KR19990039763U - Display size compensation circuit - Google Patents

Abstract

The screen size compensating circuit of the disclosed display is a screen size compensating circuit of a display for compensating the screen size uniformly by sensing the amount of brightness change as a voltage in a screen size compensating circuit in which the size of the horizontal and vertical screens of the display changes according to the brightness change will be.

The present invention includes a luminance voltage recognition unit for recognizing the intensity of the luminance by detecting the voltage output through the flyback transformer (FBT); A vertical change amount detector configured to detect an output voltage having a vertical size, the first diode being connected in series with the output terminal of the luminance voltage recognizer, and a plurality of resistors and capacitors; A vertical size compensation circuit connected to an output terminal of the vertical change amount detecting unit to constantly correct an amount of the vertical size; A second change diode connected in series with the cathode of the first change detector of the vertical change detection unit, a horizontal change detection unit configured to detect an output voltage having a horizontal size, the plurality of resistors and diodes; It is composed of a horizontal size compensation circuit connected to the output terminal of the horizontal change amount detecting unit to constantly correct the amount of the horizontal size.

Therefore, by using a diode instead of the transistor of the screen size compensation circuit, the response speed for screen size correction is increased, thereby improving product performance, and also simplifying the circuit and reducing the manufacturing cost.

Description

Display size compensation circuit

The present invention relates to a screen size compensation circuit of a display.

More particularly, the present invention relates to a screen size compensation circuit of a display that constantly corrects a screen size by sensing a luminance change amount as a voltage in a screen size compensation circuit in which a horizontal and vertical size of the display changes according to a change in brightness.

In general, low-cost low-end monitors, such as 14-inch or 15-inch, is a standard for the screen change, such as the screen shaking in accordance with the change of each monitor mode is relaxed, as a way to reduce the screen change Flyback Transformer (Flyback Transformer; Hereinafter, horizontal / vertical screen correction can be performed by a simple circuit configuration such as FBT) or a compensation circuit for screen correction.

1 is a block diagram showing an example of a compensation circuit for correcting a change in the screen size of a monitor of a conventional low-cost 14-inch or 15-inch low-cost monitor, the horizontal / input from the video card (1) provided in the computer system After the operation mode is determined based on the vertical synchronization frequency and polarity, the controller 2 outputs a mode control signal and the screen control mode voltage value corresponding to the operation mode is output according to the mode control signal output by the controller 2. Compensating the screen size according to each mode output from the mode unit 3, the FBT (4) for generating a high pressure supplied to the cathode ray tube (8), and the control unit (2) and the operation mode unit (3) It is composed of the screen size compensation circuit (5).

The color signals of R, G and B output from the video card 1 are supplied to the cathode ray tube 8 through the first amplifier 6 and the output amplifier 7.

FIG. 2 is a circuit diagram showing an example of a screen size compensation circuit of a conventional display, wherein one end of the secondary side of the FBT 4 has a capacitor C1, a diode D1, and a resistor R1, R2 in the screen change amount detector 21; ) Is connected to the base terminal of the transistor Q1 and to the cathode of a cathode ray tube (not shown). The base terminal of the transistor Q2 is connected to the emitter terminal of the transistor Q1 to amplify the output voltage.

The emitter stage of the transistor Q2 and the collector stage of the transistor Q1 are summed together at the point "B" where a direct current voltage is applied via a resistor R4, and the output signal thereof is a diode D2 and a resistor R10, R11. And the capacitor C3 are input to the vertical size compensation circuit 22.

In addition, the signal output to the collector terminal of the transistor Q2 is input to the horizontal size compensation circuit 23 through the resistors R5 to R9 and the diodes D3 and D4.

Referring to the operation of the screen size compensation circuit of the conventional display configured as described above are as follows.

When the screen becomes bright, a beam current input from the FBT 4 to the cathode of the cathode ray tube 8 increases through the resistance R1 of the screen change amount detector 21.

As the current increases, a voltage drop occurs by the resistor R1, and the voltage at the point "A" is lowered. That is, the transistor Q1 has a function of a buffer, and since the voltage at the point “A” is lowered, the emitter voltage of the transistor Q1 is also lowered.

As a result, a voltage drop occurs at the point “B” through the resistor R4 and the emitter voltage of the transistor Q1 is lowered, thereby increasing the amount of current flowing through the second transistor Q2.

The vertical size correction signal passing through the second diode D2 is properly detected by the resistors R10 and R11 and input to the vertical size compensation circuit 22. In addition, the second diode D2 has a function of blocking the vertical size correction signal from being input in the reverse direction.

Therefore, the vertical size compensating circuit 22 corrects to maintain a constant according to the change in the luminance caused by the cathode of the cathode ray tube 8 in which a high voltage is generated.

Horizontal size correction is the same principle as above. In other words, when the emitter voltage of the transistor Q1 is lowered, the base current of the second transistor Q2 is lowered, and as a result, the voltage difference is increased in the second transistor Q2, so that the collector of the second transistor Q2 is reduced. The amount of current flowing also increases and the voltage flowing to the collector of the second transistor Q2 also increases.

The horizontal size correction signal is appropriately detected by the resistors R5, R6, and R9 and input to the horizontal size compensation circuit 23. In addition, the diodes D3 and D4 and the resistors R7 and R8 are circuits for varying the amount of voltage detected according to the change in the horizontal frequency.

When the frequency increases, S1 and S2 maintain a high signal so that the diodes D3 and D4 are not turned on, so the resistors R7 and R8 are of no use. When the frequency decreases, S1 and S2 maintain a low signal according to the frequency range, and the resistors R7 and R8 are grounded to ground through the diodes D3 and D4. In other words, the detected voltage is lowered. When S1 and S2 are configured to maintain a high low according to the frequency range, the above effects can be obtained.

Therefore, the horizontal size compensation circuit 23 reduces the amount of the horizontal size when the screen is bright, and constantly corrects the amount of the horizontal size.

However, the conventional screen size compensation circuit as described above has a problem in that transistors applied for correcting horizontal and vertical screen sizes have a slow response time for screen size correction, resulting in a decrease in product performance and an increase in manufacturing cost.

Therefore, an object of the present invention is to provide a screen size compensation circuit of a monitor that uses a diode instead of a transistor in the screen size compensation circuit of a monitor that detects and corrects a luminance variation by a voltage, thereby increasing the quality of the monitor.

1 is a block diagram showing an example of a compensation circuit for correcting a change in screen size of a conventional display;

2 is a circuit diagram illustrating an example of a screen size compensation circuit of a conventional display;

3 is a circuit diagram illustrating an embodiment of a screen size compensation circuit of a display of the present invention.

Explanation of symbols on the main parts of the drawings

31: FBT (Flyback Transformer) 32: Luminance voltage recognition unit

33: vertical change detection unit 34: vertical size compensation circuit

35: horizontal change detection unit 36: horizontal size compensation circuit

Hereinafter, a screen size compensation circuit of a display of the present invention will be described with reference to the accompanying drawings.

3 is a circuit diagram illustrating a configuration and an embodiment of a screen size compensation circuit of a display according to the present invention.

As shown, the FBT 31 for generating a high voltage supplied to the cathode ray tube, the luminance voltage recognition unit 32 for detecting the intensity of the luminance by detecting the voltage output through the FBT 31, and the luminance voltage recognition Vertical change amount detector 33 and vertical change amount detector 33, each of which comprises a first diode D1 connected in series with an output terminal of the unit 32, resistors R3 and R4, and a capacitor C2 to detect an output voltage having a vertical size. A vertical size compensating circuit 34 connected to the output terminal of (33) to constantly correct the amount of the vertical size, and a second diode connected in series with the cathode of the first diode D1 of the vertical change detection unit 33 ( D2), resistors R5, R6, R7, and diodes D3, D4 and the horizontal change amount detection unit 35 for detecting the output voltage of the horizontal size, and the horizontal size connected to the output terminal of the horizontal change amount detection unit 35 And a horizontal size compensation circuit 36 which constantly corrects the amount of.

In addition, the vertical change detection unit 33 is connected to the first diode (D1) for blocking the reverse voltage to minimize the voltage change of the vertical size, and the cathode of the first diode (D1) in series to detect the vertical size And a third resistor R3, a capacitor C3 connected in parallel with the third resistor R3, and a fourth resistor R4 connected in series with the cathode terminal of the first diode D1.

In addition, the horizontal change amount detecting unit 35 is connected to the second diode D2 for blocking the reverse voltage to minimize the horizontal voltage change and the fifth terminal for detecting the vertical size in series with the cathode terminal of the second diode D2. Horizontal change amount control circuit comprising resistors R6 and R7 and diodes D3 and D4 connected in series with a resistor R5 and the cathode terminal of the second diode D2 to adjust the horizontal size change according to the change in the horizontal frequency. It consists of 37.

Hereinafter, the screen size compensation circuit of the display of the present invention will be described in detail with reference to the accompanying drawings.

First, when the amount of the beam increases on the cathode of the cathode ray tube (not shown) and the screen becomes bright, the DC power supply Vc causes a voltage drop through the resistor R1 and the voltage decreases at the point "A".

The output voltage at the point "A" is transmitted to the anode terminal of the first diode D1, and the voltage at the point "B" passing through the first diode D1 is also lowered. In particular, the first diode D1 has a function of blocking the reverse voltage such that the voltage change of the vertical size is minimized at the point “A”.

The vertical size correction signal is detected by the resistors R3 and R4 and the capacitor C2 constituting the vertical change amount detector 33 and input to the vertical size compensation circuit 34 to constantly correct the amount of the vertical size.

In addition, when the voltage at the point “B” is lowered, the voltage input to the second diode D2 of the horizontal change amount detector 35 is also lowered at the same time, and thus is output to the second diode D2 and the fifth resistor R5. The voltage is also lowered.

In particular, the second diode D2 has a function of blocking the reverse voltage such that the voltage change of the vertical size at the point “B” is minimized according to the voltage change of the horizontal size. In addition, the resistors R6 and R7 and the diodes D3 and D4 of the horizontal change amount adjusting circuit 37 connected in series with the cathode terminal of the second diode D2 adjust the horizontal change amount according to the change of the horizontal frequency.

Therefore, when the horizontal magnitude voltage is detected to be low, it is input to the horizontal magnitude compensation circuit 36 to constantly correct the amount of the horizontal magnitude.

As described above, the display size compensation circuit of the display of the present invention uses diodes instead of transistors, so that the response speed for screen size correction is improved, thereby improving product performance, simplifying circuits, and reducing manufacturing costs. It became.

Claims (3)

In the screen size compensation circuit for correcting the screen size according to the operation mode of each display output from the control unit, FBT for generating a high voltage supplied to the cathode ray tube; A luminance voltage recognition unit detecting a voltage output through the FBT to recognize intensity of luminance; A vertical change amount detector configured to detect an output voltage having a vertical size, the first diode being connected in series with the output terminal of the luminance voltage recognizer, and a plurality of resistors and capacitors; A vertical size compensation circuit connected to an output terminal of the vertical change amount detecting unit to constantly correct an amount of the vertical size; A horizontal change amount detecting unit configured to detect an output voltage having a horizontal size, the second diode being connected in series with the cathode of the first diode of the vertical change amount detecting unit, and a plurality of resistors and diodes; And And a horizontal size compensation circuit connected to an output terminal of the horizontal change amount detecting unit and configured to constantly correct an amount of the horizontal size. According to claim 1, wherein the vertical change detection unit; A first diode blocking the reverse voltage to minimize the vertical change in voltage; A third resistor connected in series with the cathode of the first diode to detect a vertical size; A capacitor connected in parallel with the third resistor; And And a fourth resistor connected in series with the cathode of the first diode. The method of claim 1, wherein the horizontal change amount detection unit; A second diode which cuts off the reverse voltage such that a horizontal change in voltage is minimized; A fifth resistor connected in series with the cathode of the second diode to detect a vertical size; And And a horizontal change amount adjusting circuit comprising a plurality of resistors and diodes connected in series with the cathode terminal of the second diode to correct S linearity according to a change in horizontal frequency.