KR950001573B1 - Multi-screen display apparatus - Google Patents

Abstract

The device displays the still image on the splitted multi-mode screen among the several images by the mode control signal of the multi-screen CCTV. The device includes (A) a mode selection block to select an image signal from several images; (B) several image storage units to convert the receiving image to digital signal, and store it in the image storage; (C) several image reproduction blocks to reproduce the stored image in the image storage, and convert it to analog signal; (D) a control signal generation block to control the image storage and the reproduction block by the mode selection signal.

Description

Multi Screen Display

1 is a multi-screen display device according to the present invention.

2 is an exemplary waveform diagram of a main part of a multi-screen display device according to the present invention.

* Explanation of symbols for main parts of the drawings

1: Video signal input terminal 2: A / D converter

3: Storage control unit 4: Buffer type memory

5: regeneration control unit 6: synchronization generator

7: 1H Delay Unit 8: Multiplex

9: D / A Converter 10: Displayer

11: key metrics 12: control signal generator

100: image storage unit 200: image playback unit

The present invention relates to a display method and apparatus in Closed Circuzt Tele-Vision (CCTV) that can monitor and display video signals transmitted from a plurality of surveillance cameras by assigning them to a plurality of divided areas of one monitor. The present invention relates to a single still screen display apparatus for displaying only a specific screen of a multi-division multi-screen as a single still screen.

In general, surveillance TVs are popular in department stores, stores, and banks. In particular, the demand for 4-screen CCTV that can monitor multiple places simultaneously on a single monitor is increasing. It has the function to display only the desired screen as a single screen, but in the process of displaying the still image, the biggest function of the monitoring TV is to stop the still image only in the 4-split mode. Not only can't stop the screen you want to see, but also the still picture in 4-split mode is difficult to determine the exact situation because the area on the screen screen is 1/4 of the area in the single mode.

Accordingly, an object of the present invention is to display a still picture of a desired channel in a single-screen mode in a four-division multi-screen mode, and to control a single-screen still picture on a multi-screen so that the still image can be clearly reported. To provide a device for displaying the.

A feature of the present invention for achieving the above object, in the apparatus for displaying a plurality of video signals through a plurality of channels in a single receiver, a single stop of any one of the video signals desired Mode selection means for controlling to display on the receiver on the screen, each of the plurality of image storage unit for converting the image signal received through each channel to digital, and compressing and storing the converted digital image signal, each of the plurality of A plurality of image reproduction units connected to any one of the image storage units and converting the image signals stored in the corresponding image storage units to analog, and controlling the image storage unit and the reproduction unit according to control signals applied from the mode selection means. A multi-screen display device including an adjustment signal generator.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. 1 is a block diagram of a display device according to a preferred embodiment of the present invention, showing an example of a four-screen CCTV. The apparatus comprises four image storage units 100 for digitalizing and storing analog image signals from four surveillance camera input terminals 1, and converting data stored in the image storage unit 100 into analog image signals. The image storage unit 100 and the image reproducing unit 200 are controlled by receiving the four image reproducing units 200 and the mode signals of the key metrics 11 and the key metrics 11 selecting the operation mode. It consists of a control signal generator 12. Here, each of the image storage units 100 is connected to each of the plurality of surveillance cameras, each of the image reproduction unit 200 is connected to the corresponding image storage unit 100 is configured to output a signal to the monitor 10 do. Since each image storage unit 100 or each image reproduction unit 200 has the same configuration, only one image storage unit and an image reproduction unit connected to one surveillance camera will be described below.

The image storage unit 100 includes an A / D converter 2 for converting an analog image signal applied from the input terminal 1 into a digital signal, a buffer type memory 4 for storing the digitally converted image signal, and the input terminal ( Storage control for controlling the operation of the A / D converter 2 and the buffer type memory 4 by receiving the horizontal synchronizing signal HD, the vertical synchronizing signal VD, and the clock signal 4fsc of the carrier frequency from 1). It consists of part (3).

The image reproducing unit 200 receives a video signal stored in the buffer type memory 4 in the image storing unit 100 and delays one horizontal synchronization, and the buffer type memory 4. Or a multiplex (8) receiving a video signal from the buffer type memory through the 1H delay unit (7), a D / A converter (9) for converting the output signal of the multiplex (8) into an analog signal, and And a reproduction control section 5 for controlling the operation of the buffer type memory 4 by receiving the synchronization generator 6 for generating the necessary synchronization signal and the reproduction synchronization signal.

FIG. 2 is a waveform diagram of the main part of FIG. 1, which describes the operation of the multi-screen display apparatus according to the present invention with reference to the drawings. When the 4-split operation mode selection signal from the key metrics 11 is applied to the control signal generator 12, the control signal generator 12 is a 4-split operation mode to the storage controller 3 and the playback controller 5. Make it aware. Then, when the video signal of the channel applied from the input terminal 1 is output to the output terminal 10, it should be reduced to 1/4. Accordingly, the storage controller 3 receives the horizontal synchronizing signal HD, the vertical synchronizing signal VD, and the carrier signal 4fsc from the image signal applied from the input terminal 1 to the A / D converter 2. The drive clock signal (A / D CK) and the buffer type memory (4) recognize the drive clock (WCK: Write Clock) necessary for storing data and valid data among data applied from the A / D converter (2). The signal (WE: Write Enable) and the signal for clearing the buffer memory 4 (WR: Write Reset) are respectively applied. At this time, the driving clock signal (A / D CK) and the driving clock signal (WCK) in the storage control unit 3 should be output by adjusting the applied carrier signal (4fsc) divided by 2fsc. This is because one horizontal period H must be reduced to H / 2.

In other words, if the applied analog video signal is sampled at a frequency of 4fsc, the pulse width of 1H is obtained with 910 image data, and when the drive clock signal (A / D CK) and the drive clock signal (WCK) of 2fsc are used, 455 pieces are used. The data alone can produce a pulse width of 1H. After that, when the memory is read with a clock of 4fsc, the horizontal data is reduced to 1/2 (see (A) and (B) in FIG. 2A). At this time, the driving clock signal WCK applied to the buffer memory 4 uses an inversion signal of the driving clock signal A / D CK. Therefore, only 455 data of the horizontal synchronization signal 1H are stored (see (B) and (C) in FIG. 2A). The buffer type memory 4 is configured to operate only when the write enable signal WE (Fig. 2A) is applied even when the drive clock signal WCK (Fig. 2A) is applied. The effective analog image signal applied to one horizontal synchronous signal H (D in FIG. 2A) is stored in the memory as the synchronization signal and unnecessary data are stored in the memory while being converted by the A / D converter 2. This is to save only the data to reduce the memory capacity and to prevent errors (see (D) and (E) in FIG. 2A). In general, a horizontal synchronization signal of 262.5H is applied between the vertical synchronization signals, and the WE signal [G] of FIG. 2A is divided into two buffers of the horizontal synchronization signal HD [F] of FIG. 4), it compresses data 1/2 by storing 131.25H instead of 262.5H in horizontal band period.

A process of compressing and storing vertical and horizontal data signals of an analog video signal to which the above operation is applied by 1/2. The process of reproducing data stored in the buffer type memory 4 will now be described.

The reproduction control unit 5, which receives the reproduction carrier signal R4fsc and the reproduction vertical / horizontal synchronization signals RHD and RVD from the synchronization generator 6, reproduces the data stored in the buffer type memory 4. The driving clock RCK is applied to the buffer memory 4.

At this time, the driving clock signal RCK reproduces the horizontal synchronization period of the stored data as it is, using the R4fsc signal in the 4-split screen mode as it is, and displays the 1/2 reduced screen in the single-screen mode. Using the divided R2fsc signal, the horizontal synchronization period of the stored data is enlarged and reproduced by 2 times, and reproduced so that it is displayed on one screen on the monitor. The horizontal synchronous line 1H delay unit 7 is operated by the state of the third output signal S ₃ applied from the adjustment signal generator 12.

The S ₃ signal is off in the 4-split mode regardless of the still image or the active screen, and in the single-screen mode. Therefore, since the 1H delay unit 7 is not operated in the 4-split mode, the multiplexer 8 receives only the image data applied directly from the buffer type memory 4 and applies it to the D / A converter 9. On the other hand, in the single still picture mode, the 1H delay unit 7 is turned on so that image data of each horizontal band stored in the buffer-type memory 4 in the image storage unit 100 is stored by one horizontal band line. The delay is applied to the multiplexer 8. The multiplexer 8 receives the image data directly applied from the buffer type memory 4 and the same image data of the previous stage delayed by the 1H delay unit and applies the same to the D / A converter 9.

The D / A converter 9 is driven by the D / A CK signal of the synchronization generator 6 and converts and outputs the digitalized image data into an analog signal.

The output signal of the D / A converter 9 is applied to the display 10, and the display 10 displays the aspect ratio of each channel to 1/4 of the full screen when the output signal is in the 4-split mode. In case of single screen mode, the screen of specific channel is displayed on the full screen.

In the operation mode of the 4-split mode, the storage controller 3 applies a write reset (WR) signal to the buffer type memory 4 for each of the 4 vertical synchronization signals among the vertical synchronization signals VD for each channel. The new image data is stored in the memory 4, while in the freeze mode or the single freeze screen mode, the storage control unit 3 releases the WR signal and turns off the WE signal. A constant image data is provided by continuously outputting an image stored in the memory 4 without deleting data or storing new data. In fact, the signal that sets the display area of each channel so that multiple video signals can be displayed on one receiver is a RE (Read Enable) signal. The RE signal is different in the 4-split mode and in the single-stop mode. It works. In the 4-split mode, RCK is used as 4 fsc as described above, and the RE signal in each channel is supplied from the playback control unit 5 to the memory 4 for the horizontal synchronization signal HD and the vertical synchronization signal VD, respectively. It is applied differently to display 4 screens. In the first channel, the RE signal is turned on (see (H), (I) and (J) in FIG. 2B) before 1 / 2RH and before 1 / 2RV. In the second channel, after 1 / 2RH and before 1 / 2RV The RE signal is turned on (see (H), (I) and (K) in FIG. 2B). Therefore, in the region of more than half of the entire horizontal band and the vertical band of the receiver, the first channel is displayed on the left side and the second channel is on the right side of the horizontal band. In the third channel, the RE signal is turned ON (see (H), (I) and (L) in FIG. 2B) before 1 / 2RH and after 1 / 2RV. In the fourth channel, after 1 / 2RH and after 1 / 2RV, The RE signal is turned on (see (H), (I) and (M) in FIG. 2B), and in the region below the vertical band and the vertical band, the third region and the right region Fourth channels are displayed respectively.

Therefore, four channels of the screen are simultaneously displayed on one receiver. In this case, when only one specific channel is displayed as a still picture, only the RE signal of the desired channel is continuously turned on for the RH and RV signals, and the RE signal of the other channel is turned off. In addition, when the memory regeneration clock (RCK) is used as the R2fsc instead of the R4fsc used as the regeneration clock (RCK) in the 4-split mode, the resolution of the image is reduced, but the horizontal band returns from 1 / 2H to 1H.

In addition, since the image data was compressed 1/2 in the vertical band, the third control signal S ₃ of the control signal generator 12 in FIG. 1 operates the 1H delay unit 7 so that 1H was once again. Restore the vertical data amount compressed to 1 / 2V to 1V. Of course, in the storage control unit 3, both the WE and WR signals are turned off to prevent the desired screen from being deleted or other unwanted screens from being stored.

As described above, the multi-screen display device according to the present invention can further maximize the effect of the surveillance TV since the 4-split operation mode, the 4-split operation mode, the 4-split stop mode, and the still picture of the desired channel can be used as a single screen. Provide the effect.

Claims (3)

An apparatus for splitting and displaying a plurality of video signals over a plurality of channels on a single receiver, the apparatus comprising: mode selection means for controlling to display a desired one of the video signals on the receiver as a single still screen; A plurality of image storage units for converting image signals received through respective channels into digital, and compressing and storing the converted digital image signals; A plurality of image reproducing units, each of which is connected to any one of the plurality of image storing units, for reproducing and converting image signals stored in a corresponding image storing unit into analog; And a control signal generator for controlling the image storage unit and the reproduction unit according to a control signal applied from the mode selection means. 2. The apparatus of claim 1, wherein each of the image storage units comprises: an A / D converter for converting an input analog image signal into a digital signal; A buffer type memory for storing a digitally converted video signal; And a storage control unit which receives a horizontal synchronization signal, a vertical synchronization signal, and a clock signal of a carrier frequency from the input terminal to control operations of the A / D converter and the buffer type memory. The image reproducing apparatus of claim 1, wherein the image reproducing unit comprises: a 1H delay unit which receives a video signal stored in a buffer type memory in the image storing unit and delays one horizontal synchronization; A multiplex to receive the image signal from the 1H delay unit and the image storage unit; A D / A converter converting the output signal of the multiplex into an analog signal; A synchronization generator for generating a necessary synchronization signal for the player; And a reproducing control unit which receives a reproducing synchronization signal and controls an operation of the buffer type memory.