JP2886874B2 - Television receiver horizontal linearity correction circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention eliminates the need for a horizontal linearity coil which is conventionally disposed near a horizontal deflection coil and which causes concentration failure and screen distortion due to the influence of the magnetic field. The present invention relates to a horizontal linearity correction circuit of a television receiver.

[Related Art] In a television receiver, circuit components have been mounted near a cathode ray tube as the whole has been downsized. In the horizontal deflection coil of the television receiver,
In order to adjust the current flowing in it, adjust the inductance by adjusting the insertion amount of the unsaturated magnetic core, and combine the coil for adjusting the size of the image in the horizontal direction and the permanent magnet with the coil, A horizontal linearity coil is connected in series to change the horizontal deflection current value flowing on the left side of the screen and the horizontal deflection current value flowing on the right side of the screen to correct the horizontal linearity of the screen so that the inductance changes according to the direction of the current flowing through the coil. Have been. The magnetic field of the permanent magnet of the horizontal linearity coil may affect the electron beam trajectory in the cathode ray tube, causing poor concentration, screen distortion, color purity degradation, and the like.

This type of technology is disclosed in, for example, Japanese Utility Model Laid-Open No. 60-47369.

[Problems to be Solved by the Invention] The present invention solves the above-mentioned problems caused in the conventional horizontal deflection system of a television receiver, and can obtain the same effect without using a conventional horizontal linearity coil. An object of the present invention is to provide a television receiver horizontal linearity correction circuit which can be used.

Means for Solving the Problems In order to achieve the above object, according to the present invention, a television receiver includes a horizontal deflection coil and a plurality of coils for adjusting a current of a horizontal deflection coil connected in series to the horizontal deflection coil. A diode is connected in parallel to one of the coils of the horizontal deflection system, whose inductance can be adjusted by adjusting the amount of magnetic core inserted, and the inductance of the entire horizontal deflection system is made different depending on the direction of current flow. By making the image horizontal length on each side variable, horizontal linearity adjustment can be performed.

[Operation] If the above-described means is taken, the horizontal deflection system flows the current of the horizontal deflection coil in the opposite direction between the left side of the screen and the right side of the screen. The diode does not conduct, and when scanning the right side of the screen, the diode conducts and current flows through the diode. As a result, the magnitude of the current flowing through the horizontal deflection coil changes between the left and right sides of the screen, and only the horizontal length (horizontal size) of the image on the left side of the screen can be reduced, and horizontal linearity correction can be performed. I can do it.

Embodiment FIG. 1 is a circuit diagram of one embodiment of the present invention, in which 1 is a horizontal output transistor, 2 is a damper diode, 3 is a resonance capacitor, 4 is a choke coil, 5 is a horizontal deflection coil, and 6 is A horizontal size coil, 7 is a diode according to the present invention, 8 is a variable coil, and 9 is an S-shaped capacitor. Both the horizontal size coil 6 and the variable coil 8 can be adjusted in inductance by inserting a ferrite core whose magnetic flux density is not easily saturated in the coil.

In this embodiment, a diode 7 is connected in parallel with the variable coil 8. When the horizontal output transistor 1 is conducting, a current flows out of the S-shaped capacitor 9 in the direction indicated by the arrow in the figure. At this time, a forward voltage is applied to the diode 7, so that the diode 7 becomes conductive, and the current mainly passes through the diode. Therefore, the inductance of the variable coil 8 does not affect the current amount of the horizontal deflection coil. Next, when the horizontal output transistor 1 is cut off, the electric charge stored in the resonance capacitor 3 is discharged. At this time, since a reverse voltage is applied to the diode 7, the diode 7 is cut off, and current flows through the variable coil 8. For this reason, the inductance component of the entire horizontal deflection system increases, and the current amount of the horizontal deflection coil decreases.

As described above, when the horizontal output transistor 1 is conducting, the inductance of the variable coil 8 does not affect the current amount of the horizontal deflection coil.
As shown by 11, the horizontal size on the right side of the screen does not change, and when the horizontal output transistor 1 is in the cut-off state, the current amount of the horizontal deflection coil decreases, and the horizontal size on the left side of the screen decreases. As a result, the horizontal size of only the left side of the screen can be changed, an effect equivalent to that of the horizontal linearity coil can be obtained, and adverse effects on screen distortion, poor concentration, and the like can be reduced.

In FIG. 2B, reference numeral 12 denotes a screen size depending on the presence or absence of the horizontal linearity correction circuit, and the correction circuit according to the present invention obtains an image in which the left and right horizontal sizes are balanced as indicated by broken lines in the figure. Can be

[Effects of the Invention] As described above, according to the present invention, the same effect can be obtained even if the horizontal linearity coil is removed,
Since the horizontal linearity coil using the permanent magnet is not used, the adverse effect is eliminated, and the original performance of the cathode ray tube can be sufficiently exhibited.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of one embodiment of the present invention, FIG.
(B) is a figure explaining the effect of the present invention. 1 horizontal output transistor, 2 damper diode, 3 resonance capacitor, 4 choke coil, 5
… Horizontal deflection coil, 6 Horizontal size coil, 7…
Diode, 8: Variable coil, 9: S-shaped capacitor, 10: Horizontal deflection current with linearity correction circuit, 11: Horizontal deflection current with linearity correction circuit, 12: Horizontal linearity correction Screen size depending on the presence or absence of a circuit.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04N 3/23

Claims (1)

(57) [Claims] A television receiver has a horizontal deflection system including a horizontal deflection coil and a plurality of coils for adjusting a current of a horizontal deflection coil connected in series with the horizontal deflection coil, and adjusts an inductance by adjusting a magnetic core insertion amount. A diode is connected in parallel to one of the coils for adjusting the horizontal deflection coil current, and the inductance of the entire horizontal deflection system is varied depending on the direction of the current flowing in the horizontal deflection coil,
A horizontal linearity correction circuit for a television receiver, characterized in that horizontal linearity adjustment can be performed by changing the length of only one of the left and right sides of the screen in the horizontal direction.