KR20020068631A - Horizontal-phase locked loop control apparatus and method for television receiver - Google Patents

Abstract

PURPOSE: A device and a method for controlling horizontal PLL in a TV receiver are provided to prevent flickering of images displayed on upper and lower parts of a TV screen so as to stabilize the images displayed on the screen. CONSTITUTION: A tuner and an intermediate frequency amplifier(1) receive and amplify a TV signal. A video signal detector(2) receives the amplified signal and outputs the signal as a composite video signal. A synchronous signal separator(6) separates a horizontal synchronous signal from the composite video signal. A phase comparator and a voltage-controlled oscillator(7) compare the phase of the synchronous signal with the phase of a signal inputted from a deflector and control the voltage of the signal. A line counter(11) counts the number of input lines. An A/D conversion and video processing unit(5) converts an RF signal from a microcomputer(12) into a digital signal and processes the composite video signal. A noise detector(4) receives the composite video signal from the A/D conversion and video processing unit and detects the quantity of noise in the composite video signal. A horizontal oscillator(9) receives the voltage controlled by the phase comparator and converts the voltage into a signal in a predetermined form. A horizontal output unit(10) receives correct video information through deflection of electron beam. A horizontal PLL error detector(8) detects the quantity of error corresponding to control voltage. The microcomputer receives the noise detected by the noise detector and the number of lines counted by the line counter to control each of the components.

Description

HORIZONTAL-PHASE LOCKED LOOP CONTROL APPARATUS AND METHOD FOR TELEVISION RECEIVER}

The present invention relates to an apparatus and a method for controlling a horizontal-phase locked loop (H-PLL) in a TV receiver. The present invention relates to a horizontal-PEL control apparatus and method in a TV receiver that detects a line input per field to increase the horizontal-PEL speed to stabilize an image signal on the upper screen.

In general, when receiving a radio frequency (RF: radio frequency or less, RF) signal from a video cassette recorder (VCR: Video Cassette Recorder) ), The horizontal synchronization becomes unstable.

This is due to the emergence of cable TV stations and private broadcasters, and also due to the problems of the VRC system such as head jumping, the signals recorded by the VRC are converted into RF signals through the RF modulator. In this case, even if the number of lines input per field is uniform, the screen shakes left and right.

In other words, some of the programs supplied by cable TV stations and private broadcasters, which are increasing, convert and record signals recorded by using a BC-AL to an RF converter, and then supply mechanical signals to the TV during recording and playback. According to the quality of the magnetic tape (Magnetic Tape), the number of input lines per field is severely changed, causing the upper part of the screen to bend from side to side.

However, even if the number of lines to be input is correct due to the horizontal-PEL speed problem, the screen becomes unstable because the amount of horizontal-PEL error is too large. Particularly, in case of receiving a specific broadcast, even if the number of lines per field is input very accurately, the TV screen is displayed. The upper or lower horizontal-Pelel speed is slow, the screen shakes.

Synchronous anxiety generated in this way can not only be improved, but also causes a large horizontal-PEL error. This horizontal-PEL error causes continuous synchronization anxiety on the screen.

That is, as described above, in the conventional technology, when a video signal recorded in a V-CAL is transmitted through a cable according to an increase in cable broadcasting channels, the upper part of the screen is jumped while jumping the V-Cal head according to the characteristics of the mechanical drive of the V-CAL. There was a problem that the lower part is bent or shaken from side to side.

Therefore, in order to solve the above problems, the present invention detects a horizontal-PEL error or detects a line, and when the line detection value is out of a specific value, the speed of the horizontal-PEL in the RF depends on the amount of noise in the current state. It is an object of the present invention to provide a horizontal-Pelel control device and method in a TV receiver to stabilize the image of the screen by preventing the top or bottom of the screen to be bent or shaken by setting fast or slow.

1 is a block diagram showing the configuration of a horizontal-PEL control device in a television receiver of the present invention.

Figure 2 is a flow chart showing the sequence of the horizontal-Pelel control method in a television receiver of the present invention.

*** Description of the symbols for the main parts of the drawings ***

1: Tuner and intermediate frequency amplifier part 2: Image detection circuit part

3: switching unit 4: noise detection unit

5: analog / digital conversion and image processing unit 6: synchronous separation unit

7: Phase comparator and voltage controlled oscillator 8: Horizontal-Piel error detector

9: horizontal oscillation unit 10: horizontal output unit

11: line counter section 12: microcomputer

The present invention for achieving the above object, a tuner (Tuner) and an intermediate frequency amplifier for receiving and amplifying a TV signal through an antenna, and a composite video signal received from the signal amplified from the tuner and the intermediate frequency amplifier An image detection circuit for outputting a signal, a switching unit for receiving a signal from an external device, and switching the same; a synchronous separation unit for separating a horizontal synchronization signal included in the composite image signal received from the switching unit; A phase comparator and a voltage controlled oscillator (VCO) unit for comparing a phase with a signal inputted from a deflector, fed back from the deflection unit, and controlling a voltage, and a signal separated from the synchronous separator unit Receive and reset every field and count the number of input lines and send them to the microcomputer. A line counter unit, an analog / digital conversion and image processing unit for converting an RF signal selected by the following microcomputer into a digital signal and processing a composite video signal, and a composite video signal from the analog / digital conversion and image processing unit The noise detector unit detects the amount of noise contained in the synchronization portion of the composite video signal and transmits it to the microcomputer, and receives a voltage controlled from the phase comparator and the voltage controlled oscillator and outputs the voltage. A horizontal oscillator converting the signal into a signal, a horizontal output unit receiving the converted signal from the horizontal oscillator, and controlling the current flowing through the deflection coil, to receive accurate image information through the deflection of the electron beam through the screen; Detects the amount of error occurrence and sends it to the microcomputer. H-PLL error detector for supplying, the amount of noise detected from the noise detection unit, and the number of lines from the line counter unit receives a microcomputer to control each component accordingly do.

Hereinafter, a description will be given in detail with reference to FIGS. 1 and 2 attached to the operation and effect of the horizontal-PEL control device in the TV receiver according to the present invention.

1 is a block diagram showing the configuration of a horizontal PEL control apparatus in a TV receiver according to the present invention. As shown in FIG. 1, a tuner and an intermediate frequency amplifier 1 for amplifying a TV signal through an antenna and the tuner And an image detection circuit unit 2 for receiving a signal amplified from the intermediate frequency amplifier 1 and outputting a composite video signal, a switching unit 3 for receiving a signal from an external device and switching the same, and the switching unit 3 Synchronous separation unit 6 for separating the horizontal synchronization signal included in the composite image signal received from the) and the synchronous signal separated from the synchronous separation unit 6 and the signal and phase fed back fed from the deflection unit Is a phase comparator and voltage controlled oscillator 7 for comparing and controlling a voltage and a signal separated from the synchronous separator 6 and reset for each field and inputted thereto. And a line counter unit 11 for counting and transmitting to the microcomputer 12, and an analog / digital conversion and image processing unit for converting an RF signal selected by the following microcomputer 12 into a digital signal and processing a composite video signal. 5) and a noise detector 4 which receives a composite video signal from the analog / digital conversion and image processing unit 5 and detects and transmits the amount of noise contained in the synchronization portion of the composite video signal to the microcomputer 12. And a horizontal oscillator 9 which receives the controlled voltage from the phase comparator and the voltage controlled oscillator 7 and converts the voltage into a signal capable of outputting the signal, and receives the signal converted from the horizontal oscillator 9 and deflects it. The horizontal output unit 10 receives the correct image information through the screen by controlling the current flowing through the coil through the deflection of the electron beam, and the control voltage The horizontal PEL error detection unit 8 which detects a corresponding error generation amount and supplies it to the microcomputer 12, the amount of noise detected by the noise detection unit 4, and the number of lines from the line counter unit 11 are received. Accordingly, the operation of the present invention constituted by the microcomputer 12 that controls each component is described as follows.

First, the TV signal input through the antenna is amplified by the tuner and the intermediate frequency amplifier 1, and then the composite image signal is output through the image detection circuit 2, which is supplied to the switching unit 3 The external input signal is transmitted to the switching unit 3.

When the external VRC signal is selected according to the control command of the microcomputer 12, the lines per field are input very unevenly, such as 220 to 350, depending on the uneven speed of the mechanical drive of the VAL and the state of the magnetic tape. In this case, the microcomputer 12 may obtain an accurate image by increasing the horizontal-Piel speed.

If the RF signal is selected by the microcomputer 12, it is transmitted to the analog / digital conversion and image processing unit 5 for processing the selected composite video signal to perform an image processing process.

This signal is also input to the noise detector 4 to detect the amount of noise carried in the synchronization portion of the composite video signal and transmit it to the microcomputer 12.

On the other hand, the signal transmitted via the switching unit 3 is transmitted to the synchronization separation unit 6, and the horizontal synchronization signal included above in the composite video signal is separated from the synchronization separation unit 6, and the line counter unit 11 Is sent).

Then, this line counter section 11 is reset every field and counts the number of input lines and transmits the counted lines to the microcomputer 12.

2 is a flowchart illustrating a horizontal-PEL control sequence in a TV receiver according to the present invention. As shown in FIG. 2, a first step of confirming the number of lines per field input to a microcomputer and a verification result of the first step are shown. The second step of setting horizontal-Pelel to "slow" when the number of lines is in the 312 ± 3 range or in the 262 ± 3 range, and whether the noise and the horizontal-Piel error input to the microcomputer are above a certain value. In the third step of checking and the determination result of the third step, when the noise is larger than the specified value or the noise is less than the specified value, the horizontal-Piel error is smaller than the specific value. And a fifth step of setting the horizontal-Piel to "fast" when the horizontal-Piel error is large as a result of the determination of the third step. Like this The operation of the present invention made as follows.

First, the value of the line counter unit 11 is referred to as PAL (Phase Alternation by Line European TV transmission / reception method, arm method) and SECAM (SEquencial Color And Memory French TV transmission / reception method, SECAM) system. Check that the value is in the 312 ± 3 range, and if it is within the range, judge the normal broadcast signal and set the horizontal-Piel to "slow".

However, if this value is out of the above range, the microcomputer 12 checks whether the value is in the range of 262 ± 3 for the NTSC system (hereinafter referred to as NTSC). If it is in the range, it judges that it is a normal broadcast signal and sets horizontal-Piel to "slow".

Here, if the value input from the line counter 11 is out of the range set for the arm method or SECAM or NTSC, the microcomputer 12 counts the number of lines of the RF signal currently input to the tuner. It is determined that the number of lines per field has fluctuated due to the abnormality of other signal equipment, and the horizontal-Pelel speed is set to "fast" to obtain accurate image information.

The signal synchronously separated by the synchronous separator 6 is supplied to the phase comparator and the voltage controlled oscillator 7 to compare the phase with the signal fed back from the deflector, and when there is a phase difference, the voltage controlled oscillator ( VCO: Voltage Controlled Oscillator (hereinafter referred to as voltage controlled oscillator) controls the voltage equivalent to the phase difference of the phase comparator and the voltage controlled oscillator 7 so that the output of the feedback signal and the inputted composite video signal are synchronized. To match.

Therefore, if the number of lines input per field is correct, the value of the noise detector 4 is read, and the horizontal-PEL error increases in proportion to the amount of noise in the input signal, which is proportional to the strength of the input electric field.

In general, the electric field of the signal input at the RF output of the VRC is input at a fairly good level, and the amount of noise is very small.

The horizontal PEL error detection unit 8 detects an amount corresponding to the control voltage and transmits the error generation amount to the microcomputer 12. When the transmitted noise value is smaller than a specific value, the microcomputer 12 The horizontal PEL error value supplied by the horizontal PEL error detection unit 8 is read again, and when this value is smaller than the specified value, the stable horizontal screen is obtained by setting the horizontal PEL speed to "slow".

On the other hand, when the horizontal PEL error value output from the horizontal PLL error detection unit 8 is large, it is determined that image information in which the RF or horizontal PEL error is generated is supplied. Convert the L speed to "fast" to get a stable picture.

The output of the phase comparator and voltage controlled oscillator 7 controlled in this way is converted into a signal in a form that can be processed by the horizontal output unit 10 and then deflected by the electron beam by controlling the current flowing through the deflection coil in the horizontal output unit 10. It allows you to receive accurate image information through the screen.

As described in detail above, the present invention detects a horizontal PLL error and detects a line so that when the number of lines deviates from a specific value, the horizontal PLL is rapidly set in the RF according to the amount of noise in the current state. It is effective to stabilize the signal by preventing the video signal of the upper and lower screens from bending or shaking from side to side by operating in a slow or slow setting.

Claims (2)

A tuner and an intermediate frequency amplifier for receiving and amplifying a TV signal through an antenna, an image detection circuit unit for receiving an amplified signal from the tuner and the intermediate frequency amplifier and outputting the signal as a composite image signal, and receiving a signal from the outside A switching unit for switching, a synchronous separating unit for separating a horizontal synchronizing signal among the composite image signals input from the switching unit, and a signal and a phase fed back from the deflecting unit by receiving a synchronous signal separated from the synchronous separating unit; A phase comparator and a voltage controlled oscillator for comparing and controlling a voltage, a line counter unit for receiving a signal separated from the synchronous separator and being reset for each field and counting the number of input lines, and an RF signal from a microcomputer To convert digital into digital signals and process composite video signals A digital converter and an image processor, a noise detector for receiving a composite video signal from the analog / digital converter and the video processor, and detecting a noise amount contained in a synchronization part of the composite video signal, and a voltage controlled from the phase comparator A horizontal oscillator that receives the signal and converts it into a signal that can be output, and a horizontal output that receives accurate image information through the deflection of the electron beam by receiving a signal converted from the horizontal oscillator and controlling the current flowing through the deflection coil through the screen And a horizontal PEL error detection unit for detecting an error amount corresponding to a control voltage, and a microcomputer for receiving the noise detected by the noise detection unit and the number of lines from the line counter unit and controlling each component accordingly. TV receiver characterized in that Horizontal-Piel control unit. A first step of checking the number of lines per field entered into the microcomputer, and the result of the first step confirms that the horizontal-Piel is "slow" if the number of lines is in the 312 ± 3 range or in the 262 ± 3 range. A second step of setting to a third step, a third step of checking whether the noise and the horizontal-Piel error inputted to the microcomputer are equal to or greater than a specific value, and when the third step determines that the noise is larger than the specific value, or If the noise is less than the specified value and the horizontal-Piel error is less than the specified value, the fourth step of setting the horizontal-Piel to "slow", and the determination of the third step, A horizontal-Pellel control method in a television receiver, characterized in that the fifth step of setting the horizontal-Piel to "fast".