ... Optical sensor.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kuninori Matsumi 292 Yoshida-cho, Totsuka-ku, Yokohama City Hitachi Image Information Systems Co., Ltd.

Claims (2)

[Claims] 1. Address counter, frame memory, DA
A coefficient memory is provided in a convergence correction device including a C, LPF, CY amplifier, CPU, display pattern generator, and adjustment keyboard, and correction points on the same scanning line are adjusted according to the ratio of coefficients in the coefficient memory during convergence adjustment. Convergence correction device, characterized in that adjustment means is provided for simultaneously changing the correction data of 1. at a fixed rate. 2. Address counter, frame memory, DA
A coefficient memory is provided in an auto-convergence correction device including a C, LPF, CY amplifier, CPU, display pattern generator, and optical sensor, and correction points on the same scanning line are adjusted according to the ratio of coefficients in the coefficient memory during convergence adjustment. An auto-convergence correction device, characterized in that adjustment means is provided for simultaneously changing the correction data of 1. at a fixed rate.