JPH0486089A - Video signal converter - Google Patents

Abstract

PURPOSE:To obtain a high definition sequential scan signal from MUSE(Multiple Sub-nyquist sampling Encoding) by adding one system consisting of conversion memory, a time expansion circuit, a line sequential decode processing circuit, and a circuit for velocity conversion memory, etc., without using a scan converter. CONSTITUTION:Another one system of conversion memory is provided, and the same signal is written on it, and a signal converted to an on-going television signal and delayed by 1/2 line is written on the conversion memory on the other side. The same processing are applied to the signals read out of two conversion memory 13, 17 at two systems of signal processing circuits 20, 23, respectively, and two systems of on-going television signals can be obtained. The on-going television signal on one side out of them is used for appreciation by an on-going television receiver. The scan speed of both on-going television signals can be doubled by using the on-going television signal on the other side as the scanning line interpolation signal of the on-going television signal, and using the velocity conversion memory 28-33. In such a way, the sequential scan signal can be obtained, and it is reproduced on a clear vision receiver.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a video signal conversion device, and particularly to a video signal conversion device that converts a MUSE signal into a signal that can be received by a current television receiver.

(Prior Art) A MUSE system has been proposed that compresses the band of a high-definition television signal so that it can be transmitted by satellite broadcasting, and experimental broadcasting is being conducted.

MUSE is M(lNiplt 5ob-nyqIIs
+ szmpliB Encoding, N
This is a method developed by HK (Japan Broadcasting Corporation).

The MUSE method is described in various documents (for example, rNHK Technical Report, 1987, Vol. 32, No. 2, pages 18 to 53), rMUSE MUSE method, "Nikkei Electronics" published by Nikkei McGraw-Hill, 1987, etc. November 2nd issue p189-p212 r Transmission method for high-definition broadcasting using satellite broadcasting MUS El
etc.), detailed explanation will be omitted here.

In the MUSE method luminance signal (Y signal), on the transmitting side, the original signal of a high-definition television signal (luminance signal) having a band of approximately 22 MHI is first AD converted at a sampling frequency of 48.6 MH+, and then, The sampling frequency is set to 16.2 MHI by inter-field and inter-frame offset sampling, and the band is compressed. This signal is converted into an analog signal (MUSE signal) and transmitted.

Through this process, 8. The high frequency component above IMHr is 8.1
The baseband band of the MUSE signal, which is a transmission signal, is compressed to 8.1 MH+ by folding back to a low frequency band below MHx.

This is because the transmission radio wave band of the MUSE signal is 27MHI, and in order to perform high-quality transmission, it is necessary to compress the baseband band to about one-third or less of the transmission radio wave band. .

The MUSE receives and demodulates the band-compressed MUSE signal.
This is a USE decoder (receiver).

However, as is well known, the MUSE decoder requires a very large circuit and a special cathode ray tube with an aspect ratio of 16:9, and is very expensive.

Therefore, the MUSE signal of 1125 scanning lines is
Video signal converter (M
A US E/NT SC down converter) is being considered.

Furthermore, in contrast to current television receivers that perform interlaced scanning, monitors that perform sequential scanning, such as clear vision receivers, have appeared. Clear Vision receivers are designed to provide high image quality while maintaining compatibility with current television systems. Many of these monitors are equipped with a scan converter that converts an interlaced scanning signal into a progressive scanning signal, and can reproduce the output signal (interlaced scanning signal) from the video signal conversion device.

Currently, there are several types of conversion methods for video signal conversion devices, and typical ones include wide mode and zoom mode.

FIG. 5(A) and FIG. 5(B) are diagrams showing the principle of method conversion in wide mode and zoom mode, respectively.

In wide mode, a high-definition television signal with a screen aspect ratio of 16:9 is provided, and mask areas with no signals are provided at the top and bottom of the screen after conversion, and the aspect ratio of the part with the video signal is reduced to 16:9.
9, and converts it into a current television signal with an aspect ratio of 4.3. This method can effectively convert the entire image of a high-definition television signal, but since there are masked areas where there is no signal after conversion, the effective number of scanning lines of current television receivers cannot be fully utilized, and the screen will also become smaller.

Zoom mode cuts off both ends of the horizontally long screen of a high-definition television signal, making it 4:3
This mode converts to the aspect ratio of .

Although images can be expressed using the entire screen of current television receivers, information present on both the left and right ends of the original image is lost.

Both conversion methods have advantages and disadvantages, and many video signal conversion devices allow a wide mode and a zoom mode to be arbitrarily selected.

FIG. 4 is a block diagram showing a state in which a conventional scan converter is connected to a video signal conversion device previously filed by the present inventor.

In FIG. 4, the MUSE signal entering the input terminal 1 is supplied to the AD converter 3 via a low pass filter (LPF) 2 that passes frequencies below about 8.1 Mtlz. And 16.2MH! The clock signal is resampled and becomes a digital signal.

The output signal of the AD converter 3 is supplied to a de-emphasis circuit 4 where it undergoes de-emphasis processing, and is also supplied to a synchronization circuit 5. The synchronization circuit 5 generates pulses 112 necessary for processing signals in the high definition television area.
Outputs a reset pulse for the 5th system counter 6. 1125
The system counter 6 generates a reset pulse for the 525 system counter 7, which generates the pulses necessary for processing the current television range signal. The pulses output by the 1125 series counter 6 and the 525 series counter 7 both change according to the switching signal input from the input terminal 40. This switching signal is supplied to all circuits that perform different processing in wide mode and zoom mode.

The output signal of the de-emphasis circuit 4 is supplied to an intra-field interpolation circuit 8 and subjected to intra-field interpolation processing.

The pixels of the MUSE signal are in a state where the pixels of the current field and the pixels of one frame before are offset between frames, and the two are alternated every frame. Therefore, in the intra-field interpolation process, data at unsampled points (interpolation points) of pixels in the current field are created from data at sampling points (sample points) of surrounding pixels, and the data is interpolated. There is. Through interpolation, the sampling frequency is
The frequency is 32.4MHz.

The output of the intra-field interpolation circuit 8 is supplied to a selector 9.

The selector 9 receives the Y signal supplied from the 1125 series counter 6.
In accordance with the C control signal, an input signal in which a luminance signal and a color difference signal are time-division multiplexed is separated into a luminance signal and a color difference signal.

The luminance signal is supplied to a vertical filter 10 connected to the Y side of the selector 9, and the color difference signal is supplied to a line sequential processing circuit 11 connected to the C side of the selector 9.

The vertical filter 10 performs LPF processing on the luminance signal in the vertical direction. First, in wide mode, Fig. 6 (A)
As shown in FIG. 3, the current line signal supplied from the selector 9 and the signal two lines before the current line signal (signal delayed by two lines) are averaged. This averaged signal and the signal one line before the current line signal are averaged.

The signal added and averaged in two stages becomes the output signal of the vertical filter 10. In this way, the addition of three consecutive lines is
This is done with a weighting ratio of 1:2:1.

Next, in the zoom mode, as shown in FIG. 6(B),
The current line signal supplied from the selector 9, the signal one line before the current line signal, and the signal two lines before the current line signal are added and averaged in three stages. This averaged signal and the signal one line before the current line signal are averaged. The addition of these three consecutive lines is 14.3 for odd fields and 3:4 for even fields.
This is done with a weight of 1.

Through this processing, the upper part of the screen is moved upward during odd fields, and the lower area is lowered during even fields, and 1/4 of the
The center phase of the screen shifts by one line. By performing this center phase shift processing, the scanning lines of the interlaced high quality television signal can be thinned out to 1/2 and the scanning lines of the signal can be converted into the current interlaced scanning television signal.

The determination of whether the field is an even field or an odd field is made by a field identification signal supplied from the 1125 system counter 6.

The line sequential processing circuit 11 has the circuit configuration shown in FIG. 7, and receives R-Y in line sequential fashion.

Processing is performed so that one of the two color difference signals B-Y is output in two consecutive lines in the zoom mode and three lines in the wide mode. As a result, the color difference signals written into the conversion memory 13 are also line sequential. less than,
The operation of the line sequential processing circuit 11 will be explained.

In the wide mode, writing to the conversion memory 13 is performed every three lines. Therefore, for each line, R-Y and B-
The color difference signals in which Y and Y are exchanged are converted so that one of the color difference signals is continuous for three lines each. - For example, R-Y, B-Y.

The R-Y color difference signal of the continuous color difference signal remains unchanged, and instead of the B-Y color difference signal, a signal is obtained by adding and averaging the R-Y color difference signals before and after the B-Y color difference signal. By replacing , three consecutive lines of RY color difference signals are obtained.

In addition, when in zoom mode, the conversion memory 13
Therefore, processing is performed so that one of the color difference signals is continuously supplied to the conversion memory two lines at a time.

Whether to output the color difference signal as it is without addition and averaging or the color difference signal obtained by adding and averaging the signals of the previous and succeeding lines is determined by the sign of the line inversion signal given from the 1125 system counter 6. FIG. 8(A) shows the relationship between the line inversion signal and the signal supplied to the line sequential processing circuit 11.
, shown in (B).

The color difference signal output from the line sequential processing circuit 11 is time-division multiplexed again by the selector 12 onto the luminance signal output from the vertical filter 10.

The output signal of selector 12 is supplied to conversion memory 13. The conversion memory 13 converts high-definition television signals (MUS
The horizontal scanning speed, aspect ratio, and number of scanning lines of the current television signal are converted into the horizontal scanning speed, aspect ratio, and number of scanning lines of the current television signal.

The write operation of the conversion memory 13 is controlled by a write control signal from the 1125 series counter 6. In wide mode, the number of scanning lines is thinned out to 1/3, so 3
The control signal becomes Hi (high) for each line, and writing to the conversion memory 13 is performed. Furthermore, in the zoom mode, the number of scanning lines is thinned out to 1/2, so the write control signal becomes Hi every two lines.

By the way, in the zoom mode, in order to convert a high-definition television signal with a wide screen into a current television signal, both sides of the screen are cut off and converted. Therefore, the write control signal does not become H4 for the entire period of one line, but becomes Hi only in the portion displayed on the screen after conversion in both the color difference signal period and the luminance signal period. At this time, the pulse width of the write control signal is selected so that when the number of scanning lines is thinned out to 1/2 and the video is reproduced on the screen of a current television receiver, there is no distortion in the video.

FIG. 9(A) is a relationship diagram between the write control signal and the video signal in the wide mode, and FIG. 9(B) is in the zoom mode.

Reading from the conversion memory 13 is performed using the 525 series counter 7.
The readout control signal given from is performed during the Hi period.

In the wide mode, the readout control signal is Lo during the blanking period and the mask portions that appear above and below the screen after conversion, and becomes Hi during the period when the image is displayed on the screen. Further, in the zoom mode, the readout control signal becomes Hi during a period corresponding to the entire video signal excluding the blanking period of the current television signal.

Note that the frequency of the read clock is selected so that one horizontal scanning period is equal to that of the current television signal.

The signal read from the conversion memory 13 is sent to the selector 18
YC is separated again by The selector 18 is 525
It is controlled by the YC control signal given from the system counter 7.

A luminance signal is output from the Y side of the selector 18, and the DA
is supplied to converter 24. From the C side of the selector 14,
A color difference signal is output and supplied to the time expansion circuit 19.

The time expansion circuit 19 expands the color difference signal whose time has been compressed to 1/4. The expanded color difference signal is supplied to the line sequential decoding processing circuit 20.

The color difference signals sent line-sequentially by the line-sequential processing circuit 11 are decoded by the line-sequential decoding processing circuit 20 to become simultaneous signals.

FIG. 10 is an explanatory diagram of the operation of the line sequential decoding processing circuit 20.

When a line having a color difference signal of R-Y is supplied to the line sequential decoding processing circuit 20, the color difference signal of R-Y is output from the color difference signal of R-Y of the current line and the color difference signal of two lines before (2 lines). This is an average signal obtained by adding the delayed) RY color difference signal. The B-Y color difference signal output is the color difference signal of one line before the current line, which is the output signal of the one line delay line.

Moreover, when a line having a color difference signal of B-Y is supplied to the line sequential decoding processing circuit 20, conversely, a line having a color difference signal of B-Y
The color difference signal is created from between two lines: the signal of the current line and the signal of two lines before.

Discrimination between the R-Y and B-Y color difference signals is performed by line sequential pulses supplied from the 525 system counter 7.

R-Y, B output from the line sequential decoding processing circuit 20
-Y color difference signals and the luminance signal obtained from the selector 18 are supplied to DA converters 24, 25 and 26.

Then, a synchronizing signal is added by the NTSC encoder 27, and a composite video signal, which is a signal receivable by current television receivers, and an S terminal output signal separated into a Y signal and a C signal are obtained.

A composite video signal and a YC separate S terminal output signal are supplied from the NTSC encoder 27 to a scan converter 41 that converts an interlaced scanning signal into a progressive scanning signal. Furthermore, in the scan converter 41,
The brightness signal and the color difference signal may be supplied as digital signals from the selector 18 and the line sequential decoding processing circuit 20.

The scan converter 41 converts the supplied interlaced scanning signal into a sequential scanning signal by scanning line interpolation using motion adaptive processing, which uses a signal from one field before for a still image and a signal within the same field for a moving image. is converting.

The progressive scanning signal thus obtained can be reproduced on a monitor compatible with progressive scanning.

(Problem to be Solved by the Invention) However, scanning line interpolation using a conventional scan converter for obtaining sequential scanning signals has the disadvantage that it tends to produce unnatural images because it performs complicated processing such as motion detection. there were. Furthermore, scanning line interpolation using a scan converter has the problem of lowering vertical resolution when moving images.

The problem to be solved by this invention is to
The problem is what measures should be taken to create a video signal conversion device that can obtain high-quality sequential scanning signals from SE signals.

(Means for Solving the Problems) Therefore, in order to solve the above problems, the present invention receives and demodulates a MUSE signal obtained by band-compressing a high-definition television signal, and converts it into a signal that can be received by a current television receiver. In the video signal conversion device for converting, the first and second converters convert the horizontal scanning speed, aspect ratio, and number of scanning lines of the high-definition television signal into the horizontal scanning speed, aspect ratio, and number of scanning lines of the current television signal. a second conversion memory; and a control circuit for controlling write and read operations of the first and second conversion memories; processing the line-sequential color difference signal of the incoming high-definition television signal and supplying it to the first and second conversion memories in a line-sequential manner so that the signal is line-sequential even when written to the conversion memory of a processing circuit; a delay circuit that delays a signal written to the second conversion memory by a predetermined amount; and a delay circuit that converts the color difference signals read from the first and second conversion memories from line-sequential signals to simultaneous signals, respectively. First thing to do
and a second line sequential decoding processing circuit; luminance signals are supplied from the first and second conversion memories, and color difference signals are supplied from the first and second line sequential decoding processing circuits, respectively. The present invention provides a video signal conversion device characterized in that it is provided with a double speed conversion circuit that outputs a sequential scanning signal.

(Embodiment) The video signal conversion device of the present invention converts a MUSE signal into a current television signal, and also converts the MUSE signal into a progressive scanning signal that can be reproduced by a clear vision receiver or the like.

The MUSE signal originally has the number of scanning lines in one field.
1125, which is more than twice the current television signal of 525.
The book exists. Therefore, the present invention solves the above problems by performing double-speed conversion within the video signal converting device to generate sequential scanning signals, thereby eliminating the need for a scan converter.

In this invention, the video signal conversion device shown in FIG. 4 is provided with another conversion memory system, the same signal as that of the device shown in FIG. 4 is written into one conversion memory, and the same signal is written into the other conversion memory. is converted to the current television signal and is 1/2
Write a signal delayed by a line. The two signal processing circuits perform the same processing on the signals read from the two conversion memories to obtain two current television signals. One of the current television signals is
This signal is equivalent to the signal obtained from the video signal converter shown in FIG. 4, and is used for viewing on a current television receiver. The other current television signal is used as the scanning line interpolation signal for this current television signal. A progressively scanned signal is obtained by doubling the scan rate of both current television signals using a rate conversion memory.

The progressively scanned signal is played back on a clear vision receiver.

FIG. 1 is a block diagram showing an embodiment of a video signal conversion device of the present invention. Note that the same parts as in FIG. 4 are designated by the same reference numerals, and a detailed explanation of the parts will be omitted.

The output signal of the selector 12 is supplied to a conversion memory 13 , a one-line delay line 14 , and an adder 15 . The output signal of the one-line delay line 14 is supplied to a selector 16 and an adder 15. The adder 15 outputs a signal obtained by adding and averaging the output signal of the one-line delay line 14 and the output signal of the selector 12, and is supplied to the selector 16. Selector 1
The output signal of 6 is supplied to a conversion memory 17.

Conversion memory 13.17 converts high definition television signals (M
USE signal) to the horizontal scanning speed, aspect ratio, and number of scan lines of the current television signal.

In the wide mode, the selector 16 selects and outputs the signal supplied from the adder 15. Therefore, conversion memory 1
7 is supplied with an average signal of the output signal of the selector 12 and a signal delayed by one line. On the other hand, the output signal of the selector 12 is supplied to the conversion memory 13 as it is.

Further, in the zoom mode, the output signal of the one-line delay line 14 is selected by the selector 16 and supplied to the conversion memory 17. The output signal of the selector 12 is supplied as is to the conversion memory 13 as in the wide mode.

The conversion memories 13.17 are each supplied with write control signals S1 and S2 from the 1125 system counter 6, and during the period when the signals S1 and S2 are Hi, the conversion memories 13.17
A signal is written to

In the wide mode, as shown in FIG. 2(A), both write control signals S1 and S2 become Hi every three lines. However, the write control signal S2 is the write control signal S
1 line earlier than Hj. Further, the period H1 of the write control signals S1 and S2 is a period corresponding to the entire video signal of one line.

In the zoom mode, both write control signals S1 and S2 become Hl every two lines, as shown in FIG. 2(B). In zoom mode, both sides of the screen are cut off to convert a high-definition television signal with a wide screen to a current television signal. Therefore, the write control signal is not H4 for the entire period of the l line, but
In both the color difference signal period and the luminance signal period, only the portion displayed on the screen after conversion becomes Hj. At this time, the pulse width of the write control signal is such that when the number of scanning lines is thinned out to 1/2 and the video is played back on the screen of a current television receiver,
Selected so that there is no distortion in the image.

Reading from each conversion memory 13, 17 is performed while the read control signal given from the 525 system counter 7 is Hi.

In the wide mode, the readout control signal is Lo during the blanking period and the mask portions that appear above and below the screen after conversion, and becomes Hi during the period when the image is displayed on the screen. Further, in the zoom mode, the readout control signal becomes Hi during a period corresponding to the entire video signal excluding the blanking period of the current television signal.

Note that the frequency of the read clock is selected so that one horizontal scanning period is equal to that of the current television signal.

The signal read out from the conversion memory 13 is converted into a luminance signal of the current television signal by a selector 18, a time expansion circuit 19, a line sequential decoding processing circuit 20, and DA converters 24 to 26, similar to the device shown in FIG. and R-Y, B-Y
This is the meat color difference signal.

These signals, as well as the NTSC synchronization signal from the 525 system counter 7, are similar to the device shown in FIG.
A composite video signal, which is a signal that is supplied to the encoder 27 and can be received by current television receivers, and Y
The S terminal output signal is separated into a signal and a C signal.

On the other hand, the signal read out from the conversion memory 17 is processed by a selector 21, a time expansion circuit 22, and a line sequential decoding processing circuit 23 in the same manner as in the apparatus shown in FIG. and R-Y, B-
This becomes the Y flesh color difference signal.

In the wide mode, the conversion memory 17 is supplied with an average signal of the output signal of the selector 12 and a signal delayed by the one-line delay line 14. This signal is a signal delayed by 1/2 line with respect to the output signal of the selector 12 that is supplied to the conversion memory 13. moreover,
Write control signal S2 supplied to conversion memory 17
is one line ahead of the write control signal S1 supplied to the conversion memory 13.

Therefore, the signal written in the conversion memory 17 becomes a signal delayed by 1.5 lines in the high definition television area with respect to the signal written in the conversion memory 13. In wide mode, three lines of the high-definition television signal correspond to one line of the current television signal, so the signal written in the conversion memory 17 is different from the signal written in the conversion memory 13, There is a 1/2 line delay in terms of television signals.

Also, in zoom mode, the output signal of the selector 12 is set to 1.
A signal delayed by one line by the line delay line 14 is supplied to the conversion memory 17.

At this time, since the write control signals S1 and S2 have the same timing, the signal written in the conversion memory 17 is delayed by one line from the signal written in the conversion memory 13. In the zoom mode, two lines of the high-definition television signal correspond to one line of the current television signal, so at this time as well, the signal written in the conversion memory 17 is the same as the signal written in the conversion memory 13. This is a signal delayed by 1/2 line in terms of the current television signal.

Therefore, the luminance signal obtained from the selector 21 and the flesh color difference signal obtained from the line sequential decoding processing circuit 23 are higher than the luminance signal obtained from the selector 18 and the flesh color difference signal obtained from the line sequential decoding processing circuit 20, respectively. This is a signal delayed by 1/2 line.

That is, each signal obtained from the selector 21 and the line sequential decoding processing circuit 23 corresponds to a scanning line interpolation signal for each signal obtained from the selector 18 and the line sequential decoding processing circuit 20.

Therefore, the line sequential decoding processing circuit 20 and the selector 18
Each signal obtained from
Each is converted at double speed by Then, by alternately switching and outputting the output signals of the speed conversion memories 28 to 33 by the selectors 34 to 36, sequential scanning signals are obtained.

FIG. 3 is an explanatory diagram of progressive scan conversion for a luminance signal. First, the speed conversion memory 30.33 selects the selector 1.
8. Double speed conversion of each luminance signal output from 8.21 is performed. The luminance signal (interlaced scanning signal) output from the selector 21 is delayed by 1/2 line with respect to the luminance signal (interlaced scanning signal) output from the selector 18.

In other words, the luminance signal output from the selector 21 is 1/1/1 in time with respect to the luminance signal output from the selector 18.
This is a luminance signal having information from two lines before.

Therefore, the amount of delay caused by the speed conversion memory 30 to the luminance signal from the selector 18 is smaller than the amount of delay caused by the speed conversion memory 33 to the brightness signal from the selector 21.
Add 1/2 line. The respective output brightness signals of the speed conversion memories 30 and 33 are output alternately by the selector 36, and sequentially scanned brightness signals are obtained. Similar processing is performed on color difference signals as well.

The progressive scanning R-YlB-Y color difference signals and luminance signals obtained in this way are converted into analog signals by the DA converters 37 to 39, and then together with the progressive scanning synchronization signal output from the 525 system counter 7. The data is supplied to a monitor compatible with progressive scanning and played back.

In this way, in this embodiment, the sequential scanning signal can be converted from the MUSE signal by simply adding one system of circuits such as a conversion memory, a time expansion circuit, a line sequential decoding processing circuit, a speed conversion memory, etc., without using a scan converter. can get. Therefore, this video signal conversion device performs scanning line interpolation using simple processing, without performing scanning line interpolation using complicated processing such as motion detection as in a scan converter.
Since the E signal can be converted into a progressive scanning signal, a high quality progressive scanning signal can be obtained. Even when converting video, there is almost no deterioration in vertical resolution.

Of course, this video signal converter can convert the MUSE signal into a current television signal which is an interlaced scanning signal.

(Effects of the Invention) As described above, the video signal conversion device according to the present invention can perform high-quality sequential scanning of MUSE signals by adding a minimum number of circuits and without performing scanning line interpolation by a scan converter, which is often harmful. It can be converted into a signal. Furthermore, this video signal converter can convert the MUSE signal into a current television signal which is an interlaced scanning signal.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a relationship diagram between a video signal supplied to a conversion memory and a write control signal, FIG. 3 is a diagram explaining the operation of double speed conversion, and FIG. 4 is a block diagram showing a state in which a conventional scan converter is connected to the video signal conversion device previously filed by the present inventor; FIG. 5 is a principle diagram of signal conversion; FIG. 7 is an explanatory diagram of the operation of the line sequential processing circuit 11, FIG. 8 is a relationship diagram between the color difference signal and line inversion signal input to the line sequential processing circuit 11, and FIG. 9 is a video signal supplied to the conversion memory 13. Relationship diagram between and write control signal, 10th
The figure is an explanatory diagram of the operation of the line sequential decoding processing circuit 20. 1... Input terminal, 2... LPF, 3... AD converter, 4... De-emphasis circuit, 5... Synchronous circuit, 6... 1125 series counter, 7... 525 series Counter, 8... Field internal circuit, 9.12, 16, 18, 21. 34-36... Selector, 10... Vertical filter, 11... Line sequential processing circuit,
13.17... Conversion memory, 14... 1 line delay line, 15... Adder, 19.22... Time expansion circuit, 20.23... Line sequential decoding processing circuit, 24-2
6.37-39...DA converter, 27...NTSC
Encoder, 28-33... Speed conversion memory. Patent Applicant: Japan Victor Co., Ltd. Representative Kirigami
Takubu Diagram High Definition Television @ Han' Current issue of the TV series Kyo I War I-'7-D Diagram (A) Noom Mode Diagram (B) Wai)' Mode. Diagram (A) Sum 7-F Diagram (B) Line reversal Ai No. 1 o'clock Wide mode 1 o'clock Diagram (A) Sum 7-H o'clock

Claims (1)

[Scope of Claims] A video signal conversion device that receives a MUSE signal obtained by band-compressing a high-definition television signal, demodulates it, and converts it into a signal that can be received by a current television receiver, comprising: first and second conversion memories for converting the scan rate, aspect ratio, and number of scan lines into the horizontal scan rate, aspect ratio, and number of scan lines of a current television signal; and the first and second conversion memories. a control circuit for controlling write and read operations of the incoming high-definition television signal, such that the line-sequential color difference signal of the incoming high-definition television signal remains a line-sequential signal even when written to the first and second conversion memories; , a line-sequential processing circuit that processes the line-sequential color difference signal of the incoming high-definition television signal and supplies it to the first and second conversion memories; a delay circuit for quantitatively delaying; and a first circuit for converting the color difference signals read from the first and second conversion memories from line sequential signals to simultaneous signals, respectively.
and a second line sequential decoding processing circuit; luminance signals are supplied from the first and second conversion memories, and color difference signals are supplied from the first and second line sequential decoding processing circuits, respectively. , and a double-speed conversion circuit that outputs a sequential scanning signal.