JPH03186081A - Magnetic recording/reproducing device and its recording time expiration recognition method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic recording/reproducing device such as a VTR, and particularly relates to a magnetic recording/reproducing device such as a VTR.
The present invention relates to a so-called time-lapse VTR capable of performing tape recording by switching to various recording times by changing the tape speed when recording fields or l frames or by changing the intervals when recording l fields or l frames.

[Prior Art] In a general home VTR that does not have a time-lapse function, the time required for one revolution of each of the take-up reel and the supply reel is The tape position (
The remaining amount of tape, etc.) was detected.

[Problems to be Solved by the Invention] The above-mentioned prior art is a tape position detection method mainly for a VTR that continuously runs the tape at a constant speed. By the way, if you try to apply the above-mentioned conventional technology to a VTR, such as a time-lapse VTR, which relatively often runs a fixed amount of tape intermittently at fixed intervals to enable long-term recording, it will be difficult to use a take-up reel. There is a problem that the number of digits of the timer used to measure the time required for each supply reel to rotate once increases dramatically (
For example, compared to standard speed, time-lapse VTR's 72
If you consider the 0 hour mode, it will be 360 times more)
In general, time-lapse VTRs are not equipped with a tape position detection function.

However, since time-lapse VTRs, which are often used for long-term monitoring and recording of observations, can record oral movements for long periods of time, users often forget that the set recording time has elapsed. . For this reason, there has been a strong desire for this type of time-lapse VTR to have a function that allows the user to recognize when there is only a small amount of tape remaining during recording.

The present invention has been made in view of the above points, and its main purpose is to provide a time-lapse VTR that can easily obtain a signal to inform the outside when there is little remaining tape remaining. Our goal is to provide the following.

[Means for Solving the Problems] In order to achieve the above object, the present invention changes the tape speed when recording one field or one frame at a time, and/or changes the tape speed when recording one field or one frame at a time. In a magnetic recording/reproducing device (in a time-lapse VTR) that can perform tape recording by switching to various recording times by changing the interval, recording starts from the beginning of the magnetic tape, and from this recording start, the recording time selected and set is changed. The means for recognizing that the same amount of time has elapsed is configured to output a signal to notify the expiration of the set recording time when the selected and set recording time has elapsed and there is only a small amount of tape remaining. Ru.

[Function] The calculation means to which the selected and set recording time has been input recognizes this when recording starts from the beginning of the magnetic tape, and calculates, for example, every second from the set recording time by outputting from the clock means. Execute the subtraction process. Then, the determination means determines whether the time measured by the calculation means indicates that the selected recording time has been reached as described above, and there is a small amount of tape remaining and the selected recording time has been reached. At the point in time, a signal is output to notify the expiration of the set recording time. Such timekeeping calculation processing can be easily realized by, for example, a microcomputer built into a VTR, and by highly accurate timing measurement, it is possible to accurately recognize the point in time when the remaining amount of tape becomes small.

[Example 1] The present invention will be explained below using an example shown in FIG.

FIG. 1 is a block diagram showing the main structure of a time-lapse VTR. In the figure, 1 is a recording time mode setting switch, and by operating this switch 1, various recording time modes can be selected and set. In this embodiment, for example, standard time (2 hours) mode, 1
2 hour mode, 24 hour mode, 72 hour mode...
..., 720 hour mode is selectable,
In standard time mode, continuous recording is performed at the standard speed, in 12-hour mode and 24-hour mode, continuous recording is performed at a tape speed (low speed) appropriate for each mode, and in 72-hour mode and above, continuous recording is performed at an interval appropriate for each mode. Intermittent recording is performed at different tape speeds and tape speeds (low speeds). In addition, in this embodiment, as will be described later using the 720-hour mode as an example, the actual recordable time on the tape is several percent of the set recording time according to each recording time mode described in "-". It is intended to increase. Note that any suitable switch means can be applied to the recording time mode setting switch 1, but in this embodiment, for example, an up/down switch is used.

Reference numeral 2 denotes a tape running control section which, in response to an input instruction from the recording time mode setting switch 1, sets the tape speed to a value corresponding to the selected recording time mode;
In the case of a mode that requires intermittent recording, a predetermined interval corresponding to the selected mode is set using its own counter function to cause the tape to run intermittently. 3
is a motor driver that drives the tape running motor 4 based on instructions from the tape running control section 2.

Reference numeral 5 denotes a calculation means which takes in the recording time selected by the input instruction from the recording time mode setting switch 1, and calculates the recording time 5 by the arrival of a signal Sl indicating the start of recording from the beginning of the tape.
Based on the output of the clock means 6, arithmetic processing is performed to subtract, for example, one second from the set recording time. Reference numeral 7 denotes a determining means that determines whether or not the subtraction content of the arithmetic unit 5 has become "0" (whether or not the set recording time has elapsed), and the point in time when the subtraction content has become "0". outputs signal S□ indicating the expiration of the set recording time. This output signal S2 is used as a drive trigger for various alarm means, such as sounding a buzzer or lighting an LED. In the case of a so-called series recording system in which multiple VTRs are installed and sequentially driven, it can be used as a signal to instruct the next VTR to start recording. At the time this signal S is output, there is a small amount of remaining space on the tape, so it is possible that the user did not notice that the tape had ended and was unable to record.
Uqcs can be avoided as much as possible.

In this embodiment, the output signal S of the determination means 7 is sent to a transmission fδ section 8 separately attached to the VTR, and from the transmission section 8 is transmitted to the video camera and the time-lapse V T.
R installation 1! The information is transmitted to a receiving means 9 installed at a location away from the lli location, and the receiving means 9 allows the monitor to recognize the set recording time. In other words, in this embodiment, it is assumed that the time-lapse VTR is used for the purpose of monitoring and recording an ATM installation location in a store, etc., and it is virtually impossible to generate an alarm at the time-lapse VTR installation location. However, if there is a certain amount of tape remaining, the supervisor should be made aware of the expiration of the set recording time in the manager's room in the same building or the monitoring room of the security company contracted for monitoring, and the tape can be stopped when there is some remaining tape. It is designed to encourage exchange.

In the above configuration, if the recording time mode setting switch 1 selects, for example, the 720-hour mode, the tape running control section 2 changes the contents of the counter that determines the interval for intermittently running the tape to, for example, 6. Select 2 seconds. In other words, if you used a tape that could record for 2 hours at standard speed, it would record just 7 hours.
In order to record only 20 hours, the interval counter was set to (720/2) x (1/60) = 6 seconds and the tape was driven a certain amount every 6 seconds. - As mentioned above, this interval counter is set not to 6 seconds but to a value a few percent higher, for example, about 3.3% plus (6.2 seconds). Therefore,
By doing this, when the 720 hour mode is selected, it becomes possible to record 720×1.033#744 hours as a whole.

Therefore, if you select 720 hours, 744
Even if the tape can record time, it will take 720 minutes from the start of recording.
When the time has elapsed, this will be notified to the outside, and if the tape is replaced during the remaining 24 hours,
This makes it possible to avoid problems such as recording omissions due to tape cuts. In this way, in the 720-hour mode, it is possible to prompt tape replacement with a 24-hour margin.
As described above, when the time-lapse VTR is used for monitoring recording or the like, the person managing the time-lapse VTR can change the tape at a convenient time with sufficient time.

Here, when used in 720 hour mode, the remaining time is 2.
There may be some doubt that output prompting tape replacement after 4 hours is too early considering the amount of tape used.However, the tape speed in 720 hour mode is 1/360 compared to standard mode. and 72
When converting 24 hours in the 0 hour mode to the am mode, there is 4 minutes of remaining tape remaining, which is a small amount and the waste of the remaining tape amount is practically negligible.

Note that the remaining amount of tape (remaining recordable time) at the time the output prompting tape replacement is made is determined by setting the interval and tape speed for intermittently running the tape to a predetermined value, depending on the type of recording time mode, etc. You can set it to anything you like by setting it to .

Although the present invention has been described above with reference to the illustrated embodiment, those skilled in the art will be able to make various modifications without departing from the spirit of the present invention. Remaining amount.

Any tape speed, tape feeding interval, etc. can be selected. In addition, the tape regular line N
i control unit 2. The operator stage 50, the clock means 69, the determination means 7,
It is obvious that this can be easily implemented using a microcomputer built into a VTR.

It is also advantageous in terms of cost.

[Effects of the Invention] As described above, according to the present invention, it is possible to easily and reliably generate a signal prompting for tape replacement when there is a recordable remaining amount of tape, thereby preventing recording omissions due to tape cuts. Problems can be avoided as much as possible in time-lapse VTRs, which are often used for recording monitoring and observation of the species.
Its value is enormous.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the main structure of a time-lapse VTR according to an embodiment of the present invention. ■・・・Recording time mode setting switch, 2...
... tape running control section, 3 ... motor driver, 4 ... motor, 5 ... calculation means,
6... Clock means, 7... Judgment means, 8
. . . Transmitting means, 9 . . . Receiving means. Figure 1

Claims (1)

[Claims] Various recording times can be achieved by changing the tape speed when recording one field or one frame at a time, and/or by changing the interval when recording one field or one frame at a time. In a magnetic recording and reproducing device capable of switching tape recording, recording is started from the beginning of the magnetic tape, and when a selected and set recording time has been recorded, a signal is output to notify the expiration of the set recording time. Features of magnetic recording and reproducing device. 2. According to claim 1, the magnetic tape has a predetermined amount of unrecorded tape remaining when the selected recording time is reached during the recording operation. Magnetic recording and reproducing device. 3. In claim 1, a clock means, a calculation means for calculating an output from the clock means upon the start of recording from the beginning of the magnetic tape, and a recording time whose time measurement by the calculation means is selected and set as described above. and determining means for determining whether or not the recording time has reached the selected recording time, and when the determining means recognizes that the selected recording time has been reached,
A magnetic recording/reproducing apparatus characterized in that the magnetic recording/reproducing apparatus outputs a signal for notifying the expiration of the set recording time.