JPS62239682A - Recording and reproducing device - Google Patents

Abstract

PURPOSE:To record a video signal inputted externally from an exclusive image pickup means and to reproduce the signal by a common mechanism by providing the image pickup means, a time base compresssion means, a recording and reproducing means and a time base expansion means. CONSTITUTION:A video signal read from the image pickup means 11 and the video signal inputted externally are recorded for one field at a period shorter than one field period by a time base conversion circuit 20. Then the video signal is recorded and reproduced by one field each at one revolution of rotary heads Ha, Hb and the turning radius of rotary heads He, Hb is decreased. Thus, the video signal inputted externally from the terminal 40 and the video signal obtained by the exclusive image pickup means 11 are recorded and reproduced in a small sized and light weight device.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a recording/reproducing device, especially! ! The present invention relates to a recording and reproducing device that has an image-throwing means.

<Prior Art> Conventionally, various video tape recorders (VTRs) that are integrally equipped with a video camera have been proposed and implemented. In this type of so-called camera-integrated VTR, the biggest challenge is to reduce the weight and size of the main body.

On the other hand, a so-called rotating two-head helical scan type VTR is generally known for home use. FIG. 3 is a diagram showing the arrangement of heads of this type of VTR. In FIG. 1, reference numeral 1 denotes a magnetic tape, and 2a and 2b denote tape guides for winding the tape 1 over an angular range of the outer circumference Vc1B[1'' of the rotating drum 3 or more.

H and HB are rotating heads respectively attached to the rotating drum 5 with a phase difference of 1800 degrees, and have different azimuth angles from each other. Head HA.

1'lBd As is well known, one field of video signals is recorded and reproduced during 180'' rotation.

In this type of VTR, the track length of the video signal for one field is predetermined in the standard, so the diameter of the rotating drum 3 is necessarily determined. Just in case it cannot be made smaller and prevents the VTR from becoming smaller and lighter.

Therefore, as a VTR whose drum diameter can be reduced, the following VTRs have been proposed and implemented in the past. Fourth
The figure shows the head arrangement in a conventional VTR having a small diameter drum. In the figure, Ha and HbFi are rotary heads with different azimuth angles, and rotate once during one field period of the video signal. 300 for tape 1 Fi drum 4
The rotating head H is wound over an angular range of 0 or more.
A and Hb each record one field of video signals while rotating by 300°. That is, during one field period, a video camera (not shown) performs a t-scan on a screen with an aspect ratio of 9:10 (indicated by a point 1mY in FIG. : Head Ha within the % field period with the screen of 4 as the valid screen.

Record in Hb.

The timing at the time of recording will be explained using the timing chart of FIG. 6. During the period indicated by T in the figure,
A video camera (not shown) scans the Y screen with an aspect ratio of 9:10, and displays 515 consecutive images as shown in Fig. 6(a)K.
A video signal t-consisting of a horizontal scan of a book is obtained.

However, since the heads Ha and Hb actually trace a percentage of the tape 1 within each field period, 262.5 horizontal scans of that amount are traced in Fig. 6 [bl
K'' is taken out as shown and recorded on the magnetic tape as a video signal with an aspect ratio of 3:4.At this time, the head Ha
, Hb are alternately traced on the magnetic tape, so the VTRIC with the head arrangement shown in FIG. 2 can perform recording similar to the VTR with the head arrangement shown in FIG. 3. However, since it is necessary to maintain a slight phase difference between the heads Ha and l1lb at this time, it is necessary to appropriately delay the video signal of the first field or the second field.

If video signals are recorded as described above using the conventional head arrangement shown in FIG. 4, the drum diameter can be reduced to the VTR% shown in FIG.

However, the VTR1/(
In this case, the recorded video signal cannot be played back. That is, even if the signals are reproduced from the tape 1 using the heads Ha and Hb of FIG. 4, a continuous reproduced video signal as shown in FIG. 6 tb+ cannot be obtained.

To solve this problem, Japanese Patent Application Laid-Open No. 60i9372 discloses a configuration that makes it possible to reproduce a video signal using a variable delay line.

With the VTR disclosed in the publication, the playback video obtained in % field period of one field period is as follows (with a playback RF waveform as shown in Fig. 6 (bJ)).
- A variable delay line is used to extend the time axis to obtain continuous reproduction video No. 1g.

Problems to be Solved by the Invention> By the way, if a VTR as described above can perform playback, it will naturally be possible to use it as a so-called stationary VTR as well. In other words, if a small VTR using this small-diameter drum could perform all functions such as camera shooting, TV recording, and even monitoring, there would be no need to go to the trouble of using an integrated VTR for camera shooting.
This eliminates the need to have two TRs and a stationary VTR, which is extremely advantageous for the user.

However, as mentioned above, conventionally known VTRs
In this case, it was not possible to record external inputs, such as television signals received by a tuner.

The present invention has been devised in view of the above-mentioned problems, and is capable of recording video signals from a dedicated imaging means as well as video signals input from the outside, and also enables reproduction thereof using a common mechanism. The purpose is to provide

Means for Solving the Problems〉 For this purpose, in the present invention, a video signal for one field to be recorded can be read out in a period shorter than one field period, and an external y) means for time-axis compressing the input video signal in units of one field;
A configuration comprising means for recording and reproducing one of the output of the photographing and operating means and the output of the time axis compression means, and means for expanding the time axis of the reproduced video signal from the recording and reproducing means in units of one field. There is.

By configuring as described above, the video signal read out from the imaging means can also be input (from the outside), and the video signal can also be input to the outside.
One field can be recorded in a period shorter than the field period, and thus video signals can be recorded and reproduced one field at a time with one rotation of the rotary head, and the rotation radius of the rotary head can be reduced. This has made it possible to record and reproduce externally input video signals and video signals obtained from a dedicated camera unit in a small diameter and lightweight device.

<Example> The following is an example of the present invention. ! I will be explained using the drawings. Figure 1 shows a camera integrated FI as an embodiment of the present invention.
FIG. 2 is a diagram showing a schematic configuration of VTH.

First, as mentioned above, in a period of % of one field period, 26
The operation of reading out a video signal having 2.5 horizontal scanning lines and recording the photographic output of the photographic hook section 11 will be described.

When the video signal as shown in FIG. As is well known, in the recording signal processing circuit 16, the luminance signal in the video signal is rilFM modulated, and the chroma signal is balanced modulated in its low frequency range and frequency multiplexed.Recording signal processing circuit 16, the video signal is sent to the head Ha, 1'I'bV via the switch 170R side terminal and the switch 18.
C is supplied. The heads Ha and Hb are arranged as shown in FIG. 4, and record video signals for one field of t/c while each rotates one time during one field period.

The switch 18 is operated by a well-known rotary drum rotation phase detection circuit.

At this time, the video signal output from the switch 14 is supplied to the time axis conversion circuit 20 and is time axis expanded. That is, at this time, as shown in FIG. 2(a), from the switch 14,
A video signal having a no-signal portion between each field is output], and this video No. 100 is subjected to time axis expansion of the video signal of each field by % in the time axis conversion circuit 20,
A normal video signal as shown in b) is obtained and outputted to the output terminal 22 via All[IIt- of the switch 21.

The output video signal is supplied to, for example, a CRT of an electronic viewfinder or a television receiver.

Here, the detailed operation of the time axis conversion circuit 20 will be explained. The nine video signals output from the switch 14 are input to a sync separator circuit 31 and a low pass filter (LPF) 52r.The sync signal in the video signal is separated in the sync separator circuit 51, and this sync signal QK sync. A clock is generated by the generator 65.The frequency of this clock is selected to be a frequency that can sample the first word of the video with sufficient resolution.For example, 4 fee' or 3 fsc'
is selected. Here, fac' is the subcarrier frequency of the chroma signal of the television signal, and the subcarrier frequency of the chroma signal of the television signal (
fgc).

The output clock from the clock generator 35 is used as a sampling signal for the analog-to-digital (A) converter 34, and is also input to the memory control circuit 35 as a timing pulse. The memory control circuit 55 generates a write control pulse (W) for the memory 36 in synchronization with the output of the frame clock generator 33 and a read control pulse (R) for the frame memory 36 in synchronization with the oscillation output of the reference oscillator 37. At this time, the frequency of the write control pulse (W) is 4 fa
c', the frequency of the read control pulse fR1 and the output signal of the reference oscillator is 4 fBQ.

In the frame memory 36, the video signal of the first field is written into the frame memory at the timing shown in FIG. 2 (C), and read out at the timing shown in FIG. It is written to another part at the timing shown in FIG. 2(e) K, and is read out at the timing shown in FIG. 2(f).

The output signal of the frame memory 36 is digital-analog (
The D/A) converter 38 converts the signal back to a normal analog video signal, and the LPF 5 ? It will be outputted to the terminal 22 via . As a result, the telephonic video tg obtained by the imaging unit 11 is sent to the switch 1 in the signal form as shown in FIG. 2(a).
8 and is recorded on tape, and is also supplied to an electronic viewfinder or an external monitor from a terminal 22 as a normal video signal.

Next, a case will be described in which a video signal input from an external device such as a tuner is recorded. Reference numeral 40 is a terminal to which the external video signal is input, and at this time switch 13.
15 and 21 are connected to the B side, respectively. The externally input friend video signal is outputted to the terminal 22 via the B side terminal of the switch 13, the R side terminal of the switch 14, and further the Bll terminal of the switch 21. The output signal from the switch 14 is compressed in time axis to % in units of one field by the time axis converter 20, and is supplied to the recording signal processing circuit 16 via the terminal on the switch 150B side. This axis converter 20 converts a video signal in the signal form shown in FIG.
The signal is inputted to the post-recording signal processing circuit 16 as a video signal in the signal form indicated by a+. That is, the video signal supplied to the recording signal processing circuit 16 has the same signal format whether the video signal read out from the imaging section 11 is recorded or the externally input virtual video signal is recorded. Therefore, recording on tape can be performed in the same way, and a normal video signal can be output from the terminal 22 to a monitor or the like.

Here, the function of the time axis converter 20 when compressing the time axis to % will be explained. If the frequency of the clock output by the clock generator 33 is 4 fsc, the frequency of the write control pulse (W) of the frame memory is also 4 fa.
c. At this time, the oscillation frequency of the reference oscillator 37 and the frequency of the read control pulse of the frame memory 56 are
fsc'. In this case, the writing timings of the video signals of the first and second fields in the frame memory 36 are as shown in FIGS. 2(d) and 2(f), respectively. The readout frequency of the second field is shown in Figure 2 (
C), as shown in (θ).

Finally, the operation during playback will be explained. During playback, switches 14 and 17 are respectively connected to pOtq. The video signals reproduced from the heads Ha and Hb are switched to the switch 18.
, the reproduction signal processing circuit 4 via the P side terminal of the switch 17.
1 and undergoes well-known signal processing in a VTR. At the time of reproduction, the video signal which is connected to the switch 21tliA side and is outputted from the reproduction signal processing circuit 41 is outputted from the terminal 22 via the time axis converter 20.

At this time, the time axis converter 20 performs the above-mentioned time axis expansion by % and converts the video signal from the signal form shown in FIG. 2(a) to the signal form shown in FIG. 2(b).

According to the above-mentioned camera-integrated VTR, it is possible to record video signals from a dedicated camera, record externally input video signals, and even playback them by just using one frame memory, and it is ultra-compact and lightweight. This is something that can be achieved.

Here, if the supply of the write control pulse (W) to the frame memory 36 during reproduction is stopped, a still image signal is not output from the terminal 22, and good still image reproduction can also be performed. Furthermore, various special effects can be obtained by appropriately controlling the writing and reading of the frame memory 36.

<Effects of the Invention> According to the present invention, as described above, there is provided a video signal recording and reproducing device which is extremely small and lightweight and can realize the output of a dedicated imaging means, as well as the recording and reproduction of an externally inputted video signal.
This is something that can be obtained.

[Brief explanation of drawings]

Figure 1 shows a camera-integrated VTR as an embodiment of the present invention.
Figure 2 is a timing chart for explaining the recording and reproducing operation of the VTR shown in Figure 1. Figure 3 is a rotating two-head helical scan/type VTR.
FIG. 4 is a diagram showing the head arrangement in a conventional VTR having a small diameter drum. FIG. 5 is a ninth diagram explaining the scanning of the video camera in the VTR shown in FIG. 6 is a timing chart during recording in the VTR of FIG. 4. Reference numeral 11 indicates a four-photographing unit, 161 indicates a recording signal processing circuit, 20 indicates a time axis conversion circuit, 41 indicates a reproduction signal processing circuit, and Ha and Hb each indicate a rotating head.

Claims (1)

[Claims] an imaging means for reading out a video signal for one field to be recorded in a period shorter than one field period; a means for time-axis compressing the video signal inputted from the outside in units of one field; and an output of the imaging means and the A recording and reproducing apparatus comprising means for recording and reproducing one of the outputs of the time axis compression means, and means for expanding the time axis of the reproduced video signal from the recording and reproducing means in units of one field.