JPH11297236A - Landing correction device for crt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce landing correction coils and their mounting components and reduce the mounting manhour. SOLUTION: An explosion-proof reinforcing bracket 40 is mounted on the outside periphery of the bonded part of a funnel part and a face panel part 10. Mounting bracket pieces 42A, 42B, 42C, 42D are formed on the four corner parts of the explosion-proof reinforcing bracket 40. A first current source 50 is connected to a pair of the mounting bracket pieces 42A, 42B on the upper side. In addition, a second current source 52 is connected to a pair of the mounting bracket pieces 42C, 42D on the lower side. Electromagnetic force is generated by supplying a landing correction direct current or alternating current from the respective current sources 50, 52 to the explosion-proof reinforcing bracket 40 and thus, the landing correction of an electron beam is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a landing correction device for correcting a scanning trajectory of an electron beam in a CRT.

[0002]

2. Description of the Related Art Conventionally, as a method of performing a landing correction for correcting a scanning trajectory of an electron beam in a CRT, for example, a large coil for landing correction corresponding to the outer peripheral size of the CRT is arranged. It is known that landing correction coils are arranged at four corners of a CRT, and the supply of current is controlled for each coil to generate an electromagnetic force for landing correction.

[0003]

However, in the above-mentioned prior art, there is a problem that the number of components increases because a dedicated coil for landing correction is provided. In addition, when coils are arranged at four corners in addition to the large-sized coil described above, a total of five coils and five current control circuits are required, and from this point, there is a problem that the number of components increases. In addition, instead of such an electric correction device, there is a device that performs correction using a magnet. However, in this case, the automatic control of the correction amount cannot be performed, and the adjustment depends on humans. It required a certain degree of temperature, which was an obstacle to production.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a CRT landing correction device which can reduce the number of landing correction coils and components for mounting the same, and reduce the number of steps for mounting the coils.

[0005]

In order to achieve the above object, according to the present invention, a neck portion having an electron gun is provided at a rear portion of a funnel portion, and a face panel portion is joined to a front opening of the funnel portion to form a CRT. A landing correction device for correcting a scanning trajectory of an electron beam from the electron gun in a CRT in which a main body is formed and a ring-shaped explosion-proof reinforcing bracket is mounted on an outer periphery of a junction between the funnel portion and the face panel portion, The explosion-proof reinforcing bracket is provided with a landing correction circuit for supplying a correction current for generating an electromagnetic force for landing correction.

In the landing correction device for a CRT according to the present invention, a correction current is supplied by a landing correction circuit to an annular explosion-proof reinforcing bracket disposed on the outer peripheral portion of the CRT main body. As a result, the explosion-proof reinforcing bracket acts as a one-turn coil, and an electromagnetic force is generated by the current flowing through the explosion-proof reinforcing bracket. Therefore, the scanning trajectory of the electron beam from the electron gun can be changed by the electromagnetic force, and the landing of the electron beam can be corrected by optimizing the current value.

As described above, by using the existing explosion-proof reinforcing bracket in a conventional CRT as a coil for landing correction, the number of dedicated coils for landing correction can be reduced. Parts to be attached can be reduced. Further, the number of steps for attaching the dedicated coil to the CRT can be reduced, and a low-cost landing correction device can be provided.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a CRT landing correction apparatus according to the present invention will be described below. FIG.
1 is a front view of a CRT showing a specific example of a landing correction device according to the present invention, and FIG. 2 is a cross-sectional view of the CRT shown in FIG. As shown in FIG. 1, the face panel section 10 of the CRT has a slightly rounded rectangular front shape, and an explosion-proof reinforcing bracket (HS band) 40 is attached to the outer periphery thereof.

As shown in FIG. 2, the face panel 10
A funnel portion 20 is joined to the rear of the device, and a neck portion 30 containing an electron gun 32 is provided at the rear portion of the funnel portion 20 to constitute a CRT main body. A fluorescent screen is provided on the inner surface of the face panel unit 10, and a shadow mask (or aperture grill) 12 is disposed on the inner surface of the face panel unit 10, and the RGB electron beams emitted from the electron gun 32 are Shadow mask 12
To illuminate the phosphor screen

Further, behind the shadow mask 12, a shield plate (not shown) for blocking the influence of external magnetism such as terrestrial magnetism on the electron beam is arranged so as to surround the path of the electron beam. . In addition, funnel 2
A deflecting device (not shown) for controlling the deflection of the electron beam is arranged on the outer periphery of the neck portion 30 from 0 to 0. Further, a wiring board ( (Not shown).

The explosion-proof reinforcing bracket 40 is mounted on the outer periphery of the joint between the funnel section 20 and the face panel section 10, and is formed in a rectangular frame shape corresponding to the front shape of the face panel section 10. The explosion-proof reinforcing bracket 40 has four mounting bracket pieces (HS band ears) 42A and 42 corresponding to the four corners of the face panel section 10.
B, 42C and 42D are provided. The two mounting brackets 42A and 42B and the mounting brackets 42C and 42D on the long sides located above and below the explosion-proof reinforcing bracket 40 are used as a set for the current supply terminal, and the upper mounting brackets 42A and 42B are used. A first current source (current supply unit) 50
And a second current source (current supply unit) 52 is connected between the lower mounting bracket pieces 42C and 42D.

Each of the current sources 50 and 52 is, for example, disposed on the above-mentioned wiring board.
Supplies a DC current or an AC current to the upper side 40A of the explosion-proof reinforcing bracket 40 via the mounting bracket pieces 42A and 42B. Further, the first current source 52 is connected to the lower side 4 of the explosion-proof reinforcing bracket 40 via the mounting bracket pieces 42C and 42D.
0B is supplied with a direct current or an alternating current.
As described above, the explosion-proof reinforcing bracket 40 is used as a one-turn coil, and a current necessary for correction is applied to generate an electromagnetic force to correct the landing of the electron beam.

For example, in the inspection process, the current source 5 is operated by operating a variable resistor or the like while viewing the screen of the CRT.
The current amounts of 0 and 52 are controlled, and the generated electromagnetic force is adjusted optimally to obtain the optimal trajectory of the electron beam.
Then, when the optimum image quality is obtained, the setting states of the variable resistors and the like are fixed. Here, in this example, by separately providing the current sources 50 and 52 for the upper and lower terminals, it is possible to perform the correction while separating the upper part and the lower part of the screen. Then, after shipping the TV receiver equipped with the CRT, when the TV receiver is used, the current sources 50 and 52 in the set state in the above-described inspection process are activated to optimize the electron beam landing. Try to get image quality.

As described above, instead of controlling the current amount of the current sources 50 and 52 independently of the surrounding environment, the surrounding environment such as the external magnetism (such as geomagnetism) and the temperature at the installation location of the shipping destination is considered. Then, the current amount of the current sources 50 and 52 may be controlled. That is, a control circuit for outputting a control signal for variably controlling the current amount of the current sources 50 and 52 is provided in a control circuit of the CRT, and a detector for detecting a surrounding magnetic environment and a temperature environment is provided in the CRT. .

On the other hand, in an inspection process, by applying external magnetism or temperature in a simulated manner, optimal current amounts of a plurality of current sources 50 and 52 corresponding to various peripheral environments are obtained. It is stored in the nonvolatile memory of the control circuit of the CRT. When a TV receiver or the like equipped with a CRT is used, its surrounding magnetism and surrounding temperature are detected by a detector, and based on the detected values, the optimal current amounts of the current sources 50 and 52 are determined from the above condition table. select. Then, the current sources 50 and 52 are controlled by the control circuit so as to realize the selected current amount, and the landing correction of the electron beam can be optimally performed according to the surrounding environment. As described above, the optimum landing state can be maintained, and the apparatus can be used in an ideal state such as color reproduction and white uniformity.

FIG. 3 is an explanatory diagram showing how the landing correction of the electron beam is performed when a DC power supply is used for the current sources 50 and 52. As shown in FIG. 3, when a DC power supply is used, upper terminals 42A and 42B and lower terminals 42A and 42B are connected.
By supplying different currents to C and 42D, the upper half and the lower half of the screen can be separated and correction can be performed. That is, FIG. 3A corrects only the upper side, and FIG.
FIG. 3B shows a state where only the lower side is corrected, and FIG. 3C shows a state where both the upper and lower sides are corrected. Further, by switching the polarity of the current sources 50 and 52, the correction direction can be individually switched up and down.

FIG. 4 is an explanatory diagram showing how the landing of the electron beam is corrected when an AC power supply is used for the current sources 50 and 52. When this AC current is used, the current waveform synchronized with the horizontal deflection is converted to the upper terminals 42A, 42A.
By supplying separately to B and the lower terminals 42C and 42D, it is possible to correct the entire screen by setting a waveform of a correction current as needed at an upper or lower part of the screen. . 4 shows an example in which a sawtooth wave is used as an example. FIG. 4 (A) corrects only the upper side, FIG. 4 (B) corrects only the lower side, and FIG. This shows a state where both sides are corrected.

[0018]

As described above, in the landing correction device for a CRT according to the present invention, a landing current is supplied to the explosion-proof reinforcing bracket mounted on the outer peripheral portion of the CRT body by supplying a correction current for generating an electromagnetic force for landing correction. Correction was made. For this reason, the existing explosion-proof reinforcing bracket is conventionally used as a coil for landing correction, so that a dedicated coil for landing correction can be reduced.
The number of components for attaching such a dedicated coil to the CRT can be reduced, the number of steps for attaching the dedicated coil to the CRT can be reduced, and a low-cost landing correction device can be provided.

[Brief description of the drawings]

FIG. 1 is a front view of a CRT showing a specific example of a landing correction device according to the present invention.

FIG. 2 is a cross-sectional view of the CRT shown in FIG.

FIG. 3 is an explanatory diagram showing a state of landing correction of an electron beam when a DC power supply is used as a current source of the landing correction device shown in FIG. 1;

FIG. 4 is an explanatory diagram showing a state of landing correction of an electron beam when an AC power supply is used as a current source of the landing correction device shown in FIG. 1;

[Explanation of symbols]

10: face panel, 12: shadow mask,
Reference numeral 20: funnel portion, 30: neck portion, 32: electron gun, 40: explosion-proof reinforcing bracket, 42A, 42B, 42
C, 42D: Mounting bracket pieces.

Claims (8)

[Claims] 1. A CRT body is formed by providing a neck portion containing an electron gun at a rear portion of a funnel portion and joining a face panel portion to a front opening of the funnel portion.
A landing correction device for correcting a scanning trajectory of an electron beam from the electron gun in a CRT in which an annular explosion-proof reinforcing bracket is attached to an outer periphery of a junction between the funnel section and the face panel section, A landing correction device for a CRT, comprising: a landing correction circuit that supplies a correction current for generating a correction electromagnetic force. 2. The explosion-proof reinforcing bracket has four mounting brackets corresponding to corners of a CRT main body, and the landing correction circuit supplies the correction current using the mounting brackets as connection terminals. The landing correction device for a CRT according to claim 1, wherein: 3. A landing correction circuit for supplying a first correction current to a first side of the explosion-proof reinforcing bracket.
2. The CRT landing correction device according to claim 1, further comprising: a current supply unit configured to supply a second correction current to a second side of the explosion-proof reinforcing bracket. 3. 4. The apparatus according to claim 1, wherein the correction current is a direct current. 5. The CRT landing correction device according to claim 1, wherein the correction current is an alternating current. 6. The landing correction circuit according to claim 6, wherein:
2. The CR according to claim 1, wherein the correction current is controlled based on a detection signal of a detector provided in the T body.
T landing correction device. 7. The detector according to claim 6, wherein the detector detects external magnetism acting on a CRT main body.
A landing correction device for a CRT as described in the above. 8. The apparatus according to claim 6, wherein said detector detects an ambient temperature acting on a CRT main body.
A landing correction device for a CRT as described in the above.