JP2586445B2 - Digital convergence device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital convergence apparatus capable of quickly and accurately adjusting convergence correction of a color television receiver.

2. Description of the Related Art As is well known, a shadow mask type color cathode ray tube (hereinafter abbreviated as CRT) used in a general color television receiver has three electron guns of red, green and blue. However, since it is structurally impossible to arrange all of the plurality of electron guns on the central axis of the CRT, the electron guns are slightly mounted on the central axis, and are slightly inclined inward with respect to the central axis. Therefore, on the screen on this central axis, each electron beam converges at the shadow mask,
At the same time, the red, green, and blue fluorescent dots emit light through the same hole, and a state of convergence is achieved. However, the radius of curvature of the shadow mask is larger than the distance from the center of deflection to the center of the shadow mask.
Outside the central axis, the three electron beams converge before the shadow mask. Therefore, the three electron beams cannot pass through the same hole at the same time, and the color shift, that is, the convergence shift increases in the reproduced image as the distance from the center of the screen increases. In order to prevent such inconvenience, it is necessary to perform convergence correction such that three electron beams converge at the shadow mask over the entire screen.

Also, in a projection type color receiver that enlarges and projects on a screen using three CRTs emitting three primary colors, a CRT
Since the angle of incidence on the screen differs for each CRT, color shift occurs on the screen.

The superposition of these three primary colors, so-called convergence, generally employs a method of obtaining a convergence correction waveform in an analog manner using passive elements such as L, C, and R by a horizontal flyback pulse and a vertical deflection waveform. However, there is a problem in terms of convergence accuracy. On the other hand, as a method of performing convergence with higher accuracy, a method of digitally performing convergence correction has been proposed.

The concept is to project a convergence correction pattern such as a cross hatch or a dot on the screen, digitally write the convergence correction amount data for each point into one frame memory, and synchronize this information with horizontal scanning and vertical scanning. The data is read out, D / A converted and amplified to perform convergence correction. Hereinafter, description will be made with reference to FIGS. 3 and 4.

First, as shown in FIG.
Cross hatches are projected from the hatch generator 9 on the adjustment points in columns and seven rows in the vertical direction. The intersection of the cross hatch is the adjustment point.

First, when, for example, an adjustment point is selected with the cursor key 10 of the control panel 14, the CPU 15 obtains the cursor address of the adjustment point and sets the cursor address in the register for displaying the cursor 16. At this time, the address of the one-frame memory 3 is also obtained. Next, desired data is written to the specified address of the one-frame memory 3 while viewing the screen with a data write key 11 of a color to be corrected, for example, red. Hereinafter, the same is performed for all adjustment points on the screen.

Next, reading of the convergence correction amount written in the one-frame memory 3 will be described. Since the one frame memory 3 has only the correction data of the position corresponding to the adjustment point, it is necessary to perform the interpolation for each scanning line between the adjustment points in the vertical direction. Therefore, for example, using the correction data of the first and second rows read from the one-frame memory 3, the correction amount in the scanning line included between the adjustment points of the first and second rows is determined. It is obtained by the interpolation operation circuit 4. Next, the output signal of the interpolation arithmetic circuit 4 is converted into an analog quantity by a D / A converter 5, smoothed by a low-pass filter (LPF) 6, amplified by an amplifier 7, and supplied to a convergence yoke.

In the digital convergence apparatus described above, the adjustment point can be arbitrarily corrected independently, so that the convergence correction can be performed with high accuracy.

Problems to be Solved by the Invention However, in the above configuration, convergence correction data is written from the beginning for each of 63 adjustment points (in the case of 7 rows × 9 columns), so that much adjustment time is required. There was a problem that.

The present invention has been made in view of the above problems, and provides a digital convergence device capable of shortening the convergence adjustment time.

Means for Solving the Problems In order to solve the above problems, the digital convergence device of the present invention has a function of transferring the convergence correction data of the horizontal adjustment point of any one row to another row, and an arbitrary one of the rows. It has a function of transferring the convergence correction data of the vertical adjustment point of a column to another column.

According to the present invention, the convergence correction data can be transferred to all the adjustment points on the screen only by performing the convergence correction of the horizontal adjustment point at the center of the screen and the vertical adjustment point at the center of the screen by the above-described configuration. It has the advantage of being simple.

Embodiment A digital convergence device according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a digital convergence device according to an embodiment of the present invention. In the figure, 1 is a control panel, 2 is a CPU, 16 is a horizontal data transfer key provided on the control panel 1, and 17 is a vertical data transfer key also provided on the control panel 1.
Other components are the same as those in FIG. 3, and the description is omitted.

The operation of the digital convergence device configured as described above will be described below with reference to FIGS. 1 and 2. First, the convergence adjustment on the fourth line in the center of the screen shown in FIG. Perform the same operation. FIG. 2A shows the convergence correction waveform at this time.
Shown in Thereafter, when the data transfer key 17 in the vertical direction is operated, the CPU 2 transfers the correction data in the fourth row to all other rows. FIG. 2B shows the convergence correction waveform at this time.

In the same manner as described above, the convergence adjustment in the center of the screen is performed in the column direction, and then the data transfer key 16 is operated to transfer the correction data to all other columns. With the above operation, the convergence coarse adjustment of the entire screen is completed. Next, the correction amount is written and the correction amount is read for each adjustment point by the same operation as the conventional convergence device.

As described above, according to the present embodiment, the function of transferring the convergence correction data of one row of horizontal adjustment points to another row and transferring the convergence correction data of one column of vertical adjustment points to another column. Is provided, coarse adjustment of convergence can be easily performed, so that convergence adjustment time can be reduced.

As described above, according to the present invention, the convergence coarse adjustment can be easily performed by providing the function of transferring the convergence correction data of an arbitrary one row and one column adjustment point to each other row and another column. The convergence adjustment time can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram of a digital convergence device according to an embodiment of the present invention, FIGS. 2A and 2B are explanatory diagrams showing a state of transfer of correction data, FIG. 3 is a block diagram of a conventional digital convergence device, FIG. The figure is a front view showing a projected state of a cross hatch signal for projecting a convergence adjustment point on a picture tube. 1 ... Control panel, 2 ... CPU, 16,17 ... Data transfer key.

Claims (1)

(57) [Claims] 1. A means for inputting positional information of a plurality of convergence adjustment points on a screen of a color television receiver in a horizontal direction and a vertical direction in a horizontal direction and a vertical direction; Means for correcting the convergence deviation in the direction, means for transferring and setting the horizontal convergence correction data of any one row of the adjustment point to another row, and means for correcting the vertical convergence of any one column of the adjustment point. Means for transferring and setting the convergence correction data to another column, and adjusting the horizontal convergence correction data of each adjustment point adjusted and corrected for each adjustment point in an arbitrary row of the adjustment points. The vertical convergence correction data corrected and adjusted for each adjustment point in an arbitrary column of the adjustment points is transferred to another column. By setting, the coarse adjustment data at all the adjustment points on the screen are set, and the coarse adjustment data of the plurality of convergence adjustment points are readjusted one by one with high accuracy, and the horizontal and vertical convergence are set. A digital convergence device wherein convergence correction data for the entire screen is set by interpolating correction amount data for each scanning line included between each adjustment point in the horizontal direction and the vertical direction based on the correction data.