KR20090067524A - Display device and method for controlling aspect ratio of the same - Google Patents

Abstract

An image display device and an aspect ratio control method are provided to enable a user to view a TV set in a stable aspect ratio by preventing abnormal operation of an aspect ratio owing to an error generated when WSS(Wide Screen Scaling) data is decoded. WSS data included in a video signal is periodically detected(S20). It is checked whether the detected WSS data is modified or not based on the currently applied WSS data(S30). The number of detected modified WSS data is counted when the WSS data is modified(S50). Application of the modified WSS data is determined based on the counted detection number(S70).

Description

Display device and method for controlling aspect ratio of the same}

The present invention relates to an image display device, and more particularly, to aspect ratio adjustment using wide screen signaling (WSS) information.

NTSC (National Television System Commitee) method implements one frame as 525 lines and analog alteration by line (PAL) method implements one frame as 625 lines. The video system consists of 59.94 fields per second, and the PAL system consists of 50 fields per second.

There is a vertical blanking interval (VBI), which is an empty space in which no data is loaded between the fields.

The VBI section transmits information for multicasting such as subtitle information, program grade and text information, price information, stock quotes, news, weather, program guides, and traffic guides.

Here, among the information transmitted through the VBI section, there is Wide Screen Signaling (WSS) data indicating an aspect ratio of a corresponding video signal.

That is, an image of a broadcast signal transmitted from a broadcasting station may have an aspect ratio of 16: 9 as well as an aspect ratio of 4: 3, and a TV signal of some broadcasting stations in Europe may include an image having an aspect ratio of 14: 9.

Such image signals having various aspect ratios must be signal processed so as to correspond to the respective aspect ratios so that the image display apparatus correctly realizes the image. As a prerequisite for this, the aspect ratio information (WSS) of the image signal included in the image signal must be normally detected in the image display apparatus. In other words, a circuit for automatically detecting WSS data should be configured in the TV receiver.

Accordingly, the existing video display device detects the WSS signal included in a specific section of the broadcast signal, determines the aspect ratio of the video signal currently received based on the detected signal, and determines the aspect ratio of the image based on the determined aspect ratio. Adjust to display.

However, if the signal state in the field is abnormal (when the signal strength is weak or the signal state is bad), an error occurs when decoding the WSS information carried in the VBI section.

That is, when the strength of the currently received broadcast signal is weak or poor, an error may occur when decoding the WSS information performed to detect the aspect ratio of the video. There is a problem that bouncing of ARC (Aspect Ratio Control) occurs due to abnormal operation.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object thereof is to prevent a malfunction due to a decoding error of WSS data by counting the number of detections according to whether or not the WSS data is changed.

In addition, another object of the present invention is to distinguish the decoding error situation of the WSS data from the occurrence of a channel switching event and to more effectively apply the aspect ratio according to the current view image.

According to an aspect of the present invention, there is provided a video display device comprising: a tuner unit for tuning a broadcast signal of a specific channel among broadcast signals input from the outside and separating the broadcast signal into a video / audio signal; A WSS detector for periodically decoding data included in a specific section of the video signal to detect WSS (Wide Screen Signaling) data; An image processor which processes the image signal based on the WSS data detected by the WSS detector; A display unit which displays the signal processed image signal; And a controller for checking whether the WSS data periodically detected is changed, and counting the number of times of detection of the changed WSS data, thereby determining whether to apply the changed WSS data.

In addition, the aspect ratio adjustment method of the image display device according to the present invention for achieving the above object of the image display device for displaying an image based on the WSS (Wide Screen Signaling) data included in a specific section of the image signal input from the outside A method of adjusting an aspect ratio, the method comprising: periodically detecting WSS data included in the video signal; Determining whether the detected WSS data is changed based on the currently applied WSS data; Counting the number of detections of the changed WSS data when the WSS data is changed; And determining whether to apply the changed WSS data based on the detection frequency.

The video display device and aspect ratio adjusting method according to the present invention checks the number of times the WSS data is detected according to whether or not the WSS data is changed to determine whether or not to change the aspect ratio. The abnormal operation of the user can be prevented in advance so that the user can watch TV at a more stable aspect ratio.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the spirit of the present invention is not limited to the embodiments presented, and other embodiments included within the scope of other inventive inventions or the scope of the present invention can be easily made by adding, changing, or deleting other elements. I can suggest.

1 is a block diagram showing the configuration of an image display device according to the present invention, Figure 2 is a flow chart for explaining a step of adjusting the aspect ratio of the image display device according to the present invention.

First, an image display device according to the present invention comprises an antenna (not shown) for receiving a broadcast signal transmitted from a broadcasting station, and a broadcast signal of a specific channel selected by a user from among the broadcast signals received through the antenna. A tuner unit 10 to be separated into; and a WSS detector 20 to detect aspect ratio data (WSS) by decoding data included in a specific section of the video signal separated by the tuner unit 10; An image processing unit 30 for signal processing the image signal based on aspect ratio data, a display unit 40 for displaying the signal processed image signal, a key input unit 50 for receiving a request command from a user, and It is periodically checked whether or not the detected aspect ratio data is changed, and accordingly, the number of times of detection of the changed aspect ratio data is counted to apply the changed aspect ratio data. It is configured to include a control unit 60 for determining parts.

The operation of the image display device according to the present invention configured as described above is as follows.

An antenna (not shown) receives a broadcast signal transmitted from a broadcasting station, and has the same function as an antenna installed in a conventional video display device. The tuner unit 10 tunes a broadcast signal of a specific channel among the broadcast signals received through the antenna according to the control signal of the controller 60, and separates the tuned broadcast signal into video and audio signals, respectively, and outputs them.

The WSS detector 20 detects WSS data by decoding data existing in a specific section of the separated and output image signal.

Here, the WSS data is included in a broadcast signal transmitted from a broadcasting station. The WSS data will be described in more detail below.

In general, WSS data is included in the 23rd horizontal signal line. The position ranges from about 11 ms to 27.4 ms from the falling edge of the horizontal synchronization signal. The WSS signal has a size of about 500 mV and includes 14 bits of data at a clock frequency of 5 MHz.

This WSS data is divided into four groups, as shown in Table 1 below, where the first group represents aspect ratio data, the second group represents extended service data, the third group data for subtitles, and Four groups represent undefine data.

 First group b0 Aspect data b1 Aspect data b2 Aspect data b3 Data error correction (odd parity bit)  2nd group b4 0: camera mode, 1: film mode b5 0: standard PAL, 1: motion adaptive b6 0: no helper, 1: helper for PAL PULS b7 Reserved bit, set to 0  Third group b8 0: no subtitles, 1: subtitles b9 00: subtitle not displayed, 01: subtitle information is present in the signal 10: subtitle information exists outside the signal, 11: reserved bit (undefined) b10  Fourth group b11 Set to undefined bit 0 b12 Set to undefined bit 0 b12 Set to undefined bit 0

Detailed description of the first group disclosed in Table 1 is as shown in Table 2 below.

b3 b2 b1 b0 Display mode Aspect ratio How to display location Image display line One 0 0 0 Mode 0 4: 3 full format - 576 0 0 0 One Mode 1 14: 9 letter box center 504 0 0 One 0 Mode 2 14: 9 letter box top 504 One 0 One One Mode 3 16: 9 letter box center 432 0 One 0 0 Mode 4 16: 9 letter box top 432 One One 0 One Mode 5 16: 9 or above letter box center not defined One One One 0 Mode 6 14: 9 full format center 576 0 One One One Mode 7 16: 9 full format - 576

The image display mode is achieved as shown in Table 2 by the data bits of the first group.

That is, if the data bit of the first group is 1000, the video signal tuned by the tuner unit 10 includes an image of mode 0, and if 0001, an image of mode 1 is included. If the data bit of the first group is 0010, a picture of mode 2 is included in the video signal, a picture of mode 3 is 011, a picture of mode 4 is 0100, and a mode 5 picture is 1110, mode 6 Image is included, and if it is 0111, the image of mode 7 is included in the video signal selected by the tuner unit 10.

In this case, the full format image is an image displayed on all horizontal signal lines, and the letterbox image is an image displayed on some horizontal signal lines.

As such, the WSS detection unit 20 periodically detects the WSS data of the above type, and transmits the detected WSS data to the control unit 60.

The controller 60 sets the aspect ratio of the received video signal based on the transferred WSS data, and outputs a control signal to perform signal processing of the video signal based on the set aspect ratio.

Accordingly, the output image signal is signal-processed by the image processor 30 and displayed on the display unit 40.

The key input unit 50 refers to a remote controller or a TV keypad, and receives various user commands such as a channel switching event generation command according to a user's desired viewing.

The controller 60 controls the aspect ratio of the video signal to be adjusted based on the detected WSS data, and determines whether to apply the changed WSS data by checking whether the WSS data that is periodically detected is changed.

That is, the controller 60 determines whether the initially detected WSS data is valid after power on, and sets the aspect ratio of the current image by applying the WSS data if the detected WSS data is valid. .

In addition, periodically receiving and analyzing WSS data detected through the WSS detection unit 20, and when WSS data different from the currently applied aspect ratio is detected, the changed WSS data is not immediately applied as the aspect ratio of the current image. The changed WSS data is set to a temporary aspect ratio.

Subsequently, if WSS data equal to the currently applied aspect ratio is redetected, the current setting is maintained, and if the changed WSS data, that is, the WSS data set to the temporary aspect ratio is continuously detected, the number of times of detection of the changed WSS data is counted. .

In other words, if the detected WSS data is not the same as the currently applied aspect ratio, the detected WSS data is set as the temporary aspect ratio, and then it is determined whether the WSS data set as the temporary aspect ratio is continuously detected.

If the WSS data set as the temporary aspect ratio is continuously detected, the number of times of detection is counted. If the counted number of times exceeds the preset number of times, the current WSS data according to the set temporary aspect ratio is applied. Change the set aspect ratio.

Accordingly, when the changed WSS data is detected at the time of decoding error of the WSS data, the number of times of detection of the WSS data is checked without applying the changed WSS data, and at the time when the changed WSS data is continuously detected more than a predetermined number of times. Change the currently applied aspect ratio.

Therefore, it is possible to prevent an aspect ratio malfunction caused by applying wrongly recognized WSS data due to a decoding error, and to perform aspect ratio adjustment more efficiently.

In addition, when the WSS data is changed, channel switching may have occurred, so that the aspect ratio adjustment can be performed by distinguishing between the change of WSS data due to the general decoding error and the change of WSS data due to the channel switching. do.

That is, when the WSS data is changed, the controller 60 determines whether a current channel change event has occurred, and when the channel change event occurs, determines that the WSS data change situation due to the channel change has occurred, and immediately changes the change. Applies WSS data to control aspect ratio adjustment.

As described above, the video display device and the aspect ratio adjusting method according to the present invention checks the number of times the WSS data is detected according to whether the WSS data is changed and determines whether to change the aspect ratio. As a result, the abnormal operation of the aspect ratio can be prevented in advance so that the user can watch TV at a more stable aspect ratio.

In the aspect ratio adjustment method of the image display device according to the present invention configured as described above, as shown in FIG. 2, first, an image received from the outside is displayed (S10).

Subsequently, the WSS data detected in the received image is periodically analyzed (S20).

In operation S30, it is determined whether the detected WSS data is the same as the currently applied WSS data.

Subsequently, the determination result (S30) is terminated if the detected WSS data and the currently applied WSS data is the same, otherwise it is determined whether the detected WSS data and the predetermined temporary WSS data is the same (S40). Here, the temporary WSS data is previous detection WSS data set when the previously detected WSS data is not the same as the currently applied WSS data.

If the detected WSS data and the temporary WSS data are not the same as the determination result (S40), the detected WSS data is set as the temporary WSS data, and the number of times of detection of the temporary WSS data is set to 1 (S50). .

Next, it is determined whether a channel switch event has occurred (S60).

If the determination result (S60) channel switching event occurs, the set temporary WSS data is applied to the current aspect ratio (S70), otherwise, the process returns to the step (S20).

Subsequently, the aspect ratio of the input image is adjusted based on the applied aspect ratio (S80).

On the other hand, if the detected WSS data and the temporary WSS data are the same (S40), the detection frequency of the temporary WSS data is increased by one (S90).

Subsequently, it is determined whether the detection frequency of the temporary WSS data has exceeded a preset number of times (S100).

If the number of times of detection of the temporary WSS data exceeds a preset number of times, the process proceeds to step S70, or enters step S60.

As described above, the video display device and the aspect ratio adjusting method according to the present invention checks the number of times the WSS data is detected according to whether the WSS data is changed and determines whether to change the aspect ratio. As a result, the abnormal operation of the aspect ratio can be prevented in advance so that the user can watch TV at a more stable aspect ratio.

1 is a block diagram showing the configuration of a video display device according to the present invention.

2 is a flowchart illustrating a step-by-step method of adjusting an aspect ratio of an image display device according to the present invention.

<< Explanation of symbols for main part of drawing >>

10: tuner unit 20: WSS detection unit

30: image processing unit 40: display unit

50: key input unit 60: control unit

Claims (6)

A tuner unit for tuning a broadcast signal of a specific channel among broadcast signals input from the outside and separating the broadcast signal into a video / audio signal; A WSS detector for periodically decoding data included in a specific section of the video signal to detect WSS (Wide Screen Signaling) data; An image processor which processes the image signal based on the WSS data detected by the WSS detector; A display unit which displays the signal processed image signal; And, And a controller for checking whether the WSS data that is periodically detected is changed, and counting the number of detections of the changed WSS data accordingly to determine whether to apply the changed WSS data. The method of claim 1, And the controller is configured to change the currently applied aspect ratio with reference to the detected specific WSS data, when specific WSS data different from the currently applied WSS data is continuously detected for a predetermined number of times. The method of claim 1, And the controller determines whether to switch channels when the detected WSS data is changed, and immediately applies the changed WSS data when the channel switching event occurs. In the aspect ratio adjustment method of a video display device for displaying an image based on the WSS (Wide Screen Signaling) data included in a specific section of the video signal input from the outside, Periodically detecting WSS data included in the video signal; Determining whether the detected WSS data is changed based on the currently applied WSS data; Counting the number of detections of the changed WSS data when the WSS data is changed; And, And determining whether to apply the changed WSS data on the basis of the detection frequency. The method of claim 4, wherein Determining whether to apply the changed WSS data is Determining whether the changed specific WSS data is continuously detected more than a preset number of times; And applying the specific WSS data when the specific WSS data is continuously detected more than the set number of times. The method of claim 4, wherein Determining whether a channel switching event occurs when the detected WSS data is changed; And if the channel switching event occurs, immediately applying the changed WSS data.

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