JPS6221378A - Television receiver - Google Patents

Abstract

PURPOSE:To prevent the output position of a synthesized picture from being changed on a screen even when a horizontal deflection frequency is changed over by changing a setting data of a counter positioning the synthesized picture on the screen simultaneously when a deflection signal generating section is changed over. CONSTITUTION:A data synthesizing a picture at a proper position is stored in a memory 13 in each deflection system and as soon as a microcomputer 12 changes over a deflection signal generating section 4 at the changeover of the deflection system, a data of a presettable counter 9 is changed over into a corresponding value. Thus, the relative position of a picture synthesis horizontal pulse (e) to a horizontal pulse (a) is changed and the position of the synthesized picture on the screen is made practically equal.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides a television receiver that is compatible with a plurality of deflection methods and that can combine and output two or more signals on the same screen. It is related to.

2. Description of the Related Art Conventionally, different signals have been combined and displayed on the same screen. For example, two-screen televisions (Television Society Technical Report ``Monitor, In, Television JTEB'')
S99-2 (September 20, 1988), and superimpositions such as personal computers, character multiplexing, and channel display for video screens.

An example of a conventional television receiver will be described below with reference to the drawings. FIG. 2 is a block diagram of a conventional television receiver, centering on an image synthesis section. Second
In the figure, 1 is an input terminal for a composite video signal, 2 is a circuit unit that processes a synchronization signal in the composite video signal, 3 is a circuit unit that processes a video signal in the composite video signal, and 4 is a synchronization signal A deflection signal generation section which generates a signal for deflecting the CRT 5 based on the output of the processing section 2; 6 is an image synthesis circuit section; 7 a signal section; 8 a synchronization section; 9 a presettable counter;
It is composed of data switches.

Reference numeral 11 denotes an image synthesis switch that selects one of the outputs of the video signal processing unit 3 and the output of the signal unit 7 and outputs the image to the CRT 5. Regarding the television receiver, its operation is explained below.
This will be explained with reference to the waveform diagram in FIG. When the image composition switch 11 is connected to the video signal processing section 3, the CRT
5 outputs the contents of the decoded video signal 1, and when connected to the output of the signal section 7, the characters and images to be synthesized are output. The switching control is performed by the output of the synchronizer 8. a is the horizontal pulse of the deflection signal generator 4 which is input to the synchronizer 8; b, c.

is the output of the synchronization unit 8 and is given to the presettable counter 9, b is a counting clock, and C is a differential horizontal pulse obtained by differentiating the rising edge of the horizontal pulse a with the counting clock b. When the differential horizontal pulse is input to the presettable counter 9, the data of the data switch 1° is preset in synchronization with the rising edge of the counting clock b. Thereafter, the count is counted up using the counting clock b.

The operation is shown at d in the waveform diagram. Here, the data
The value of switch 1o is set to 120. 2 as a counter
If a base number is used, when the count value is (2 to the power of n)-1, a carry output is output, and the next count value becomes 0.

It is assumed that the carry output of the presettable counter 9 is used as the horizontal pulse for image synthesis given to the synchronization unit 8. Here, assuming a 7-bit binary counter, 127
Then, the horizontal pulse e for image synthesis is output. After this pulse, the switch 11 is controlled through the synchronization section 8, and image composition is started. The value of the data switch 1o is selected so that the synthesized signal, that is, the output of the signal section 7, is at the correct position on the screen with respect to the signal to be synthesized, that is, the output of the video signal processing section 3.

Problems to be Solved by the Invention In recent years, with the diversification of video sources and the aim of improving image quality, the horizontal deflection frequency has been changed not only to the 15.75 convex of the conventional NTSC system but also to 24k)h and 31.6. There is a demand for a television receiver that can be used by switching between different modes. In traditional configurations, switching the horizontal deflection frequency results in a composite signal,
There is a problem in that the output position of the synthesized image on the screen changes and oscillates due to time differences in the signal processing circuits of the signals to be synthesized and errors in the image display range on the CRT.

In view of the above problems, the present invention provides a television receiver in which the output position of a composite image on the screen does not change even if the horizontal deflection frequency is switched.

Means for Solving the Problems In order to solve the above problems, the television receiver of the present invention includes a deflection signal generator that switches in response to a plurality of deflection methods, and data corresponding to each deflection method. , a counter that is set by a horizontal pulse, and an image synthesis switch that is controlled by the output of the counter and whose output is connected to an image display device.

According to the present invention, the position of the composite image on the screen is determined by changing the setting data of the counter at the same time as the deflection signal generator is switched, so that the position of the composite image on the screen can be adjusted in a practical manner. Above, it will be equivalent.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a television receiver according to an embodiment of the present invention.

1 is an input terminal for a composite video signal, 2 is a synchronization signal processing section, 3
is a video signal processing section, 4 is a deflection signal generation section, 6 is a CRT,
6 is an image synthesis circuit section, R is a signal section, 8 is a synchronization section, 9 is a presettable counter, 11 is a switch for image synthesis, a is a horizontal pulse, b is a counting clock, C is a water supply pulse,
e is a horizontal pulse for image synthesis, and the above configuration is the same as that in FIG. 2.

12 is a microcomputer (hereinafter referred to as a microcomputer); 13 is a nonvolatile memory.

The operation of the television receiver configured as described above will be described below. The basic operation is the same as the conventional example, but in the conventional example, the preset and
What used to be fixed data becomes variable. That is,
Data for combining images at appropriate positions for each deflection method is stored in the memory 13, and when switching the deflection method, the microcomputer 12 simultaneously switches the deflection signal generator 4. , presettable counter 9
data is also switched to the corresponding value. Thereby, the relative position of the horizontal pulse e for image synthesis with respect to the horizontal pulse a can be changed, and the output position of the synthesized image on the screen can be made practically the same.

Note that the presettable counter 9 can also be used in common with the counter that determines the composite video display period in the synchronization section 8. In that case, the lower digit of the precent data of that counter This can be controlled by the microcomputer 12.

Effects of the Invention As described above, the present invention changes the setting data of the counter that determines the position of the composite image on the screen at the same time as switching the deflection signal generator, thereby changing the position of the composite image on the screen from each other. , it can be used as a practical dirt floor.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a television receiver according to an embodiment of the present invention, Fig. 2 is a block diagram of a conventional television receiver, and Fig. 3 - Sanichi is a waveform diagram for explaining the operation of Fig. 2. It is. 4... Deflection signal generation unit, 9... Presettable counter, 11... Image synthesis switch. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2

Claims (1)

[Claims] A deflection signal generator that switches in response to multiple deflection methods, a counter that sets data corresponding to each deflection method using horizontal pulses, and a counter output that is controlled by the output, which is connected to an image display device. What is claimed is: 1. A television receiver comprising: an image compositing switch;