JPH10224716A - Heater voltage supply circuit to cathode ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heater voltage supply circuit that applies a heater voltage to each heater connecting respectively to red(R), green(G) and blue(B) electron guns so as to allow the R, G and B electron guns to emit electrons quickly. SOLUTION: The circuit is provided with R, G and B electron guns 20. In this case, a heater 40 is driven independently by using a transformer 50 that has a primary winding receiving a heater voltage and secondary windings which applies a voltage induced from the primary winding to each heater 40 connecting to the R, G and B electron guns 20. Thus, the drive time of a cathode ray tube 10 is reduced, the impedance matching is facilitated and the efficiency is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heater voltage supply circuit for a cathode ray tube, which can quickly drive a cathode ray tube by independently supplying current to a heater connected to an electron gun of the cathode ray tube using a transformer. .

[0002]

2. Description of the Related Art In general, a cathode ray tube displays an image by irradiating a phosphor with an electron beam to emit light, as is well known. Electrons of the electron beam are generated from a cathode in the electron gun. The cathode is coated with, for example, an oxide (oxide) on its tip surface, and is heated by a heater to generate electrons. The electrons generated in this way are focused and accelerated on the grid to become an electron beam.

FIG. 1 shows a conventional cathode ray tube (CR) as described above.
2 shows a heater voltage supply circuit T). Conventional cathode ray tube 10
Is composed of red (R), green (G), and blue (B) electron guns 20 for indicating the three primary colors. This electron gun generates an electron beam. One heater 30 is connected to the R, G, and B electron guns 20. The heater 30 is a flyback transformer (FBT) for supplying a driving voltage to each part of the cathode ray tube.
Heat is generated by a heater voltage supplied from a power supply (not shown). The R, G, and B electron guns 20 are heated by the heat generated by the heater 30 and emit an electron beam.

However, the conventional heater voltage supply circuit has R,
To facilitate the electron emission of the G and B electron guns 20, R,
One heater 3 so that the G and B electron guns 20 have a constant temperature.
Since it must be heated at a stretch through 0, it takes a long time to reach a certain temperature. Thus, the time from when power is supplied to the cathode ray tube to when the electron gun 20 is heated and the electron beam is generated is extended. Also, R, which operates independently,
Since the G and B electron guns 20 are heated at once by one heater 30, there is a problem that the impedance matching is not performed and the initial image becomes unstable.

[0005]

SUMMARY OF THE INVENTION The present invention has been devised to solve the above-mentioned problems, and its object is to connect one heater to each of R, G, and B electron guns of a cathode ray tube. To provide a heater voltage supply circuit for a cathode ray tube capable of rapidly driving the cathode ray tube by shortening the starting time of the electron gun.

Another object of the present invention is to independently apply a heater voltage to the R, G, and B electron guns by using a transformer, thereby facilitating impedance matching and increasing efficiency. Is to provide a circuit.

[0007]

In order to achieve the above-mentioned object, a feature of the present invention is to provide a heater voltage supply circuit for a cathode ray tube having respective R, G, B electron guns. In a heater voltage supply circuit of a cathode ray tube, a heater is connected to an electron gun, and a transformer is connected to the heater so that a heater voltage applied from outside through the transformer is independently applied to the heater.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 2 shows a heater voltage supply circuit for a cathode ray tube according to a preferred embodiment of the present invention. The cathode ray tube 10 includes R, G, and B electron guns 20. One heater 40 is provided for each of the R, G, and B electron guns 20.
Concatenate. The heater 40 is connected to a transformer 50 to which a heater voltage from a flyback transformer (not shown) is supplied. The transformer 50 outputs a heater voltage from the primary winding to the secondary winding from the flyback transformer. Transformer 50-2
The output of the secondary winding is independently applied to a heater 40 connected to each of the R, G, and B electron guns 20 one by one.

When power is supplied to the cathode ray tube, the heater voltage from the flyback transformer is induced in the primary winding of the transformer 50, and the induced voltage is applied to the secondary winding connected to the heater 40 one by one. Guided to the line. The heater 40 connected to each of the R, G, and B electron guns 20 generates heat by a heater voltage applied from a secondary winding of the transformer 50. The R, G, and B electron guns 20 are each heated by independent heating of the heater 40 to emit electrons. In addition, since the independently induced heater voltage is supplied to the heater 40, impedance matching is easy.

[0010]

As described above, according to the present invention, one heater is connected to each of the R, G, and B electron guns of the cathode ray tube.
By independently supplying a heater voltage using a transformer, quick driving and impedance matching are facilitated, and efficiency is increased.

[Brief description of the drawings]

FIG. 1 is a diagram showing a conventional heater voltage supply circuit for a cathode ray tube.

FIG. 2 is a diagram illustrating a heater voltage supply circuit of a cathode ray tube according to a preferred embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 cathode ray tube 20 R, G, B electron gun 40 heater 50 transformer

Claims (2)

[Claims] 1. A heater voltage supply circuit for a cathode ray tube having respective R, G, and B electron guns, wherein a heater voltage of a cathode ray tube including a heater connected to each of the R, G, and B electron guns is provided. Supply circuit. 2. A primary winding to which a heater voltage is applied;
2. The transformer according to claim 1, further comprising a secondary winding that independently supplies a voltage induced from the secondary winding to each of the heaters connected to the R, G, and B electron guns.
3. A heater voltage supply circuit for a cathode ray tube according to claim 1.