KR100190959B1 - Color burst signal position distinction apparatus - Google Patents

Abstract

The present invention relates to a color burst signal position determining apparatus, and in the related art, when a position of a color burst signal is changed by a signal state, a color burst signal can not be separated from an image signal and the image signal is demodulated into a primary color signal Or a color video signal is displayed on a cathode ray tube in a monochrome state. The present invention provides a color burst signal position determining apparatus capable of determining the position of a color burst signal included at a predetermined time from a rising edge of a horizontal synchronizing signal and displaying the position of the color burst signal.

Description

Color burst signal position determination device

FIG. 1 is a circuit diagram according to an embodiment of the present invention; FIG.

FIG. 2 is a waveform showing the output state of each node in FIG. 1 (when the color burst signal is included in the normal position).

FIG. 3 is a waveform showing the output state output from each node in FIG. 1 (when the color Burst signal is included in the abnormal position).

4 is a circuit diagram according to a conventional invention;

FIG. 5 is a waveform diagram showing an example of a video signal transmitted from a broadcasting station.

DESCRIPTION OF THE REFERENCE NUMERALS

11: clamp circuit 13: amplification section

15: analog / digital conversion unit 17: data analysis unit

19: Burst position discriminator 21: Sync signal separator

23: Burst flag pulse oscillation unit 25: PLL and clock oscillation unit

27: 1 / N divider 29: Reversal

The present invention relates to a color burst signal position determining apparatus and, more particularly, to a color burst signal position determining apparatus for determining a position of a color burst signal included at a predetermined time from a rising edge of a horizontal synchronous signal, And a discriminating device.

Generally, as shown in FIG. 4, a composite video signal filter 100 for filtering a composite video signal from a video signal processed at a front end (not shown) is connected to a chroma IC The luminance signal Yin and chrominance signal Cin are applied to the chroma IC 200 and the luminance signal Yin and chrominance signal Cin Is output to the electron gun, the viewer can view the video signal transmitted from the broadcasting station through the cathode ray tube.

Here, a video signal and a sync signal are applied to the video signal applied to the composite video signal filter 100, which is output from the broadcasting station, as shown in FIG. 5a, and a predetermined time tw from the rising edge of the horizontal synchronization signal H.sync, And a color burst signal having a width of a predetermined time tb is included at a distance. The chroma IC 200 separates the color burst signal from the rising edge of the horizontal synchronizing signal H.sync for a predetermined time tw and outputs the luminance signal Yin and chrominance bin Cin The video signal filter 100 processes the signals into RGB signals and supplies them to the electron gun so that viewers can view the broadcast signals transmitted from the broadcasting stations.

However, when the position of the color burst signal included in the video signal changes according to the signal state of the broadcasting signal transmitted from the broadcasting station, the chroma IC 200 completely separates the color burst signal An anomaly occurs during the demodulation of the luminance signal Yin and chrominance signal Cin into the RGB signals or the chroma IC 200 does not completely process the video signal applied from the composite video signal filter 100 The video signal is displayed on the cathode ray tube in a black and white state.

That is, the color burst signal, which must be included at a place where a predetermined time (tw) has elapsed from the rising edge of the horizontal synchronizing signal H.sync, as shown in FIG. 4a, (Tw + tw ') elapsed from the edge of the chroma IC 200, which is separated from the color burst signal by the burst pulse pulse output from the burst pulse pulse generator, (Tb-tw ') for a predetermined period of time without separating all the color burst signals input during a predetermined period of time (t). Therefore, the luminance signal Yin and chrominance signal Cin are completely The color burst signal is input to the composite image signal filter 200 because the color burst signal is input to the composite image signal filter 200 because the color burst signal can not be demodulated, The wrong decision to be input to the black-and-white state, so controls the operation of the chroma IC (200) to which the black and white video signal to the cathode ray tube display.

The present invention can process a video signal more effectively while preventing a malfunction that may occur in a television receiver that processes a video signal by a conventional color Burst signal and outputs a color video signal to a cathode ray tube, That is, an object of the present invention is to provide a color burst position determining apparatus for determining a position of a color burst signal to be inputted after a predetermined time after a horizontal synchronizing signal is input, and outputting the result to the following stage.

According to an aspect of the present invention, there is provided a plasma display apparatus including a clamp circuit for clamping an image signal so that an image signal including a pedestal and a color burst signal is maintained at a constant DC level, And a clock signal CLK by a reference signal H. ref which is fed back by a frequency divided by a 1 / N frequency divider and a horizontal synchronizing signal H.sync output from the synchronizing signal separating unit. A 1 / N frequency divider that receives a clock pulse output from the PLL and the clock oscillating unit and divides the frequency by 1 / N; and a clock pulse generator that receives a clock pulse generated by the PLL and the clock oscillating unit, And a Burst flag pulse generator for generating a Burst flag pulse from the clamp circuit, An amplification unit for amplifying a color Burst signal transmitted through the switching element, and a controller for converting the amplified color burst signal to a digital signal A data analyzer for determining an input state of a color burst signal output from the analog / digital converter after the burst pulse pulse is raised, and outputting a determination signal for informing the input state of the color burst signal; Counts from the rising edge of the horizontal synchronizing signal (H.sync) applied in the inverter for inverting the horizontal synchronizing signal (H.sync) of the separating unit until the judgment signal of the data analyzing unit is applied to read the position of the color Burst signal And a burst position determining unit for outputting a counting value corresponding to the counted value to the rear stage Will.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a configuration according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, a pedestal and a color burst signal, which are reference levels of a video signal V that is input from a broadcasting station and are processed at a front end not shown, A clamping circuit 11 for clamping the video signal V to maintain a constant DC level, a synchronizing signal separating section 21 for separating the synchronizing signal from the video signal V, And a clock oscillator 25 for oscillating the clock pulse CLK from a reference signal H. ref that is fed back by the 1 / N divider 27 and is fed back, A 1 / N frequency divider 27 for receiving the clock pulse CLK output from the PLL and the clock oscillating unit 25 and dividing the frequency by 1 / N, a clock generating unit 25 for generating a clock And is adapted to receive a pulse (CLK) and oscillate a burst pulse pulse The burst pulse pulse generator 23 and the Burst flag pulse generator 23 to switch only the color burst signal of the video signal output from the clamp circuit 11 The switching element SW1 to be applied to the amplifying section 13 and the amplified amplified signal to amplify the color Burst signal passed through the phase shifting element SW1 to a level required by the analog / An analog / digital converter 15 for converting the color burst signal amplified by the amplifier 13 into a digital signal and supplying the digital signal to the data analyzer 17, After the flag pulse has been raised, the input state of the color burst signal output from the analog / digital converter 15 is determined and a determination signal (high or low level) A horizontal synchronization signal (H.sync) applied from an inverter 29 for inverting the horizontal synchronization signal H.sync of the synchronization signal separation unit 21)of And a burst position determining unit 19 that counts the rising edge of the color burst signal until the judgment signal of the data analyzing unit 17 is applied at the rising edge and outputs the counted value to the succeeding stage .

The operation and effect according to the embodiment of the present invention will be described as follows.

In the present invention, the pedestal level of a video signal is changed according to the magnitude of a broadcast signal, and the slicing point of the sync signal is changed, so that the sync signal can not be accurately separated. To clamp the input video signal (V) as shown in FIG. 2a or 3a to adjust the DC level of the video signal so that the level of the video signal including the pedestal level and the color Burst signal can maintain a constant DC level do. Thus, a video signal in which the level of the pedestal level and the level of the color burst signal is stable, that is, the input video signal Sa shown in FIG. 2a or FIG. 3a, is applied to the input terminal of the switching element SW1.

When an input video signal V including a stable DC level pedestal level and a color Burst signal is inputted, the sync signal separator 21 separates the horizontal sync signal H.sync included in the input video signal V The lower signal of the horizontal synchronization signal H.sync is separated around the slicing point and amplified to the TTL level to apply the horizontal synchronization signal H.sync to the PLL and the clock oscillation unit 25. [

The PLL and the clock oscillating unit 25 receiving the horizontal synchronizing signal H.sync separated by the synchronizing signal separating unit 21 receive the reference signal H.ref applied in the 1 / Detects the error state of the oscillation frequency by detecting the phase change of the signal H.sync, and when it is determined that no error occurs, the clock pulse (CLK) is continuously oscillated in the present oscillation state, The clock pulse CLK corresponding to the input horizontal synchronizing signal H.sync is oscillated and the burst pulse oscillation unit 23 and the analog / digital Conversion section 15 and the burst position determining section 19, respectively.

Here, in order for the PLL and the clock pulse oscillator 25 to oscillate a clock pulse of 14.3 MHz, there are 910 clock pulses during 1H (15.734 KHz), so that after 455 clock pulses, the PLL and the clock pulse oscillator 25 are falling and 909 clock pulses And a reference clock signal H. ref that oscillates in the 1 / N divider 27 generated as described above is supplied to the PLL and the clock pulse oscillator 25 (H.sync) and the clock pulse (CLK) applied by the synchronizing signal separation unit 21 and adjusts the oscillation frequency of the clock pulse (CLK) Is applied to the burst pulse oscillation section 23, the analog / digital conversion section 15, and the burst position determination section 19, respectively.

PLL and the clock pulse CLK of the clock pulse oscillation section 25 are applied to the oscillation circuit 23 to oscillate the Burst flag pulse Sb as shown in FIG. 2B or FIG. 3B, And the data analysis unit 17, respectively.

Thus, the switching element SW1 maintains the ON state only during the time when the color burst signal is applied to the video signal applied from the clamp circuit 11, and the color burst signal Sc similar to the second, third, The amplification unit 13 amplifies the color burst signal Sc similar to that of FIG. 2b or 3c to a level that can be processed by the analog / digital conversion unit 15 To the analog / digital converter 15. The analog / digital converter 15, to which the amplified color burst signal Sd is applied as shown in FIG. 2d or 3d, is supplied to the PLL and the rising edge of the clock pulse CLK oscillated by the clock pulse oscillator 25, The microcomputer 20 detects the highest voltage VT and the lowest voltage VB and the intermediate voltage VM of the color burst signal Sd and outputs the digital signal Se to the data analysis unit 17 .

That is, the analog / digital conversion unit 15 converts the color burst signal Sd input into the waveform of the second or third waveform into a PLL and a clock pulse CLLK input from the clock pulse oscillation unit 25 The signal is converted into a digital signal Se such as the second g or the third g signal during the rising edge and applied to the data analysis unit 17.

Here, the digital signal Se applied to the data analysis unit 17 as shown in FIG. 2g or 3g is a value obtained by multiplying the data analysis unit 17 by FFh, that is, +1 when the color Burst signal is the highest voltage VT. When the color burst signal is the intermediate voltage MT, it is applied to the data analysis unit 17 at the value of 80h, that is, 0, and when the color Burst signal is the lowest voltage BT, 00h, that is, 1 value to the data analysis unit 17.

Accordingly, the data analyzer 17 confirms the input state of the color burst signal Se from the rising edge of the burst pulse pulse, and outputs the determination signal Sf corresponding thereto to the burst position discriminator 19, . That is, the data analysis unit 17 calculates the number of bits of the color burst signal from the rising edge of the Burst flag pulse Sb by 1, 0, -1, 0, +1, 0, When the digital signal of 0, +1, 0, -1 is repeatedly inputted in the analog / digital conversion unit 15, it is determined that the color Burst signal is inputted and the decision signal Sf of the high level is inputted to the burst position determining unit (19).

Then, the burst position determining unit 19 determines whether or not the horizontal synchronizing signal (horizontal synchronizing signal) output from the synchronizing signal separating unit 21 and inverted by the inverter 29 The counting operation is started at the moment when the determination signal Sf output from the data analyzer 17 is applied to the high level and the count value is used to determine whether the position of the color burst signal is normal And determines how far the color burst signal is shifted from the correct position.

That is, the burst position determining unit 19 determines the horizontal sync signal ) And the count value up to the moment when the high-level determination signal output from the data analysis unit 17 is input is detected as a certain time tw (which is the time specified in the NTSC rule) It is determined that the color burst signal is included in the normal position, and the corresponding signal is output to the subsequent stage, and the horizontal synchronizing signal ) And counting up to the moment when the high-level determination signal output from the data analyzer 17 is input is detected as being smaller or larger than the predetermined time tw, the color burst signal (The count value at the previous position is subtracted from the count value detected at the normal position when the color burst signal is ahead of the normal position), and a count value for informing the position of the color burst signal If the color burst signal is later than the normal position, a counting value detected at the normal position is subtracted from the count value detected at the late position, and a positive counting value is outputted to the succeeding stage) And outputs it to the rear end.

Therefore, it is possible to know whether the color burst signal is in the normal position or not, and it is also possible to know the position of the color burst signal included in the abnormal position.

As described above, according to the present invention, it is determined whether a color burst signal is input after a predetermined time elapses at a rising edge of an inverted horizontal synchronizing signal, and it is determined whether a color burst signal is included in a normal position. The count value from the rising edge of the inverted horizontal synchronizing signal to the moment when the color burst signal is detected and the rising edge of the inverted horizontal synchronizing signal when the color burst signal is abnormal when the signal is included in the normal position, It is possible to determine the position of the color burst signal by subtracting or adding the count value up to the moment when the signal is detected.

Claims (2)

A clamp circuit for clamping a video signal so that a video signal including a pedestal and a color burst signal is maintained at a constant level; A sync signal separator for separating a sync signal from the video signal and inverting and amplifying the sync signal; A PLL and a clock oscillator for generating a clock pulse (CLK) by a horizontal synchronizing signal (H.sync) output from the synchronizing signal separator and a reference signal (Href) fed back in a 1 / N frequency divider; A 1 / N frequency divider that receives a clock pulse output from the PLL and a clock oscillator and divides the frequency by 1 / N; A Burst flag pulse oscillation unit that receives a clock pulse oscillated by the PLL and the clock oscillation unit and oscillates a burst pulse; A switching element for performing switching operation by a Burst flag pulse generated in the Burst flag pulse oscillation section and passing only a color Burst signal of the video signal output from the clamp circuit and applying the signal to the amplification section; An amplifying unit for amplifying a color Burst signal via the switching element; An analog / digital converter for converting the amplified color burst signal into a digital signal; A data analyzer for determining an input state of a color burst signal output from the analog / digital converter after the burst pulse is raised and outputting a determination signal for informing the input state; A horizontal synchronizing signal (H.sync) applied in the inverter for inverting the horizontal synchronizing signal (H.sync) of the synchronizing signal separating unit And a burst position determining unit for reading the position of the color burst signal and outputting a count value corresponding to the counted value to the succeeding stage by counting the rising edge of the color burst signal until the determination signal of the data analyzing unit is applied. Burst signal position determining device. The data analyzing apparatus according to claim 1, wherein the data analyzing unit determines whether the position of the color burst signal is normal by inputting a color burst signal at the rising edge of the burst pulse pulse, and outputs a determination signal of a high or low level To the burst position determining unit (20).