KR20000021573A - Method for controlling screen quality according to transmission path of tv - Google Patents

Abstract

PURPOSE: A method for controlling screen quality is provided to compensate the difference of the screen quality, caused by the difference of a transmission path of a TV broadcasting signal. CONSTITUTION: A method for controlling screen quality controls the screen quality on the basis of an image signal for testing, inserted in a predetermined horizontal line of a vertical blanking interval of a TV broadcasting signal. The method for controlling screen quality comprises the steps of: detecting the image signal for testing in the received broadcasting signal, when a channel is converted; converting the detected image signal for testing into a digital signal; reading an image signal for a standard test, which is pre stored, and which is the identified with the image signal for testing, and compensating screen quality of the image signal for processing display on the basis of the level difference of the image signal for the standard test and the converted image signal for testing.

Description

METHOD FOR CONTROLLING PICTURE QUALITY AS TRANSMISSION PATH IN A TELEVISION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling image quality according to a transmission path in a television, and in particular, inserts and transmits a test video signal on an arbitrary horizontal line within a vertical blanking period, and stores the inserted test video signal upon reception. The present invention relates to a method for controlling image quality according to a transmission path in a television that is capable of automatically maintaining the same image quality regardless of a transmission path of a broadcast signal such as airwaves or satellites based on a comparison with a test video signal.

In general, a video signal, i.e., a composite video signal in a television, has a horizontal blanking period, a video signal for one horizontal line, and a vertical blanking period as known. interval, in particular the image signal for one horizontal line actually displayed increases in amplitude in proportion to the brightness of the image from the dark level to the white level.

On the other hand, in any horizontal line section from 11H to 19H except for equalizing pulse and vertical sync pulse section among 21 horizontal line sections H in the vertical blanking period, Broadcasting system providing Extended Data Service, for example, data for broadcasting programs and scheduled recording on a broadcast signal according to KBPS (Korea Broadcasting Program System), for example, channels, broadcast categories (for example, news, Drama, sports, etc.), broadcast start / end time, viewing grade, and standard time data, etc., are converted into digital signals and transmitted, and the signals are decoded by a KBPS decoder on the video receiving device side to schedule broadcast program reservation recording. To be done.

On the other hand, when the same broadcast program is transmitted on a plurality of channels on a television, for example, when played on a video cassette recorder, receiving a general over-the-air broadcast, or receiving a satellite broadcast, the user may noticeably feel the same. Image quality (e.g., contrast, brightness, color, tint, sharpness, etc.) may be different in the same television setting state, respectively.

That is, when the transmission paths of broadcast programs are different, the picture quality is different based on external factors and differences in modulation of broadcast stations, causing inconvenience to users.

Therefore, in the present invention, a method of inserting a test video signal into an arbitrary horizontal line of the vertical blanking period described above and correcting such a difference in image quality is explored.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and an object thereof is within the above-described vertical blanking period in a broadcast signal transmitted to correct a difference in image quality caused by a difference in a transmission path of a television broadcast signal. Inserts and transmits a test video signal to an arbitrary horizontal line of the broadcast signal, detects the test video signal from the received broadcast signal, and processes the received broadcast signal based on a difference from the pre-stored reference test video signal. The present invention provides a method of controlling image quality according to a transmission path in a television, so that the image can be automatically adjusted to the same level of quality regardless of a signal transmission path or modulation.

1 is a schematic block diagram of a television employed in accordance with the present invention;

2 is a flowchart illustrating a quality control process according to a transmission path in a television according to a preferred embodiment of the present invention.

<Explanation of symbols for main parts of the drawings>

10: key input unit 20: microcomputer

30: tuner 40: video detector

50: video signal processor 60: monitor

70: A / D conversion unit 80: synchronous separation unit

90 memory

The image quality control method according to the transmission path in a television according to the present invention is a method of adjusting the image quality on the basis of a test video signal inserted in a predetermined horizontal line of a vertical blanking period of a broadcast signal in a television. Detecting a test video signal from a received broadcast signal; converting the detected test video signal into a digital signal; and storing a reference test that is previously stored and is the same video signal as the test video signal. And compensating for the image quality of the image signal to be displayed and processed based on the level difference between the test image signal digitally converted by reading the image image signal and the previously stored reference test image signal.

The above objects and various advantages of the present invention will become more apparent from the preferred embodiments of the invention described below with reference to the accompanying drawings by those skilled in the art.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a television employed in accordance with the present invention, which includes a key input unit 10, a microcomputer 20, a tuner unit 30, an image detector 40, an image signal processor 50, and a monitor 60. ), An A / D converter 70, a sync separator 80, and a memory 90.

In this configuration, the key input unit 10 is an input means for performing the operation of the television, and has a plurality of keys for performing each operation including a channel up / down key for channel switching, etc. It outputs a key signal corresponding to the operation, and transmits / receives a key signal carried on a predetermined infrared carrier wave to a microcomputer 20 which will be described later by using a remote controller that can be input at a remote place.

The microcomputer 20 is a means for controlling the overall operation of the television based on the key signal from the key input unit 10. When the channel up / down key signal is applied from the key input unit 10, the tuner unit 30 to be described later will be described. ), And the channel is tuned to the corresponding channel, and the vertical retrace is performed in the digitally converted sync signal applied from the A / D converter 70 to be described later based on the frequency of the sync signal applied from the sync separator 80 to be described later. A test video signal inserted into a predetermined horizontal line in the erase section is detected.

In addition, the microcomputer 20 compares each pixel level of the detected test image signal with each pixel level of the reference test image signal digitized and stored in the memory 90 to be described later, and adjusts and controls the image quality according to the difference. In order to control the video signal processor 50 to be described later.

That is, the image signal processing unit 50 controls the image signal output to the monitor 60, for example, contrast, brightness, color, tint, sharpness ( sharpness) is controlled to remain constant regardless of the modulation state of the broadcasting station or the transmission path of the broadcasting signal.

Meanwhile, the tuner unit 30 outputs a broadcast signal (intermediate frequency signal) received by being tuned to a channel corresponding to the control of the microcomputer 20.

The image detector 40 separately detects and outputs an image signal (composite image signal) from the broadcast signal output from the tuner unit 30.

In addition, the image signal processing unit 50 processes the image signal applied from the image detector 40 as a displayable signal and outputs the signal to the monitor 60, in particular based on the control of the microcomputer 20 (PWM signal). The above-described image quality of the video signal is adjusted and output.

The A / D converter 70 converts the analog sync signal, which is separated and applied from the sync separator 80, to a digital sync signal under the control of the microcomputer 20, and outputs the digital sync signal to the microcomputer 20.

Meanwhile, the sync separator 80 separates the sync signal from the broadcast signal received by the tuner 30 and outputs the sync signal to the microcomputer 20.

In addition, the memory 90 digitally converts the same signal as the test video signal inserted into any horizontal line in the vertical blanking period of the broadcast signal and stores it as a reference test video signal (one horizontal line video signal). The reference test image signal stored under the control of the microcomputer 20 is read and output to the microcomputer 20.

Next, the television having the above-described configuration will be described in detail with reference to the flowchart of FIG. 2 attached to the image quality control process according to the path in the television according to the preferred embodiment of the present invention.

First, the viewer operates a channel up / down key provided in the key input unit 10 to switch channels to watch a desired broadcast program.

On the other hand, each broadcast channel may have a different modulation of its broadcasting station and a different transmission path of the broadcast signal, and thus, in television, always, in particular, a large number of channels regardless of the difference of the modulation and the difference of the broadcasting signal transmission path. When the same broadcast program is received as a channel, the microcomputer 20 processes a video signal with the same image quality to maintain a constant image quality. First, the microcomputer 20 receives a channel up / down key signal for channel switching from the key input unit 10. It is then determined whether it is authorized (step 200).

At this time, when the channel up / down key signal is applied from the key input unit 10, the microcomputer 20 controls the tuner unit 30 to switch the current channel in response to the applied channel up / down key signal (step 202). ).

Next, in order to correct the change in the image quality according to the channel switching, the microcomputer 20 detects the test video signal carried on any horizontal line section within the vertical blanking period of the broadcast signal (step 204).

In more detail, the microcomputer 20 counts the pulses of the sync signal separated from the sync separator 80 and applied to the internal A / D port or the event count port, so that any horizontal line section within the vertical blanking period in the sync signal is performed. It is to detect the position of the test video signal inserted in the.

Next, when the position of the test video signal described above is confirmed, the A / D converter 70 is controlled at this point to convert the test video signal into a digital signal and receive the input signal (step 206).

Thereafter, the control unit 300 reads and controls the reference test image signal previously stored in the memory 90 (step 208).

Next, the microcomputer 20 performs a test video loaded on the level of each pixel of the one-line reference test video signal applied from the memory 90 and the actual broadcast signal applied from the A / D converter 70. The level of each pixel of the signal is compared to determine whether the difference has occurred (step 210).

In this case, when the difference occurs, the microcomputer 20 controls the image signal processing unit 50 based on the generated difference and the image quality of the image signal output to the monitor 60, for example, contrast and brightness. Brightness, color, tint, sharpness, and the like are controlled to remain constant regardless of the modulation state of the broadcast station or the transmission path of the broadcast signal (step 212).

That is, when a broadcast signal is transmitted to a television system, the reception state of the test video signal inserted into a predetermined horizontal line in the vertical blanking period is judged, and the image quality is corrected in response to the reception state.

On the other hand, it will be understood by those skilled in the art that various changes and modifications can be made without departing from the spirit of the present invention.

As described above, according to the present invention, when a broadcast signal is transmitted in a television broadcasting system, the test video signal is inserted and transmitted in an arbitrary horizontal line within the vertical blanking period of the broadcast signal, and the same as the test video signal described above in the television. Based on the comparison between the reference test video signal pre-stored in the test signal and the test video signal read out from the received broadcast signal, the image quality of the displayed image remains constant regardless of the modulation and transmission path according to the change of the channel. There is an effect that can be maintained.

Claims (1)

A method of controlling image quality on the basis of a test video signal inserted in a predetermined horizontal line of a vertical blanking period of a broadcast signal in a television, Detecting the test video signal from a broadcast signal received when a channel is switched; Converting the detected test video signal into a digital signal; An image that is stored in advance and reads out a reference test image signal, which is the same as the test image signal, and is displayed and processed based on a level difference between the digitally converted test image signal and the previously stored reference test image signal. Comprising the step of compensating for the image quality of the signal quality control method according to the transmission path in a television.