KR0148141B1 - Control method of blanking level and its apparatus - Google Patents

Abstract

The present invention relates to a blanking level adjusting method and a device thereof, and more particularly, by inputting a value converted by a DC level of a main screen signal input through an integration process to a 4: 3 screen left and right blanking interval level on a wide screen. The blanking level is also adjusted to correspond to the brightness of the main screen. Therefore, the present invention provides the effect that the left and right blanking levels do not affect the main screen so that the main screen brightness can be kept constant at all times.

Description

Blanking level adjusting method and device

1 is a block diagram showing an apparatus for displaying an image signal on a wide screen according to the related art.

2 is a block diagram showing an apparatus for displaying an image signal on a wide screen to which the present invention is applied.

* Explanation of symbols for main parts of the drawings

21: Integrator 23: A / D Converter

25: switch unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for displaying a video signal having a narrow aspect ratio on a television receiver having a wide aspect ratio. Particularly, the present invention relates to a wide aspect ratio such as high definition television (HDTV). A blanking level adjustment method and apparatus for adjusting blanking levels so that the brightness of a main screen can be constantly maintained in the margin processing on the display generated when displaying a video signal having a narrow aspect ratio on a television having the same. .

Currently, NTSC (National Television System Comittee) televisions have an aspect ratio of 4: 3, but the aspect ratio that a person can feel the most realistic or lively is the 16: 9 aspect ratio of an HDTV. Methods and devices for displaying NTSC broadcasting or VISTA (Visual System Transmission Algorithm) size video cassette recorder video signals are being developed. When NTSC broadcasting is displayed on 16: 9 receiver, if time compression processing is not performed, a phenomenon that a picture spread from side to side is displayed on a normal output screen, so time compression processing must be performed. The time compression process allows 4: 3 images to be reproduced on a 16: 9 television set, allowing users to watch normal screens, but the lack of horizontal band results in the left or / and right side of the screen. A space was encountered. A conventional apparatus for displaying 4: 3 images on such a wide screen is shown in FIG.

FIG. 1 is a block diagram of a conventional device for displaying an image signal on a wide screen, and includes an A / D converter 11 for receiving an analog luminance signal Y and converting it into a digital form. The output terminal of the A / D converter 11 is connected with a line memory 12 for storing digital luminance data in units of scan lines. FIG. 1 also includes a switch unit for selectively switching a '128' level, which is an intermediate value between luminance data and 8-bit data supplied from the line memory 12 in units of scan lines, in accordance with a predetermined control signal CTL. (13) is provided. The output terminal of the switch unit 13 is connected to the D / A converter 14 for converting the digital luminance data selectively output to an analog signal. The output terminal of the D / A converter 14 receives a gain adjusting unit 15 for adjusting the gain of the output signal according to a predetermined feedback signal and an output signal of the gain adjusting unit 15 and compares it with a preset gain to obtain a gain adjusting unit ( 15 is an automatic brightness limiting circuit (hereinafter referred to as ABL) 20 which is composed of a deflection and high pressure section 16 for feeding back. The output terminal of the gain adjusting unit 15 of the ABL circuit 20 is connected to the CRT driving unit 17 for driving the CRT. An output terminal of the CRT driver 17 is configured such that a CRT 18 having a 16: 9 aspect ratio is connected. In FIG. 1, the A / D converter 11 receives an analog luminance signal Y of an image signal divided into a luminance signal Y and a color difference signal RY, BY, and converts the analog signal into a digital signal to convert a line memory ( 12). The line memory 12 having a first-in-first-out (FIFO) method receives digital luminance data in units of 8 bits from the A / D converter 11 and stores it in units of scan lines. The switch unit 13 has a first contact a connected to an output terminal of the line memory 12 and a second contact b connected to a signal having a '128' level, which is a preset value, respectively. According to the control signal CTL, the switching contactor c is connected to one of the two contacts a and b and outputs the same. Here, the preset value '128' means an intermediate level of digital luminance data (2 ⁸ = 256) represented by 8 bits. That is, an output signal of the first contact point a is displayed on a screen having an aspect ratio of 4: 3 on a CRT of 16: 9, and a signal of '128' level is displayed on the left and right margins. The D / A converter 14 converts 8-bit digital data alternately output from the switch unit 13 into an analog signal. The gain subtractor 15 in the ABL circuit 20 applies a signal applied from the D / A converter 14 to the deflection / high voltage unit 16. The deflection / high voltage section 16 generates a control signal to the gain adjustment section 15 by comparing the signal received from the gain adjustment section 15 with a preset level. The gain adjusting unit 15 adjusts the gain of the signal applied from the D / A converter 14 according to the control signal applied from the deflection and high voltage unit 16 and applies it to the CRT driving unit 17. The CRT driver 17 receives the gain-adjusted signal and displays it on the CRT 18. The color difference signals RY and BY are also subjected to the same process, and the color signals R, G and B to be displayed on the CRT 18 by being combined with the luminance signal Y in a matrix (not shown) including the ABL circuit 20. )

Thus, when displaying an image signal having an aspect ratio of 4: 3 on a main screen on a CRT having an aspect ratio of 16: 9, the left and right margins are set to a constant value of '128' level. If the level of the video signal to be displayed on the main screen area is large, that is, when the main screen is bright, the difference between the blanking level of the left and right margins increases, so that the saturation phenomenon appears on the main screen even when the ABL circuit operates. On the contrary, when the level of the image signal to be displayed in the main screen area is small, that is, when the main screen is dark, the difference between the blanking level of the left and right margins becomes small, and thus the ABL circuit operates to convert the main picture level to the average picture level. APL) dropped, causing the main screen to be relatively darker than the blanking section.

Accordingly, an object of the present invention is to set the left and right margins generated when displaying an image signal having a small aspect ratio on a wide screen so as to solve the above-mentioned problems. It is possible to adjust the blanking level by setting the value corresponding to the component so that the level between the main screen and the blanking screen can be kept constant at all times.

Another object of the present invention is to provide an apparatus for implementing the above-described blanking level adjustment method.

The object of the present invention is to provide a method for adjusting the level of left and right blanking intervals generated when a video signal composed of a first aspect ratio is displayed on a water pipe having a structure having a second aspect ratio wider than the first aspect ratio. The method may include: integrating the video signal to obtain a value corresponding to a direct current (DC) level of the video signal; receiving the video signal and storing the video signal in units of scan lines; and storing the stored video signal and the obtained video signal. A value corresponding to the DC level of is selected according to the input control signal to correspond to the bottom surface appearance state of the water pipe is achieved by the step of applying to the water pipe.

Another object of the present invention is to provide a device for displaying an image signal having a first aspect ratio on a water pipe having a structure having a second aspect ratio wider than the first aspect ratio, and blanking a value corresponding to a DC level of an input image signal. A predetermined level corresponding to the present state of the water pipe by connecting contacts to a blanking level generator for outputting at a level, a first-in first-out memory for storing the video signal in scanning lines, and an output terminal of the first-in first-out memory and the blanking level generating unit. This is achieved by a switch which switches the corresponding contact in response to the signal.

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

2 is a block diagram showing an apparatus for displaying an image signal on a wide screen to which the present invention is applied. In FIG. 2, the same reference numerals are used for the same operations as those of the apparatus of FIG. 1, and the description of the same reference numerals will be omitted. The apparatus of FIG. 2 includes an integrator 21 in which a resistor R and a capacitor C are connected in parallel, and integrate an analog luminance signal Y inputted according to the time constant value. An A / D converter 23 is connected to the output terminal of the integrator 21. The switch unit 25 for selectively switching the output terminal of the line memory 12 and the A / D converter 23 according to a predetermined control signal CTL is connected.

In FIG. 2, the luminance signal Y in analog form input through the input terminal is input to the A / D converter 11 and the integrator 21, respectively. The A / D converter 11 converts the input analog luminance signal Y into a digital signal and supplies it to the line memory 12. The line memory 12 having a first-in first-out (FIFO) method receives digital luminance data in units of 8 bits from the A / D converter 11 and stores the data in units of scan lines. On the other hand, the integrator 21 integrates the analogue luminance signal (Y) input according to the time constant value determined by the resistor (R) and the capacitor (C) connected in parallel to adjust the value of the DC component. Obtain The A / D converter 23 converts the DC component value of the luminance signal Y obtained by the integrator 21 into digital data in units of 8 bits. The switch unit 25 has a first contact d connected to an output terminal of the line memory 12, a second contact e connected to an output terminal of the A / D converter 23, and a D / A converter 14. Switching contact (f) is connected to the input terminal of. The switch unit 25 is connected to a switching contact f to one of the two contacts d and e in accordance with a control signal CTL corresponding to the current state of the screen of the CRT 18 applied from a controller (not shown). That is, the switch unit 25 is provided with a switching contact f in response to the main screen area in which a video signal having a 4: 3 aspect ratio is displayed on the 16: 9 screen of the CRT 18 by the control signal CTL. Switched to one contact point d, the luminance data read from the line memory 12 is output to the D / A converter 14. The switch unit 25 switches and connects the switching contact f to the second contact e in response to the control signal CTL corresponding to the left and right blanking interval areas other than the main screen on the CRT 18. The digital data corresponding to the DC value of the luminance data converted by the converter 23 is output to the D / A converter 14. That is, the blanking section area is not fixed to the '128' level as in the first embodiment, and the blanking level is adjusted to a value changed by the DC level of the image signal to be displayed on the main screen area. The D / A converter 14 converts 8-bit digital data selectively applied from the switch section 25 into an analog signal. The gain adjusting section 15 of the ABL circuit 20 applies a signal to be displayed on the CRT 18 applied from the D / A converter 14 to the deflection and high voltage section 16, and compares it with a preset level to control accordingly. Receive the input of the signal. The gain adjusting unit 15 adjusts the gain according to the control signal input from the deflection and high voltage unit 16 and applies it to the CRT driving unit 17. The CRT driver 17 drives the CRT 18 according to the adjusted gain of the signal received from the gain adjuster 15 to display a signal having an aspect ratio of 4: 3 on the CRT 18 of 16: 9.

As described above, the blanking level adjusting method and the apparatus of the present invention adjust the 4: 3 screen left and right blanking section of the current wide screen TV to a value changed by the DC level of the main screen to be input. It is set to a value to eliminate the phenomenon affecting the main screen, and the left and right blanking does not affect the main screen, thereby maintaining a constant brightness at all times.

Claims (5)

An apparatus for displaying an image signal having a first aspect ratio on a water pipe having a structure having a second aspect ratio wider than the first aspect ratio, the apparatus comprising: generating a blanking level for outputting a value corresponding to a DC level of an input image signal as a blanking level part; A first-in, first-out memory for storing the video signal in units of scan lines; And a switch unit connected to an output terminal of the first-in first-out memory and the blanking level generator to switch the corresponding contact in response to a predetermined control signal corresponding to the appearance state of the water pipe. The apparatus of claim 1, wherein the blanking level generator comprises: an integrator configured to obtain a signal of a DC component by integrating an image signal to be displayed; And an A / D converter for converting a signal applied from the integrator into digital data. 3. The apparatus of claim 2, wherein the integrator is controlled by time constant values of a resistor and a capacitor connected in parallel. A method for adjusting the level of left and right blanking intervals generated when displaying an image signal composed of a first aspect ratio on a water pipe having a structure having a second aspect ratio wider than the first aspect ratio, the method comprising: receiving the image signal; Obtaining a value corresponding to a direct current (DC) level of an image signal by integrating; Receiving the image signal and storing the scan signal in units of scan lines; And selecting and applying a value corresponding to a DC level of the stored video signal and the obtained video signal to correspond to a screen display state of the water pipe according to an input control signal to the water pipe. How to adjust the level. 5. The control signal according to claim 4, wherein the control signal includes the stored video signal in a section in which the video signal of the first aspect ratio is to be displayed on the water pipe screen in the second aspect ratio, and the DC signal of the obtained video signal in the other left and right blanking sections. And a signal for controlling a value corresponding to the (DC) level to be selected.