JPS6350281A - Recording and reproducing device - Google Patents

Abstract

PURPOSE:To allow one unit to record and reproduce plural video signals by taking plural video signals for digital signals, applying time base compression to said signals, recording them, selectively taking out specific signals in a reproducing mode and executing interpolation and time base expansion. CONSTITUTION:Plural signals are inputted to a mixing circuit 14 through encoder circuits 10 and 11 and time base compression circuits 12 and 13. The signals are transmitted to a head 2a or 2b through a switching circuit 15 in such a way that a video signal carrying contents A and a video signal carrying contents B can lie within one field at 262.5 H. Since in the reproduction mode one track has two pieces of information about the contents A and B, a separator circuit 20 separates signals obtained from the heads 2a and 2b. A time base expansion circuit 21 and an interpolation circuit 22 restore the contents A and B so that they can be approximate to their original information, and a making analog circuit 23 reproduces them.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a recording/reproducing apparatus such as a video tape recorder using digital technology.

BACKGROUND OF THE INVENTION In recent years, home video recording and reproducing devices (especially VTRs) have become more and more popular, and their performance and multi-functionality are increasing rapidly.

Problems to be solved by the invention However, the recording time is 2 times on one cassette tape.
Although the time has been extended to 8 hours, it was necessary to prepare two pieces of equipment in order to simultaneously record and play back the contents of multiple broadcasts, for example NHK and commercial stations.

In view of the above-mentioned problems, the present invention digitizes a plurality of video signals, compresses them on a two-time axis, records them as one video signal, and when playing back, selectively selects a specific signal from among the recorded signals. The present invention provides a device in which a plurality of different video signals can be reproduced using a single recording and reproducing device by extracting the signals, extending the time axis, complementing the signals, and reproducing them.

Means for Solving the Problems In order to solve the above problems, the recording and reproducing apparatus of the present invention includes:
an encoding circuit for encoding a video signal; a time-base compression circuit for time-base compression of the video signal encoded by the encoding circuit; a time axis expansion circuit for time axis expansion of a video signal obtained by the time axis expansion circuit; and a complement circuit for complementing each code of the video signal time axis expanded by the time axis expansion circuit, and a plurality of video signals. The video signal is encoded by the encoding circuit and the time axis compression circuit, compressed on the time axis, and recorded as one video signal, and during playback, a specific video signal is selectively extracted from the recorded signal, and the video signal is compressed on the time axis. It has a configuration in which playback is performed through an expansion circuit and a complementation circuit.

According to the present invention, a plurality of video signals are converted into digital signals, time-axis compressed, and recorded using the above-described configuration, and during playback, a specific signal is selectively extracted, time-axis expanded and complemented, and thereby one device It becomes possible to record and play back multiple video signals.

Embodiments Hereinafter, recording and reproducing apparatuses according to embodiments of the present invention will be described with reference to the drawings.

FIG. 2 shows a mechanical part related to recording and reproduction according to an embodiment of the present invention. 1 is the direction of arrow 1a 1800
It is a rotating head cylinder that rotates at rpm and has heads 2a and 2b. 3 and 4 are tape guide posts,
The tape 6 is wound and guided around the tape guide post 3 as shown in the figure, and is wound approximately 180 degrees around the rotating head cylinder 1.
Thereafter, the tape is wound around the tape guide post 4, and the moving direction of the tape is in the direction of the arrow 6.

FIG. 1(,) is a circuit diagram of a recording system according to an embodiment of the present invention. 16 and 17 are independent video input signal terminals, each of which has an encoding circuit 10. jl and time axis compression circuit 12.
13 is connected, and beyond that is a mixing circuit 14.
The switching circuit 15 transmits the signal to the heads 2a and 2b.

FIG. 1(b) is a circuit diagram of a reproduction system according to an embodiment of the present invention. A switching circuit 16, a decomposition circuit 2o, a time axis expansion circuit 21, a complementation circuit 22, an analogization circuit 23, and a video signal amplification circuit 24 are connected in series to the heads 2a and 2b, and 26 is an output terminal.

The operation of the recording/reproducing apparatus of this embodiment configured as described above will be explained.

First, refer to FIGS. 1(a) and 3. In FIG. 1(,), the video input terminal 16 receives a video signal containing the content of A shown at 30 in FIG. A video signal containing the contents of B shown at 32 is included.

Each signal passes through each encoding circuit 10.11 and time axis compression circuit 12.13 and is input to the mixing circuit 14. In the mixing circuit, as shown in Fig. 3, a video signal 30 containing the content of A and a video signal 32 containing the content of B are used.
and falls between 1 field, 262.5H, indicated by section 60, resulting in a signal like 31, and signal 31 contains about half of the contents of A and B as information during section 50. . The signal 31 in such a form is transmitted to the head 2a or head 2b via the switching circuit 15.

The heads 2a and 2b are in contact with the tape 5 in a configuration as shown in FIG. 2, and a tape pattern as shown in FIG. 4 is drawn. In FIG. 4, 6a is the direction in which the head moves, and tracks 40a and 40b are head trajectories drawn by heads 2a and 2b, respectively.
This truck 40a.

Each of the 4ob corresponds to section 5Q in Fig. 3, so-called 1 field, 262.6H.

The above is the time of recording, but now the time of playback will be explained.

In FIG. 1(b), the signals obtained by the heads 2a and 2b are sent to the separation circuit 20, where one track contains two pieces of information, content A and content B, as described above. Therefore, this is separated, and then A and B are restored in a form close to the original information by the time axis expansion circuit 21 and the complementation circuit 22, and then reproduced in the form of video signal 3o or 32 by the analogization circuit 23. is output to the output terminal 2 via the video signal amplification circuit 24.
5 is output. Although not shown in FIG. 1(b), when separating in the separation circuit 20, for example, either A or B is selected and separated using a selection signal from a separate 2 selection circuit (not shown). becomes.

In this embodiment, a magnetic recording/reproducing apparatus using a magnetic tape or the like is used, but this can also be applied to optical recording, and the recording medium is not specified.

Effects of the Invention As described above, according to the present invention, for example, video signals sent from two different broadcasting stations are encoded and time-axis compressed, so that they can be displayed as one screen on a TV monitor. For example, if the above-mentioned multiple broadcast contents are sequentially recorded in one track of a helical scan VTR, and when played back, one of the information of two different broadcast stations recorded in one track is recorded. By selecting, extending the reproduced signal on the time axis, and complementing it, it is possible to obtain a video signal that almost matches the original broadcast content. According to this, for example, it is possible to record broadcasts of a plurality of channels with one VTR, greatly improving convenience for users. In addition, by using signals from multiple surveillance television cameras instead of the multiple channels mentioned above, these safety systems can be operated efficiently, that is, the screens of multiple cameras can be displayed and played back on one screen at all times. It is also possible to enlarge and display the screen of a specific camera on the same screen.

Due to these factors, this effect is very large.

[Brief explanation of the drawing]

FIG. 1(a) is a block diagram of a recording system circuit of a recording and reproducing apparatus according to an embodiment of the present invention, FIG. 1(b) is a block diagram of a reproducing system circuit, and FIG. 2 is a block diagram of a recording system circuit of a recording and reproducing apparatus according to an embodiment of the present invention. A top view of the mechanical part of the device, Figure 3 is a conceptual diagram of the signal processing of the device, Figure 4
The figure is a diagram of the same tape pattern. 10... Encoding circuit, 12... Time axis compression circuit, 21... Time axis expansion circuit, 22...
...Complementary circuit. Name of agent: Patent attorney Toshio Nakao and one other name
1 Figure (b) Figure 2 Figure 3

Claims (1)

[Claims] an encoding circuit that encodes a video signal; a time-base compression circuit that compresses the video signal encoded by the encoding circuit; and an encoded video signal that is time-base compressed by the time-base compression circuit. a time axis expansion circuit for time axis expansion of a plurality of video signals; and a complementation circuit for complementing each code of the video signal time axis expanded by the time axis expansion circuit; The time-base compression circuit encodes and compresses the time-base and records it as a single video signal. During playback, a specific video signal is selectively extracted from the recorded signal and reproduced through the time-base expansion circuit and the complementation circuit. A recording/reproducing device characterized in that it is configured to.