JPH01174179A - Picture inserting device - Google Patents

Abstract

PURPOSE:To prevent a delay of an inserted picture by compensating a horizontal synchronizing signal and outputting the result if the horizontal synchronizing signal of a television signal of the inserted picture is missing. CONSTITUTION:A horizontal synchronizing signal compensation circuit 20 outputs one horizontal synchronizing signal synchronously with an inputted horizontal synchronizing signal to a counter decoder 14 if one pulse of the inputted horizontal synchronizing signal is missing. An inserted picture stored in a DRAM 7 is inserted to the picture to be inserted of the NTSC television signal inputted to a video signal input terminal 1 and displayed on a CRT display device 5. Even if one pulse is missing in the horizontal synchronizing signal in the NTSC television signal inputted to the terminal 1, the horizontal synchronizing signal compensation circuit 20 compensates the signal and outputs the result.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image insertion device that inserts a television signal of an inserted image into a television signal of an inserted image.

[Conventional technology] FIG. 2 is a block diagram of a conventional image insertion device.

In Fig. 2, N
The TSC television signal is input to the RGB separation circuit 2 and also input to the sync separation circuit 3 . The RGB separation circuit 2 separates the human-powered NTSC television signal into RGB signals, and then switches the changeover switches 4a, 4b,
4c is output to the CRT display 5 via each a side. On the other hand, the synchronization separation circuit 3 separates the vertical synchronization signal (■η) and the horizontal synchronization signal (■) from the manually inputted NTSC television signal, and outputs each signal to the counter decoder I4 in the CRT controller 6.

The CRT controller 6 is connected to a dynamic random access memory (hereinafter referred to as DRAM) 7 that stores, for example, one frame of image information, and is connected to a switch 1.
R of the image to be inserted when the insert mode is turned on
Switches 4a and 4b for switching each GB separated signal
, 4c to the CRT controller 6 through each side. The CPU10 in the CRT controller 6 has a C
A ROM (not shown) that stores a system program for controlling each circuit in the RT controller 6, and an RA that operates as a working area for performing the control operations.
M (not shown) is connected, and the CPU10 is connected to the R
It operates according to the system program stored in OM. A switch 13 for setting the CRT controller 6 to the insertion mode is also connected to the CPUIQ, and when the switch 13 is turned on, the CPUl0 becomes the insertion mode, and in response, the CPUl0 switches the changeover switch 4.
Switch a, 4 b, 4 c from side a to side b. Furthermore, 16 registers 11a to Ilo used as look-up tables are connected to CPU10 via a 12-bit data bus. CPU10
outputs and stores 16 types of color signals represented by 4 bits per RGBg color and a total of 12 bits per pixel, and stores them in each register Ila to Ilo.
Each of la to llo outputs the stored 12-bit color signal to the color code selection decoder 16.

The DRAM 7 stores image data regarding each pixel of the inserted image for 1 frames, and the image data per pixel consists of a 4-bit color designation signal and 4-bit 1 for each RGB color.
It has a total of 12 bits of gray level designation signals in 6 layers.

The counter decoder 14 receives a manually input vertical synchronization signal ■η
In response to the positive and horizontal synchronizing signals Hsyπ, a signal DC indicating the image display start position of one frame of the image of the NTSC television signal and a signal HB indicating the image display start position of each horizontal line of the NTSC television signal are generated, and an address is generated. Output to counter 12.

The address counter 12 responds to the signal DB by DR.
The addresses are sequentially output from the address of the first pixel of one frame of the inserted image stored in AM7 and from the address of the first pixel of each horizontal line of the inserted image in response to the signal HI3. The DRAM 7 outputs image data of 16 bits per pixel stored at the address input from the address counter I2 in parallel to a parallel/norial shift register (hereinafter referred to as P/s shift register) 15. In response to this, the P/S shift register 15 receives the input! The 6-bit image data is converted into serial image data and output to the color code selection decoder 16.

In response to the image data input from the P/S shift register I5, the color code selection decoder 16 selects the r( Each color signal of GB is read out, and 4 of each color of RGB corresponds to the 12-bit density designation signal in the image data and corresponds to the above color signal.
A digital/analog converter (hereinafter referred to as a D/A converter) converts the RcBl;j signal of 12 bits in total.

)17. In response to this, the D/A converter 17
converts the input RGB separated digital signals of 4 bits for each RGB color into analog RGB separated signals, and outputs them to the CRT display 5 via each side of the changeover switches 4a, 4b, and 4c.

In the image insertion device configured as described above, when the switch 13 is turned on after the NTSC television signal of the image to be inserted is input to the video input terminal 1, the CRT controller 6 enters the insertion mode, and the CPU 10 operates as a changeover switch. 4 Switch a, 4 b, and 4 c from the a side to the b side. The address counter 12 in the CRT controller 6 sequentially outputs each address of the inserted image of one frame to the DRAM 7 in response to the signals DC and HB generated from the input NTSC television signal. In response, the DRAM 7 transfers the 16-bit image data per pixel stored at the input address to the 1.1. Passport register I5. In response, the CRT controller 6 generates analog RGB separation signals corresponding to the image data as described above, and switches each signal to the switch 4a.
, 4b, and 4c to the CRT display 5 via the b side. This allows the video signal input terminal 1
The image in which the inserted image stored in the DRAM 7 is inserted into the inserted image of the NTSC television signal input to the C
displayed on the RT display 5.

[Problems to be Solved by the Invention] However, in the conventional device described above, if, for example, one pulse of the horizontal synchronizing signal π5ync in the input NTSC television signal is lost in the transmission line or transmission equipment, As shown in FIG. 3, when inserting an insert image 52 into the inserted image screen 50, one blank line image 52 is displayed on the inserted image 50.
Therefore, only one line of the inserted image 5I is displayed with a delay of one horizontal period. This is because one pulse of the horizontal synchronizing signal H5ync input to the counter decoder 14 disappears, and thereby the signal HB output from the counter decoder 14 is delayed by one horizontal period.

An object of the present invention is to solve the above problems, and even if the horizontal synchronization signal disappears in the input television signal of the inserted image, the horizontal synchronization signal is compensated for, and the inserted image is An object of the present invention is to provide an image insertion device that does not cause any delay.

[Means for Solving the Problems] The present invention separates a vertical synchronizing signal and a horizontal synchronizing signal from a television signal of an input inserted image, and stores the vertical synchronizing signal and the horizontal synchronizing signal in advance in response to the vertical synchronizing signal and the horizontal synchronizing signal. In an image insertion device that inserts a television signal of an inserted image stored in the device into the television signal of the inserted image, a detection means outputs a detection signal when detecting disappearance of a horizontal synchronization signal of the television signal of the inserted image. and synchronization signal output means for outputting a horizontal synchronization signal in response to the detection signal output from the detection means.

[Operation] With the above configuration, the detection means outputs a detection signal when it detects disappearance of the horizontal synchronization signal of the television signal of the inserted image, and the synchronization signal output means outputs the detection signal from the detection means. A horizontal synchronization signal is output in response to the detected signal. Therefore, for example, even if the horizontal synchronization signal in the television signal of the input image to be inserted disappears, the detection means detects this, and the synchronization signal output means compensates for the horizontal synchronization signal. Output.

[Embodiment] FIG. 1 is a block diagram of an image insertion apparatus that is an embodiment of the present invention. Components in FIG. 1 that are the same as those in FIG. 2 are designated by the same reference numerals.

The image insertion device of this embodiment is different from the conventional image insertion device shown in FIG. This is because a horizontal synchronizing signal compensation circuit 20 is inserted between the two.

The above differences will be explained in detail below.

In FIG. 1, the horizontal synchronization signal Hsync output from the synchronization separation circuit 3 is input to the counter decoder 21, and is also input to the NOR gate N through the impark INV2.
A second input terminal of the OR is input manually. Clock generator 22 generates a 3.58 MHz clock signal and outputs it to counter decoder 2I.

The counter decoder 21 is composed of a 9-bit counter decoder, and after being reset at the positive rising edge of the manually inputted horizontal synchronizing signal Hsy, counts up to 241 pulses of the clock signal.

If the horizontal synchronization signal Hsync is input normally without disappearing, when 227 clock signals are counted after being reset, the next horizontal synchronization signal "■" is input manually to the counter decoder 21 and the counter decoder 21 receives the next horizontal synchronization signal "■". 21 is reset.Therefore, the counter decoder 21 is reset to 23.
Zero or more clock signals will be reset without counting. At this time, the positive horizontal synchronizing signal Hsy input to the horizontal synchronizing signal compensation circuit 20 is applied to the inverter INV.
2 and the counter decoder 14 via the NOR gate NOR.
is output to.

On the other hand, if the pulse of the horizontal synchronizing signal H5ync following the horizontal synchronizing signal H5ync at the time of resetting the counter decoder 2I disappears and there is no manual input, the counter decoder 21 is not reset and the counter decoder 2I is 241111
At this time, a horizontal synchronizing signal Hsync with a pulse width of about 4 μs is generated and outputted to the first input terminal of the NOR gate NOH via the inverter rNV1, and it also resets the counter decoder 20 by itself and performs the above-mentioned process. Similarly, the clock signals inputted are counted until the next horizontal synchronization signal H5sync is inputted. Noah Gate NOH
The signal output from the output terminal of is the horizontal synchronization signal H5y
It is output as nc to the counter decoder I4.

Note that the counter decoder 21 includes a detection means that outputs a detection signal when detecting disappearance of the horizontal synchronization signal of the television signal of the inserted image, and a response to the detection signal output from the detection means, as set forth in the claims. This corresponds to synchronization signal output means for outputting a horizontal synchronization signal.

The horizontal synchronization signal compensation circuit 20 configured as described above is as follows:
When one positive pulse of the input horizontal synchronizing signal Hsy disappears, one horizontal synchronizing signal Hsyπ which compensates for the horizontal synchronizing signal = and synchronizes with the previously input horizontal synchronizing signal Hsync is output to the counter decoder. Output to 14.

The image insertion device shown in FIG. 1, which includes the horizontal synchronization signal compensation circuit 20, is configured such that when an NTSC television signal is normally input to the video signal input terminal 1, the image insertion device shown in FIG. Insert the inserted image stored in the DRAM 7 into the inserted image of the NTSC television signal,
The inserted image can be displayed on the CRT display 5. Furthermore, since the image insertion device is equipped with the horizontal synchronization signal compensation circuit 20, the horizontal synchronization signal Hsy in the NTSC television signal inputted to the video signal input terminal I is
Even if one pulse of nc disappears, the horizontal synchronizing signal compensation circuit 20 compensates for the horizontal synchronizing signal "i positive" and outputs it. Therefore, as shown in FIG. 3 of the conventional example,
When inserting the insert image 52 into the inserted image screen 50,
An image 52 of one blank line on the inserted image 50
is displayed, and insert image 5! It is possible to prevent only one row of images from being displayed with a delay of one horizontal period. Therefore, the present invention provides a video signal input terminal l.
Horizontal synchronization signal H5y of the NTSC television signal input to
This is particularly effective for systems where nc frequently disappears in transmission lines or transmission equipment.

In the above embodiment, the RGB separated signal of the inserted image stored in the DRAM 7 is inserted into the RGB separated signal converted from the NTSC television signal of the inserted image, but the invention is not limited to this. The NTSC television signal of the inserted image may be inserted into the NTSC television signal of the image in a known manner.

[Effects of the Invention] As detailed above, according to the present invention, an image insertion device includes a detection means for outputting a detection signal when detecting disappearance of a horizontal synchronization signal of a television signal of an inserted image, and the detection means. and a synchronization signal output means for outputting a horizontal synchronization signal in response to a detection signal output from the synchronous signal output means, so that even if the horizontal synchronization signal in the television signal of the input image to be inserted disappears, for example, , the horizontal synchronization signal is compensated and output, and as shown in FIG. 3 of the conventional example, the screen 5 of the inserted image is
When inserting the insert image 52 into the inserted image 50, one blank line of the image 52 is displayed on the inserted image 50, and only the one line of the insert image 51 is delayed by one horizontal period and displayed. It is possible to prevent this from happening.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an image insertion device that is an embodiment of the present invention, FIG. 2 is a block diagram of a conventional image insertion device, and FIG. 3 is a CRT showing problems in the image insertion device of FIG. FIG. 3 is a front view of the screen of the display. DESCRIPTION OF SYMBOLS 1... Video signal input terminal, 2... RGB separation circuit, 3... Synchronization separation circuit, 4 a, 4 b, 4 c... Changeover switch,
5...CRT display, 6...CRT controller, 7...Dynamic random access memory (
DRAM), 20...Horizontal synchronization signal compensation circuit, 2I...Counter decoder, 22...Clock generator, INVI, rNV2-...Inverter, NOR...Nor gate.

Claims (1)

[Claims] (1) Separate the vertical synchronization signal and horizontal synchronization signal from the input television signal of the inserted image, and in response to the vertical synchronization signal and the horizontal synchronization signal, extract the television signal of the insertion image stored in advance in the storage device. In the image insertion device for inserting into the television signal of the inserted image, a detection means outputs a detection signal when detecting disappearance of a horizontal synchronization signal of the television signal of the inserted image; and a detection signal outputted from the detection means. 1. An image insertion device comprising: synchronization signal output means for outputting a horizontal synchronization signal in response to a horizontal synchronization signal.