KR200191352Y1 - TV contour correction device - Google Patents

Abstract

The present invention relates to a contour correction apparatus for a television, and more particularly, to a contour correction apparatus for a television that improves image quality while simplifying a circuit configuration for correcting a contour by emphasizing the contrast of a television screen. Not only is the composition itself complicated, but also the time delay is caused by delaying the luminance signal to emphasize the contrast. As a result, the delayed luminance signal delays the color signal as much as the delay, so that the contour is more clearly identified and the contour is more clearly defined. For the sake of brevity, the smaller the slope part of the luminance signal is, the smaller the larger the larger one is, the larger the slope can be, but this leads to unnecessary contour correction, which deteriorates the image quality. In this invention, the switching agent A switch for turning on / off a circuit by a negative control signal, a second differential that receives a luminance signal when the switch is turned on, and outputs a differential signal for the second derivative, and inverts the output of the second differential An inverter for outputting, an adder for receiving the output and the luminance signal of the inverter, adding the same and outputting the inverter, and the switching for outputting a switching control signal for determining the on / off of the switch by receiving the output of the inverter Synchronization between the color signal and the luminance signal after contour correction by eliminating the delay process during contour correction process by simplifying the system as much as possible by the control unit is not necessary, and it is unnecessary to determine the contour correction automatically according to the state of the screen. By not calibrating, there is an effect of minimizing image degradation.

Description

TV contour correction device

1 is a block diagram of a general television outline correction device.

2 is an output waveform diagram of each stage of FIG.

3 is a block diagram of another general television outline correction device.

4 is an output waveform diagram of each stage of FIG.

5 is a block diagram of a contour correction apparatus of a television of the present invention.

6 is an output waveform diagram of each stage of FIG.

FIG. 7 is a diagram illustrating an embodiment of a configuration of a switching controller of FIG. 5;

8 is another embodiment of the present invention to stabilize the operation of the switching controller of FIG.

* Explanation of symbols for main parts of the drawings

300: second order differentiator 301: inverter

302: switching control unit 303: switch

304: Adder

The present invention relates to a contour correction apparatus of a television, and more particularly, to a contour correction apparatus of a television that simplifies a circuit configuration for correcting a contour by emphasizing the contrast of a television screen and improves image quality.

FIG. 1 is a block diagram of a general television outline correction device, in which a luminance signal Y separated from a composite video signal as shown in FIG. 2 (a) is input to a delay unit 100 and a second (b) As shown in FIG. 2, the delay unit 101 is delayed for a predetermined period and input to the delay unit 101 and the amplifier 102. The delay unit 101 delays the input signal again and outputs a signal as shown in FIG. 2 (c). .

In addition, the amplifier 102 receives the signal output from the delay unit 100 and outputs the amplified signal to the adder 105 as shown in FIG. The output outputs the signal as shown in FIG. 2 (f) to the adder 105 via the inverter 104, and the inverter 103 also outputs the luminance signal Y to the second (d). The signal as shown in the figure is output to the adder 105.

Thus, the adder 105 receives the outputs of the amplifiers 102 and the inverters 103 and 104, and adds the outputs of the luminance signal Y 'whose contour is corrected as shown in FIG. 2 (g). Done.

However, in this case, the output contrast is emphasized, i.e., the luminance signal Y 'whose contour is corrected is twice as wide as the luminance signal Y which is input, so that the slope becomes gentle and the corrected contour appears thicker. .

FIG. 3 is a block diagram of another conventional television outline correction device. When the luminance signal Y shown in FIG. 4 (a) is input to the delay unit 200, FIG. The delayed signal is delayed as described above, and the delayed signal is inputted to the subtractor 201 and subtracted from the luminance signal Y as shown in FIG. d) delayed again as shown in FIG.

In addition, the delayed signal from the delay unit 202 is input to one terminal of the AND gate 203, and the output of the subtractor 201 is input to the other terminal of the AND gate 203, and the fourth is inputted and combined. The waveform shown in (e) is outputted.

The output of the AND gate 203 is input to a differentiator consisting of a buffer 204 and an inverter 205 and a capacitor C and a coil L. The output of the buffer 204 is shown in FIG. 4 (f). The signal is applied to one terminal of the switch 207 in a waveform as shown, and the signal through the inverter 205 is switched to the inverted signal of the AND gate 203 as shown in FIG. 4 (g). It is applied to the other terminal of).

The output of the AND gate 203 is differentiated by the capacitor C and the coil L and input to the trigger 206, as shown in FIG. 4 (h). As shown in FIG. 4 (i), a three-level switching pulse is output to control the control terminal of the switch 207. The output of the buffer 204 and the output of the inverter 205 are controlled by the three levels. By switching at the edge of the switching pulse, a differential signal for correction having an ideal edge characteristic is output to the subtractor 208 as shown in FIG. 4 (j), and the subtractor 208 is a delay unit ( By subtracting the output signal of the switch 207 from the output signal of 200, the contrast as shown in FIG. 4 (k), that is, the luminance signal Y 'whose contour is corrected, is output.

The luminance signal Y 'whose contour is thus corrected is inclined so that the outline of the screen appears more clearly than the contour correction apparatus of the television shown in FIG.

However, the above-described outline correction device of a television not only has a complicated circuit configuration but also a time delay due to delaying the luminance signal in order to emphasize the contrast. Accordingly, as the luminance signal is delayed, the color signal is delayed by that much to synchronize the synchronization. In order to express the contour more clearly and to make the contour more clearly, the smaller the slope portion of the luminance signal is smaller, while the larger the larger one can increase the slope, but this is not necessary. This has a problem that deteriorates the image quality rather.

Accordingly, the present invention aims to simplify the circuit configuration in consideration of these problems and to prevent image deterioration due to unnecessary contour correction by operating the circuit according to the image quality during contour correction. It explains in detail.

5 is a block diagram of the contour correction apparatus of the television according to the present invention. As shown therein, a switch 303 for turning on / off a circuit by a control signal of the switching controller 302, and when the switch 303 is turned on, And a second derivative 300 that receives the luminance signal Y and differentially outputs the second derivative. Inverter 301 which inverts the output of the second differentiator 300 and outputs (X), and receives the output (X) and the luminance signal (Y) of the inverter (301) and adds it to the output ( Y ') adder 304 and the switching control unit 302 receives a switching control signal for determining the on / off of the switch 303 for a predetermined time (T) by receiving the output (X) of the inverter 301 ).

The operation and effects of the present invention constructed as described above will be described in detail.

The luminance signal Y as shown in FIG. 6 (a) is input to the second derivative 300 and differentiated and then the luminance signal as shown in FIG. 6 (b) through the inverter 301. (Y) is converted into the differentially inverted signal (X) and input to the adder 304 and the switching controller 302. The adder 304 outputs the outputs of the luminance signal Y and the inverter 301. It receives the input and adds it to output the luminance signal Y 'whose contour is corrected as shown in FIG.

However, as mentioned in the conventional problem, the slope of the waveform is increased to make the contour clearer. If the slope portion of the waveform is made too large or too small, the image quality is deteriorated. A switching control unit 302 and a switch for turning on / off the contour correction circuit to turn on the contour correction circuit for this unclear signal and turning off the circuit for the clear signal to provide the viewer with a rejection-free screen. 303) is further configured. As shown in FIG. 6 (b), the switch 303 is turned off for a predetermined time interval T from the time when the pulse is emitted.

Therefore, the switching controller 302 receives the output (X) of the inverter 301 and outputs a switching control signal according to the state of the image quality to turn on / off the switch 303, the switching controller 302 Can be simply configured as a counter, and the operation thereof will be described in more detail with reference to FIG.

The counter receives the output X of the inverter 301 and turns off the switch 303 at a moment when a pulse is generated, as shown in FIG. After counting T), the switch 303 is turned on again.

When controlling the switch 303 using the counter, an important factor is to determine the frequency of the clock CLK and the predetermined time T, that is, the off time of the switch 303, which is a horizontal resolution of the screen. ), The predetermined time T that determines the off time of the switch 303 is the maximum frequency (5.175 MHz) of the video signal bandwidth (e.g., 5.175 MHz in the case of the PAL method) that determines the horizontal resolution. If the predetermined time (T) is small, the outline of the dense pattern of the screen is emphasized. If the predetermined time (T) is too small, the dense pattern is emphasized too much to the viewer. Make the decision appropriately because it can cause a sense of rejection.

In addition, the clock CLK inputted to the counter is such that the period is a divisor of a predetermined time T, and its frequency may be appropriately determined in the range of an integer multiple of the horizontal frequency (5.175 MHz).

As a result, the luminance signal Y is input to the second differentiator according to the state of the image quality through the switch 303, so that the luminance signal Y is corrected only for the image quality whose contour is degraded.

FIG. 8 is another embodiment of the present invention that stabilizes the operation of the switching controller. In addition to FIG. 5 of the present invention, an amplifier 305 for amplifying the output X of the inverter 301 and the amplifier 305 ) Is composed of a limiter 306 for converting the output of the pulse into a constant pulse train, the output (X) of the inverter 301 is a pulse train of unstable amplitude, so amplify it in the amplifier 305 and then limit the limiter 306 By limiting the amplitude through this, a stable pulse operation can be achieved by converting the pulse string into a constant pulse string and outputting the same to the switching controller 302.

As described in detail above, the present invention does not require synchronization between the color signal and the luminance signal after the contour correction by simplifying the system as much as possible and eliminating the delay process during the contour correction process. By judging as follows, unnecessary contour correction is avoided, thereby minimizing deterioration of image quality.

Claims (3)

A switch for turning on / off a circuit by a control signal of a switching controller, a second differential that receives a luminance signal when the switch is turned on, and outputs a differential signal for the second derivative, and an output of the second differential An inverter for inverting and outputting; an adder for receiving and outputting the output and the luminance signal of the inverter; and a switching control signal for determining the on / off of the switch for a predetermined time by receiving the output of the inverter Contour correction device for a television, characterized in that consisting of the switching control unit for outputting. 2. The contour correction according to claim 1, further comprising an amplifier for amplifying the output of the inverter to stabilize the operation of the switching control unit, and a limiter for converting the output of the amplifier into a pulse train having a constant amplitude. Device. The apparatus of claim 1, wherein the predetermined time for deciding on / off time of the switch is an integer multiple of one cycle of the maximum frequency of the bandwidth of the television video signal.