KR20000014589U - Tilt Correction Circuit of Monitor - Google Patents

Abstract

The present invention relates to a tilt correction circuit of the monitor, the apparatus of the present invention includes a key input unit 10 for inputting the up / down key for the user to correct the tilt; A microcomputer 20 for outputting a correction voltage of 0 to 5 V in response to the key input; An amplifying transistor Q1 that receives the correction voltage of 0 to 5 V and amplifies the correction voltage to Va to Ve; A first charging unit C1 for charging the correction voltages Va to Ve; A second charging unit C2 that charges the Vc power voltage that is greater than the Va correction voltage and less than the Ve correction voltage; A switching diode D1 connected in parallel with the second charging unit 2; And a tilt correction coil L connected in series between the first charging unit C1 and the second charging unit C2, so that the second charging voltage Vc2 is greater than the first charging voltage Vc1. 2 The charging current Ic2 flows into the tilt correction coil L and is discharged to the ground through the amplifying transistor Q1. When the first charging voltage Vc1 is greater than the second charging voltage Vc2, the first charging is performed. Tilt correction circuit for correcting the screen tilt caused during the manufacturing process or by the influence of the geomagnetic field, as the current Ic1 flows into the tilt correction coil L and is discharged to the ground through the switching diode D1. The effect is to reduce manufacturing costs by simplifying the process.

Description

A circuit of compensating tilt in a monitor

The present invention relates to a tilt correction circuit of a monitor, which is designed to correct an inclination of a screen generated during a manufacturing process of a CRT or by a geomagnetic field.

In general, CRT (Cathode Ray Tube) focuses and accelerates hot electrons emitted from R, G and B electron guns, and then collides with R, G and B fluorescent surfaces through a point on a shadow mask to form pixels, and vertical and horizontal deflection coils. Sawtooth current flows to form a two-dimensional screen.

Since the CRT requires very precise operation to form a high density pixel on a narrow screen, various correction devices such as a push magnet and a convergence magnet are mounted on the neck portion of the CRT. In order to prevent deterioration of the image quality, an element coil is provided in the panel portion of the CRT.

FIG. 1 is a view illustrating a structure of a general CRT, and as shown in FIG. 1, the CRT includes a base 1, an electron gun 2, a net 3, a corner 4, a panel 5, and a fluorescent plate 7 ), A shadow mask 8 and the like.

Here, the base 1 is for connecting an electrical signal to the CRT, and the net 3 has an electron gun 2 for forming R, G, and B electron beams, which are emitted from this electron gun and focused and accelerated. It concentrates on this shadow mask 8 and impinges on the fluorescent surface 7.

When the display surface and the shadow mask 8 do not coincide with each other in the manufacturing process of such a general CRT, the screen is slightly tilted.

Also, the display is slightly inclined due to the influence of the geomagnetic field. As is well known, the earth forms a geomagnetic field with a huge magnet, which is a display operated by an electric magnetic field such as a CRT. It affects the device, and since this geomagnetic field is different depending on the position on earth, it is difficult to uniformly correct it.

The phenomenon that the screen is tilted due to such various causes is called tilt, and in order to compensate for this electromagnetically, the monitor is generally provided with a tilt correction circuit.

FIG. 2 is a circuit diagram illustrating a tilt correction circuit of a general monitor. As shown in FIG. 2, the tilt correction circuit includes a tilt correction coil L wound around a CRT net 3 and then the tilt correction coil L. As shown in FIG. By adjusting the current flowing through the screen, the tilted screen is corrected by rotating the tilted screen as a whole.

That is, when the user inputs a key to correct the tilt, the microcomputer detects this and outputs a correction signal of 0 to 5 V to control the magnitude of the tilt correction current.

The differential amplifier OP outputs a low voltage driving signal of + Va to -Va by the correction signal of 0 to 5V input from the microcomputer, and the driving voltage of + Va to -Va input from the differential amplifier OP. As a result, the push-pull amplifiers Q1 and Q2 provide sufficient tilt correction current to the tilt correction coil L.

For example, when a driving voltage of + Va is applied to the base terminals of the push-pull amplifiers Q1 and Q2, the first transistor Q1 is turned on and the second transistor Q2 is turned off, so that a power supply voltage of + 12V is applied. The effect is applied to the emitter stage through the collector stage of the first transistor Q1, so that the tilt correction coil L I ₁ Tilt correction current in the direction flows.

On the contrary, when a driving voltage of -Va is applied to the base terminals of the push-pull amplifiers Q1 and Q2, the first transistor Q1 is turned off and the second transistor Q2 is turned on, so that a power supply voltage of -12V is applied to the base terminal of the push-pull amplifiers Q1 and Q2. An effect is applied to the emitter stage through the collector stage of the two transistors Q2, and the tilt correction coil L is applied to the emitter stage. I ₂ Tilt correction current in the direction flows.

Accordingly, a magnetic field is generated according to the magnitude and direction of the tilt correction current to change the direction of the deflection current, thereby correcting the tilt of the screen.

However, since the conventional tilt correction circuit uses a differential amplifier (OP) to convert the 0-5V correction signal supplied from the microcomputer into a low voltage driving signal of + Va-Va as described above, the circuit is implemented. There was a problem that causes the increase in costs.

Accordingly, the present invention has been made to solve the above problems, and an object thereof is to provide a tilt correction circuit of a monitor designed to reduce the manufacturing cost by simplifying the circuit configuration.

Tilt correction circuit of the monitor according to the present invention for achieving the above object,

A key input unit for inputting an up / down key for the user to correct the tilt;

A microcomputer that outputs a correction voltage of 0 to 5 V in response to the key input;

An amplifying transistor which receives the correction voltage of 0 to 5 V and amplifies the correction voltage to Va to Ve;

A first charging unit for charging the correction voltages Va to Ve;

A second charging unit configured to charge a Vc power supply voltage greater than the Va correction voltage and less than the Ve correction voltage;

A switching diode connected in parallel with the second charging unit; And

It is composed of a tilt correction coil connected in series between the first charging section and the second charging section,

If the second charging voltage is greater than the first charging voltage, the second charging current flows to the tilt correction coil and is discharged to the ground through the amplifying transistor. If the first charging voltage is greater than the second charging voltage, the first charging current is measured. Flow to the tilt correction coil and is discharged to the ground through the switching diode.

1 is a diagram illustrating a structure of a general CRT;

2 is a circuit diagram showing a tilt correction circuit of a general monitor;

3 is a circuit diagram illustrating a tilt correction circuit of the monitor according to the present invention.

* Names of symbols for main parts of the drawings

10: key input unit 20: micom

Q1: amplifying transistor C1: first charging section

C2: second charging unit D1: switching diode

L: Tilt correction coil R1: Resistance

Hereinafter, an embodiment according to the present invention will be described with reference to the accompanying drawings.

3 is a circuit diagram illustrating a tilt correction circuit according to the present invention.

As shown in FIG. 3, the device of the present invention includes a key input unit 10 for inputting an up / down key by a user to correct tilt; A microcomputer 20 for outputting a correction voltage of 0 to 5 V in response to the key input; The base terminal receives the 0 to 5 V correction voltage from the microcomputer 20, the emitter terminal receives the Vcc power supply voltage, the collector terminal is grounded, and the 0 to 5 V correction voltage input from the microcomputer 20 is inputted from Va to An amplifying PNP type transistor Q1 that is amplified by a correction voltage of Ve and output through an emitter stage; A first charging unit having one end connected to the emitter terminal of the amplifying PNP transistor Q1 and the other end being grounded to charge a correction voltage of Va to Ve output from the amplifying PNP transistor Q1 ( C1); A second charging unit C2 connected to one Vc power supply voltage larger than the Va correction voltage and smaller than a Ve correction voltage and grounded at the other end to charge the Vc power supply voltage; A switching diode (D1) having an anode end connected in parallel between one end of the second charging unit (C2) and a Vc power supply voltage and a cathode end connected in parallel between the other end of the second charging unit (C2) and ground; And a tilt correction coil L connected in series between the first charging unit C1 and the second charging unit C2 to generate a magnetic field according to the direction and magnitude of the flowing current to correct the tilt of the screen. When the second charging voltage Vc2 is greater than the first charging voltage Vc1, the second charging current Ic2 flows into the tilt correction coil L and is discharged to the ground through the amplifying transistor Q1. When the first charging voltage Vc1 is greater than the second charging voltage Vc2, the first charging current Ic1 flows into the tilt correction coil L and is discharged to the ground through the switching diode D1.

Next, the operation and effects of the present invention configured as described above will be described in detail.

The key input unit 10 is a portion in which a user inputs a key to correct the tilt, and includes an up / down key for controlling the magnitude of the correction current.

In response to a user's up / down key input, the microcomputer 20 outputs a correction voltage to control the magnitude of the tilt correction current. In this case, the correction voltage is a variable DC voltage between 0 and 5V.

The correction voltage of 0 to 5 V output from the microcomputer 20 is applied to the base terminal of the amplifying PNP transistor Q1 through the resistor R1, amplified by a variable correction voltage between Va and Ve, and then emitter stage. Is output via

The correction voltages Va to Ve output from the emitter terminal of the amplifying PNP transistor Q1 are charged in the first charging unit C1.

On the other hand, the second charging unit C2 is charged with a Vc (e.g., 12V) power supply voltage larger than the Va (e.g., 20V) correction voltage and smaller than the Ve (e.g., 5V) correction voltage.

When the voltage Vc2 charged in the second charging unit C2 is greater than the voltage Vc1 charged in the first charging unit C1, the second charging current Ic2: the second correction current is the tilt correction coil L ) And is discharged to ground through the amplifying transistor Q1.

On the contrary, when the voltage Vc1 charged in the first charging unit C1 is greater than the voltage Vc2 charged in the second charging unit C2, the first charging current Ic1: the first correction current is the tilt correction coil L. ) Is discharged to ground through the switching diode (D1).

Accordingly, a magnetic field is generated according to the magnitude and direction of the tilt correction currents Ic1 and Ic2 to change the direction of the deflection current, thereby correcting the tilt of the screen.

As described above, the device of the present invention changes the direction and magnitude of the current flowing through the tilt correction coil by changing the voltage at one end of the tilt correction coil, thereby causing the screen to be tilted during the manufacturing process or under the influence of the geomagnetic field. In addition to correcting the phenomenon, the effect is that the manufacturing cost is reduced by simplifying the circuit configuration.

Claims (1)

A key input unit 10 for inputting an up / down key for the user to correct the tilt; A microcomputer 20 for outputting a correction voltage of 0 to 5 V in response to the key input; An amplifying transistor Q1 that receives the correction voltage of 0 to 5V and amplifies it to the correction voltage of Va to Ve; A first charging unit C1 for charging the correction voltages Va to Ve; A second charging unit C2 that charges the Vc power voltage that is greater than the Va correction voltage and less than the Ve correction voltage; A switching diode D1 connected in parallel with the second charging unit 2; And It is composed of a tilt correction coil (L) connected in series between the first charging unit (C1) and the second charging unit (C2), When the second charging voltage Vc2 is greater than the first charging voltage Vc1, the second charging current Ic2 flows into the tilt correction coil L and is discharged to the ground through the amplifying transistor Q1, and the first When the charging voltage (Vc1) is greater than the second charging voltage (Vc2) of the monitor characterized in that the first charging current (Ic1) flows to the tilt correction coil (L) is discharged to the ground through the switching diode (D1) Tilt Compensation Circuit.