JPH03127575A - Video signal processing unit - Google Patents

Abstract

PURPOSE:To suppress flicker at a border between a portion of a video display and a portion other than the video display on a CRT screen by providing a circuit applying color processing at a blanking period for each other field. CONSTITUTION:A coloring processing circuit 15 inserting a coloring data to other period than a vertical scanning period (for background processing period) being a blanking period for each other field to a Y signal and both color difference signals (R-Y), (B-Y) subject to blanking insertion with a blanking insertion circuit 11 is provided between the blanking insertion circuit 11 and a D/A converter 12. The coloring processing circuit 15 replaces a blanking data inserted by the blanking insertion circuit 11 into a prescribed coloring data inputted from a color data output section (not shown) to an input terminal 16 for each other field to apply coloring processing to the background and switches a field for coloring processing for each prescribed number of frames with a field identification signal inputted to an input terminal 17 from a field identification signal output section. Thus, flicker is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a video signal processing device used in a television format converter or the like that converts a high-definition signal band-compressed by the MUSE method into an NTSC signal.

[Conventional technology]

FIG. 3 is a block diagram of a conventional video signal processing device for converting television formats. MU by converter 2
After the SE signal is converted into a digital signal, it is manually input to the de-emphasis circuit 3 and the first PLL circuit 4.

Then, the first PLL circuit 4 forms a sampling clock based on the phase information in the MUSE signal.
is supplied to the D converter 2, and the MUS
The E signal is sampled at the correct phase based on the sampling clock from the first PLL circuit 4.

On the other hand, the sampling clock of the first P'LL circuit 4 is also supplied to the second PLL circuit 5, and the second PLL circuit 5 forms a sampling clock based on the time axis of the NTSC signal.

By the way, the MUSE signal is a signal with 1125 scanning lines, a field frequency of 60 Hz, and an interlace ratio of 2:1.In order to transmit it using one channel of broadcasting satellite, the baseband band is set to 8 MHz by the MUSE method.
This compression is performed by so-called offset sampling, and field and frame offset sampling is applied to the still image part.
Line offset subsampling is applied to the video part, and the two color difference signals (R-Y) and (B-Y) are time-compressed multiplexed during the horizontal blanking period of the luminance signal (hereinafter referred to as the Y signal). .

Then, the frequency characteristics of the A/D converted MUSE signal are corrected by the de-emphasis circuit 3, and the corrected signal is input to the scanning line conversion circuit 6, which is the first scanning line conversion means. 112 per frame due to
Seventy-five of the five scanning lines are discarded and converted into 1050 lines, and the conversion circuit 6 outputs a signal with 1050 scanning lines, a field frequency of 60 Hz, and an interlace ratio of 2:1.

At this time, for example, a memory is used, and the first PLL circuit 4
The write speed based on the clock supplied by M
The human input signal is written into the memory at a speed determined from the time axis of the USE signal, and at the same time, the readout speed based on the clock supplied from the second PLL circuit 5, that is, the NTS
The signal is read from the memory at the speed obtained from the inter-axis of the C signal.

Next, the signal subjected to scanning line conversion by the scanning line conversion circuit 6 is input to the Y signal processing circuit 7 and the color difference signal processing ri-il path 8, and this Y signal processing amount 'jf57 is integrated into an IC, and the Y signal The function of the Y signal interpolation processing means is performed without performing intrafield interpolation processing corresponding to line offset subsampling, and the inclace conversion means for Y signal converts the Y signal subjected to the intrafield interpolation processing into an interlaced signal. The Y signal processing circuit 7 restores the band-compressed Y signal to its original band, and processes the ink with 525 scanning lines per frame, 60 Hz field frequency, and 2:L ink crease ratio. A race signal is output.

On the other hand, the color difference signal processing circuit 8 is also integrated circuit, and time compression multiplexing (R-Y) is performed during the blanking period of the Y signal.
Functions as a time axis extension means to extend the time axis of the two color difference signals (B-Y), and a function as a color difference signal internal compression processing means to perform in-field internal volatilization processing on the time axis expanded flesh color difference signal. and a function as a color difference signal interlace conversion means for converting the flesh color difference signal subjected to intra-field interpolation processing into an ink race signal, and the color difference signal processing circuit 8 compresses (R-Y) , (B-Y) are returned to their original bands, and an inclace signal with 525 scanning lines per frame, a field frequency of 6 QHz, and an interlace ratio of 2:1 is output.

Next, the Y signal from the image processing circuit 7.8 and (RY)
, (B-Y) are input to a scanning line conversion filter circuit 9 consisting of a vertical digital filter, which is a second scanning line conversion means, and the filter circuit 9 converts 525 scanning lines per frame. Two out of three scanning lines are converted, resulting in 525 scanning lines per frame, as shown in Figure 4 (a).
), the aspect ratio of high-definition (1,6:
9), the number of scanning lines per frame is 350, and a signal with a field frequency of 60H2 is input to the speed conversion memory circuit 10 as a compression means, and reading is performed at a speed faster than the writing speed. As a result, the scanning line-converted Y signal and flesh color difference signal are time-compressed in the vertical direction, and the scanning line gap is compressed as shown in FIG. 4 (1>).

Furthermore, by switching the changeover switch built in the blanking insertion circuit 11, the speed conversion memory circuit 10 and the output of the blanking data output section are switched at a predetermined timing, and the blanking insertion circuit 11 allows the output of the blanking data output section to be switched in the vertical direction. Blanking corresponding to 175 scanning lines corresponding to one frame is added to the time-compressed output of the speed conversion memory circuit 10, and the shaded area in FIG. Corresponds to the ranking part, and the number of effective scanning lines is 35 out of 525 scanning lines per frame.
The Y signal and (R-Y) with a field frequency of 60 Hz make the number of scanning lines H.

The color difference signal (B-Y) is inputted to the D/A converter 12,
After being converted into an analog signal by the D/A converter 12, primary color signals of RlG and B are formed by the inverse 7-trix circuit 13 and supplied to the CRT 14, and an image is displayed in the center of both sides of the CRT 14. The upper part and -1 part of the screen are displayed black with no image.

At this time, the inverse matrix circuit 13 is similar to that in the current NTSC television receiver.

(Problems to be Solved by the Invention) As explained above, in the conventional television format conversion device, images are displayed only in the center part of the screen of the CRT 14, so only the center part of the CRT 4 where the image is displayed. There was a problem of deterioration.

Therefore, in order to prevent such local deterioration of the CRT 14, the blanking portion indicated by diagonal lines in FIG. It is conceivable to color both the second field, but in this case there is a problem that flicker occurs at the boundary with the image display portion of the CRT 14, resulting in poor visibility.

This invention was made to solve the above-mentioned problems, and aims to average out the deterioration of the CRT and suppress flicker at the boundary between the non-image area of the CRT screen and the image display area. purpose.

[Means to solve the problem]

The video signal processing device according to the present invention includes a scanning line converting means for converting a predetermined number of scanning lines of a video signal into a number of 7L scanning lines according to an aspect ratio, and a scanning line converting device that converts a predetermined number of scanning lines of a video signal into a number of 7L scanning lines according to an aspect ratio, and a scanning line converting unit f. a compression means for time-compressing the video signal in the vertical jj direction to compress the scanning line gap; and a blanking matchmaker means for matching blanking to a predetermined number of scanning lines to the output of the compression means. The video signal processing device is characterized in that a coloring processing circuit is provided for coloring the blanking portion in every other field.

[Effect]

In this invention, since the coloring processing circuit colors the blanking part every other field, C
The deterioration of the RT is not concentrated in the center of the screen where the image is affected as in the past, and the deterioration of the CRT is evened out, and the deterioration of the CRT is
Flicker at the boundary between the portion of the RTiiffI surface other than the video and the video display section is suppressed.

〔Example〕

FIG. 1 is a block diagram showing an embodiment of a video signal processing device of the present invention.

Referring to FIG. 1, the difference from FIG. 3 is that for the Y signal and the (RY) and (B-Y) flesh color difference signals for which blanking has been performed by the blanking insertion circuit 11, A coloring processing circuit 15 that performs coloring by inserting coloring data into a period other than the vertical scanning period (hereinafter referred to as background) which is a blanking portion every other field is connected to a blanking insertion circuit 11 and a D/A converter 12. This was established between the two parties.

Then, the coloring processing circuit 15 replaces the blanking data inserted by the blanking insertion circuit 11 with predetermined coloring data input manually from a coloring data output section (not shown) to the human power terminal 16 every other field, and backs up the blanking data inserted by the blanking insertion circuit 11. The ground is colored, and the field to be colored is switched every predetermined number of frames by a field identification signal inputted to the manual end T-17 from a field identification signal output section (not shown).

At this time, based on the operation timing of the blanking insertion circuit 11 and the field identification signal, the coloring processing circuit 15 alternately outputs colored data and blanking data for each field, and outputs these data for each predetermined frame. The order will be reversed.

Therefore, if we take the Y signal whose blanking has been intermediated by the blanking insertion circuit 11 as an example, as shown in FIG. ), the field in which coloring data is injected into the background by the coloring processing circuit 15 is repeated over and over again, and the order of these two fields is reversed every predetermined number of frames based on a field switching signal. For example, if inversion is performed every 300 frames, the colored fields will be switched approximately every 10 seconds.

Note that the coloring processing circuit 15 may be provided after the D/A converter 12 or after the inverse matrix circuit 13, and receives the Y signal converted into an analog signal.

Background coloring processing may be performed on the (RY) and (B-Y) color difference signals and the R, G, and B primary color signals.

Further, the coloring processing circuit 15 may be provided before the blanking insertion circuit 11, and the present invention can be implemented in the same manner.

Further, in the above embodiment, the application is applied to the case of converting the MUSE signal to the NTSC signal, but the invention is not limited to this. The number of scanning lines of the video signal is converted according to the asbestos ratio, and the scanning line gap is compressed. Needless to say, it can be widely applied in cases where

〔Effect of the invention〕

As described above, according to the present invention, since the blanking part is colored every other field by the coloring processing circuit, deterioration of the CRT is likely to be concentrated in the center of the screen where the image is displayed. It is possible to prevent IL, and it is possible to average out the deterioration of the CRT, and it is possible to suppress flicker at the boundary between the non-image part of the CR7 screen and the image display section, and to prevent local deterioration of the CRT and improve visibility. Striving for improvement becomes ijj ability.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the video signal processing device of the present invention, FIGS. 2(a) and (b) are signal waveform diagrams for explaining the operation of FIG. 1, and FIG. 3 is a general video signal A block diagram of the processing device, and FIGS. 4(a) and 4(b) are explanatory diagrams of the operation of FIG. 3. In the figure, 9 is a scanning line conversion filter circuit, 10 is a speed conversion memory circuit, and 11 is a blanking insertion 5 is a coloring circuit. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] (1) A scanning line conversion means for converting a predetermined number of scanning lines of a video signal into a number of scanning lines according to an aspect ratio, and a method for vertically time-compressing the video signal subjected to scanning line conversion by the scanning line conversion means. A video signal processing device comprising compression means for compressing scanning line gaps, and blanking insertion means for inserting blanking corresponding to a predetermined number of scanning lines into the output of the compression means, wherein the blanking is inserted every other field. A video signal processing device characterized in that a coloring processing circuit for coloring the portion is provided.