JPH03249892A - Digital convergence circuit - Google Patents

Abstract

PURPOSE:To easily and correctly execute the adjustment of an adjusting point excluding both ends by constituting the circuit so that in the case three or more adjusting points exist in a horizontal blanking period, a linear interpolation is executed automatically with respect to unadjusted point data existing between them from adjusting point data of both ends in its horizontal blanking period. CONSTITUTION:The misconvergence of each adjusting point is adjusted and inputted to a microprocessor 2 through a keyboard on a control panel 1. In this case, in the case three or more adjusting points A-C exist in a horizontal blanking period, from adjusted adjusting data of both ends A, B in its horizontal blanking period, a linear interpolation is executed automatically with respect to data of an unadjusted point C between them. In such a way, even other adjusting point than both ends in the horizontal blanking period can be adjusted correctly, and color slurring of the left end can be prevented.

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention is directed to the problem of color shift on the screen of a color display,
That is, the present invention relates to a digital convergence circuit configured to digitally correct convergence.

[Prior Art] In correcting convergence, it is necessary to add a magnetic field in which a parabolically changing magnetic field is superimposed on the horizontal and vertical synchronizing signals.

Fig. 3 is a configuration diagram of a conventional digital convergence circuit. In the figure, (1) is a control panel, and a keyboard (not shown) is used to adjust misconvergence at adjustment points that are equally divided into one horizontal period. It is equipped with (2) is a microprocessor, and the misconvergence of each adjustment point is controlled by the control panel (
1) Input via .

(3) is a read address generation circuit, and (4) is a field memory, which records the correction data output from the microprocessor (2). (5) is a backup memory, which includes the field memory (4) and the read address generation circuit (3).
) constitutes a memory section (15).

(6) is a crosshatch generating circuit, (8) is a cross cursor generating circuit, and (7) is an output circuit. These constitute a pattern generating section (16), and the pattern generated here is displayed on a color display (hereinafter referred to as "color display"). , CRT).

(9) is a vertical interpolation circuit which calculates and interpolates a correction value for each scanning line from vertical correction data among the correction data read out from the field memory (4) in response to horizontal scanning. (10) is a serial/parallel conversion circuit (hereinafter referred to as
(referred to as a D/A conversion circuit) converts the horizontal correction data into an analog waveform. (11) is an A/D conversion circuit, which constitutes a signal output section (17).

(12) is a low-pass filter (hereinafter referred to as LPF),
(13) is an output circuit, (14) is a correction coil, and the output from the signal output section (17) is interpolated by L P F (12) and corrected by the correction coil (14) via the output circuit (13). Supply current.

Next, the operation of the above configuration will be explained with reference to the flowchart shown in FIG.

The misconvergence at multiple adjustment points equally divided into one horizontal period is adjusted individually via the keyboard on the control panel (1), and the microprocessor (2)
Then, a predetermined digital convergence is performed by manually outputting the adjusted correction data (step 520) and outputting the adjusted correction data (step 521).

That is, the misconvergence at each of the plurality of adjustment points is adjusted using the keyboard on the control panel (1), and the correction data is stored in the memory section (15).
The correction data is recorded in the field memory (4) of the field memory (4), and the correction data is read out from the field memory (4) in accordance with horizontal scanning.

Regarding the correction of parts other than the plurality of adjustment points mentioned above, in the vertical direction, a vertical interpolation circuit (9) calculates and interpolates correction values for each scanning line from adjacent vertical direction correction data, while in the horizontal direction Regarding the D/A conversion circuit (1
0) into an analog waveform, the A/D conversion circuit (
11), a digital value is interpolated by L P F (12), and a correction current is passed from the output circuit (13) to the correction coil (14), thereby performing a predetermined color shift correction.

[Problems to be Solved by the Invention] Since the conventional digital convergence circuit is configured as described above, if there are three or more adjustment points during the horizontal blanking period, the adjustment points excluding both ends of the blanking period It is difficult to make adjustments because it is necessary to make adjustments while looking at the screen. Additionally, depending on the adjustment point data, the convergence output circuit may become saturated, resulting in color shift at the left end.

This invention was made to solve the above-mentioned problems, and it is possible to automatically make appropriate adjustments even at adjustment points other than both ends of the horizontal blanking period.
It is an object of the present invention to provide a digital convergence circuit that can prevent color shift at the left end regardless of adjustment point data.

[Means for solving the LI problem] When there are three or more adjustment points in the horizontal blanking period, the digital convergence circuit according to the present invention calculates the adjustment points between them based on the adjusted adjustment point data at both ends of the horizontal blanking period. The present invention is characterized in that it is configured to perform linear interpolation on unadjusted point data located in .

[Operation] According to the present invention, when there are three or more adjustment points in a horizontal blanking period, the data of the unadjusted points between them are automatically calculated from the adjusted adjustment data at both ends of the horizontal blanking period. By performing linear interpolation, it is possible to perform appropriate adjustment even at adjustment points other than both ends of the horizontal blanking period, and color shift at the left end can be reliably prevented.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described based on the drawings.

The configuration diagram of the digital convergence circuit according to an embodiment of the present invention is the same as the conventional example shown in FIG.
Its description will be omitted.

The difference from the conventional method is a misconvergence adjustment program executed by a microprocessor (2), which will be explained below with reference to the flowchart shown in FIG.

FIG. 2 is an explanatory diagram of the adjustment operation near the horizontal blanking period when there are three adjustment points A, B, and C in the horizontal blanking period among the adjustment points that are divided equally into a plurality of one horizontal cycle period. .

First, the misconvergence of each adjustment point is adjusted and input to the microprocessor (2) via the keyboard on the control panel (1) (step 530). At this time, the input misconvergence adjustment point is It is determined whether the adjustment point is A or B at both ends of the ranking period (Step 331), and if No is not A or B, the data is output (Step 532).
Record it in field memory (4).

If the determination in step S31 is Yes, it is determined whether the adjustment point is point A in FIG. 2 (right end on Cm plane) or point B < left end on m plane).
, in the case of point A, the adjustment data of point B, and in the case of point B, the adjustment data of point A are read out from the field memory (4) (step S34.535).

Next, from the read adjustment data, the data of the unadjusted point C between the above points A and B is converted into a straight line using the formula c-(A-B)/2+A or C-(B-A)/2+B. Interpolation interval (step S36゜537)
, output the correction data of point A or point B and point 0 (step 538), and record it in the field memory (4).

After that, the correction data is read out from the field memory (4) in accordance with horizontal scanning, and the output circuit (
13), correction currents in the vertical and horizontal directions are passed through the correction coil (14) to perform predetermined digital convergence, that is, color shift correction.

[Effects of the Invention] As described above, according to the present invention, when there are three or more adjustment points in a horizontal blanking period, the unadjusted point data between them is calculated from the adjustment point data at both ends of the horizontal blanking period. can be automatically linearly interpolated, so adjustment points other than both ends can be easily and appropriately adjusted.

Furthermore, regardless of the adjustment point data, it is possible to eliminate saturation of the output circuit and reliably prevent color shift at the left end.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing the adjustment operation in a digital convergence circuit according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of the operation near the horizontal blanking period, FIG. 3 is a configuration diagram of the digital convergence circuit, and FIG. 4 is a flowchart showing the conventional operation. (1) ...control panel, (2) ...microprocessor, (4) --field memory, (
13) --- Output circuit, (14) --- Correction coil. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] (1) In a digital convergence circuit that is equipped with a digital circuit that generates and outputs a correction waveform for correcting color shift on the screen of a color display, the adjustment points that are divided into equal parts of one horizontal period are set in the horizontal blanking period. means for determining whether or not there are three or more adjustment points, and when the determination means determines that there are three or more adjustment points, a means for determining whether or not there are three or more adjustment points; and a means for determining whether or not there are three or more adjustment points; A digital convergence circuit comprising means for linearly interpolating certain unadjusted point data.