JPH01272276A - Magnetic recording/reproducing device - Google Patents

Abstract

PURPOSE:To facilitate editing point retrieve at the time of editing by setting an output switch at a condition in which a regenerative signal that does not pass through a picture memory is always outputted, in addition to the condition in which the control of the output switch is effected by a controller. CONSTITUTION:A switching means 4 is provided which selectively takes out the regenerative signal accumulated in a picture memory 6 and the regenerative signal which does not pass through the picture memory 6. The switching means 4 is set in an editing mode, and set in the condition in which the regenerative signal that does not pass through the picture memory 6 is outputted during a period corresponding to the transit period at a variable speed reproduction. Thus, at the time of the editing and at mode transit period, the tape position corresponds to the reproduced picture, and the editing point can be correctly retrieved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording/reproducing device equipped with an image memory.

[Summary of the invention]

This invention provides a magnetic recording/reproducing device equipped with an image memory, in which the output switch is controlled by a controller, and the output switch is also set to a state in which a reproduction signal not passed through the image memory is always output. This allows settings to be made, allows noiseless variable speed playback, and allows editing points to be easily searched during editing.

[Conventional technology]

VTRs equipped with field memory are becoming popular. FIG. 5 shows an example of the configuration of a reproduction system of a conventional VTR equipped with a field memory.

In FIG. 5, the recording signal of the tape 51 is transmitted to the rotating head 5.
It is played on 2A and 52B. Rotating head 52A, 5.2
The reproduced signal of B is supplied to the video signal processing circuit 53.

In the video signal processing circuit 53, the luminance signal is FM demodulated,
The chroma signal is frequency-converted, and the luminance signal and chroma signal are combined to form, for example, an NTSC composite video signal.

The output of the video signal processing circuit 53 is supplied to the terminal 54A of the switch circuit 54, and the A/D converter 55
supplied to The output of the video signal processing circuit 53 is digitized by the A/D converter 55 and supplied to the output field memory 56 of the A/D converter 55 .

Field memory 56 is controlled by controller 57. A mode setting signal is given to the controller 57 from a key switch 58.

The output of field memory 56 is supplied to D/A converter 59. A D/A converter 59 converts the output of the field memory 56 back into an analog video signal. D/A
The output of the converter 59 is connected to the terminal 54B of the switch circuit 54.
supplied to

The switch circuit 54 is controlled by a switch control signal Sll from the controller 57 according to the setting mode. The output from the terminal 54C of the switch circuit 54 is output from the output terminal 60.

In this way, when the field memory 56 is installed in the VTR, mosaic, solarization,
It becomes possible to perform special playback such as picture-in-picture. Also, using this field memory 56,
A noise reducer, a TBC (time base collector), etc. can be configured, and image quality can be improved.

Furthermore, by using this field memory 56, noiseless variable speed reproduction can be realized without arranging a large number of heads. That is, in a VTR not equipped with the field memory 56, in order to perform noiseless variable speed playback,
It is necessary to arrange a large number of heads. On the other hand, if the field memory 56 is used, the field memory 56
By controlling the addresses of the images and controlling the switch circuit 54, noiseless variable speed playback can be performed without arranging a large number of heads by synthesizing the noise-free portions of the screen. For example, the noiseless picture search can be realized by replacing the portion that becomes noise for each screen with the signal of the i-revised screen stored in the field memory 56 when the servo is locked at an even multiple speed.

However, even when performing a noiseless picture search using the field memory 56 in this way, the servo lock is not completed during the transition from the normal playback state or pause state to the picture search state, so a noise-free screen cannot be obtained. It is difficult to play.

Therefore, in conventional VTRs of this type, during the transition from the normal playback state or pause state to the picture search state, or during the transition from the picture search state to the normal playback state or pause state, until the servo lock is completed, The image immediately before the mode transition starts is stored in the field memory 56, and the image immediately before the mode transition starts is reproduced as a still image. Thereby, noiseless reproduction can be achieved even during the mode transition period.

That is, assume that in a conventional VTR of this type, the normal m raw mode is switched to the picture search mode at time T, as shown in FIG.

When the mode is switched at time T1, the tape 51 is controlled to be fed at speed 2 during picture search. However, a servo lock time is required to set the tape 51 from the normal speed v1 to the picture search speed Vg.

In order to prevent a screen with noise from being played until the servo lock is completed, a still image will not be displayed from the time the mode is switched at time T until the servo lock is completed at time T2. Regeneration takes place. That is, the playback screen at time T1 is captured into the field memory 56. Then, the switch circuit 54 is switched so that the terminal 54B and the terminal 54C are connected. As a result, the playback screen at time T is output from the output terminal 60.

When the servo lock is completed at time T2, the switch circuit 54 is appropriately switched so that the noise portion on the screen is not output.

[Problem to be solved by the invention]

When editing a video, to search for the desired scene,
Transition from normal playback or pause to picture search,
Or, conversely, a transition from picture search to normal playback or pause is frequently performed. During editing, it is desirable to be able to search for a desired editing point with high accuracy.

As mentioned above, in order to prevent the noise generated during the transition of the playback mode from appearing on the screen, the image immediately before the mode transition starts is stored in the field memory 56 until the servo lock at the time of the mode transition is completed. If the image immediately before this mode transition starts is reproduced as a still image, from time T1 to time T2 in FIG.
The screen is played as a still image. For this reason, time T, ~T
, it becomes difficult to know exactly which position on the tape 51 is currently being reproduced. This causes a problem that a desired editing point cannot be accurately searched during editing.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a magnetic recording and reproducing apparatus that can perform noiseless variable speed reproduction and can accurately detect editing points during editing.

[Means to solve the problem]

The present invention provides a magnetic recording and reproducing apparatus having an image memory 6, which is provided with a switch means 4 for selectively taking out a reproduction signal stored in the image memory 6 and a reproduction signal not passed through the image memory 6. is a magnetic recording/reproducing device that can be set to always output a reproduction signal that is not passed through the image memory 6.

When the switch means 4 is set to the editing mode, it is always set to output a reproduction signal that is not passed through the image memory 6.

This switch means 4 is set to a state in which it always outputs a reproduction signal that is not passed through the image memory 6 during a transition period during variable speed reproduction.

This switch means 4 is set to edit mode, and
During a period corresponding to a transition period during variable speed reproduction, a state is set in which a reproduction signal not passed through the image memory 4 is always output.

[Effect]

A switch 13 is provided for always outputting a video signal that is not passed through the field memory 6.

When editing, this switch 13 is turned on. As a result, during editing, the tape position i and the playback screen correspond to each other at the time of mode transition, and the editing point can be accurately searched.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment of the invention.

In FIG. 1, the recording signal of tape 1 is transmitted to rotary head 2A.
, 2B. Reproduction signals from the rotary heads 2A and 2B are supplied to a video signal processing circuit 3. In the video signal processing circuit 3, the luminance signal is FM demodulated, the chroma signal is frequency-converted, and the luminance signal and chroma signal are combined to form, for example, an NTSC system composite video signal.

The output of the video signal processing circuit 3 is the terminal 4 of the switch circuit 4.
A and is also supplied to the A/D converter 5. An A/D converter 5 digitizes the output of the video signal processing circuit 3.

The output of A/D converter 5 is supplied to field memory 6.

Field memory 6 is controlled by controller 7. A mode setting signal is given to the controller 7 from a key switch 8.

The output of field memory 6 is supplied to D/A converter 9. The D/A converter 9 converts the output of the field memory 6 back into an analog video signal. The output of the D/A converter 9 is supplied to the terminal 4B of the switch circuit 4.

The output from the terminal 4C of the switch circuit 4 is taken out from the output terminal 10.

Switch circuit 4 is controlled by the output of AND gate 11. When the output of the AND gate 11 is, for example, at a low level, the switch circuit 4 is switched so that the terminals 4A and 4C are connected.

For example, when the output of the AND gate 11 is at a high level,
The switch circuit 4 is switched so that the terminal 4B and the terminal 4C are connected.

The AND gate 11 is supplied with the last inch control signal Sl from the controller 7, and the flip-flop 1
A forced setting signal S2 from 2 is supplied. The switch control signal Sl is at a low level during normal playback or pause, and at a high level during a mode transition period until servo lock is completed, and during picture search, to prevent noise from appearing. The level becomes high or low as appropriate.

Flip-flop 12 is set by switch 13. When switch 13 is turned off, flip-flop 1
The forced setting signal S2 from 2 becomes high level. When the switch 13 is turned on, the forced setting signal S2 from the flip-flop 12 becomes low level.

In this embodiment, by manually setting the switch 13, it is possible to realize a noiseless picture search in which no noise appears on the screen even during mode transitions when no editing is performed, and when editing, the desired editing point is accurately located. Can be searched.

That is, the switch 13 is turned off when not editing, and the switch 13 is turned on when editing.

When switch 13 is off, flip-flop 12
The forced setting signal S2 from is at high level. Therefore, the switch control signal Sl from the controller 7 is AND
The signal is supplied to the switch circuit 4 via the gate 11. As mentioned above, the switch control signal Sl is at a low level during normal playback or pause, and during a mode transition period, it is at a high level until the servo lock is completed. The level will be set to high or low as appropriate to prevent it from appearing.

The switch circuit 4 is configured such that when the output of the AND gate 11 is at a low level, the switch circuit 4 is connected to the terminal 4A.
When the output of the AND gate 11 is at a high level, for example, the switch circuit 4 is switched so that the terminal 4B and the terminal 4C are connected. Therefore, during the mode transition period, the screen stored in the field memory 6 is reproduced as a still image, and the screen with noise is not reproduced. When the servo lock is completed, the switch circuit 4 is appropriately switched by the switch control signal 31, and noiseless variable speed reproduction can be performed.

During editing, the switch 13 is turned on. switch 13
When turned on, the forced setting signal S2 from the flip-flop 12 is set to low level. Forced setting signal S2
When ? is set to low level, the output of AND gate 11 is switched from controller 7? Regardless of II signal SL, it is always at a low level. When a low level is supplied to the switch circuit 4, the switch circuit 4 always connects to the terminal 4A.
and terminal 4C are connected. If the switch circuit 4 is always switched to the terminal 4A side, still playback will not be performed even during the mode transition period, so that the edit point can be searched for a positive value.

FIG. 2 shows a second embodiment of the invention.

In FIG. 2, the same parts as in one embodiment are given the same reference numerals. In this embodiment, the switch 13 is also used as an editing switch. That is, a VTR intended for video editing is provided with an editing switch. This editing switch changes the characteristics of the video signal correction circuit in order to cope with image quality deterioration during dubbing.

In FIG. 2, the switch 13 is turned off when not editing, and turned on when editing. When the switch 13 is off, the output of the flip-flop 12 is set to high level, and when the switch 13 is on, the output of the flip-flop 12 is set to low level. The output of the flip-flop 12 is supplied to the AND gate 11 as a forced setting signal S2, and is also supplied to the correction circuit 20 of the video signal processing circuit 3 as a correction value switching signal.

The editing switch 13 is turned off except when editing. (When the concentration switch 13 is turned off, the output of the flip-flop 12 becomes high level, and the correction circuit 20 of the video signal processing circuit 3 has the normal characteristic.The normal characteristic is the playback screen This characteristic emphasizes the high range a little in order to improve the performance.Also, at this time, the forced setting signal S2 becomes high level.Therefore, the switch control signal S from the controller 6 via the AND gate 11
l is supplied to the switch circuit 4. Therefore, during the mode transition period, the screen stored in the field memory 6 is reproduced as a still image, and the screen with noise is not reproduced.

When editing, the editing switch 13 is turned on.

When the edit switch 13 is turned on, the flip-flop 1
The output of 2 becomes low level. When the output of the flip-flop 12 is at a low level, the correction circuit 20 of the video signal processing circuit 3 is set to the editing characteristic. The editing characteristics are characteristics in which the high frequency characteristics are made flat in order to prevent image quality deterioration due to editing. Also, at this time, the forced setting signal S2 from the flip-flop 12 goes low, so the output of the AND gate 11 always goes low regardless of the switch control signal from the controller 7.

Therefore, the switch circuit 4 is switched so that the terminal 4A and the terminal 4C are connected. This makes it possible to accurately search for edit points even during the mode transition period.

FIG. 3 shows a third embodiment of the invention.

In the first and second embodiments described above, the switch 1
When the switch 3 is turned on, the switch circuit 4 is switched so that the terminal 4A and the terminal 4C are always connected not only during the mode transition period but also at all times. On the other hand, in this third embodiment,
When the switch 13 is turned on, the switch circuit 4 is switched so that the terminal 4A and the terminal 4C are connected only at the time of mode transition.

That is, in FIG. 3, the same parts as in FIG. 1 are given the same reference numerals. The output of the flip-flop 12 is switched by a switch 13. switch 1
3 is turned off, the output of the flip-flop 12 becomes high level. When the switch 13 is turned on, the output of the flip-flop 12 becomes low level. The output of flip-flop 12 is inverted and supplied to NAND gate 21.

Further, a mode transition period signal S3 is taken out from the controller 7, and this mode transition period signal S3 is supplied to the other input terminal of the NAND game 21. As shown in FIG. 4, this mode transition period signal S3 becomes high level from t to t2 until the servo lock is completed when switching from the normal mode to the picture search mode, for example.

A forced setting signal s2 is obtained from the NAND gate 21, and this forced setting signal S2 is supplied to the AND gate 1].

When not editing, the switch 13 is turned off and the output of the flip-flop 12 becomes high level.

For this reason, the forced setting signal S2 output from the NAND gate 21 does not depend on the mode transition signal s3 and is always at a high level. When the forced setting signal s2 output from the NAND gate 21 is set to high level, the switch control signal S1 from the controller 7 is set to AND
The signal is supplied directly to the switch circuit 4 via the gate 11. As a result, during the mode transition period, the screen stored in the field memory 6 is reproduced as a still image.

During editing, the switch 13 is turned on. When the switch circuit 13 is turned on, the output of the flip-flop 12 becomes low level. When the output of the flip-flop 13 becomes low level, the mode transition signal S3 is inverted and outputted from the NAND gate 21. That is, switch 1
3 is turned on, the forced setting signal S2 output from the NAND gate 21 becomes low level until time t and xjz in FIG. 4A. When the forced setting signal S2 becomes low level, the output of the AND gate 11 becomes low level regardless of the switch control signal S1 from the controller 7. Therefore, during the mode transition period at times t and xtz, the terminals 4A and 4C of the switch circuit 4 are connected, and the video signal that is not passed through the field memory 6 is output from the output terminal 10. This makes it possible to accurately search for edit points.

Note that in the third embodiment shown in FIG.
3 may also be used as an editing switch, and when the switch 13 is turned on, the characteristics of the correction circuit of the video signal processing circuit can be changed.

Further, in the above embodiment, the field memory stores composite video signals, but component video signals may also be stored. Furthermore, a frame memory may be used instead of a field memory.

〔Effect of the invention〕

According to the present invention, a switch 13 is provided for always outputting a video signal not passed through the field memory 6, and this switch 13 is turned on during editing. As a result, during editing, the tape position and playback screen are matched at the time of mode transition, making it possible to accurately search for editing points. By turning off this switch 13 when not editing,
Still images are played during mode transitions, allowing for noiseless variable speed playback.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a first embodiment of the invention. FIG. 2 is a block diagram of a second embodiment of the invention. FIG. 3 is a block diagram of a third embodiment of the invention. FIG. 4 is a timing chart used to explain the third embodiment of the present invention. FIG. 5 is a block diagram of the configuration of a reproduction system of a conventional VTR. FIG. 6 is a graph used to explain the conventional VTR. Explanation of main symbols in the drawings 4: Swiss circuit, 6: Field memory, 7: Controller, 12: Flip-flop, 13: Switch. Agent Patent Attorney Tadashi Sugiura Figure 1 Figure 2 Shoko Book] Figure 3 h t2 Toshiaki's first birthday 1 Figure 5 June 1986 6ei Commissioner of the Japan Patent Office Kunio Ogawa 1 , Indication of the case 1986 Patent Application No. 102277 2, Title of the invention Magnetic recording and reproducing device 3, Person making the amendment Relationship to the case Patent applicant address 6-7-35, Kitashinyo, Tokyo Parts Co., Ltd. Name ( 21
8) Sony Corporation Representative Director Norio Ohga 4, Agent 170 Address 1-48-10-6 Higashiikebukuro, Toshima-ku, Tokyo, Claims column 2 of the specification subject to amendment, Claims (1) In a magnetic recording and reproducing device having an image memory, a switch means is provided for selectively taking out a reproduction signal stored in the image memory and a reproduction signal not passed through the image memory, and the switch means is always A magnetic recording and reproducing device that can be set to a state that outputs a reproduction signal that is not passed through the image memory. (2) The magnetic recording/reproducing apparatus according to claim 1, wherein the switch means is set to always output a reproduction signal not passed through the image memory when the editing mode is set. 2. The magnetic recording and reproducing apparatus according to claim 1, wherein said switch means is always set to output a reproduction signal not passed through said image memory during a period corresponding to a transition period during variable speed reproduction. (4) The switch means is set to an editing mode and is always set to output a playback signal that is not passed through the image memory during a transition period during variable speed playback. 1. The magnetic recording and reproducing device according to 1.

Claims (1)

[Scope of Claims] (1) A magnetic recording and reproducing apparatus having an image memory, further comprising a switch means for selectively extracting a reproduction signal stored in the image memory and a reproduction signal not passed through the image memory, The magnetic recording and reproducing apparatus is characterized in that the switch means can be set to a state in which a reproduction signal not passed through the image memory is always output. (3) The magnetic recording/reproducing apparatus according to claim 1, wherein the switch means is set to always output a reproduction signal not passed through the image memory when the editing mode is set. (4) The magnetic recording and reproducing apparatus according to claim 1, wherein said switch means is always set to output a reproduction signal not passed through said image memory during a period corresponding to a transition period during variable speed reproduction. (5) The switch means is set to an editing mode and is always set to output a playback signal that is not passed through the image memory during a transition period during variable speed playback. 1. The magnetic recording and reproducing device according to 1.