JPH01264480A - Reduction device on television receiver screen - Google Patents

Abstract

PURPOSE:To display a picture at a prescribed size by storing video signals in a video RAM after thinning the number of picture data and outputting the content of the RAM at the timing of a prescribed displaying area at every content. CONSTITUTION:Video signals obtained by a television receiver are subjected to thinning at an RGB converter circuit 1 through external operations and separation of horizontal and vertical signals from each other at a synchronizing separator circuit 2. Then digital picture data are stored in VRAM 4 through an A/D converter circuit 3. At this time, the sampling clock of the frequency corresponding to the external operations is transmitted to the circuit 3 from a variable transmitter 5. The picture data sampled at the timing of the clock are converted into analog signals by a D/A converter 6. A carriage generator circuit 7 generates carrier pulses of a prescribed width based on the horizontal and vertical signals separated at the circuit 2. Then a mixing circuit 8 outputs the R, G, and B signals of the picture data synchronously to the horizontal and vertical signals and carrier pulses. Thus a picture of a prescribed size can be displayed in corresponding to the external operations.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is used in digital television receivers, VTR devices, and other digitizable personal computers, etc., and displays images obtained by these devices in reduced size. The present invention relates to a reduction device that can arbitrarily reduce the display area of a television screen, and more specifically to a reduction device that can arbitrarily reduce the display area of a television screen.

[Conventional example] In recent years, with the spread of digital television receivers and VTR devices, digital image processing technology has developed, and it is now possible to receive images processed by a personal computer or input television images in real time. TV (television screen) inTV
There is a way. This is a small TV on one TV screen.
By inserting a screen (child screen), the TV screen can be used in multiple ways.

In this way, by performing various displays on the television screen, the use of the screen can be expanded.

[Problems to be Solved by the Invention] By the way, in the case of the TVinTV method described above, the size of the sub-screen to be inserted into the TV screen is fixed in advance, so the TV screen is made smaller and the sub-screen is It was not possible to make one larger or smaller. In other words, it is not possible to freely change the size of the TV screen and the sub-screen, which is inconvenient when, for example, you want to enlarge the image on the sub-screen. Met.

In this way, the size of the child screen is fixed in advance by the screen control unit, which is a drawback when using more unusual screens.

This invention was made in view of the above problems, and its purpose is to freely change the size of the television screen and to reduce the image to that size.

To provide a reduction device for a television that can further expand the use of the television screen.

[Means for Solving the Problems] In order to achieve the above object, a reduction device of the present invention is a reduction device that reduces an image displayed on a television screen, and is a reduction device that reduces an image displayed on a television screen. An HGB converter circuit that obtains R, G, and B signals such as images from the video signal, a sync separation circuit that separates horizontal and vertical sync signals from the video signal, and an A/B converter circuit that converts the R9G and B signals into digital image data. A D conversion circuit, a video RAM that stores this image data, a D/A converter circuit that converts the image data stored in this video RAM into analog, and converts the R, G, and B signals of the above image etc. into digital. A variable oscillator that generates a sampling pulse with a timing of G
, a mixing circuit that outputs the B signal in synchronization with the horizontal/vertical synchronizing signal and the carrier pulse, and the frequency of the sampling clock and the width of the carrier pulse are varied according to an external instruction, and the frequency of the sampling clock and the width of the carrier pulse are varied according to the input video signal. The number of image data is thinned out to a predetermined value and stored in the video RAM, and this image data is converted into analog R, G, B
The signal is converted into a signal and output at a predetermined timing.

Further, in the reduction device of the present invention, the frequency of the sampling clock is lower than the horizontal synchronizing signal, the carrier pulse is a horizontal carrier pulse generated in synchronization with the horizontal synchronizing signal, and the frequency of the sampling clock is lower than the horizontal synchronizing signal, and the carrier pulse is a horizontal carrier pulse generated in synchronization with the horizontal synchronizing signal. It is designed to output R, G, and B signals of images, etc. to be displayed after being reduced in the horizontal direction.

Furthermore, in the reduction device of the present invention, the frequency of the sampling clock is lower than the vertical synchronization signal,
The carrier pulse is a vertical carrier pulse that is generated in synchronization with the vertical synchronization signal, and is a vertical carrier pulse that is used for R, G, B of an image etc. to be displayed on the television screen after being reduced in the vertical direction.
It is designed to output a signal.

Furthermore, in the reduction device of the present invention.

The frequency of the sampling clock is lower than the vertical synchronization signal, and the carrier pulse is a vertical carrier pulse generated in synchronization with the vertical synchronization signal and a horizontal carrier pulse generated in synchronization with the horizontal synchronization signal, It outputs R, G, and B signals such as images to be displayed on the television screen after being reduced in the vertical and horizontal directions.

[Example] Hereinafter, one embodiment of the present invention will be described based on the drawings.

In FIG. 1, a video signal obtained from a television receiver or the like (digital: not shown) is transmitted to an RGB converter circuit 1.
The video signal is decoded into R, G, and B signals, and a synchronization separation circuit 2 separates horizontal and vertical synchronization signals from the video signal. The R, G, and B signals are each converted into digital image data by the A/D converter circuit 3 and stored in the video RAM 4. At this time, the sampling clock in the A/D converter circuit 3 is oscillated by the variable oscillator 5, and the frequency of this sampling clock is changed depending on the degree of variation of an external device, for example, a volume (not shown). Therefore, the number of data stored in the video RAM 4 varies depending on the frequency of the carrier clock, which is varied by an external instruction. Also, video R
The contents of AM 4 are converted to analog by a D/A converter circuit 6.

On the other hand, the separated horizontal and vertical synchronizing signals are input to a carrier generator circuit 7, and instructions from the external volume or the like are input to this carrier generator circuit 7. As a result, the carrier generator circuit 7 generates a horizontal carrier pulse having a width according to an instruction from an external device such as the volume controller, in synchronization with the horizontal synchronizing signal. Also, from the mixing unit 8, RlG, B
A signal is output.

Next, the operation of the television screen reduction device having the above configuration will be explained based on the time chart of FIG. 2 and the television screen display state diagram of FIG. 3.

First, it is assumed that an external volume or the like is operated such that an image or the like based on an input video signal is reduced by half only in the horizontal direction of the screen 9 (shown in FIG. 3).

Then, the frequency of the sampling clock by the variable oscillator 5 is made lower than the horizontal synchronization signal by an external volume control, and the input R, G, and B signals are applied to one pixel of the screen 9 (pixel of the TV screen 9) at the A/D converter circuit 3. ) and converted to digital image data. That is, since image data for every other line in the vertical direction is obtained for the screen 9, the number of image data stored in the video RAM 4 is usually half of the total number of pixels of the television screen 9.

The image data stored in the video RAM 4 in this manner is read out at regular intervals and is read out from the D/A converter circuit 6.
The signal is converted into an analog signal and input to the mixing circuit 8.

At this time, as shown in FIG. 2(b), by operating the external volume or the like, the horizontal carrier pulses generated from the carrier generator circuit 7 are made to have widths at equal intervals of tl. Then, the R, G, and B signals of the image read out from the video RAM and converted to analog in the mixing circuit 8 are synchronized with the horizontal and vertical synchronizing signals, and the H level of the horizontal carrier pulse (corresponding to the display area 9a) is synchronized with the horizontal and vertical synchronizing signals. do)
is output at the timing of Therefore, as shown in FIG. 3, in a television receiver into which R, G, and B signals such as these images are input, images that have been reduced by 1/2 in the horizontal direction are displayed on the screen 9. It will be displayed in the right half display area 9a (shaded area).

In addition, when the frequency of the sampling clock is made higher than in the above case by operating an external volume control, etc., and the pulse width t1 of the horizontal carrier pulse is made smaller and closer to the horizontal synchronization signal, the display area 9a of the screen 9 is If the frequency of the sampling clock is made lower than in the above case and the pulse width ti of the horizontal carrier pulse is increased, the display area 9a of the screen 9 is made smaller in the direction of arrow B. That is, the display area 9a of the screen 9 can be arbitrarily changed according to the operation of an external volume or the like. Moreover, since the image data based on the input video signal is thinned out according to the display area 9a and stored in the video RAM 4, the image based on the video signal is displayed on the screen 9 in a reduced size.

Therefore, by arbitrarily changing the display area 9a while displaying another screen in an area other than the display area 9a of the screen, a different usage method can be considered in which the screen is transformed.

FIG. 4 is a block diagram of a reduction device showing a second embodiment of the present invention. In the figure, the same parts as in FIG. 1 are given the same reference numerals, and redundant explanation will be omitted.

In the figure, the vertical synchronization signal obtained by the synchronization separation circuit 2 and instructions from the operation of an external volume are input to the variable oscillator 5a, and the variable oscillator 5a outputs frequency sampling according to the operation of the volume, etc. A clock is output in synchronization with the vertical synchronization signal. Further, an instruction by operating an external volume or the like is input to the carrier generator circuit 7a, and a vertical carrier pulse having a width corresponding to the operation of the volume or the like is outputted from the carrier generator circuit 7a.

Further, from the mixing circuit 8a, the R,
G and B signals are output.

Next, the operation of the reduction apparatus having the above configuration will be explained based on the time chart of FIG. 5 and the display state diagram of the television screen of FIG. 3.

First, it is assumed that an external volume is operated so as to reduce an image or the like based on a human-powered video signal to half only in the vertical direction of both sides 9 (shown in FIG. 6).

Then, the frequency of the sampling clock by the variable oscillator 5 is made lower than the vertical synchronization signal by external volume control, and the input R, G, and B signals are input every other line (in the horizontal direction of the screen 9) at the A/D converter circuit 3. The images are thinned out and converted into digital image data. That is, 1 side 9
Since image data for every other horizontal line is obtained,
The number of image data stored in the video RAM 4 is half of the normal number. The data thus stored in the video 1 (AM 4) is periodically read out, converted into analog data by the D/A converter circuit 6, and input to the mixing circuit 8.

At this time, as shown in FIG. 5(b).

By using horizontal/vertical synchronization signals and external volume control,
A vertical synchronization signal (21
A vertical carrier pulse having a width t2 that is half of 2) is output.

Then, the R, G, and B signals of the image read out from the video RAM 4 and converted to analog in the mixing circuit 8 are synchronized with the horizontal and vertical synchronizing signals, and the H level of the vertical carrier pulse (in the display area 9a) is synchronized with the horizontal and vertical synchronizing signals. output at the corresponding timing). Therefore, as shown in FIG. 6, in a television receiver into which these image R, G, and B signals are input, the image reduced by 1/2 in the vertical direction is displayed on the lower half of the screen 9. It will be displayed in the display area 9a (shaded area).

Furthermore, when the frequency of the sampling clock is made higher than in the above case by operating an external volume control, etc., and the pulse width t2 of the vertical carrier pulse is increased to be close to that of the horizontal synchronization signal, the display area 9a of the screen 9 is If the sampling clock frequency is made lower than in the above case and the pulse width t2 of the horizontal carrier pulse is made smaller, the display area 9a of the screen 9 is made smaller in the direction indicated by the arrow. That is, the display area 9a of the screen 9 is changed according to the operation of an external volume or the like. Furthermore, since the image data based on the input video signal is thinned out according to the display area 9a, a reduced image is displayed on the screen.

FIG. 7 is a block diagram of a reduction device showing a third embodiment of the present invention. In the drawings, the same parts as in FIGS. 1 and 2 are denoted by the same reference numerals, and redundant explanation will be omitted.

In the figure, an instruction by operating an external volume or the like is input to the carrier generator circuit 7b, and a vertical carrier pulse and a horizontal carrier pulse are output from the carrier generator circuit 7b in accordance with the operation of the volume or the like.

Next, the operation of the reduction apparatus having the above configuration will be explained based on the time chart of FIG. 8 and the display state diagram of the television screen of FIG. 9.

First, it is assumed that the external volume is operated so as to reduce the image based on the input video signal by half in both the horizontal and vertical directions of the screen 9 (shown in FIG. 9). Then, the frequency of the sampling clock by the variable oscillator 5 is varied in accordance with the external volume control, and the input R, G, and B signals are thinned out in the A/D converter circuit 3 as shown in the previous two embodiments. Converted to image data. That is, since this is a combination of the previous two embodiments, the video RAM 4 stores 1/4 of the normal image data.

At this time, as shown in FIGS. 8(b) and 8(d), horizontal carrier pulses are output from the carrier generator circuit 7 at equal intervals t1 by the horizontal and vertical synchronizing signals and external volume control. , and also the vertical synchronization signal (
A vertical carrier pulse of half t2 of 2tz) is output. Therefore, it is synchronized with the horizontal and vertical synchronizing signals from the mixing circuit 8b.

Image R9 based on image data stored in video RAM4
The G and B signals are output at the timing of the H level (corresponding to the display area 9a) of the horizontal carrier pulse and the vertical carrier pulse. That is, as shown in Figure 9,
For television receivers into which R, G, and B signals such as these images are input, images that have been reduced by 1/2 in the vertical and horizontal directions (1/4 reduced image) are displayed in the lower right half of the screen 9. will be displayed in the display area 9a (shaded area).

Further, by operating an external volume control or the like, the display area 9a of the screen 9 can be changed laterally in the directions of arrows E and F shown in FIG. 9, as in the first embodiment. Furthermore, by operating an external volume control, etc., the display area 9 of the screen 9 can be moved in the directions of arrows G and H shown in FIG.
a is varied in the vertical direction.

In this way, according to the operation of the external volume, etc., the number of image data based on the input video signal is thinned out to a predetermined value and stored in the video IIAM 4.
, B signals are output at the timing of the predetermined display area 9a, so a reduced image is displayed on the screen of a television receiver or the like to which these R, G, and B signals are input, and the size can be changed arbitrarily. be able to.

[Effects of the Invention] As explained above, according to the reduction device of the present invention, the R, G, B
The number of image data according to the signal is thinned out to a predetermined value and the video RAM is
The content of this video rlAM is output as R, G, and B signals at the timing of a predetermined display area. A reduced image can be displayed in a predetermined size according to the operation of the volume, etc., and the reduction ratio and display area ratio of the screen can be arbitrarily changed by predetermined operation of the volume etc.

Therefore, there is an effect that display usage of the television screen can be further expanded.

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram of a reduction device showing an embodiment of the present invention, FIG. 2 is an operation time chart of the reduction device, FIG. 3 is a screen display state diagram by the display reduction device, and FIG.
The figure is a schematic block diagram of a reduction device showing a second embodiment of the present invention, FIG. 5 is an operation time chart of the reduction device shown in FIG. 4, and FIG. 7 is a schematic block diagram of a reduction device showing a third embodiment of the present invention, FIG. 8 is an operation time chart of the reduction device shown in FIG. 7, and FIG. 9 is a diagram of the reduction device shown in FIG. 7
FIG. 3 is a diagram showing a screen display state of the reduction device shown in the figure. In the figure, 1 is an RGB converter circuit, 2 is a synchronous separation circuit,
3 is an A/D converter circuit, 4 is a video RAM (VRA)
M), 5, 5a are variable oscillators, 6 is a D/A converter circuit, 7, 7a, 7b are carrier generator circuits, 8,
8a and 8b are mixing circuits, 9 is a screen (such as a television receiver), and 9a is a display area. Patent Applicant: Fujitsu General Co., Ltd. Representative, Patent Attorney: Taku Ohara Figure 5 Figure 6

Claims (4)

[Claims] (1) A reduction device that reduces an image displayed on a television screen, including an RGB converter circuit that obtains R, G, and B signals of the image from a video signal obtained from the television receiver, etc., and the video signal. a synchronization separation circuit that separates horizontal and vertical synchronization signals; an A/D conversion circuit that converts the R, G, and B signals into digital image data; a video RAM that stores this image data; and a video RAM that stores this image data. Converting stored image data to analog D
/A converter circuit; a variable oscillator that generates a sampling pulse at a timing to convert the R, G, and B signals of the image, etc. into digital; and a carrier that generates a carrier pulse of a predetermined width based on the horizontal and vertical synchronization signals. R of the image data obtained by the generator circuit and the D/A converter circuit.
, G, and B signals in synchronization with the horizontal/vertical synchronizing signal and the carrier pulse, the frequency of the sampling clock and the width of the carrier pulse are varied according to instructions from an external source, and the frequency of the sampling clock and the width of the carrier pulse are varied according to instructions from an external source, The number of image data by the signal is thinned out to a predetermined value and
At the same time, this image data is stored in analog R,
A reduction device for a television screen, characterized in that it converts into G and B signals and outputs them at predetermined timing. (2) the frequency of the sampling clock is lower than the horizontal synchronization signal, and the carrier pulse is a horizontal carrier pulse generated in synchronization with the horizontal synchronization signal;
Claim (1) wherein R, G, and B signals of an image, etc. to be displayed on the television screen after being reduced in the horizontal direction are outputted.
1) The reduction device for the television screen described above. (3) The frequency of the sampling clock is lower than the vertical synchronization signal, and the carrier pulse is a vertical carrier pulse generated in synchronization with the vertical synchronization signal,
Claim (1) wherein R, G, and B signals of an image, etc. to be displayed on the television screen after being reduced in the vertical direction are output.
1) The reduction device for the television screen described above. (4) The frequency of the sampling clock is lower than the vertical synchronization signal, and the carrier pulse is a vertical carrier pulse generated in synchronization with the vertical synchronization signal and a horizontal carrier pulse generated in synchronization with the horizontal synchronization signal. 2. The apparatus for reducing a television screen according to claim 1, wherein the apparatus outputs R, G, and B signals of an image to be displayed on the television screen after being reduced in the vertical and horizontal directions.