JP2000041154A - Crt display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the CRT display device that is provided with an image pattern tilt correction means. SOLUTION: A horizontal sawtooth wave circuit 4 generates a horizontal sawtooth wave synchronously with a received horizontal synchronizing signal H and a sawtooth wave modulation circuit 5 generates a modulated horizontal sawtooth wave based on the horizontal sawtooth wave. Then a vertical deflection current circuit 7 superimposes a modulated horizontal sawtooth wave on a vertical deflection current generated by a vertical output circuit 6 and the result is fed to a vertical deflection coil 8, which corrects a vertical inclination of an image. Thus, a modulation amount of a horizontal modulation circuit 21 is controlled by a control signal 1 to correct a horizontal tilt of the image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CRT display, and more particularly to a CRT provided with a means for correcting the inclination of a displayed image.
It relates to a display device.

[0002]

2. Description of the Related Art A conventional CRT display device comprises a CRT 301 having a fluorescent screen 302 as shown in FIG.
The CRT 301 includes a terrestrial magnetism correction coil 303 arranged in parallel with the fluorescent screen 302, and a current control circuit 304 for supplying a current for generating a magnetic field to the terrestrial magnetism correction coil 303 in a direction to cancel the terrestrial magnetism.

The operation of this conventional CRT display device is shown in FIG.
As shown in (b), the electron beam emitted from the electron gun of the CRT 301 is bent in the direction of movement depending on the strength and direction of the magnetic field generated from the horizontal deflection coil and the vertical deflection coil, and is scanned across the fluorescent screen 302. Then, through a shadow mask, as shown in FIG.
When an image like the image 1 and the raster R1 is formed, the direction of movement of the electron beam is bent if geomagnetism is present, and the image 12 and the raster R2 are inclined on the fluorescent screen 302.

[0004]

As described above, the conventional CRT display device must be provided with a terrestrial magnetism correction coil for generating a magnetic field in a direction to cancel terrestrial magnetism in order to correct the inclination of an image due to the influence of terrestrial magnetism. There was a problem that must be done.

It is an object of the present invention to provide a CRT display device which corrects an image inclination without providing a geomagnetic correction coil.

[0006]

In order to solve the above-mentioned problems, a CRT display device according to the present invention provides a CRT for displaying an input image signal based on a horizontal synchronizing signal and a vertical synchronizing signal.
RT, a horizontal deflection coil and a vertical deflection coil for horizontally and vertically deflecting an image signal displayed on the CRT,
A horizontal modulation means for modulating a horizontal deflection current with the vertical synchronization signal, and varying a modulation amount with a preset control signal and sending it to the horizontal deflection coil; and generating a vertical deflection current based on the vertical synchronization signal. A vertical output circuit, a horizontal sawtooth circuit that generates a sawtooth wave in synchronization with the horizontal synchronization signal, a sawtooth wave from the horizontal sawtooth circuit modulated by the vertical synchronization signal, and a modulation amount by the control signal. And a vertical deflection current circuit that superimposes the sawtooth wave modulated by the sawtooth modulation circuit on the vertical deflection current and sends it to the vertical deflection coil.

In order to solve the above-mentioned problems, a CRT display device according to the present invention modulates the horizontal synchronizing signal with a vertical synchronizing signal and varies the modulation amount with the control signal. A horizontal output circuit for generating the horizontal deflection current based on an output signal from the horizontal modulation circuit and sending the generated horizontal deflection current to the horizontal deflection coil.

Further, in order to solve the above-mentioned problems, a CRT display device according to the present invention comprises a horizontal output circuit for generating a horizontal deflection current from the horizontal synchronization signal, and a sawtooth wave in synchronization with the vertical synchronization signal. A vertical sawtooth circuit that varies the magnitude with the control signal, and a horizontal deflection current circuit that superimposes the sawtooth wave from the vertical sawtooth circuit on the horizontal deflection current and sends it to the horizontal deflection coil. And the horizontal modulation means.

[0009]

Next, a CRT display device according to a first embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a first embodiment of the present invention.
FIG. 2 is a block diagram of an RT display device.

FIG. 2 is a circuit diagram of a first embodiment of the present invention.
The horizontal synchronization signal (a), the vertical synchronization signal (b), the modulated horizontal synchronization signal (c), the horizontal drive signal (d), and the horizontal deflection current (e) of the RT display device.

FIG. 3 is a circuit diagram of a first embodiment of the present invention.
6 is an image display example of an RT display device.

As shown in FIG. 1, the CRT display device according to the first embodiment of the present invention displays an image signal D input based on a horizontal synchronizing signal H and a vertical synchronizing signal V.
RT 9, a horizontal deflection coil 3 and a vertical deflection coil 8 for horizontally and vertically deflecting the image signal D displayed on the CRT 9, and a horizontal synchronization signal H is modulated by a vertical synchronization signal V and a control signal 1 is used to control the modulation amount. A horizontal modulation circuit 2 having a variable horizontal modulation circuit 21, a horizontal output circuit 22 for generating a horizontal deflection current based on an output signal from the horizontal modulation circuit and transmitting the generated horizontal deflection current to a horizontal deflection coil 3, and a vertical synchronization signal V A vertical output circuit 6 for generating a vertical deflection current by using a horizontal synchronizing signal H
A sawtooth wave circuit 4 for generating a sawtooth wave in synchronism with a sawtooth wave circuit; a sawtooth wave modulation circuit 5 for modulating a sawtooth wave from the horizontal sawtooth wave circuit 4 with a vertical synchronizing signal V and varying the modulation amount with a control signal 1 And a vertical deflection current circuit 7 for superimposing the sawtooth wave modulated by the sawtooth wave modulation circuit 5 on the vertical deflection current and sending it to the vertical deflection coil 8.

Next, the CR according to the first embodiment of the present invention will be described.
The operation of the T display device will be described with reference to the drawings.

The operation of the CRT display device according to the first embodiment of the present invention is as follows. As shown in FIGS. 1 to 3, an input horizontal synchronizing signal H (FIG. 2A) is converted into a vertical synchronizing signal V ( FIG.
(B)), the horizontal modulation circuit 21 generates a modulated horizontal synchronizing signal ((c) in FIG. 2), and the horizontal driving signal ((d) in FIG. 2) is generated by the modulated horizontal synchronizing signal. By
The horizontal deflection current ((e) in FIG. 2) is modulated, and the left and right inclination of the image is corrected as in the image I1 in FIG.

Next, the CR according to the second embodiment of the present invention will be described.
The T display device will be described with reference to the drawings.

FIG. 4 is a circuit diagram of a second embodiment of the present invention.
FIG. 2 is a block diagram of an RT display device.

FIG. 5 shows C according to a second embodiment of the present invention.
The horizontal synchronization signal (a), the horizontal deflection current (b), the vertical synchronization signal (c), the vertical sawtooth wave (d), and the horizontal deflection current (e) of the RT display device.

FIG. 6 is a circuit diagram of a second embodiment of the present invention.
6 is an image display example of an RT display device.

As shown in FIG. 4, the CRT display device according to the second embodiment of the present invention is a CRT for displaying an image signal D inputted based on a horizontal synchronizing signal H and a vertical synchronizing signal V.
RT9, a horizontal deflection coil 3 and a vertical deflection coil 8 for horizontally and vertically deflecting the image signal D displayed on the CRT 9, a horizontal output circuit 21 for generating a horizontal deflection current from the horizontal synchronization signal H, and a vertical synchronization signal V Vertical sawtooth wave circuit 2 that generates a sawtooth wave in synchronization with
4, the horizontal modulation means 2 having a horizontal deflection current circuit 23 for superimposing the sawtooth wave from the vertical sawtooth wave circuit 24 on the horizontal deflection current and sending it to the horizontal deflection coil 3; A vertical output circuit 6 for generating a current, a horizontal sawtooth wave circuit 4 for generating a sawtooth wave in synchronization with the horizontal synchronization signal H,
The sawtooth wave modulation circuit 5 modulates the sawtooth wave from the horizontal sawtooth wave circuit 4 with the vertical synchronizing signal V and varies the modulation amount with the control signal 1.
And a vertical deflection current circuit 7 for superimposing the sawtooth wave modulated by the sawtooth wave modulation circuit 5 on the vertical deflection current and sending it to the vertical deflection coil 8.

Next, the CR according to the second embodiment of the present invention will be described.
The operation of the T display device will be described with reference to the drawings.

The operation of the CRT display device according to the second embodiment of the present invention is as follows. As shown in FIGS. 4 to 6, a vertical sawtooth wave is applied to an input vertical synchronizing signal V (FIG. 5C). The circuit 24 generates a vertical sawtooth wave ((d) in FIG. 5), and the horizontal deflection current circuit 23 converts the vertical sawtooth wave into a horizontal deflection current ((b) in FIG. 5) generated by the horizontal output circuit 22. After being superimposed, the image is sent to the horizontal deflection coil 3 to correct the left and right inclination of the image as in the raster R1 and the image I1 in FIG.

[0023]

As described above, according to the CRT display device of the present invention, the inclination of the image can be corrected by controlling the horizontal deflection current and the vertical deflection current. This has the effect of eliminating the terrestrial magnetism correction coil.

[Brief description of the drawings]

FIG. 1 is a block diagram of a CRT display device according to a first embodiment of the present invention.

FIG. 2 shows a horizontal synchronizing signal (a), a vertical synchronizing signal (b), a modulated horizontal synchronizing signal (c), a horizontal driving signal (d), and a horizontal deflection current (C) of the CRT display device according to the first embodiment of the present invention. e).

FIG. 3 is an image display example of the CRT display device according to the first embodiment of the present invention.

FIG. 4 is a block diagram of a CRT display device according to a second embodiment of the present invention.

FIG. 5 shows a horizontal synchronization signal (a), a horizontal deflection current (b), a vertical synchronization signal (c), a vertical sawtooth wave (d), and a horizontal deflection current (e) of a CRT display device according to a second embodiment of the present invention. ).

FIG. 6 is an image display example of a CRT display device according to a second embodiment of the present invention.

FIG. 7 is a block diagram of a conventional CRT display device.

FIG. 8 shows an example of a screen display of a conventional CRT display device (a), and an example of a screen display deformed by an electron beam (b).

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 control signal 2 horizontal modulation means 3 horizontal deflection coil 4 horizontal sawtooth circuit 5 sawtooth modulation circuit 6 vertical output circuit 7 vertical deflection current circuit 8 vertical deflection coil 9 CRT 21 horizontal modulation circuit 22 horizontal output circuit 23 horizontal deflection current circuit 24 Vertical sawtooth circuit

Claims (3)

[Claims] 1. A CRT for displaying an image signal inputted based on a horizontal synchronizing signal and a vertical synchronizing signal, and the CRT
A horizontal deflection coil and a vertical deflection coil for horizontally and vertically deflecting the image signal displayed in the step (a), and a horizontal deflection current modulated by the vertical synchronization signal, and the modulation amount is varied by a preset control signal to vary the horizontal deflection current. A horizontal modulation means for sending to a deflection coil, a vertical output circuit for generating a vertical deflection current based on the vertical synchronization signal, a horizontal sawtooth wave circuit for generating a sawtooth wave in synchronization with the horizontal synchronization signal, A sawtooth wave modulation circuit that modulates the sawtooth wave from the wave circuit with the vertical synchronization signal, and varies the modulation amount with the control signal, and superimposes the sawtooth wave modulated by the sawtooth modulation circuit on the vertical deflection current. And a vertical deflection current circuit for sending the vertical deflection current to the vertical deflection coil. 2. A horizontal modulation circuit for modulating the horizontal synchronization signal with a vertical synchronization signal and varying a modulation amount with the control signal, and generating the horizontal deflection current with an output signal from the horizontal modulation circuit. 2. The CRT display device according to claim 1, wherein said horizontal modulation means comprises a horizontal output circuit for sending out to a horizontal deflection coil. 3. A horizontal output circuit for generating a horizontal deflection current from the horizontal synchronizing signal, a vertical sawtooth circuit for generating a sawtooth wave in synchronization with the vertical synchronizing signal, and varying the magnitude with the control signal. A horizontal deflection current circuit for superimposing a sawtooth wave from the vertical sawtooth wave circuit on the horizontal deflection current and sending the superposed waveform to the horizontal deflection coil. The CRT display device as described in the above.