JPH08214181A - Wide television receiver - Google Patents

Abstract

PURPOSE: To get rid of the roughness of an image pattern on the CRT screen in the wide television receiver by oscillating an electronic beam at high frequencies in the vertical direction only in a zoom mode and shaping scanning lines longer in the longitudinal direction on the screen because the interval of scanning lines in the zoom mode is wider than in a switching mode to another aspect ratio and the roughness is conspicuous in a zoom mode. CONSTITUTION: An electron beam shape modification coil 4 deflected only in the vertical direction is mounted to a neck 1a of a CRT1 and a high frequency current is supplied to the electron beam shape modification coil 4 in the zoom mode only to oscillate the electron beam in the vertical direction. Then interval of scanning lines on a CRT screen is made narrow and the roughness of image pattern is not conspicuous.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wide-screen television receiver, and more particularly, it eliminates the roughness of scanning lines in the zoom mode, eliminates the deterioration of the image quality in each aspect ratio, and always provides a high-quality image. To get to.

[0002]

2. Description of the Related Art Recently, a television receiver has a screen having an aspect ratio of 4: 3. However, recently, the demand for a more powerful wide television receiver having an aspect ratio of 16: 9 has increased, and a demand for a high quality wide television receiver has been urged. The shape of the electron beam in the CRT tube in the conventional wide television receiver is the same as that in the normal mode shown in FIG. Similarly, as shown in FIG. 4 (2), the shape was circular without any special correction.

[0003]

However, with such a conventional beam shape, when the aspect conversion is performed in the wide television receiver and the zoom mode is set,
The interval l ₂ between the scanning lines in the horizontal direction is wider than the interval l ₁ in the normal mode of FIG. 4 (1) as shown in FIG. 4 (2), and the roughness of the scanning lines is conspicuous on the screen. Had a problem that

An object of the present invention is to solve the above-mentioned problems, and it is an object of the present invention to narrow the scanning line interval in the zoom mode in a wide television receiver to realize an image that is easier to see.

[0005]

In order to achieve the above object, the present invention has an electron beam shape deforming coil for deforming the shape of an electron beam in a CRT neck portion, and the coil is provided only in the zoom mode. It is characterized in that a high-frequency current is supplied to vibrate the electron beam at a high frequency in the vertical direction.

Further, when the mode discriminating circuit for discriminating the mode discriminating signal and the zoom discriminating circuit are discriminated by the mode discriminating circuit, the high frequency current from the high frequency generating circuit is applied to the electron beam shape deforming coil mounted on the CRT neck portion. And a switching circuit for supplying to

[0007]

According to the present invention, with the configuration described above, the shape of the electron beam in the CRT tube can be oscillated in the vertical direction by passing a high frequency current through the electron beam shape deforming coil attached to the CRT neck portion. , Electron beam is CRT
When scanning the tube surface, the distance between the beams becomes narrow, and the roughness of the scanning line becomes inconspicuous.

[0008]

1 is a side view showing the structure of a CRT section of a wide television receiver according to an embodiment of the present invention, and FIG. 2 is an enlarged perspective view of an electron beam shape deforming coil in a CRT neck section of FIG. is there. In FIGS. 1 and 2, 1
Is a CRT, 2 is a deflection yoke provided in the CRT neck portion 1a, 3 is a convergence yoke, and 5 is an electron gun. These are components such as a conventional CRT neck portion, but in this embodiment, the electron beam shape deforming coil 4 is mounted on the CRT neck portion 1a.

As shown in the enlarged perspective view of FIG. 2, the electron beam shape deforming coil 4 is mounted at positions facing each other with the CRT neck portion 1a interposed therebetween, and has a substantially rectangular frame shape. Here, when a high-frequency current (4 MHz to 5 MHz) is applied to the electron beam shape deforming coil 4, a magnetic field 6 is generated in the vertical direction in the CRT neck portion 1a, and an electron beam emitted from the electron gun 5 (not shown) is generated. As shown by arrow 7, the scanning line on the CRT tube surface is thickened by the vibration of the electron beam in the direction perpendicular to the magnetic field 6.

FIG. 3 is a circuit diagram for applying a high-frequency current to the electron beam shape deforming coil in the zoom mode in this embodiment. A mode discrimination signal 11 is input to the mode discrimination circuit 10 and the mode is discriminated. When the switching circuit 8
Is operated to connect the high frequency generation circuit (self-excited oscillation circuit) 9 and the electron beam shape deforming coil 4.

When a high frequency current is supplied from the high frequency generating circuit 9 to the electron beam shape deforming coil 4 in the zoom mode, the magnetic field 6 is generated as shown in FIG.
The electron beam emitted from the electron gun 5 oscillates as shown by an arrow 7, and as shown in FIG. 4 (3), the shape of the scanning line on the CRT tube surface is made vertically long and thick, and the scanning line spacing is increased. As a result, the roughness of the shape of the electron beam is eliminated, and a high quality image can be realized.

[0012]

As described above, in the wide television receiver of the present invention, the scanning line interval becomes constant on the CRT screen regardless of the aspect ratio switching of the wide television, resulting in zooming. The roughness of the scanning line interval only in the mode is inconspicuous, the sense of roughness in the shape of the electron beam is eliminated, and a high quality image can be realized.

[Brief description of drawings]

FIG. 1 is a side view showing a configuration of a CRT unit of a wide television receiver according to an embodiment of the present invention.

FIG. 2 is an enlarged perspective view of an electron beam shape deforming coil in the CRT neck portion of FIG.

FIG. 3 is a circuit diagram of applying a high-frequency current to the electron beam shape deforming coil in the zoom mode of FIG.

FIG. 4 is a configuration diagram showing a shape of an electron beam in a conventional example and an embodiment of the present invention in each mode.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... CRT, 1a ... CRT neck part, 2 ... deflection yoke, 3 ... convergence yoke, 4 ... electron beam shape deformation coil, 5 ... electron gun, 6 ... magnetic field, 7 ... electron beam oscillation direction, 8 ... switching circuit, 9 ... High frequency generation circuit, 10 ... Mode discrimination circuit, 11 ... Mode discrimination signal.

Claims (2)

[Claims] 1. A CRT neck portion has an electron beam shape deforming coil for deforming the shape of an electron beam, and a high frequency current is supplied to the coil only in a zoom mode to vibrate the electron beam at a high frequency in a vertical direction. A wide television receiver characterized by: 2. A mode discriminating circuit for discriminating a mode discriminating signal, and a high frequency current from a high frequency generating circuit when the mode discriminating circuit discriminates a zoom mode, and an electron beam shape deforming coil mounted on a CRT neck portion. And a switching circuit for supplying the wide television receiver.