JPS61105752A - Magnetic recording/reproducing device - Google Patents

Abstract

PURPOSE:To complete loading in a short time by eliminating excessive fast-feed and rewind on loading. CONSTITUTION:Devices 30 and 31 to detect a leader 3L of the beginning of a magnetic tape 3 are mounted to detect the leader 3L on loading and initiate unloading. At that time, the quantity of the magnetic tape's movement is figured up 51, and a prescribed quantity of the tape 3 is transferred to a take-up reel 2T according to the figured value; then loading is initiated again by a controlling device, starting recording/reproducing at a prescribed position at the beginning of the tape. Hence, excessive fast-feed and rewind on loading is eliminated, which will result in the completion of loading in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a magnetic recording and reproducing apparatus that allows a magnetic tape to be transferred satisfactorily in, for example, a video tape recorder.

[Conventional technology]

For example, in a video tape recorder, when a tape cassette is inserted or inserted, one reel in the cassette is braked, and only the other reel is used to pull out or wind the magnetic tape, especially during recording. Even when the cassette is removed, there will be no double recording with the previously recorded portion or unrecorded portions, and good transition operations can be performed.

However, in this case, for example, if the brake is applied to the supply reel of the cassette, and the magnetic tape is pulled out or wound up by the take-up reel, the magnetic tape and league tape are When inserting a cassette that has been completely wound up on the supply reel, the magnetic tape cannot be pulled out from the take-up reel, and in order to pull out the magnetic tape from the supply reel against the brake, the magnetic There is a high risk of damage to the tape or rotating drum head.

Therefore, when the cassette is inserted and the leader tape at the leading edge of the magnetic tape is detected, the applicant stops the loading, returns the magnetic tape to the cassette, and enters the fast forward mode for a predetermined time. , and then proposed loading again (Patent Application 1986-15).
No. 3462). According to this, since the magnetic tape is not pulled out from the supply reel, there is no risk of damage to the magnetic tape due to this.

That is, FIG. 3 schematically shows a mechanism for transporting a magnetic tape to a so-called 8 mm video tape recorder. In this figure, the dashed line indicates the inserted video cassette. This cassette contains a so-called supply reel (2S) and take-up reel (2T), The recording tape (3) is passed through an opening on the front side of the cassette (upper side in the drawing), and this opening is provided with a lid that can be opened and closed.

When the cassette (1) is inserted, the lid is opened and the tape (3) is exposed through the opening, and the tape (3) is inserted into the recess of the cassette (1) provided on the back side of the tape (3). The loading bin αη and moving guide pins (13, (11, 04, etc.) provided on the ring CII are inserted, and as these move, the tape (3) is pulled out from the cassette (1), and the rotating head drum (E) Further, when the winding is completed, a pinch roller (c) provided near the loading pin Op is pressed against the capstan, and the tape (3) is driven.

Note that (4) is a reel motor, and the motor (4) is
The rotation of the reel (28) via the swing gear (5)
t is transmitted to (2T). Here swing gear (
5) transmits rotation to the reel (2S) or (2T) by being brought down to the side.

Also, 01 is a loading motor, and this motor!
The rotational force of j is transmitted to the loading ring OQ via the gear 0Q. In the middle of this gear 01, there is a rotary encoder 0' that detects the rotational position of the loading ring OIO.
i) is provided.

Furthermore, (c) is a key capstan motor, and the rotation of this motor (c) is transmitted to the capstan (c) via a belt (c). (c) is the flywheel.

The above-mentioned mechanism performs loading when inserting the cassette (1), unloading when ejecting the cassette (1), and transporting the normal tape (3). Further, unloading is performed, and the tape (3) is fast-forwarded and rewound with only the movable bin 04 returned. At this time, the tape (3) is transferred to a position where it does not come into contact with the rotating head drum, as indicated by the broken line (3)'.

Furthermore, in the above-mentioned apparatus, the reel (
2S) A hole into which a light emitting element (G) to be described later is inserted is provided at a position closer to the opening in the middle of (2T), and a transparent IJ is provided at least at the starting end of the tape (3). Tezo will be established. Then, the light emitted from the light emitting element (G) inserted into the above-mentioned hole is received by the photodetector 0 through the above-mentioned leader tape and the transparent window provided on the side wall of the cassette (1). Placement takes place.

Therefore, in the above-mentioned device, when the boundary between the magnetic tape and the leader tape of tape (3) comes on the dashed-dotted line connecting the light emitting element (g) and the photodetector, it can be detected. .

Therefore, FIG. 4 shows a system control device using a so-called microcomputer. In this figure, a tape (3) is inserted in the optical path from the light emitting element (7) to the photodetector 01, and this tape (3)
consists of an opaque magnetic tape (3M) and a transparent leader tape (3L), and when the leader tape (3L) comes to the position of the optical path, it is detected by the photodetector (31) and the signal at the top of the tape is detected. is formed.

This signal is supplied to the data input circuit of the microcomputer @η of the system control device through the amplifier. Furthermore, the rotary encoder 0'I),
Rewind control switch (43a), reverse high-speed playback control switch (43b), recording pause control switch (43a)
3c) etc. are supplied to the data input circuit 0.

Furthermore, the signal from the microcomputer (t4υ) is supplied to the data output circuit @◆.This data output circuit 0◆
The empty signal is the reel motor (4), loading motor 05, capstan motor (c), swing gear (
5) etc. In this device, the following operations are performed at the time of loading.

That is, FIG. 5 shows the loading control routine. In this figure, when loading is started, first, in step [1] it is determined whether the tape top (TT) has been detected, and in step [2] it is determined whether loading is complete. And if step [1] is no, step [2]
If the result is YES, the stop mode is set in step (3), and this routine ends. Further, if step [2] is negative, the process returns to step [1].

Furthermore, if step [1] becomes YES, step (1)
Unloading is performed in step 1), and its completion is determined in step [12]. When this unloading is completed, short fast forwarding (SFF) is performed in step [13], and a predetermined time elapses in step [14]. When this h1 fixed time period has elapsed, loading is performed in step [15], and its completion is determined in step [16].

When this loading is completed, rewinding is performed in step [17], and the tape top is detected in step [18]. When this tape top is detected, step [19]
The tape is temporarily stopped, short fast forwarding is performed in step [20], and the top of the tape is detected in step [21].

Then, when the tape top signal disappears, step [22]
After a delay time is provided to compensate for variations in the length of the tape/base of the loading system due to differences in models, the process returns to step [3].

In this way, it is possible to eliminate the risk of damage to the magnetic tape or the like when loading is performed at the leading end of the tape.

In this case, the magnetic tape (3M
) can be set to a predetermined value, and the positional accuracy of the recording start can be reduced by -F.

However, in this device, in order to improve the accuracy of the starting end t)γ position of the magnetic tape (3M), after the loading is completed (step [16)), rewinding is performed (step [16)].
7]), a short fast forward (step [20]) must be performed, which requires a lot of time and takes a long time to load.

[Problem that the invention seeks to solve]

Conventional devices were constructed as described above. However, this device has a problem in that it requires a lot of time for loading.

[Means for solving problems]

The present invention provides a magnetic recording and reproducing apparatus that draws out a magnetic tape (3) from a take-up reel (2T) and winds it onto the same take-up reel (2T) during loading and unloading. A detecting means c3Ioe is provided to detect the leader part (3L) provided at the tip, and when the leader part (3L) is detected during the loading, the unloading is performed and the amount of movement of the magnetic tape (3) at this time is detected. and transfers a predetermined amount of the magnetic tape (3) to the take-up reel (2T) according to the measured value, and then performs the loading again, This is a magnetic recording and reproducing device characterized in that recording and reproducing in the magnetic recording device always starts from a predetermined position.

[For production]

According to this device, since no extra fast forwarding or rewinding is performed during loading, loading can be completed in an extremely short time, and the accuracy of the starting end position of the magnetic tape can also be improved.

〔Example〕

In Fig. 1, a frequency generator ←9 is provided on the reel shaft of the take-up reel (2T), and the output pulse of this generator Q51) is supplied to the interrupt terminal of the microcomputer O through the amplifier ←. Ru. The rest of the structure is the same as that shown in FIG.

When a signal is then supplied to the interrupt terminal of the microcomputer (b), the interrupt routine shown in FIG.
will be added.

Further, during loading, a control routine shown in FIG. 2B is operated. In the figure, steps [1] to [3]
is the same as in FIG. Furthermore, if step [1] becomes YES, the contents of the counter register are set to '0' in step [41], unloading is performed in step [42], and completion is determined in step [43]. When the unloading is completed, the value X of the counter register at that time is detected in step [44], and the above-mentioned X is subtracted from the count value α corresponding to the length of the tape required for original loading to obtain the value y. Ru.

α−x = y Furthermore, in step [45], the contents of the counter register are “
0#, short fast-forwarded in step [46], and counter register value X and σ) in step [47].
A match of the values y is determined.

-y If they match, the rotation is performed in step [48], and its completion is determined in step [49], and when the rotation number 1 is completed, the process returns to step [3].

Therefore, in this device, when a tape slip is detected during loading, the amount of rotation of the reel shaft of the take-up reel (2T) at that time is detected, although the tape is unloaded once. When detecting tape tension, use the take-up reel (2T).
is substantially empty, the winding diameter of the magnetic tape is, for example, φ16, and the length of the wound tape can be determined from the amount of rotation of the reel shaft.

On the other hand, the length of tape required for loading is known in advance. Therefore, from these, the length of the tape to be short-fast fed to the take-up reel (2T) side is determined. Therefore, by short-fast forwarding the length while detecting the amount of rotation of the reel shaft, the position of the starting end of the magnetic tape at the time of completion of reloading can be determined extremely accurately.

Loading is performed in this manner, and according to the above-described apparatus, unnecessary fast forwarding or rewinding is not performed during loading, so loading can be completed in a short time. Furthermore, the starting position of the magnetic tape can be determined with great precision.

Note that the variation in the length of the loading thread tape i9 due to differences in models can be corrected by adjusting the value of α.

Further, when the capstan and the reel are driven by a so-called one motor, the amount of rotation of the take-up reel (2T) described above can also be obtained from a frequency generator provided on the capstan shaft.

〔Effect of the invention〕

According to the present invention, since no extra 5-speed feed or rewind is performed during loading, loading can be completed in an extremely short time, and the accuracy of the starting end position of the magnetic tape can also be improved. O

[Brief explanation of drawings]

FIG. 1 is a block diagram of an example of the present invention, FIG. 2 is a diagram for explaining the same, and FIGS. 3 to 5 are diagrams for explaining a conventional device. (2T) is a take-up reel, (3) is a magnetic tape, 0 is a photodetector, is an alpha microcomputer, and 6 is a frequency generator. ;1T9Win rule

Claims (1)

[Claims] In a magnetic recording and reproducing apparatus which draws out a magnetic tape from a take-up reel and winds it onto the same take-up reel during loading and unloading, a detection means for detecting a leader section provided at the leading end of the magnetic tape is provided, When the leader section is detected during loading, the unloading is performed and the amount of movement of the magnetic tape at this time is measured, and a predetermined amount of the magnetic tape is transferred to the take-up reel according to the measured value. 1. A magnetic recording and reproducing apparatus, comprising a control means for performing the above-mentioned loading again after that, so that recording and reproducing at the leading end of the magnetic tape always starts from a predetermined position.