JPH06261298A - Video signal converter - Google Patents

Abstract

PURPOSE:To reduce the vertical size without reducing the picture resolution and without generating a flicker at the time of converting a picture from a computer system into a signal for TV receiver display. CONSTITUTION:The primary color signal of the line sequence scanning from an input section 1 is inputted to a luminance/color difference signal separation section 2, then it is separated into a luminance signal and a color difference signal. An A/D conversion section 3 converts it into a digital signal. A scanning line compression section 7 performs compression processing the number of scanning lines. Then, a flickerless processing section 8 performs the flickerless processing. A scanning conversion section 9 converts it into an interlaced scanning signal to generate into the required television signal through an encoder 10. A D/A conversion section 11 converts it into an analog signal, then an output section 12 inputs it to a TV receiver. A clock signal generation section 5 generates into a clock signal being an integer multiple of the frequency of a horizontal synchronizing signal from a synchronizing signal input section 4. The scanning line compression section is controlled through a control section 6. The clock signal being the 4-fold color sub carrier wave frequency of the TV signal is generated and the scanning conversion section is controlled through the control section.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal converter, and more particularly to a video signal converter for converting a video signal from a computer or the like into a signal for displaying on a television receiver (hereinafter referred to as a TV receiver).

[0002]

2. Description of the Related Art It is premised that the size of an image by a computer device is set to a size smaller than the effective screen size of a monitor and the entire image including the peripheral portion is displayed on the screen of the monitor. By the way, most monitors for computer devices have a relatively small screen size because a monitor with a large screen is expensive, and are not suitable for use by a large number of people at a time. Further, even if an image created by a computer device is recorded on a magnetic recording tape or a magneto-optical recording disk, and only the recording medium is sent to another place to be displayed on the screen, the display will not be displayed unless the destination has a monitor for the computer device. It is possible.

[0003]

In the above-mentioned case, if the computer image can be displayed on a normal TV receiver, everybody has a TV receiver, and when viewed by a large number of people, a large screen size is required. The above problem can be solved because the above problem can be used. For this purpose, the video signal of the line-sequential scanning from the computer device is converted into the video signal of the interlaced scanning which is the television signal of the standard system. However, if the line-sequential scanning is simply converted into the interlaced scanning. The problem that flicker (flickering of the screen) occurs and the screen becomes difficult to see, or, as described above, the computer image must display the entire image including the peripheral part on the screen, but with the TV receiver, Since the peripheral part of the captured image is overscanned (scans a range wider than the effective screen size), it is necessary to reduce the image size. If the vertical size is reduced by thinning out horizontal scanning lines, it is decimated. There is a problem that the image information of the scanning line portion is missing. In view of such a point, the present invention converts a line-sequential scanning video signal from a computer device into an interlaced scanning television signal with a reduced image size without causing performance deterioration due to loss of image information or the like. To provide things.

[0004]

In order to solve the above-mentioned problems, the present invention separates an input unit for inputting a video signal and a synchronizing signal from a computer device and the like into a luminance signal and a color difference signal from the input video signal. An A / D conversion unit for converting the generated signal into a digital signal, a clock signal generation unit for generating a required clock signal with the synchronizing signal from the input unit as a reference, and the clock signal generation unit based on the signal from the clock signal generation unit. A scanning line compression unit that compresses the number of scanning lines of the signal from the A / D conversion unit, a flickerless processing unit that performs flickerless processing on the signal from the scanning line compression unit, and a signal from the flickerless processing unit for interlaced scanning. A scan conversion unit for converting into a signal,
An encoder for generating a desired television signal based on a signal from the scan conversion unit and a D / A conversion unit for converting the signal from the encoder into an analog signal.
The present invention provides a video signal conversion device in which a signal from the A conversion unit is input to a TV receiver.

[0005]

With the above construction, in the video signal converting apparatus according to the present invention, the video signal from the computer or the like is separated into the luminance signal and the color difference signal, and after being converted into the digital signal, the vertical size of the image is changed. To shrink,
For example, the number of scanning lines is compressed by converting 6 horizontal scanning lines into 5 horizontal scanning lines, and flickerless processing is performed to prevent flicker from occurring during conversion into an interlaced scanning signal. After that, the signal is converted into an interlace scanning signal, generated into a luminance signal and a chromaticity signal, or a composite video signal, converted into an analog signal, and input to a TV receiver.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a video signal conversion device according to the present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram of essential parts of an embodiment of a video signal conversion device according to the present invention. In the figure, reference numeral 1 is an input unit for inputting video signals of three primary colors of red, green and blue from a computer device or the like. Two
Is a luminance / color-difference signal separation unit that separates the video signals of the three primary colors from the input unit 1 into a luminance signal and a color-difference signal via a matrix circuit or the like. An A / D conversion unit 3 converts the brightness signal and the color difference signal from the brightness / color difference signal separation unit 2 into digital signals. Reference numeral 4 denotes a sync signal input section for inputting the sync signal output from the computer device at the same time as the video signal. Reference numeral 5 denotes a clock signal generation unit, which is a clock signal used as a reference for the operation of the scanning line compression unit 7 described later with reference to the horizontal synchronization signal from the synchronization signal input unit 4, and a reference for the operation of the scan conversion unit 9 described later. To generate a clock signal for each. A control unit 6 controls a scanning line compression unit 7, a flickerless processing unit 8 or a scanning conversion unit 9 which will be described later based on the clock signal from the clock signal generation unit 5.

In the scanning line compression unit 7, the A / D conversion unit 3
On the basis of the above data, processing such as superposing a part of the data of the previous line with a part of the data of the next line to form a new data of one line is performed, and the number of horizontal scanning lines of one frame is changed to, for example, Compress to 5/6. Further, the flickerless processing unit 8 performs processing such as adding a part of the data of the previous line from the scanning line compression unit 7 to the next line so that flicker does not occur when converted into an interlaced scanning signal. To do.
The scan conversion unit 9 converts the signal of the frame by the line-sequential scanning from the flickerless processing unit 8 into the signal of the odd-order field and the even-order field, that is, generates the interlaced-scan signal. An encoder 10 generates a signal from the scan conversion unit 9 into a luminance signal and a chromaticity signal, or performs matrix processing of these signals to generate a composite video signal. Reference numeral 11 is a D / A converter which converts a digital signal from the encoder 10 into an analog signal. 12 is an output unit, D /
The signal from the A converter 11 is output. The A / D conversion unit 3, the scanning line compression unit 7, the flickerless processing unit 8 and the scanning conversion unit 9 separately process the luminance signal and the color difference signal from the luminance / color difference signal separation unit 2 in the same manner. I do.

Next, the operation of the video signal converter according to the present invention will be described. A video signal of a primary color from a computer device or the like is input through the input unit 1, and a luminance / color difference signal separation unit 2
Thus, for example, it is separated into a luminance signal and a color difference signal using a matrix circuit or the like. Then, it is input to the A / D conversion unit 3, the luminance signal and the color difference signal are respectively converted into digital signals, and the digital signals are input to the scanning line compression unit 7. on the other hand,
The sync signal input section 4 receives the sync signal output simultaneously with the primary color video signal from the computer. This synchronization signal is input to the clock signal generator 5 and, for example,
A clock signal having an integral multiple of the frequency of the horizontal synchronizing signal is generated, and the scanning line compression unit 7 is controlled via the control unit 6.

In the scanning line compressing section 7, the video signal from the input section 1 has, for example, a horizontal scanning frequency of about 31 KHz (kilohertz) with reference to the signal from the clock signal generating section 5, and one frame horizontally. When the number of scanning lines is 480, the compression processing is performed so that the image information of these 480 scanning lines is displayed by 400 horizontal scanning lines, that is, 400 ÷
480 = 5/6 compression, for example, input signal 1
Each line is recorded in the line memory and is read out when the signal of the next line is input, and as shown in the example of FIG. 1 line, (2nd line x 4/5 + 3rd line x 2 /
5) × 5/6 ··· New second line, (3rd line × 3/5)
+ 4th line x 3/5) x 5/6 ... new 3rd line,
(4th line x 2/5 + 5th line x 4/5) x 5/6
..New 4th line, (5th line * 1/5 + 6th line * 5/5) * 5/6 Repeat. As a result, the image information by 6 scanning lines is displayed by 5 scanning lines, and the vertical size of the image displayed on the TV receiver is 5/6 that in the case where the scanning line compression processing is not performed. Compressed. Further, unlike the case where the number of scanning lines is compressed by thinning out horizontal scanning lines, loss of image information due to thinned scanning lines does not occur.

When the horizontal scanning frequency of the video signal from the input unit 1 is about 24 KHz and the number of horizontal scanning lines is 400, the signal with the horizontal scanning frequency of 31 KHz is compressed. The same number as the scanning line compression processing unit 7
Is not processed. When the horizontal scanning frequency of the video signal from the input unit 1 is about 15.7KHz, the number of horizontal scanning lines is 4
Even if it is 80 lines, this signal overscans the monitor screen even when it is displayed on the monitor dedicated to the computer device, and since it is an image created on the premise of this, the compression processing of the number of scanning lines is performed. Does not.

The signal from the scanning line compression unit 7 is input to a flickerless processing unit 8 and is subjected to processing for preventing flicker when it is converted into an interlaced scanning signal. This is because a computer apparatus generates a video signal by line-sequential scanning, and thus different information may be displayed for each scanning line. If this signal is directly converted to an interlaced scanning signal,
Flickering in the human eye when there is information (high brightness) on one side and no information (low brightness) on the other side of adjacent scan lines of the odd-order field and even-order field on the screen of the TV receiver. In some cases, flickerless processing is performed to avoid this. In this process, for example, the input signal of each line is recorded in the line memory, and when the signal of the line to be processed is input, the data of the previous line read from the line memory is added at an appropriate ratio. However, if the amount of addition is too large, the resolution of the field image deteriorates, so an appropriate amount is added so that flicker does not occur and the resolution does not deteriorate.

The signal processed by the flickerless processing unit 8 is input to the scan conversion unit 9. The scan conversion unit 9 records the input frame-sequential scanning frame signal into the required recording area with the data of all odd-numbered lines of the first frame,
At the end of recording, the data is read, and before and after this reading, the data of all even-numbered lines of the second frame is recorded in a recording area different from the recording area, and the data is read at the end of recording. Repeat the recording / reading process for the signals of the third and subsequent frames in the same manner as above,
As a result, an interlaced scanning signal is generated. The timing of the reading is based on the signal from the clock signal generation unit 5, and the clock signal generation unit 5 outputs, for example, a clock signal four times the frequency of the color subcarrier signal of the television signal. The signal read from the field memory is transferred to the encoder 10 to generate a luminance signal and a chromaticity signal or a composite video signal. Then, this data is converted into an analog signal via the D / A converter 11, and is input from the output unit 12 to the TV receiver. By setting the clock frequency of the clock signal generator 5, the horizontal size of the image displayed on the TV receiver has a reduction ratio corresponding to the vertical size.

In the above description, the video signal of the primary color is separated into the luminance signal and the color difference signal and processed. By separating the luminance signal and the color difference signal in this way,
Since the color difference signal has a narrow frequency band, the amount of data to be processed is small, and a data processing element or the like having a smaller capacity can be used as compared with the case of processing the primary color signal as it is.

[0014]

As described above, according to the video signal converter of the present invention, when an image from a computer is displayed on a normal TV receiver, it is displayed on a monitor for the computer. As described above, although the vertical size is compressed, the image resolution in the vertical direction is hardly reduced, and even if the image is converted into the interlaced scanning signal, almost no flicker is felt in the image. Further, it becomes possible to record and send an image on a magnetic recording tape or the like to a place where there is no monitor for a computer device, and display the same image as a dedicated monitor using a TV receiver. Since the video signal of the primary color is separated into the luminance signal and the color difference signal for processing, there is an advantage that the data processing element used in each circuit may have a relatively small capacity.

[Brief description of drawings]

FIG. 1 is a block diagram of a main part of an embodiment of a video signal conversion device according to the present invention.

FIG. 2 is a diagram illustrating scanning line compression processing of the video signal conversion device according to the present invention.

[Explanation of symbols]

 1 Input Section 2 Luminance / Color Difference Signal Separation Section 3 A / D Conversion Section 4 Sync Signal Input Section 5 Clock Signal Generation Section 6 Control Section 7 Scan Line Compression Section 8 Flickerless Processing Section 9 Scan Conversion Section 10 Encoder 11 D / A Conversion Part 12 Output part

Claims (1)

[Claims] 1. An input unit for inputting a video signal and a synchronizing signal from a computer device and the like, and an A / D conversion unit for converting a signal separated from the input video signal into a luminance signal and a color difference signal into a digital signal. , A clock signal generation unit that generates a required clock signal with reference to a synchronization signal from the input unit, and compresses the number of scanning lines of the signal from the A / D conversion unit based on the signal from the clock signal generation unit. A scanning line compression unit, a flickerless processing unit that performs flickerless processing on a signal from the scanning line compression unit, a scanning conversion unit that converts a signal from the flickerless processing unit into an interlaced scanning signal, and a signal from the scanning conversion unit And a D / A conversion unit for converting a signal from the encoder into an analog signal, the signal being generated from the D / A conversion unit. Video signal conversion device adapted to input the signal to a television receiver.