JPH0759040B2 - Side pin correction control switching circuit - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a side pin correction control for a television receiver, and more particularly to a side pin correction control switching circuit that switches the correction amount according to a use mode. is there.

[Conventional technology]

In recent years, with the rapid development of digital technology and semiconductor integrated circuits, various functions have tended to be added to television receivers. And, as this additional function, there is a tendency that a display terminal function of using the television receiver as a display terminal of various devices is provided. In other words, this display terminal function has an 8-pin terminal for handling digital signals and a 9-pin and 15-pin terminal for handling analog signals for a personal computer, a 24-pin multi-terminal for new media, and an AV terminal. Has various types of terminals such as video signal terminals, and displays information supplied from various personal computers, new media devices, and AV devices.

Here, for various devices, the horizontal frequency is distributed in the range from 15KHz in the case of TV / video to 31KHz in the case of new media such as teletext, but in the frequency mode of almost 15KHz, 24KHz and 31KHz Can be divided. The signals handled here can also be classified into television / video mode, RGB mode, and RGB multimode.

In a television receiver having such a display terminal function, a dummy coil, a Wise coil, an S-shaped correction capacitor, etc. connected in series with the horizontal winding of the deflection yoke are compatible with each of the above frequency modes. The horizontal deflection amplitude is made constant by switching the switch.

[Problems to be solved by the invention]

However, in the television receiver having the display terminal function, the horizontal deflection amplitude in each frequency mode is made constant by switching the inductance connected in series to the horizontal winding of the deflection yoke.
Along with this inductance switching, a deviation occurs in the horizontal deflection characteristics in each frequency mode. As a result, there is no problem in the frequency mode of 15 KHz for displaying TV / video images, but when switching to the frequency mode of 24 KHz and 31 KHz, the horizontal winding amplitude is accordingly kept constant and the horizontal winding Since the inductance connected in series with the switch is also switched, there is a problem that the deflection characteristic changes and the display screen is distorted.

It is an object of the present invention to provide a side pin correction control switching circuit that can obtain a stable screen without distortion even when the frequency mode is switched to any of 15KHz, 24KHz and 31KHz.

[Means for solving problems]

The side pin correction control switching circuit according to the present invention is provided with a first side pin correction element for correcting a side pin for a frequency mode of 15 KHz as a normal state which is provided in advance, and a frequency mode of 24 KHz and 31 KHz. The first
24KHz with 2nd and 3rd side pin correction elements that correct side pins in cooperation with the side pin correction elements
Switch for connecting the second side pin correction element to the first side pin correction element to set side pin correction for a 24 KHz frequency mode when the frequency mode is set to Means and, when set to the 31 KHz frequency mode, connecting the third side pin correction element to the first side pin correction element to cooperate with both to perform side pin correction for the 31 KHz frequency mode. Second switch means is provided.

[Operation] In the side pin correction control switching circuit configured as described above, for the frequency modes of 24 KHz and 31 KHz,
Corresponding to each of these frequency modes, the first and second switch means automatically select the corresponding second and third side pin correction elements and connect them to the first side pin correction element. Since the side pin correction element selected corresponding to this frequency mode pair performs the side pin correction in cooperation with the first side pin correction element, 15 KHz,
For any frequency mode of 24KHz and 31KHz,
You will always get a stable screen with no distortion.

Example of Invention

FIG. 1 is a circuit diagram showing an embodiment of a side pin correction control switching circuit according to the present invention. In the figure, 1 is a vertical winding connected between terminals 2a and 2b to which a vertical output is supplied, 3 is a first side pin correction element connected to the return side of the vertical winding 1, and is a capacitor 4 and a resistor 5 in series. 6a is a transistor for amplifying the output of the first side pin correction element 3, 6b is a transistor for controlling the primary coil current of the side pin correction transformer 7 according to the output of the transistor 6, and 8 and 9 are first side pins. Compensation elements 3 are second and third side-pin compensation elements connected to the output side via a capacitor 10, and are composed of a parallel body of a capacitor 8a and a resistor 8b and a parallel body of a capacitor 9a and a resistor 9b. Has been done. 10 is 24KHz to terminal 11
The second side pin correction element 8 is turned on by the 24 KHz mode signal supplied in the frequency mode of
The other side of the third side pin correction element 9 is grounded by turning on the other end of the transistor 12 as a switching means by the 31KHz mode signal supplied to the terminal 13 in the 31KHz frequency mode. A transistor serving as a switching means connected to the device, 14 is a horizontal winding to which a horizontal output is supplied, 15 is a switching S-shaped correction capacitor that is switched according to a frequency mode, 16 is a switching wise coil that is switched according to a frequency mode, 17 Is a switching dummy coil which is switched according to the frequency mode, and these are connected in series between the terminal 18 to which the horizontal output is supplied and one end of the secondary winding of the side pin correction transformer 7. The other end of the side pin correction transformer 7 is connected to the ground via a linearity coil 19.

In the side pin correction control switching circuit configured in this way, both the 24KHz mode signal and the 31KHz mode signal are at the L level in the 15KHz frequency mode for receiving television / video images, so that the transistor
By turning off 10,12 and disconnecting one end of the second and third side pin compensation elements 8,9 from ground,
The first side pin correction element 3 is not affected. Therefore, the vertical output return signal supplied through the vertical winding 1 is supplied to the transistor 6a after the side pin correction process is performed by the capacitor 3 and the resistor 5 in the first side pin correction element 3. Be done.
Then, by supplying the output of the transistor 6a to the transistor 6b, the primary current of the side pin correction transformer 7 is controlled and generally known side pin correction is performed. That is, the secondary side of the side pin correction transformer 7 serves as a horizontal output passage by being interposed in a series circuit of the horizontal winding 14, the switching S-shaped correction capacitor 15, the switching wise coil 16, the switching dummy coil 17 and the linearity coil 19. As a result, the horizontal deflection current flowing through the horizontal winding 14 is controlled as a result.

Next, when the frequency mode is set to 24 KHz, the H-level 24 KHz mode signal is supplied to the terminal 11, so that the transistor 10 is turned on and the second side pin correction element 8 is set to the first side. It is connected between the output side of the pin correction element 3 and ground. As a result, since the side pin correction element 3 of 1 and the second side pin correction element 8 cooperate to execute the correction of the side pin, the correction of the side pin for the reception screen in the frequency mode of 24 KHz is surely performed. .

Next, when the frequency mode of 31 KHz is set, the H-level 31 KHz mode signal is supplied to the terminal 13, so that the transistor 12 is turned on and the third side pin correction element 9 is set to the first side. It is connected between the output side of the pin correction element 3 and ground. As a result, the first side pin correction element 3 and the third side pin correction element 9 cooperate to execute the side pin correction, so that the side pin correction for the reception screen in the 31 KHz frequency mode is surely performed. Be seen.

However, as described above, the switching S-shaped correction capacitor 15, the switching wise coil 16, and the switching dummy coil 17 are 24 KHz and
Switching is performed for the 31 KHz frequency mode, and its characteristics are set to suit each mode.

〔The invention's effect〕

As described above, according to the side pin correction control switching circuit according to the present invention, for the frequency modes of 24 KHz and 31 KHz, the first and second switch means are automatically operated corresponding to these frequency modes. Second and third corresponding to
Since the side pin correction element of is selected and connected to the first side pin correction element, the side pin correction element selected corresponding to this frequency mode pair cooperates with the first side pin correction element. Since the correction of the side pin is performed, a stable screen without distortion is always obtained for any frequency mode of 15 KHz, 24 KHz and 31 KHz, which is effective.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of a side pin correction control switching circuit according to the present invention. 1 ... Vertical winding, 3 is the first side pin correction element, 7 ...
… Side pin compensating transformers, 8,9 …… Second and third side pin compensating elements, 10,12 …… Transistors, 14 ……
Horizontal winding.

Claims (1)

[Claims] 1. A pre-established normal state of 15 KH
1st side pin correction for z frequency mode
24KHz frequency mode and second and third sidepin correction elements for sidepin correction in cooperation with the first sidepin correction element for the 24KHz and 31KHz frequency modes First switch means for connecting the second side-pin correction element to the first side-pin correction element to set the side-pin correction for the 24 KHz frequency mode in cooperation with each other when set to The second side pin correction element is connected to the first side pin correction element to set the side pin correction for the 31 KHz frequency mode when the frequency mode is set to 31 KHz. A side pin correction control switching circuit characterized in that a switch means is provided.