JPH05176191A - Flyback transformer for television receiver - Google Patents

Abstract

(57) [Abstract] [Purpose] The focus and the screen volume are controlled by an electronic adjustment means using a low voltage to improve the efficiency of the adjustment work of the entire television receiver. [Configuration] In the flyback transformer 3, the resistor 3
d11, 3d12, 3d21, 3d22 and control elements 3k1, 3k2 have a voltage dividing configuration, and the control element 3k
The focus voltage and the screen voltage corresponding to the input voltage applied to the first and third k2 are extracted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flyback transformer used in a color television receiver or the like.

[0002]

2. Description of the Related Art FIG. 4 is a diagram showing a schematic internal structure of a general television receiver, in which a cathode ray tube 2, a flyback transformer 3 and a horizontal output transistor 4 are arranged in a receiver main body 1. In driving the cathode ray tube 2, driving power such as an anode voltage, a focus voltage, and a screen voltage is boosted by a flyback transformer 3 and then supplied.

In general, the cathode electrode 2a of the cathode ray tube 2
Is about 30 KV, the focus terminal 2b is a variable voltage of about 10 KV, and the screen terminal 2c.
Therefore, it is necessary to apply a variable voltage of about 800 KV. Each of these voltages is supplied from the flyback transformer 3. FIG. 5 shows an internal configuration diagram of a flyback transformer 3 of a conventional television receiver. In the figure,
Reference numeral 3a is a primary coil of the flyback transformer 3, to which a pulse from the horizontal output transistor 4 is applied. 3b1
Reference numeral 3b4 is a high voltage coil on the secondary side of the flyback transformer 3, which is connected in series with the diodes 3c1 to 3c4, and a high voltage is taken out to a terminal 3t3. Further, a variable volume for focus voltage (hereinafter referred to as VR) 3d1 and a variable volume for screen voltage (hereinafter referred to as VR) 3d2 are connected to a part of the secondary coil, and the respective variable voltages are connected to terminals 3t4 and 3t5. It has a structure that can be taken out more. Further, in FIG. 5, 3e is a coil for low voltage, so-called tertiary voltage.

[0004]

Since the flyback transformer of the conventional television receiver is constructed as described above, it is necessary to adjust the respective VR3t4 and 3t5 when adjusting the focus voltage and the screen voltage. For this reason, while the electronic adjustment of the other parts of the television receiver is proceeding, only the adjustment of VR3t4, 3t5 remains, which hinders the adjustment work efficiency of the entire television receiver. In addition, the above VR3t4, 3t
Since No. 5 is a mechanical type, it was very difficult to give an arbitrary pattern of voltage change.

The present invention has been made in order to solve the above problems, and a television capable of adjusting the focus voltage and the screen voltage at a relatively low voltage and improving the efficiency of the entire adjustment work. It is intended to provide a flyback transformer for a John receiver.

[0006]

A flyback transformer of a television receiver according to the present invention has control elements connected to the low voltage sides of a focus volume and a screen volume, and responds to changes in input voltage to these control elements. The focus voltage and the screen voltage are variable.

[0007]

According to the present invention, by connecting the control element to the low voltage side of the focus and screen volume to control the input voltage to the control element, each high voltage of the focus and screen is adjusted electronically. It can be changed to.

[0008]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is an internal configuration diagram of a flyback transformer of a television receiver according to an embodiment of the present invention. In FIG. 1, 3k1 and 3k2 are control elements such as semiconductors, which are connected to control voltage input terminals 3t41 and 3t51. Depending on the input voltage, the voltage dividing resistors 3d11, 3d12, 3d21,
The voltage is divided via 3d22, and the terminals 3t4 and 3t5 are divided.
The voltage can be varied. Since the other configurations of the flyback transformer 3 are the same as those of the conventional example shown in FIG. 5, the same reference numerals are given to the corresponding portions, and the description thereof will be omitted.

Next, the operation of the above configuration will be described. A control voltage as a predetermined focus voltage is applied to the input terminal 3t41. With this voltage, the control element 3
The impedance of k1 changes, which causes resistance 3d
A voltage determined by the impedance ratio of 11, 3d12 and the control element 3k1 is taken out to the terminal 3t4, and this voltage changes corresponding to the voltage of the input terminal 3t41.

Also, for the screen voltage 3t5,
With the same operation as above, a voltage corresponding to the voltage of the input input terminal 3t51 can be taken out from the terminal 3t5.

FIG. 2 is a diagram showing the internal structure of a flyback transformer of a television receiver according to another embodiment of the present invention, which corresponds to a focus voltage applied to the cathode ray tube 2 which requires a second control voltage. In this example, the impedance of the control element 3k3 is changed by the input voltage to the third control terminal 3t61, and the voltage corresponding to the input voltage is taken out to the terminal 3t6 by the same operation as described above.

Conventionally, such a voltage has been obtained by dividing or controlling a high voltage, which requires a large number of parts, and a relatively high voltage is applied to the parts. Although there is a drawback that it has to be applied and controlled, by adopting the configuration of FIG. 2 described above, by applying a changed voltage to the input terminal 3t61 or 3t41, a corresponding voltage is applied to the terminal 3t6 or 3t4. You can take it out. In this case, since the voltage can be changed with a relatively low voltage, the object can be achieved by a cheaper and more reliable means than the conventional method.

FIG. 3 is an internal block diagram of a flyback transformer of a television receiver according to still another embodiment of the present invention. In order to reduce the variable voltage range in charge of the control element 3k1 in FIG. After the variable volume 3d14 is connected and the variable volume 3d14 is precisely set, the control voltage by the control element 3k1 is taken out to the terminal 3t4 by the same operation as in FIG.

[0014]

As described above, according to the present invention, it becomes possible to control the focus and screen voltages with a relatively low voltage, and therefore the efficiency of the adjustment work of the entire television receiver can be improved. it can. Further, the focus can be arbitrarily changed according to the position or state of the screen by dynamically controlling the voltage applied to the control terminal.

[Brief description of drawings]

FIG. 1 is a diagram showing an internal configuration of a flyback transformer of a television receiver according to an embodiment of the present invention.

FIG. 2 is a diagram showing an internal configuration of a flyback transformer of a television receiver according to another embodiment of the present invention.

FIG. 3 is a diagram showing an internal configuration of a flyback transformer of a television receiver according to still another embodiment of the present invention.

FIG. 4 is a schematic configuration diagram of the inside of a general television receiver.

FIG. 5 is a diagram showing an internal configuration of a flyback transformer of a conventional television receiver.

[Explanation of symbols]

 2 cathode ray tube 3 flyback transformer 3t1-3t6 terminal 3t41-3t61 control input terminal 3k1, 3k2, 3k3 control element

Claims (1)

[Claims] 1. In a flyback transformer for supplying an anode voltage, a focus voltage and a screen voltage of a television receiver, a control element is connected to a low voltage side of the focus volume and the screen volume, and an input voltage to these control elements. A flyback transformer for a television receiver characterized in that the focus voltage and the screen voltage are configured to be variable in response to changes in the.