JPH02305090A - Digital convergence correcting circuit - Google Patents

Abstract

PURPOSE:To obtain the convergence correcting circuit of simple circuit constitution while maintaining a display function for the kind of a color being adjusted which is necessary at the time of convergence correction by providing a means which displays a marker in the same color as the color being adjusted. CONSTITUTION:A CPU 1 sends selected color information (s) to a color selecting circuit 2 as color information being adjusted currently and adjustment point position color information (p) and adjustment color information (c) to an adjustment point indication pattern generator 116 and a grating pattern generator 115. The adjustment point indication pattern generator 116 supplies only an R signal and a B signal to the color selecting circuit 2. A G signal is not supplied since green (G) is a reference color. The color selecting circuit 2 supplies the selected R signal or B signal to a signal synthesizer 3. Consequently, the marker which indicates a grating point being adjusted currently is displayed in the same color as the color being adjusted, so the kind of the color being adjusted can be recognized without using any character generator which generates character information.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a digital convergence correction circuit for a color television receiver, and in particular to an improvement of a marker that displays an adjustment point on the screen where convergence correction is currently being performed. Regarding.

[Conventional technology]

As shown in FIG. 4, a projection color television receiver 100 generally includes a red projection tube (hereinafter referred to as R tube) 101, a green projection tube (hereinafter referred to as G tube) 102, and a blue projection tube (hereinafter referred to as B tube). A color image (elephant) is created by converging the monochromatic red, green, and blue lights emitted from each of the red, green, and blue monochromatic lights onto a single point on the projection screen 104. An R tube 101 and a B tube 103 are arranged.In this case, the optical axis of the projection light of the G tube 102 is perpendicular to the plane of the projection screen 104, and the optical axes of the R tube 101 and the B tube 103 are The optical axis of the G tube 102 and the projection screen 104 are arranged at a predetermined angle so as to coincide with the intersection point.However, the curvature of the projection screen 104 is different from the curvature of an arc centered on the projection tube. Since they do not match, projection screen 1
04, the red (R) and blue (B) projection lights cause a positional shift with respect to the reference green (G).

Since such positional misalignment appears as color misalignment, it is necessary to align the three colors. Such correction is called convergence correction. Convergence correction is performed during manufacturing of the receiver at a factory, or during installation and maintenance in a general household.

Traditional convergence correction uses sidewave signals in response to horizontal and vertical synchronization signals by analog circuits.

This was done by generating parabolic wave signals and controlling the amount of deflection of each electron beam using a correction signal obtained by combining these signals. However, in recent years, a digital convergence correction circuit that digitally generates a correction signal has been proposed as a means for performing highly accurate convergence correction over the entire projection screen 104. This digital convergence correction circuit displays each adjustment point on the projection screen 104 with an appropriate adjustment point indication pattern (hereinafter referred to as a marker), and digitally stores the amount of correction at each adjustment point in a memory. The stored correction amount is read out in synchronization with screen scanning, and is converted from digital to analog to create a correction signal.

Here, a conventional digital convergence correction circuit will be explained with reference to FIG. As shown in Figure 5, the CPU
111 includes a memory 112 storing data on convergence correction amounts, a correction waveform generator 113, a character generator 114, a lattice pattern generator 115,
An adjustment point indication pattern generator 116 is connected thereto.

A convergence coil 118 corresponding to green is connected to the correction waveform generator 113 via an amplifier 117. Note that there are other convergence coils for red and blue, but their illustrations are omitted.

The character generator 114. Both the grid pattern generator 115 and the adjustment point indication pattern generator 116 are connected to a signal synthesizer 119. Signal combiner 1
R, G emitted from 19.

Each signal of B is supplied to an electron gun section of a projection tube (not shown). An input unit 120 for manually specifying adjustment points is connected to the CPU 11.

Next, a brief explanation of the operation will be given.

As shown in FIG. 5, when a predetermined instruction is input from the human power section 120, adjustment color information C is sent from the crtrl 11 to the grid pattern generator 115, from which grid pattern signals of three colors R, G, and B are generated. The signal is sent to a signal combiner 119. Further, adjustment point position information p is sent from the CPUI 11 to an adjustment point instruction pattern generator 116, from which R, G, B
Adjustment point indication (marker) signals corresponding to the three colors are sent to the signal synthesizer 119. Furthermore, display pattern information d is sent from the CPUI 11 to a character generator 114, from which a character signal indicating one of the three colors R, G, or B is sent to a signal synthesizer 119. These lattice pattern signals, one marker signal, and one character signal are synthesized as signals on one screen by a signal synthesizer 119, and the synthesized R, G, and B signals are supplied to the projection tube (not shown). And the sixth
As shown in the figure, a white grid pattern 121, a white marker 122, and text information 123 indicating the type of color currently being adjusted are projected on the projection screen 104, respectively. To display the type of color currently being adjusted in this way,
This is because the coordinator may forget. Note that white is used as the display color because it is easy to see, and text information 1
23 is displayed in a predetermined character display area 124.

[Problem to be solved by the invention]

The problem with the conventional digital convergence correction circuit described above is that it requires a character generator to display the type of color currently being adjusted on the projection screen.
The problem is that the number of parts is large and the circuit and configuration are complicated.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a convergence correction circuit that has a simplified circuit configuration while maintaining the function of displaying the type of color being adjusted, which is necessary during convergence correction.

[Means to solve the problem]

In order to solve the above problems, the present invention projects a marker on a display screen that indicates an adjustment point for convergence correction, and stores the convergence correction amount at the adjustment point in a memory. In the digital convergence correction circuit that reads out the stored convergence correction amount in synchronization with screen scanning to create a convergence correction waveform, the digital convergence correction circuit is provided with means for displaying the marker in the same color as the color currently being adjusted. It is characterized by

[Effect]

According to the present invention, the marker displaying the grid point currently being adjusted is displayed in the same color as the color being adjusted. Therefore, the type of color related to adjustment can be recognized without using a character generator that generates character information.

〔Example〕

Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 shows an embodiment of a digital convergence correction circuit according to the present invention. Note that the same reference numerals are given to the parts that have already been explained in FIG. 5, and detailed explanation thereof will be omitted.

The difference between FIG. 1 and FIG. 5 is that the character generator 114 has been deleted and the selection color information S has been changed to 1.
The two points are that a co-supplied color selection circuit 2 is provided, and that the configuration of the signal synthesizer 3 is reduced in size.

From the CPUI, selected color information S, which is color information currently being adjusted, is sent to the color selection circuit 2, as well as adjustment point position information p, ! , adjustment color information C are sent to an adjustment point indicating pattern generator 116 and a grid pattern generator 115, respectively.

The adjustment point indication pattern generator 116 outputs an R signal and a B signal.
Only the signal is supplied to the color selection circuit 2. The reason why the G signal is not supplied is because green (G) is the standard. The selected R signal or B signal is supplied from the color selection circuit 2 to the signal synthesizer 3. This signal synthesizer 3 is different from the signal synthesizer 119 shown in FIG.

Since the number of inputs to B is small, its processing circuit is also simplified.

Next, the operation during convergence adjustment will be explained.

When a convergence adjustment start key (not shown) is operated from the input unit 120 and an instruction is input, adjustment color information C issued from the CPU is supplied to the grid pattern generator 115, from which R, G.

The B signal is sent to the signal combiner 3. Then, as shown in FIG. 2, a reference green grid pattern 121A is projected on the projection screen 104.

If the lattice pattern 121A does not have a regular shape, the volume or the like is manipulated to display a regular lattice pattern as shown in FIG.

In this state, first, red (R) convergence adjustment is performed. When red is designated using a color designation key (not shown) on the input unit 120, for example, as shown by the dotted line in FIG.
is displayed. Next, press the address key (
When a grid point X1 that requires convergence adjustment is inputted by operating the lattice point X1 (not shown), red cross-shaped markers 5 surround and specify the grid point X1, as shown in FIG. Furthermore, while operating the red data writing key (not shown) of the human power section 120 and visually checking the marker 5,
Code X serving as a reference from the position of code X1. Move marker 5 to the position. Then, this amount of movement (i.e., Xl−X
o) is written into the memory 112 as data on the amount of correction of convergence shift. Thereafter, in the same manner, the 7'-points of the lattice points that all have a convergence shift are written into the memory 112. Note that for the intermediate portion between adjacent grid points, the CPU calculates convergence shift data using the function interpolation method, and the calculated value is stored in the memory 11.
2. Once the red convergence adjustment is completed as described above, continue to display the blue color and perform the blue convergence adjustment in the same manner. In this way, red and blue convergence adjustment is completed for all grid points where convergence deviations have occurred.

When a screen is projected on the projection screen 104, the convergence correction amount is read out by the CPU in synchronization with screen scanning. Correcting waveform generator 113 outputs vertical and horizontal correction signals in accordance with this correction amount, which are further amplified by amplifier 117 and correction currents are added to red and blue convergence coils (not shown). This correction current allows a screen without convergence deviation to be displayed.

In this embodiment, the case of a projection color television receiver has been described, but it goes without saying that the present invention can also be applied to a direct viewing tube type television receiver.

〔Effect of the invention〕

As explained above, according to the present invention, even if the character generator is omitted and the circuit configuration is simplified, the marker is displayed in the color currently being adjusted, so the type of color being adjusted can be easily recognized, and the You can increase your speed.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 is a diagram showing a grid pattern in an embodiment of the present invention, and Fig. 3 is a diagram of specifying the deviation of the grid pattern with a marker in an embodiment of the present invention. , Fig. 4 is a diagram showing the positional relationship between the projection screen and the R, G, and B projection tubes in a projection television receiver, Fig. 5 is a block diagram of the conventional example, and Fig. 6 is the digital convergence correction of the conventional example. It is a figure which shows the screen situation inside. 1...CPU. 2... Color selection circuit, 3... Signal synthesizer, 4... Grid pattern, 5... Marker, 101... Red projection tube, 102... Green projection tube, 103... Blue Projection tube, 104... Projection screen, C... Adjustment color information, p... Adjustment point position information, S... Selected color information. Figure 1 Figure 2 O Figure 3 Figure 4

Claims (1)

[Claims] A marker indicating an adjustment point for convergence correction is displayed on a display screen, and a convergence correction amount at the adjustment point is stored in a memory, and the stored convergence correction amount is A digital convergence correction circuit that creates a convergence correction waveform by reading out in synchronization with screen scanning, the digital convergence correction circuit comprising means for displaying the display color of the marker in the same color as the color currently being adjusted. .