JPH05328374A - Color cathode ray tube device - Google Patents

Abstract

PURPOSE:To reduce the number of coils for compensating mislanding generated due to earth magnetism in a color cathode ray tube (CRT). CONSTITUTION:Eight-shaped coils 22, 23 are arranged on both the sides of a neck part 21 out of a fan neck part 2 along the minor axis direction L of the tube face 20 of the color CRT 1. The directions of mislanding generated by earth magnetism are mutually reversed the upper and lower parts of the minor axis direction L and their mislanding variables are equal, mislanding can be compensated by the two coils 22, 23. Although four or six independent coils are required for a convensional method, the compensation can be attained only by the two coils in this method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color cathode ray tube device having a correction coil for correcting mislanding due to the earth's magnetism and suitable for use in a consumer large-screen image receiver or a commercial high-definition image receiver.

[0002]

2. Description of the Related Art Conventionally, for example, in a color cathode ray tube having a color selection mask, the orbit of an electron beam is shifted due to geomagnetism, and a predetermined electron beam does not collide with a predetermined phosphor corresponding thereto correctly. , So-called mislanding occurs. When mislanding occurs, color purity deteriorates.

As a conventional technique for correcting the above mislanding, there is a technique of "color cathode ray tube device" disclosed in Japanese Patent Application No. 2-171706 filed by the present applicant.

FIG. 5A and FIG. 5B show a rear surface configuration and a side surface configuration of a color cathode ray tube to which this conventional technique is applied, respectively.

As shown in FIGS. 5A and 5B, according to this conventional technique, 6 of the funnel portion 2 of the color cathode ray tube 1 is used.
1 coil for each position, 6 coils in total 3
~ 8 are provided. Only the coil 5 has an annular shape because the anode cap 10 is provided. Two lead wires of each of the coils 3 to 8 are connected to terminals provided on the deflection yoke portion 9.

FIG. 6 shows the configuration of an electric circuit for supplying a correction current to the coils 3-8. That is, the coils 3 to
8 is grounded at one end via the terminal of the deflection yoke section 9,
The other end is connected to the output side of the drive circuit 11. A correction voltage generation circuit 12 is connected to the input side of the drive circuit 11.

In this case, the correction voltage generating circuit 12 supplies a signal based on the value of the geomagnetism to the drive circuit 11. Then, the correction currents based on the signals from the six amplifiers constituting the drive circuit 11 are supplied to the respective coils 3 to 8 to correct the mislanding.

It should be noted that the number of amplifiers is set such that the magnetic flux is generated in the coils 3 and 4, the coils 5 and 6, and the coils 7 and 8 which are arranged along the minor axis direction L of the tube surface 20 of the color cathode ray tube 1. It can be reduced to three by connecting in series so that the directions of occurrence are opposite. For example, in Japan, the surface 20 of the color cathode ray tube 1 is
, The electron beam rotates clockwise when viewed from the tube surface 20 side due to the influence of the earth's magnetism, while the electron beam rotates counterclockwise in the north direction. This is because at the upper and lower positions in the minor axis direction L, the shift directions are opposite and the shift amounts are the same.

FIG. 7B shows, for example, the current i flowing in the coils 3 and 4 and the direction of the magnetic flux generated by the current i. The magnetic flux 15 generated in the coil 3 is directed from the outside of the coil 3 toward the center side, and the magnetic flux 16 generated in the coil 4 is directed from the center side of the coil 4 toward the outside.

As described above, according to the above conventional technique, the mislanding due to the geomagnetism can be corrected.

[0011]

However, according to the above-mentioned conventional technique, one coil 3 to 8 is required at each of the six positions of the funnel portion 2, and further, the six coils 3 to 8 are used. Since two lead wires are required for each, the man-hours for manufacturing the coils 3 to 8 themselves, the man-hours for attaching the coils 3 to 8 to the funnel portion 2 and the man-hours for assembling the lead wires are considerably large, and eventually, However, there is a problem that the product cost becomes high.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a color cathode ray tube device capable of reducing the number of coils in half and reducing the product cost.

[0013]

The first aspect of the present invention is, for example, as shown in FIG. 1, along the minor axis direction L of the tube face 20 of the color cathode ray tube 1 and in the neck of the funnel portion 2. 8 shaped coils 2 arranged on both sides of the part 21 respectively
2 and 23, and these two 8-shaped coils 22 and 2
3 is used to perform the mislanding correction due to the geomagnetism.

The second aspect of the present invention is, for example, as shown in FIG. 3, along the minor axis direction L of the tube surface 20 of the color cathode-ray tube 1 and on both sides of the funnel section 2 of the neck section 21. The 8-shaped coils 22 and 23 arranged and the 8-shaped coil 58 arranged along the short axis direction L of the tube surface of the color cathode-ray tube 1 and in the funnel portion 2 on the substantially central axis. By using these three 8-shaped coils 22, 23, 58, the mislanding correction by the geomagnetism is performed.

[0015]

According to the first aspect of the present invention, the two 8-shaped coils 22 and 23 are used to correct the mislanding due to the geomagnetism, so that the number of coils is less than half and the product cost is reduced. can do.

According to the second aspect of the present invention, since the mislanding correction due to the geomagnetism is performed by using the three 8-shaped coils 22, 23, 58, the number of coils can be reduced by half and the product cost can be reduced. Can be reduced.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the color cathode ray tube device of the present invention will be described below with reference to the drawings. In the drawings referred to below, parts corresponding to those in FIGS. 5A, 5B and 6 are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 1A shows the rear structure of a color cathode ray tube device according to this embodiment. FIG. 1B shows a side configuration of the example of FIG. 1A.

As shown in FIGS. 1A and 1B, the color cathode ray tube device according to this embodiment has a color cathode ray tube 1. This color cathode ray tube 1 is a single electron gun three-beam cathode ray tube having a color selection mask (not shown). Eight-shaped coils 22 and 23 are attached along the minor axis direction L of the tube surface 20 of the color cathode ray tube 1 and on both sides of the neck portion 21 of the funnel portion 2.

Each of the eight-shaped coils 22 and 23 is formed by first forming a ring-shaped coil and then setting the central portion to one.
It can be formed by twisting. The ring-shaped coil may be formed of a heat-sealed electric wire or a flexible sheet-shaped printed wiring board made of polyimide.

The figure-eight coil 22 has two lead wires 24, 2 as input wires at the winding start and winding ends.
5 is attached. Two lead wires 26 and 27 are similarly attached to the other 8-shaped coil 23. The eight-shaped coil 22 and the eight-shaped coil 23 have the same structure, so that management is easy. Therefore, the management cost is reduced.

A deflection yoke portion 30 is arranged across the funnel portion 2 and the neck portion 21. The deflection yoke portion 30 has two terminals (31a, 31b),
A terminal 31 and a terminal 32 having (32a, 32b) are formed.

Lead wires (24, 25), (26, 27) of the figure-eight coils 22, 23 are connected to these terminals 31, 32, respectively.
Are connected.

FIG. 2 shows the configuration of an electric circuit for supplying the correction currents i ₁ and i ₂ to the 8-shaped coils 22 and 23.

The input sides of the 8-shaped coils 22 and 23 are connected to the output side of the drive circuit 40, and the input side of the drive circuit 40 is connected to the output side of the correction voltage generating circuit 41.
The input side of the correction voltage generating circuit 41 is connected to a magnetic sensor 42 which is a geomagnetic detecting means.

The magnetic sensor 42 detects the geomagnetism, detects the direction in which the color cathode ray tube 1 is placed, and supplies the detection signal S ₀ to the correction voltage generation circuit 41. The magnetic sensor 42 is a well-known one, and for example, a magnetic field measuring device using a Flux Gate can be used. In addition, Flux
A magnetic field measuring device using a Gate changes magnetic permeability, loss, and magnetic flux of a magnetic material such as permalloy when it is symmetrically and periodically excited by an alternating magnetic field in the magnetic field to be measured. It is based on the fact that these changes are proportional to the strength of the magnetic field ("Introduction to Magnetic Optics", author: Kenji Narita, Ohmsha, published July 10, 1965) ).

The correction voltage generating circuit 41 is composed of, for example, a microprocessor, and the detection signal S of the magnetic sensor 42 is detected.
Phase (θ-α) or phase (θ + α) determined in advance based on the bearing θ determined from ₀ (for example, 0 ° eastward, 90 ° southward, 180 ° westward, 270 ° northward) And outputs an output signal S ₁ or an output signal S ₂ having an amplitude of A.

Therefore, the output signal S ₁ is S ₁ = A ·
It is represented by sin (θ−α). The output signal S ₂ is S ₂
= A · sin (θ + α)

Here, the amplitude A and the phase α depend on the deviation of the actual arrangement positions of the figure-eight coils 22 and 23 and the assembly error of the electron gun (not shown) of the color cathode ray tube 1. It is also possible to set different values.

The drive circuit 40 includes an 8-shaped coil 22.
And 8-shaped coil 23 for operational amplifier 4
The feedback amplifiers 44 and 45 using the amplifiers 3 and 43 are configured. Since the feedback amplifier 44 and the feedback amplifier 45 have the same circuit configuration, the feedback amplifier 44 will be mainly described below.
Will be described only.

The gain of the feedback amplifier 44 is represented by the ratio R ₂ / R ₁ of the resistor 47 (having a resistance value R ₁ ) and the resistor 48 (having a resistance value R ₂ ). The resistor 49 connected between the non-inverting input terminal of the operational amplifier 43 and the ground is for offset adjustment, and its resistance value is selected to be a parallel value of the resistance value R ₁ and the resistance value R ₂ . The output current (hereinafter referred to as a correction current, if necessary) i ₁ of the feedback amplifier 44 is supplied to the 8-shaped coil 22 to generate a necessary correction magnetic field.

The current flowing through the 8-shaped coil 22 is flown to the ground through the current detecting resistor 50. Resistor 50
The current detected by is converted into a voltage value as the voltage drop of the resistor 50, and is converted through the resistor 48 into the operational amplifier 43.
It is fed back to the inverting input terminal of. The capacitor 51
Is for preventing oscillation.

FIG. 7A shows the direction of the magnetic flux generated when the correction current i ₁ flows through the 8-shaped coil 22.
That is, the direction of the magnetic flux 55 generated in the upper loop 22a of the 8-shaped coil 22 is from the outside to the center side, and the direction of the magnetic flux 56 generated in the lower loop 22b is the center of the coil 4. The direction goes from the side to the outside.

Therefore, the magnetic fluxes 15 and 16 formed by the two coils 3 and 16 according to the prior art shown in FIG. 7B.
It is in the same direction as.

In Japan, the mislanding is sin (θ +
α), and at the lower left, it occurs as −sin (θ + α). In addition, it occurs as sin (θ-α) in the upper right of the tube surface and sin (θ-α) in the lower right.

Therefore, above and below the minor axis direction L of the tube surface 20, the direction of mislanding caused by geomagnetism is opposite and the amount of mislanding is equal. Therefore, mislanding correction is performed by supplying the same current. It can be carried out. According to the example of FIG. 1, the mislanding correction due to the geomagnetism can be performed by using the two 8-shaped coils 22 and 23, and the number of coils is less than half as compared with the conventional technique shown in FIG. 5A. Become. Therefore, the number of lead wires of the coil is reduced by that amount as compared with the conventional technique. After all, the man-hours for attaching the coil to the funnel portion 2 and the man-hours for wiring the lead wires 24 to 28 to the terminals 31, 32 are reduced, and the product cost is reduced.

Further, according to the configuration of FIG. 1, it is possible to efficiently correct the four corners of the tube surface 20 where the deterioration of color purity due to mislanding is noticeable, so that the number of consumers will increase in the future. It is suitable to be applied to a large screen for use, such as a 25-inch or larger receiver or a high-definition receiver for business use.

In the example of FIG. 1, a magnetic sensor 42 (see FIG. 2) for detecting the azimuth of the color cathode ray tube 1 based on the geomagnetism is provided. However, even when the magnetic sensor 42 is not provided, the correction voltage generating circuit is provided. Amplitude A and phase (θ−α) of the output signal S ₁ and the output signal S ₂ output from 41,
(Θ + α) may be manually variable by a volume or the like. In this case, after the color cathode ray tube device is installed, by variably adjusting them, mislanding at the installation position can be adjusted to the minimum, and the color purity is optimized.

FIG. 3 shows the rear structure of another embodiment of the present invention. In the example of FIG. 3, in order to perform more accurate landing correction, a third eight-shaped coil 58 is provided along the short axis direction L of the color cathode-ray tube 1 and in the funnel portion 2 having a substantially central axis shape. Is attached. For the electric circuit for driving the figure-eight coil 58, one additional feedback amplifier having the same configuration as the above-described feedback amplifier 44 may be provided. In this case, mislanding occurs as sin θ on the upper side of the center of the tube surface and −sin θ on the lower side of the tube, so that it can be similarly driven by the feedback amplifier for one circuit.

FIGS. 4A, 4B, 4C and 4D show a modified example of the figure 8 coil.

FIG. 4A shows the left and right 8-shaped coils 60, 61.
The reverse of the winding direction is shown. FIG. 4B shows an 8-shaped coil 62, 63 having different loop sizes at the top and bottom. FIG. 4C shows an increased number of figure eight coils 64.
~ 67 are shown. FIG. 4D shows eight-shaped coils 68 to 70 in which the loop shape is formed in a shape other than the round shape.

By using the configuration of FIG. 1, FIG. 3 and any of FIG. 4A, FIG. 4B, FIG. 4C, and FIG. 4D, optimum mislanding correction can be performed according to the installation conditions and characteristics of the color cathode ray tube 1. The configuration to be performed can be selected.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various configurations can be adopted without departing from the gist of the present invention.

[0044]

As described above, according to the first aspect of the present invention, the mislanding correction due to the geomagnetism is performed by using the two 8-shaped coils. Therefore, the number of coils for landing correction is less than half, and the effect that the product cost can be reduced can be obtained.

According to the second aspect of the present invention, the mislanding correction due to the geomagnetism is performed by using the three 8-shaped coils. Therefore, the number of coils for landing correction can be reduced by half, and the product cost can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of a color cathode ray tube device according to the present invention.

2 is an electrical circuit diagram related to the example of FIG. 1. FIG.

FIG. 3 is a diagram showing the configuration of another embodiment of the color cathode ray tube device according to the present invention.

FIG. 4 is a diagram showing the configuration of still another embodiment of the color cathode ray tube device according to the present invention.

FIG. 5 is a diagram showing a configuration of a color cathode ray tube device according to a conventional technique.

FIG. 6 is an electric circuit diagram related to the example of FIG.

FIG. 7 is a diagram showing a comparison of states of magnetic flux generated in coils.

[Explanation of symbols]

 1 Color Cathode Ray Tube 2 Funnel Section 20 Tube Surface 22, 238 Shaped Coil L Minor Axis Direction

Claims (2)

[Claims] 1. An eight-shaped coil disposed along the minor axis direction of the surface of the color cathode ray tube and on both sides of the neck portion of the funnel portion. A color cathode ray tube device characterized by performing mislanding correction due to geomagnetism using a coil. 2. An 8-shaped coil arranged along the minor axis direction of the surface of the color cathode ray tube and on both sides of the neck portion of the funnel portion, and in the minor axis direction of the color cathode ray tube. And an eight-shaped coil arranged along the substantially central axis on the funnel portion, and mislanding correction by geomagnetism is performed using these three eight-shaped coils. Color cathode ray tube device.