JPH01129584A - Helical scanning type vtr - Google Patents

Abstract

PURPOSE:To record two kinds of images simultaneously by incorporating two video recording signal processing circuits which supply mutually independent recording signals to two heads and two playback signal processing circuits which convert playback signals into two independent video signals. CONSTITUTION:The video recording signal processing circuits 2A and 28 process signals applied to video input terminals 1A and 1B and supply the processed signals to rotary transformers 4A and 4B. A changeover switch 3 is used for mode switching between one image recording and two-image recording. The output signals of recording/playback heads 5A and 5B are inputted to preamplifiers 6A and 6B through rotary transformers 4A and 4B and changeover switches 71 and 72 change paths between one-image reproduction and two-image reproduction. At the time of the two-image reproduction, the playback signal processing circuits 9A and 9B output individual video signals to video output terminals 10A and 10B. When the changeover switches 71, 72, and 73 are set on the opposite sides from those in a figure, the mode of one-image reproduction is entered.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a helical scan type VTEt recording and playback system.

[Conventional technology]

In a conventional helical scan type VTR, for example, as shown in "NHK Home Video Technology" edited by Japan Broadcasting Corporation, written by Katsuya Yokoyama, page 69, Figure 6-6, the recording signal processing circuit from LPE'-1 to the recording amplifier is used. Considering the circuit from the LPF-2 to the output amplifier as a reproduced signal processing circuit, one of each of the above two types of processing circuits is built into the VTR.

[Problem that the invention seeks to solve]

According to the above-mentioned prior art, only one type of screen can be recorded or played back at the same time in a helical scan type VTR, and for example, recording of a counter program often used in a stationary VTR is also limited to one type.

The present invention compensates for these drawbacks of conventional VTRs.
Its purpose is to enable recording or playback of two programs at the same time.

[Means for solving problems]

The helical scan type VTR according to the present invention is a helical scan type VTR having two recording and playback heads (hereinafter referred to as recording heads) arranged at points symmetrical positions with respect to the center of rotation. Regarding the system, there are two systems of recording signal processing circuits that provide independent recording signals to each of the two heads, and the same goes for the playback system. It features a built-in reproduction signal processing circuit.

[Effect]

Two types of video signal inputs are each provided to independent recording signal processing circuits and converted into individual input signals to the head. Two types of data are recorded on the tape by individual input signals to these heads. During reproduction, the two heads pick up the data independently and alternately in time.

Next, as with recording, the head output is processed by two independent playback signal processing circuits and converted into a video signal, which reduces the information cover by half compared to normal video playback, but allows two independent screens to be played back.

[Embodiment] FIG. 1 (α) and (/l) are block diagrams showing the configuration of a first embodiment of the present invention.

FIG. 1(α) shows the recording system, and FIG. 1(b) shows the playback system.

First, the configuration will be explained. In Figure 1 (α), one person is video input terminal A, IB is video input terminal B, two people are recording signal processing circuit A, 2B is recording signal processing circuit B, 3 is changeover switch A, and 4A is rotary Transformers A and 4B are rotary transformers B, 5A is a recording/reproducing head A, and 5B is a recording/reproducing head B.

In FIG. 1(A), 6A is preamplifier A, 6B is preamplifier B, and 71 is a changeover switch B172 is a changeover switch C! ,
73 is a changeover switch D, 8 is a synthesis switcher, 19A is a reproduction signal processing circuit A, 9B is a reproduction signal processing circuit B,
10A is video output terminal A, IOB is video output terminal B
It is.

Next, the operation will be explained. First, the operation of the recording system will be explained.

Two types of video signals from a television tuner and a video camera are applied to video input terminals iA and IB. The recording signal processing circuits 2A and 2B process the signals applied to the video input terminals IA and IB and transmit the signals to the rotary transformers 4A and 4B.
It works to give. Since this processing operation is the same as that in a conventional VTR, a detailed explanation will be omitted here.

The changeover switch 3 is a switch for switching the mode between one screen recording and two screen recording, and the state shown in FIG. 1 (α) is the two screen recording mode. As you can see from the state of this switch 1
In the case of screen recording, the rotary transformers 4A and 4B and the recording/playback headsets 5A and 5B, which selectively record signals applied to one video input terminal, are conventional helical scan type VTs.
It may be the same as that used in R, and its operation is the same as before, so the explanation here will be omitted.

Next, the reproduction system will be explained.

Output signals from the recording/reproducing heads 5A, 5B pass through rotary transformers 4A, 4B and enter preamplifiers 6A, 6B. The process up to this point is the same as a conventional helical scan VTR. The output of preamplifiers 6A and 6B is selected by switch 71.7.
2, the route is divided into one-screen playback and two-screen playback. Figure 1 (Ch) shows the state of the switch in the case of two-screen playback. That is, the outputs of the preamplifiers 6A and 6B are separately applied to reproduction signal processing circuits 9A and 9B.

The reproduction signal processing circuits 9A and 9B are each equivalent to the reproduction signal processing circuit built in a conventional helical scan VTR. Reproduction signal processing circuits 9A and 9B output separate video signals to video output terminals 10A and 10B, respectively.

When the changeover switches 71, 72, and 73 are set to the opposite side to the position shown in FIG. 1(b), the mode is set to one-screen playback.

In this case, the signals from the preamplifiers 6A and 6B are applied to the synthesis switcher 8, and the signals from the two recording/reproducing heads 5A and 5B are synthesized and input to the reproduction signal processing circuit 9A. Therefore, in this case, nothing is output to the video output terminal 10B.

FIG. 2 shows a block diagram of a recycled yarn according to a second embodiment of the present invention.

The difference from the first embodiment is that a field memory 21A is provided between the changeover switches 71 and 72 and the reproduction signal processing circuits 9A and 9B.
, 21B, adders 22A, 22B and changeover switch E7
5 was added. While one frame of a normal TV is made up of two fields, the two fields of the first embodiment
In the case of screen reproduction, there is only one field of data in a 17V frame, and every other horizontal scanning line of the television screen is displayed.

This embodiment aims to improve this point by rewriting the previous data in every other blank space to ensure the same image quality as a single screen playback screen.

Next, the operation will be explained.

Heads 5A and 5B alternately contact the tape.

During one field period when each head is in contact with the tape, it outputs a video signal with data to the Guga amplifier, but during one field period when other heads are in contact with the tape, a video signal without data is output to the preamplifier. Output to.

Field memories 21A, 21B are preamplifiers 6A, 6
Of the output of B, the video signal part with data is stored for one field. During the period when the 0th order amplifier output is outputting a video signal without data, the field memory outputs the stored video signal to the adder. do.

Adders 22A and 22B add the preamplifier output and the video signal from the field memory during a period when the preamplifier output has no data. Note that this adder is a composite switcher.
It is also possible to perform a switching operation between the preamplifier output and the field memory output as shown in 8.

By the above operation, the video signals applied to the reproduced signal processing circuits 9A and 9B become signals with no gaps.

When the signals output from the video output terminals IOA and 10B are reproduced, the same data is written in two horizontal scanning lines (that is, 2H), but the actual image quality is not inferior to that of normal one-screen reproduction.

Note that the changeover switch 75 is the same as the other changeover switches 71, 72, .
75, it is possible to switch between 1-screen playback and 2-screen playback.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to record two types of screens on a helical scan type VTR by simple improvement.
It is effective for recording TV programs, etc.

[Brief explanation of the drawing]

FIG. 1(a), Ch) is a block diagram showing the configuration of a first embodiment of a helical scan VTR according to the present invention. FIG. 2 shows a second helical scan VTR according to the present invention.
FIG. 2 is a block diagram showing the configuration of an embodiment. IA, IB...Video input terminals 2A, 2B...
...Recording signal processing circuit 5.71, 72, 73. ．．
75...Selector switch 4A, 4B...
Rotary transformer 5A, 5B...Recording/playback head 6A, 6B...Preamplifier 8...Synthesis switcher 9A, 9B...
...Reproduction signal processing circuit 1DA, 10B...
...Video output terminals 21A, 21B...Field memory 22A, 22B...Adder or higher Applicant: Seiko Epson Corporation representative Patent attorney Mogami (1 other person)

Claims (1)

[Claims] This is a helical scan type VTR that has two recording and playback heads (hereinafter referred to as recording heads) arranged symmetrically with respect to the center of rotation, and regarding the recording system, each of the two heads has an independent There are two recording signal processing circuits that provide recording signals, and the playback system also has two built-in playback signal processing circuits that convert the playback signals from the two heads into two independent video signals. A helical scan type VTR.