JPH04140994A - Signal generator - Google Patents

Abstract

PURPOSE:To use a signal generator in the deflecting yoke mounting work of a color cathode ray tube by shifting a dot to an arbitrary position in the horizontal and vertical directions of a display device by using memory, a delay line, and a DC generation circuit. CONSTITUTION:The output of a video signal generator 1 is added on the red, green, and blue of delay line 3, respectively, and delay quantity is decided by data in memory 2, and the delay quantity in the horizontal direction is decided. Respective output is added on the video circuit 6 of a color video set 5. In such a case, the delay quantity is equivalent to 0 to 0.8mm as deviation on a screen. Meanwhile, as for the vertical direction, the current of a DC generator 4 is adjusted by the data in the memory 2. To perform such operation, shift quantity on the screen is set in unit of 0.05mm that is equivalent to 0 to 0.8mm by using a D/A converter by an insulating type operational amplifier. Also, two bits out of memory output are for switching for red, green, and blue, and a system in which two colors are switched alternately on the surface frame and back frame of an interlace screen is employed. Display can be shifted in the vertical direction by adding such output current on a vertical deflecting power source 8, and applying it on a vertical deflecting coil 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a signal generating device used in the process of attaching a deflection yoke to a color cathode ray tube.

[Conventional technology]

The work of attaching a deflection yoke to a color cathode ray tube involves determining whether or not other colors are emitted when the entire surface is emitted in a single color, whether or not there is a doming phenomenon when emitting underscan light, how well the focus is cut when emitting characters, and when emitting crosshatch patterns. While adjusting the presence or absence of deviation due to static convergence and dynamic convergence, screen distortion, screen rotation, etc., the installation position of the deflection yoke is finally determined and the deflection yoke is fixed. During this installation work, especially when adjusting the dynamic convergence, when the crosshatch pattern is emitted, although the image appears normally in the center of the screen, the three color patterns do not match near the corners, for example red A phenomenon occurs in which the image is shifted upward and the green is shifted to the right. This convergence deviation is adjusted by operating a deflection yoke and a utility magnet so that the deviation is minimized, and then the set is shipped to a manufacturer. However, when a color cathode ray tube is installed in a color receiver manufactured by a set manufacturer, the dynamic convergence may deviate due to differences unique to the color receiver, such as the placement of the power transformer, and readjustment may become necessary. This amount of deviation reaches about 0.1 mm to 0.5 mm depending on the color receiver. Due to recent miniaturization of color receivers, restrictions on the arrangement of various components, and higher horizontal frequencies such as 64 KHz, there is a tendency for dot misalignment to increase even with the slightest external magnetic field. For this reason, if a set manufacturer's color receiver is not equipped with a digital convergence circuit or the like to correct misalignment, dynamic convergence is adjusted in advance by 0.1 mm to 0.0 mm to match the color receiver of each set manufacturer. Color cathode ray tubes must be shipped with a difference of 5 mm, and a signal generator for this purpose is required.

[Problem to be solved by the invention]

However, conventional signal generators do not have a function of continuously and minutely shifting the pattern when outputting the crosshatch pattern. For this reason, color CRTs are shipped with the red, green, and blue patterns on the screen intentionally shifted during dynamic convergence adjustment.
The disadvantage is that the degree of correction depends largely on the intuition of the operator.

[Means to solve the problem]

The present invention is a signal generating device used when attaching a deflection yoke to a color cathode ray tube, which is equipped with a memory, a delay line, and a DC current generator, and reads out the contents of the memory and applies a DC current to a vertical deflection circuit. Dynamic convergence can be adjusted by shifting the display position of each dot on the screen.

〔Example〕

Next, the present invention will be explained with reference to the drawings. FIG. 1 is a block diagram of a circuit according to an embodiment of the present invention. The output of the video signal generator 1 is applied to each of the red, green, and blue delay lines 3, and the amount of delay is determined based on the data in the memory 2, and the amount of shift in the horizontal direction is determined. Each output is applied to a video circuit 6 of a color television set 5.

Here, the delay amount is 0 to 35nS in 8 steps in 5nS units.
The amount of deviation on the screen at this time is 0 to 0.8m.
Corresponds to m. On the other hand, regarding the vertical direction, memory 2
The current of the DC current generator 4 is adjusted based on the data.

For this purpose, by using a D/A converter using an isolated operational amplifier, it is possible to
A can be controlled, and the amount of deviation on the screen is 0.05 mm.
The unit corresponds to 0 to 0.8 mm. Note that two bits of the memory output are for switching red, green, and blue, and the two colors are alternately switched and output in the front frame and back frame of the interlaced screen. This output current is applied to the vertical deflection power supply 8 and then to the vertical deflection coil 7, thereby making it possible to shift the display in the vertical direction.

Next, the operation of the signal generator of the present invention will be described. As shown in the display screen of FIG. 2, the crosshatch outputs are shifted in advance, adjusted so that they match, and the deflection yoke is fixed to the color cathode ray tube.

〔Effect of the invention〕

As explained above, the signal generating device of the present invention has the effect of being able to shift a dot to any position in the horizontal or vertical direction of the display device by using a memory, a delay line, and a DC current generating circuit. In the work of attaching the deflection yoke of a color cathode ray tube, it can be used to correct dynamic convergence deviations caused by differences in the color receivers of each set manufacturer.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a circuit according to an embodiment of the present invention, and FIG. 2 is a diagram showing a display screen during crosshatch output. 1...Video signal generator, 2...Memory, 3...
・Delay line, 4...DC current generator, 5...
Color television set, 6...Video circuit, 7...Vertical deflection coil, 8...Vertical deflection power source, 9...Display screen, 10...Red cross hatch, 11...Blue cross hatch.

Claims (1)

[Claims] A video signal generator, a delay line for delaying the signal, a memory for determining the delay amount of the delay line, a generator for direct current applied to the vertical deflection coil, and a memory for adjusting the current of the direct current generator. A signal generating device comprising: