JPS6333992A - Video signal transmitter - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a video signal transmission device such as a video tape recorder.

2. Description of the Related Art Conventionally, as a video signal transmission device such as a video tape recorder that transmits video signals using a magnetic recording medium, input video signals are converted into component signals of a luminance signal and two color difference signals (or engineering signal, Q signal). There is a component recording method in which the signal is recorded separately into two channels: a luminance signal recording/reproducing section and a two-color difference signal (or ! signal, Q signal) recording/reproducing section. In this recording method, two systems of input signals are compressed in the time axis direction for each horizontal scanning period, as shown in Figure 4, as a method of transmitting two color difference signals (or I signal, Q signal) in one channel. First thing to do. Second
The signal portion of the output of the time axis compression means 23 and 24 and the second time axis compression means 24 is transmitted to the first time axis compression means 23.
first delay means 2 for adjusting to the no-signal portion of the output of
6, and a mixing means 26 for mixing the output of the first time compression means 23 and the output of the first delay means 26 (inside the broken line 27 in FIG. 4), The time required to convert the two-color difference signal (or engineering signal, Q signal) into a time-axis compression multiplexed signal and transmit it through one system of transmission means 2, and to expand the output of the transmission means 29 on the time axis and separate it into two systems. Axis extension means 3o and time axis extension means 3o
The second step is to match the time relationship between the two outputs. Third delay means 3
1.32, the original two-color difference signal (or optical signal).

A time-base compression multiplexing method (for example, the Television Society technical report PP0E38-s) for restoring the Q signal).

There is a recording method (as described in the July 29, 1986 announcement).

When the time axis compression/multiplexing means is configured digitally, as shown in FIG.
It is abbreviated as ) and a first data storage means 44 for storing and compressing the output of the first A/D. Further, the second time axis compression means 24 and the first delay means 2
6 is constituted by a second A/D 46 and a second data storage means 46, and the part constituted by the above-mentioned first. The outputs of the second data storage means 44 and 46 are converted into time-base compression multiplexed data by the digital-to-analog conversion means 48 (hereinafter referred to as D/A).
The time axis compression multiplexing means is constructed by adding a control means 49 for outputting data to the data switching means 4, and a D/A 48 for converting the output data of the data switching means into an analog signal. .

Problems to be Solved by the Invention However, the above configuration requires two systems of expensive A/Ds, and there is a problem that the entire device cannot be constructed at low cost.

The present invention solves the above-mentioned problems and constitutes an inexpensive device.

Means for Solving the Problems In order to solve the above problems, the present invention provides two color difference signals (t
or I signal, Q signal) as input, and these are alternately input to the A/D.
an A/D for digitizing the output of the signal switching means; and an A/D for digitizing the output of the signal switching means.
data converting means and control means for converting the output data of the data converting means into time axis compression multiplexed video signal data, a D/A for converting the output data of the data converting means into an analog signal, and the D/A. This system includes a transmission means for transmitting the output signal of the above-mentioned transmission means, and a time-axis expansion means for time-axis expansion of the signal transmitted by the transmission means and separating it into two systems.

Effects The present invention uses the above-described configuration to compress and multiplex two color difference signals (or engineering signals, Q signals) using one system of A/D, so that the device can be constructed at low cost. Examples will be described with reference to the drawings. FIG. 1 is a block diagram showing the main configuration of the present invention.

Two color difference signals (or I signal, Q signal) are input to input terminals 1 and 2.
signal) is supplied. 2 input to input terminals 1 and 2
The color difference signal is sent to the A/D 4 alternately by the signal switching means 3.
supplied to The output data of the A/D 4 is converted into time-base compression multiplexed data by the data conversion means 5 and is supplied to the D/A s. The output signal of the D/A e is supplied to the transmission means. The signal transmitted by the transmission means 7 is time-axis expanded by the time-axis expansion means 8 and separated into two systems.

The two outputs of the time axis expansion means 8 are supplied to output terminals 11 and 12 via a first delay means 9 and a second delay means 10, respectively.

FIG. 2 shows signal waveforms at each part in FIG. 1. Figure 2 (-
) is the RY color difference signal input to input terminal 1, the second
Figure (b) shows the B-Y color difference signals input to the input terminal 2, respectively. FIGS. 2C and 2D show the rise and fall of data when the RY signal and the BY signal are individually analog-to-digital converted at the switching period of the signal switching means 3. In the configuration shown in FIG. 1, the output of the A/D 4 is in the form of data as shown in FIG. 2 (,).

The data conversion means 6 rearranges the input data shown in FIG. 2(,) as shown in FIG. 2(f) and outputs the rearranged data. Figure 2 (
When the data in f) is converted into analog data by the D/A 6, the output signal becomes a time-base compression multiplexed signal as shown in FIG. 2(q).

The output signal of D/A e is transmitted by transmission means a,
It is input to the time axis expansion means 8. The time axis expansion means 8 is, for example, the A/Ds1° data storage means 52, as shown in FIG. 1st D/A53. 2nd D/Ar54. 1st
The clock generation circuit 56. Second clock generation circuit 56
Consists of. For example, the A/D 61 has a
A time-base compression multiplexed signal as shown in FIG. It is digitized and output at ts MHz.

The data output from the A/D 51 is shown in Figure 2 (f
) and are input to the data storage means 52 and stored in that order. The frequency of the clock output from the second clock generation circuit 56 is set to half the frequency of the clock output from the first clock generation circuit 66, and the data of hld, 7s, R-Y, and B-Y are sequentially read, respectively first D/A 53. Second
By separately supplying the first D/A 54 to the first D/A 54,
For example, the color difference signal RY as shown in FIG. 2(a) is output from the A53, and the color difference signal RY as shown in FIG. 2(b) is output from the second D/A54.
A color difference signal B-Y as shown in is output.

The two color difference signals separated and expanded by the time axis expansion means 8 of FIG.
The delay means 1o removes the time axis deviation between the two color difference signals or the luminance signal transmitted on another channel, and outputs the signals to output terminals 11 and 12, respectively.

Effects of the Invention As described above, the video signal transmission device of the present invention can convert a two-color difference signal into a time-base compression multiplexed signal and transmit it using only one A/D system. can be constructed at low cost.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the main parts of an embodiment of the present invention, and FIG. 2 (
a) , (b) , (e) , (f) , (q
) is a signal diagram of each part of the block diagram shown in Figure 1, and Figure 2 (O
L(d) is a signal diagram of each part of the block diagram shown in FIG.
The figure is a block diagram showing one embodiment of the time axis expansion means.
The figure is a block diagram showing a conventional example, and FIG. 6 is a block diagram when a part of the conventional example is constructed with a digital circuit. 3... Signal switching means, 4... Analog-digital conversion means, 5... Data conversion means, 6... Digital-analog conversion means, A.
...Transmission means, 8... Time axis expansion means,
9...First delay means, 1o...Second
delay means, 51...analog-digital conversion means, 62...data storage means, 53...
...first digital-to-analog conversion means, 64...
. . . second digital-to-analog conversion means, 65.
...First clock generation circuit, 56...
Second clock generation circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 3 Figure 5

Claims (1)

[Claims] A signal switching means that takes a two-color difference signal of a video signal as an input signal and outputs the two color difference signals alternately, an analog-to-digital conversion means for converting the output of the signal switching means into a digital signal, and an analog-to-digital conversion means for converting the output of the signal switching means into a digital signal. a data conversion means for rearranging the output into a time-base compressed multiplex signal; a digital-to-analog conversion means for converting the output of the data conversion means into an analog signal; and a transmission means for transmitting the output signal of the digital-to-analog conversion means; A video signal transmission device characterized by comprising time axis expansion means for time axis expansion of the signal transmitted by the transmission means and separating it into two systems.