JPH0160992B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a continuous color video signal composed of three types of video signals, such as a Y signal and an R signal.
- Of the Y signal and the B-Y signal, the Y signal is transmitted continuously, and the R-Y signal and the B-Y signal are sequentially converted into signals for each horizontal scanning line and are transmitted. The present invention can be used in a video signal converter for satellite broadcasting that broadcasts line-sequential video signals, a video tape recorder that records and reproduces line-sequential video signals, and the like.

Conventional configuration and its problems As a device using the line sequential video signal system,
Many devices have been proposed that use the SECAM method or devices that convert an NTSC signal into a line-sequential video signal and then transmit (including recording and reproducing) the line-sequential video signal.

However, these line-sequential video signals transmit information by thinning it out for each horizontal scanning line, so they have many advantages such as improving the S/N and expanding the one-dimensional frequency band by the amount of thinning. Because of the problem that the line-sequential system suffers from deterioration peculiar to highly saturated diagonal images, it has not become as popular as continuous signal systems (for example, NTSC signals or PAL signals).

Purpose of the Invention The present invention solves the above-mentioned conventional problems and allocates the reduction in information amount caused by line sequentialization to improving the S/N and expanding the one-dimensional frequency band. It is an object of the present invention to provide a line-sequential signal transmission device that reduces the deterioration phenomenon peculiar to the line-sequential system while still allowing the use of the line-sequential system.

Structure of the Invention In order to achieve the above object, the present invention converts a continuous color video signal made up of three types of video signals into one set of images with two frames, the first and second images.
Of the second and third video signals of the three types of video signals having the same horizontal scanning line number in the frame,
The video signal transmitted in the first frame is configured to stop being transmitted in the second frame, and the video signal whose transmission is stopped in the first frame is transmitted in the second frame.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on the drawings. FIG. 1 shows a block diagram of essential parts of an embodiment of the line sequential signal transmission device of the present invention, which includes an input terminal 1, a decoder 2, a vertical synchronizing signal separation circuit (hereinafter referred to as VSS
) 7, 1/4 frequency divider 8, horizontal synchronizing signal separation circuit (hereinafter referred to as HSS) 9, 1/2 frequency divider 10, switch 11, switch 12, Y signal output terminal 13
and a line sequential color signal output terminal 14. For example, an NTSC color video signal as illustrated in FIG. 2a is applied to the input terminal 1.
In that case, the decoder 2 uses a well-known circuit configuration to separate the NTSC color video signal supplied to the decoder input terminal 3 into three types of video signals, such as the Y signal, the RY signal, and the BY signal. The signal is output to the Y signal output terminal 4, the RY signal output terminal 5, and the BY signal output terminal 6, respectively. Each of those output terminals 4,
Examples of signal waveforms output to ports 5 and 6 are shown in Figure 2 e, f,
Shown in g. In addition, the HSS9 uses a well-known circuit configuration to separate the horizontal synchronization signal and, for example,
By using an AFC circuit (not shown) etc.
It is assumed that a horizontal synchronizing signal with the equalization pulse removed is output.

Suppose that in such a circuit configuration, an NTSC color video signal as shown in a of FIG. 2 is supplied to the input terminal 1. At the output end of the HSS 9, a horizontal synchronizing signal H as shown in FIG. 2b is obtained. This horizontal synchronizing signal H is divided by a 1/2 frequency divider 10, and the Q terminal is
Signals as shown in Fig. 2 c and d are obtained at the Q terminal.
This 1/2 frequency divider 10 is constituted by a normal flip-flop circuit, and is reset by a reset signal R once every two frames, which will be described later. The Q terminal and the terminal are connected to a switch 11, and the movable piece of the switch 11 is controlled by a pulse signal P having a two-frame period, which will be described later. As a result, when the P signal is at H level, the output pulse of the Q terminal becomes the output signal of switch 11, and when the P signal is at L level, the output pulse of the terminal becomes the output signal of switch 11.

On the other hand, a vertical synchronizing signal V as shown in FIG. 3a is outputted to the output terminal of VSS7. The VSS typically includes a low-pass filter (not shown), a Schmitt circuit (not shown), and the like. This vertical synchronizing signal V is frequency-divided by a 1/4 frequency divider 8, and the third
A pulse signal P as shown in Figure b is obtained. The 1/4 frequency divider 8 is composed of, for example, two stages of flip-flop circuits (not shown). The pulse signal P controls the movable piece of the switch 11, as described above.
As a result, the output end of the switch 11 receives two frames each as a set, and two frames whose phases are inverted for each frame.
A signal having a period equal to the horizontal synchronization interval is obtained. This signal also controls the movable piece of the switch 12.
The switch 12 is connected to the R-Y signal output terminal 5 and the BY-signal output terminal 6 of the decoder 2, and when the output signal of the switch 11 is at H level, the switch 12 outputs the R-Y signal. When the output signal of switch 11 is at L level, switch 12 outputs the BY signal. As a result, the line-sequential color signal output terminal 14 transmits two frames as one set, and transmits the first frame of the R-Y signal and B-Y signal having the same horizontal scanning line number in the first and second frames. The transmission of either the R-Y signal or the B-Y signal is stopped in the second frame, and the R-Y signal whose transmission is stopped in the first frame
-Y signal and BY signal are transmitted in the second frame. That is, for an image made up of two frames, the above-mentioned transmission device transmits all information. An example of the output signal waveform of the line sequential color signal output terminal 14 is shown in FIG. 2h.

The reset signal R for resetting the 1/2 frequency divider 10 is obtained by differentiating the output signal of the 1/4 frequency divider 8 using a differentiating circuit 15. The reset signal R is shown in FIG. 3c.

In the above explanation, as examples of three types of video signals, Y signal, R-Y signal, and B-Y signal are used.
Although the explanation has been made using signals, a combination of the G signal, R signal, and B signal, or the Y signal, I signal, and Q signal can also be used.

Furthermore, if each signal output from the Y signal output terminal 13 and the line sequential signal output terminal 14 requires a signal indicating two frames every two frames,
The output signal of the 1/4 frequency divider 8 may be processed and added to the output signal of the Y signal output terminal 13 and each signal output from the line sequential color signal output terminal.

Effects of the Invention As is clear from the above description, according to the present invention, two types of video signals among three types of video signals are transmitted line-sequentially using two frames as a unit of one set of images, and , in the horizontal scanning period in which the horizontal scanning line numbers in the first and second frames are the same, one of the two types of video signals is transmitted in the first frame, not transmitted in the second frame, and the other This signal is not transmitted in the first frame but in the second frame, so through these transmission systems,
When the image is finally displayed on a television receiver and viewed, due to the afterimage effect of the television receiver's picture tube and the afterimage effect of the human eye, it appears as if three types of signals were transmitted successively. looks like. In particular, the effect is great when two types of video signals related to color signals are selected as line sequential signals.

These afterimage effects can reduce the deterioration phenomenon peculiar to the line-sequential method, and also allocate the reduction in information amount caused by line-sequentialing to improving the S/N of the transmission system, and It is possible to take advantage of the advantages of the line-sequential method, such as by allocating it to expand the frequency band.

[Brief explanation of drawings]

FIG. 1 is a block diagram of main parts showing an example of the configuration of a line sequential signal transmission device according to the present invention, FIG. 2 is a signal waveform diagram of each part of FIG. 1, and FIG. 3 is a diagram of another part of FIG. It is a signal waveform diagram of each part. 7... Vertical sync signal separation circuit, 8... 1/4 frequency divider, 9... Horizontal sync signal separation circuit, 10... 1/2
Frequency divider, 11... switch, 12... switch,
15... Differential circuit.

Claims (1)

[Claims] 1. Of a continuous color video signal composed of three types of video signals, the first video signal is transmitted continuously, and the second and third video signals are sequentially converted into signals for each horizontal scanning line. The device is equipped with a signal conversion switch that converts a continuous signal into a sequential signal, and a control circuit that controls the signal conversion switch, and the control circuit is configured to convert a vertical synchronization signal and a horizontal synchronization signal of an input video signal. By counting the synchronization signals, the signal conversion switch converts the two frames of the second and third video signals into one set of images, and converts the two frames of the second and third video signals into one set of images.
Among the second and third video signals having the same horizontal scanning line number in the second frame, the video signal to be transmitted in the first frame is a video whose transmission is stopped in the second frame, and the transmission is stopped in the first frame. A line sequential signal transmission device characterized in that a signal is transmitted in a second frame.