JPH06217248A - Camcorder provided with unrecorded part detecting function - Google Patents

Abstract

PURPOSE:To prevent an unrecorded part (blank part) from being left by detecting the tail of a recorded part on a video tape before recording is started and holding the camera in a recording temporary stop state at the part. CONSTITUTION:A reproduced FM signal which is picked up by a video head 2 from the video tape 1 is amplified by a preamplifier 3, inputted to a comparator 6 through a detector 4 and a low-pass filter 5, and compared with a previously set voltage 7. Consequently, the comparator 6 outputs 'Lo' when the reproduced FM signal is larger than the voltage 7 or 'Hi' when not. The output of this comparator 6 is inputted to a servo part 9 through a microcomputer 8 for control. Then the tape is rewound by searching until the output of the comparator 6 becomes 'Hi' when 'Lo' or 'Lo' when 'Hi', and the camera is switched to a recording stand-by state at this time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is intended to prevent an unrecorded portion (blank portion) generated on a video tape to be recorded when the VTR integrated camera intermittently records on the video tape. Yes, the present invention relates to a function of detecting the end of a recorded portion before the start of recording and holding the recording paused state at that portion.

[0002]

2. Description of the Related Art In a conventional VTR-integrated camera, when a video tape is set in the VTR-integrated camera and the power source on the camera side is turned on, the VTR-integrated camera starts loading and enters a recording standby state. Then turn on the camera power
Since the tape maintains the loading state as long as it is turned off, even if recording is performed intermittently, an unrecorded portion does not occur in the middle of the recorded video tape.

However, at the time of recording to some extent, the VTR side is mistakenly turned on when the VTR side power is turned on for reproduction in order to confirm the recorded portion or when the camera side power is turned on due to an operation error. If the loading state is changed to the unloading state by turning the power on, there is a possibility that an unrecorded portion may be created on the video tape.

When the video tape containing the unrecorded portion is reproduced, the unrecorded portion becomes a screen with only noise, which makes it very unsightly.

To improve this, there is a method of editing and dubbing, but few people actually do this.

Therefore, in the past, Japanese Patent Laid-Open No. 59-126388 has been used.
As described in Japanese Patent Publication No. JP-A-2003-187, the trick play head detects the end of the recorded portion of the tape.

Further, as described in Japanese Patent Laid-Open No. 64-50263, by rewinding a predetermined amount of magnetic tape onto a supply reel after loading, the generation of an unrecorded portion is prevented.

[0008]

SUMMARY OF THE INVENTION The former conventional technique described above is
Since a special reproducing head is required, there is a problem of cost increase.

In the latter conventional technique, except for loading,
That is, there is a problem in that the occurrence of unrecorded portions cannot be prevented when the tape is fast forwarded.

An object of the present invention is to detect the end of a recorded portion and maintain the recording paused state at that portion regardless of the state of the tape without using a special reproducing head. This is to prevent the occurrence of an unrecorded portion (blank portion) in which nothing is recorded.

[0011]

In order to achieve the above object, a reproduction video FM output detection function is provided in the video circuit of the VTR.

An external switch is provided to forcibly turn on / off this function.

[0013]

In order to search for an unrecorded portion (blank portion), the end of the recorded portion is detected by using the reproduced video FM signal detection circuit immediately after the camera power is turned on, and then the recording is temporarily stopped.

Further, since an external switch is provided so that manual operation can be performed, when newly recording on an already recorded tape, it is possible to prevent malfunction by turning off the search function.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

The reproduced FM signal picked up from the video tape 1 by the video head 2 is amplified by the preamplifier 3, passes through the detector 4 and the low pass filter 5, and then enters the comparator 6. Compare with the preset voltage 7.

As a result, when the reproduced FM signal is larger than the preset voltage 7, the comparator 6 outputs "Lo",
If it is smaller, "Hi" is output.

The output of the comparator 6 enters the servo section 9 through the control microcomputer 8.

When the output of the comparator 6 is "Lo", "H"
When the output of the comparator 6 is "Hi", it is rewound by the search until it becomes "Lo". At this time, the end of the recording portion on the video tape is reached. Has been detected.

Next, the end of the recording portion is detected while the video tracks are continuously connected by rewinding a little from the end of the recording portion and playing back the rewound portion for phase matching. become.

By switching to the recording standby state here,
It is possible to create videotapes with no blank areas.

If this series of operations is programmed in the control microcomputer 8 so as to be automatically activated at the same time when the power of the camera is turned on, the operator forgets to activate the unrecorded detection function, You no longer make a mistake that erases a portion of the recorded videotape or creates an unrecorded portion.

On the other hand, if an attempt is made to newly record on an already-recorded tape, the above-mentioned system malfunctions. Therefore, the switch 11 for turning off the non-recording detection functional operation is provided.

[0024]

According to the present invention, the end of the recorded portion of the video tape can be detected before the start of recording, and the recording paused state can be held at that portion. There is an effect of preventing an unrecorded part (blank part) which occurs in the video tape which is recorded, and an effect of preventing a part of the recorded video tape from being accidentally erased.

If the operation is started at the same time when the power of the camera is turned on, the operator forgets to activate the unrecorded detection function, and creates an unrecorded portion on a recorded video tape, or records a recorded video. You no longer make mistakes like erasing tapes.

By providing a switch for forcibly turning off the operation of the present invention, malfunction can be prevented.

[Brief description of drawings]

FIG. 1 is a block diagram of unrecorded portion detection according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Video tape, 2 ... Video head, 3 ... Pre-amplifier part, 4 ... Detector, 5 ... Integrator, 6 ... Comparator, 7 ... Variable voltage device, 8 ... Microcomputer for control, 9 ... Servo part, 10 ... VTR mechanical part, 11 ... Switch, 12 ... Rotating cylinder.

Front Page Continuation (72) Inventor Akihiko Maruyama 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Stock Information Company Hitachi Image Information System (72) Inventor Takashi Sato 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Prefecture Hitachi Image Information In the system

Claims (3)

[Claims] 1. A VTR-integrated camera including a camera section for photographing a subject and a video tape recorder for recording / reproducing the same, detects an unrecorded portion of a video tape, and returns the tape to the end of the already recorded portion. A VTR-integrated camera with an unrecorded portion detection function, which has a function of holding the recording in a paused state. 2. A VTR-integrated camera with an unrecorded portion detection function according to claim 1, wherein the function is operated by turning on the power supply on the camera side. 3. A VTR integrated camera with an unrecorded portion detection function according to claim 1, wherein the function is turned on / off by a manual switch.