JPH031352A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To reduce a dislocation between the cases immediately before a withdrawing operation and immediately after a next mounting operation by taking up a magnetic tape by rotating reversely a 1st reel by a rotation amt. approximately equivalent to a rotation amt. detected immediately after the completion of the mounting operation. CONSTITUTION:In order to decide whether or not the rotation amt. of the reel 13 in the direction of (h) becomes the same amt. as the rotation amt. at the loading time in the direction of (g), a count data of a rotation amt. stored by inputting sequential pulses from a photosensor 7 one by one in accordance with the rotation in the direction of (h) is applied by making decrement. Then, immediately after the loading is over, the reel 13 is rotated in the opposite direction to that at the loading time, i.e, in the direction of (h) by the same rotation amt. as a rotation amt. of the reel 13 in the direction of (g), and then the magnetic tape 12 is taken up to the reel 13 by the same length as a length drawn from the reel 13 at the loading time. By this method, a shift of the magnetic tape in the lengthwise direction as against the reel before and after loading is offset, and hence the position of the magnetic tape in the lengthwise direction as against the reel becomes the same, thus resolving the dislocation immediately after the mounting operation.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic recording/reproducing device for magnetically recording or reproducing information on or from a magnetic tape as a magnetic recording medium, and particularly relates to a magnetic recording/reproducing device that magnetically records or reproduces information on a magnetic tape of a magnetic recording medium. Magnetic recording and playback that involves loading the rotated cassette, pulling out the magnetic tape from the cassette and loading it onto the magnetic head, and winding up the loaded magnetic tape from the magnetic head and withdrawing it into the cassette. It is related to the device.

[Prior Art] A VTR (video tape recorder) is an example of this type of device. In other words, in a VTR, a magnetic tape cassette (hereinafter referred to as a cassette) containing magnetic tape wound on two reels is loaded, the magnetic tape is pulled out from the cassette, and the magnetic tape is placed against a drum around which a magnetic head rotates along the outer periphery. Recording and reproducing operations are performed after winding and mounting, so-called loading. Further, when the recording/reproducing operation is completed, the mounted magnetic tape is removed from the winding drum into the cassette, ie, so-called unloading. The magnetic tape is pulled out from the cassette by moving a tape guide that contacts the magnetic tape and regulates its running position.

In such a VTR, it is necessary to prevent a positional shift in the length direction of the mounted magnetic tape immediately before unloading and immediately after the next loading. For this purpose, the following method (a) or (b) has conventionally been adopted.

(a) Both loading and unloading operations are 2
This is done by locking one of the two reels and rotating the other. If the magnetic tape is at the tape end and there is no remaining magnetic tape on the reel being rotated during loading, the magnetic tape cannot be pulled out from the cassette, so if the end of the tape is detected in the unloading state before loading, the reel being rotated as described above cannot be pulled out. The magnetic tape is fed to the end of the tape, and loading is performed after the tape end condition is resolved.

(b) The unloading operation is performed by locking one side of the reel and rotating the other. Before the loading operation, the tape end state is detected, and if the tape is not at the end, one side of the reel is locked and the other is rotated. If it is the end, load with both reels unlocked and allowed to rotate.

According to such a method, as long as the tape is not at the tape end in the unloaded state, it is possible to eliminate positional deviation in the length direction of the mounted magnetic tape immediately before unloading and immediately after the next loading.

Note that both of the above methods require tape end detection in the unloaded state. The configuration of the detection is shown in FIG. In FIG. 7, the reference numeral 1 in □ is the exterior case of the VTR. 2 removably holds the above-mentioned cassette, d, e
It is a cassette slide mechanism that slides in the direction. The cassette slide mechanism is provided so as to be slidable into and out of an opening 1a provided on the front surface of the exterior case 1.

Reference numerals 3a and 3b are optical sensors provided inside the outer case 1 facing both sides of the cassette slide mechanism 2, which detect the tape end state of the cassette.

[Problems to be Solved by the Invention] However, in any of the above methods, it is necessary to detect the tape end state in the unloaded state, and the configuration shown in FIG. 7 requires detection from the edge of the opening 1a, etc. In order to prevent erroneous detection due to the intrusion of ambient light 4, it is necessary to double the outer case, which is difficult in practice due to high cost.

Therefore, a method has been adopted in which loading and unloading are performed by applying a light brake to one side of the cassette reel. In this case, even if the reel on which the brake is not applied during loading is at the end of the tape, the reel applied the brake rotates due to the force of pulling out the magnetic tape, and the magnetic tape is pulled out, allowing loading to be performed.

However, with this method, if the above-mentioned brake force is weak, the magnetic tape will be pulled out from the reel on the brake side during loading even if the tape is not at the end, resulting in a large misalignment of the magnetic tape before and after unloading and loading. If you increase the braking force, the positional deviation of the magnetic tape will be reduced, but if the tape is at the end during loading, a strong pulling force corresponding to the braking force will apply strong tension to the magnetic tape, damaging the tape. There is.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic recording and reproducing apparatus of this type that can eliminate the positional deviation of the loaded magnetic tape immediately before the unloading operation and immediately after the next loading operation, without the above-mentioned problems. There is a particular thing.

[Means for Solving the Problems] In order to solve the above problems, according to the magnetic recording and reproducing apparatus of the present invention, a cassette containing a magnetic tape wound around a first reel and a second reel is mounted, and The mounted magnetic tape is removed by pulling out the magnetic tape from the cassette with the reel in a rotatable state and mounting it on the magnetic head section, and by rotating the second reel with the first reel locked. a magnetic recording and reproducing apparatus that performs an operation of winding up and withdrawing a magnetic tape from a magnetic head section into a cassette, comprising: means for detecting the amount of rotation of the first reel during the loading operation of the magnetic tape; Immediately after completion of the first rotation, the first rotation amount is approximately equal to the rotation amount detected by the detection means.
A configuration is adopted in which a control means is provided for rotating the reel in a direction opposite to that during the mounting operation to wind up the magnetic tape.

[Function] According to such a configuration, immediately after the magnetic tape mounting operation is completed, the first rotational amount is approximately equal to the rotation amount during the mounting operation.
The reel is rotated in the opposite direction to that during the loading operation, and the loaded magnetic tape is wound onto the first reel to a length that is approximately the same as the length pulled out from the first reel during the loading operation. The movement of the magnetic tape in the length direction due to the loading operation is almost canceled out, and the position of the magnetic tape in the length direction becomes almost the same as the position immediately before the previous unloading operation.

[Embodiment] Hereinafter, the configuration of a VTR according to an embodiment of the present invention will be described with reference to the drawings. The VTR of this embodiment employs the configuration related to the present invention regarding the loading and unloading of the magnetic tape described above.

First, the configuration related to the loading and unloading operations of the VTR of this embodiment will be explained with reference to FIGS. 5 and 6. Figures 5 and 6 show the VT of this example, respectively.
The unloading state and loading completion state of the magnetic tape in R are shown.

In both figures, the reference numeral 11 is a cassette, and the magnetic tape 1
2 is wound around two rotatable reels 13 and 14 and stored. 15 is a drum around which a magnetic head (not shown) rotates along its outer periphery. Guides 16 and 17 are in contact with the magnetic tape 12 and regulate the running position of the magnetic tape 12. The guide 16 is movably provided, and the guide 17 is fixed. Further, 18 is a capstan that rotates to feed the magnetic tape 12, and 19 is a capstan that rotates to feed the magnetic tape 12.
This is a pinch roller that presses the capstan 18 against the capstan 18. Further, 20 is a chassis that supports the entire device.

With such a configuration, the cassette 11 is slid toward and away from the drum 15 in the directions of arrows d and e by a slide mechanism (not shown). In the unloaded state, the cassette 11 is slid in the e direction and separated from the drum 15 as shown in FIG. I haven't.

When loading from this state, the cassette 11 is slid in the direction d to approach the drum 15 as shown in FIG.
2 is pulled out, wound around the drum 15, and mounted.

Recording and playback are now possible. pinch roller 1
9 is in pressure contact with the capstan 18, the magnetic tape 11 is fed in the f direction by the rotation of the capstan 18 and the reels 13 and 14, and the magnetic head is rotated to feed the magnetic tape 11.
Recording and reproduction are performed by sliding contact with 1.

When unloading after recording and playback, the cassette 11 is slid in the e direction as shown in FIGS. 6 to 5, and the tape guide 16 and pinch roller 19
is moved. At the same time, the magnetic tape 12 is wound up from the drum 15 into the cassette 11 and withdrawn.

In this embodiment, during the unloading described above, one of the reels 13 and 14 is locked and the other is rotated to wind the magnetic tape 12. Although not limited in any way, here it is assumed that the reel 13 is locked and the reel 14 is rotated in the direction shown in FIG. 5 for winding.

Further, during the above-mentioned loading, the magnetic tape 12 is pulled out from the cassette 11 with both reels 13 and 14 of the cassette 11 in a rotatable state without being locked. That is, at this time, the reels 13 and 14 rotate in the directions of arrows g and j in FIG. 6, respectively, due to the force with which the magnetic tape 12 is pulled out, and the magnetic tape 12 is pulled out from the cassette 11.

In this embodiment, during this loading, the reel 13
Immediately after loading is completed, the reel 13 is rotated in the h direction opposite to that during loading by an amount of rotation equal to the detected rotation amount, and the magnetic tape 12 is It shall be rolled up. The configuration of the VTR control system for this purpose is shown in FIG. 1, and the configuration will be explained below.

In the configuration shown in FIG. 1, reference numeral 10 is a controller that controls the entire VTR, and includes a CPU 10I consisting of a microprocessor element and a memory ROID connected to it.
M102. It is composed of a microcomputer including RAM 103 and the like. Various instructions including loading and unloading instructions are input to the controller 10 from the operation unit 9.

Further, reference numeral 5 denotes a reel stand, which is rotated in the g and h directions by the drive of a reel motor 8 controlled by the controller 10. A reel 13 is fitted and held on this reel stand 5, and as the reel stand 5 rotates, the reel 13 rotates in both directions.

On the bottom surface of the reel stand 5 is a ring-shaped reflective plate 6 as shown in FIG.
High reflectance portions 6a and low reflectance portions 6b are alternately formed at a predetermined pitch in the circumferential direction on the lower surface of the zero reflection plate 6 to which the reflectance plate 6 is fixed.

Furthermore, a reflective optical sensor 7 is provided near the bottom of the reflector. As the reel stand 5 rotates, the reflection plate 6 rotates, and the high-reflection portion 6a and the low-reflection portion 6b alternately pass over the optical sensor 7, causing the reflectance to alternately change, causing the optical sensor 7 to detect light. The same number of pulse signals as the number of passages through the high reflection portion 6a and the low reflection portion 6b on the sensor surface are generated, and the pulse signals are inputted to the controller 10. The controller 10 detects the amount of rotation of the reel 13 based on the amount of rotation (rotation angle) of the reflection plate 6, that is, the amount of rotation of the reel stand 5, by counting the number of input pulses.

Note that the illustration of the other reel stand on which the other reel 14 is fitted and held is omitted. The other reel stand is also rotationally driven by the reel motor 8 or another motor under the control of the controller 10, and the reel 14 thereon is rotated. The controller 10 also controls the driving parts of the other mechanisms of the VTR, but illustration and description of its configuration will be omitted.

Under such a configuration, the CPLJI of the controller 10
The OI controls the entire VTR by performing various data processing and signal processing using the RAM 103 as a working area in accordance with a control program stored in the ROM 102.

During the above-mentioned loading, control is performed as follows according to the control procedure shown in FIG.

First, after the cassette is installed, in step S1, a drive section of a loading mechanism (not shown) is driven in response to an instruction from the operation section 9, and the above-described loading operation is started.

Next, in step S2, the number of pulses input from the optical sensor 7 is counted from immediately after the start of the loading operation until the end of the loading operation in step S3, and the reel is rotated in the g direction by the pulling force of the magnetic tape. 13 rotation amount is counted and memorized.

Immediately after the loading is completed in step S3, the reel 13 is turned on in step S4, and the reel 13 is rotated in the h direction, which is the opposite direction to that during loading.

Next, in step S5, it is determined whether the amount of rotation of the handle 13 in the h direction has become the same amount as the amount of rotation in the g direction during loading. Specifically, each time one pulse is sequentially inputted from the optical sensor 7 with the rotation in the h direction, the rotation amount count data stored in step S2 is decremented, and the result becomes O. Judgment will be made based on whether or not. If the amount of rotation has not reached the same amount, the process loops to step S4 to continue rotating the reel 13 in the h direction, and when the amount of rotation has reached the same amount, the reel motor 8 is turned off in step S6 to stop the reel 13. , ends the process.

As described above, in this embodiment, immediately after loading is completed, the reel 13 rotates by an amount of rotation equal to the amount of rotation of the reel 13 in the g direction at the time of loading.
the reel 1 by the same length as the length that the magnetic tape 12 was pulled out from the reel 13 during loading.
It is wound up in 3. As a result, the longitudinal movement of the magnetic tape relative to the reel 13 is canceled out before and after loading, and the longitudinal position of the magnetic tape relative to the reel 13 becomes the same. Since the reel 13 is locked during unloading as described above, the longitudinal position of the magnetic tape 12 with respect to the reel 13 does not change between immediately before unloading and after unloading, that is, before the next loading. Therefore, the lengthwise position of the loaded magnetic tape 12 with respect to the reel 13 is the same immediately before unloading and immediately after the next loading, and there is no displacement in the lengthwise direction of the magnetic tape.

In this embodiment, loading is performed with both reels 13 and 14 of the cassette 11 in a rotatable state without being locked, so even if one of the reels 13 and 14 is at the tape end, the magnetic tape 12 can be loaded from the other without applying strong force. The magnetic tape can be easily pulled out and loaded without any damage to the magnetic tape. Therefore, there is no need to detect the tape end state in the unloaded state for loading, and there is no need to double up the outer case to prevent false detection, thereby reducing the cost of the VTR.

FIG. 4 shows the relationship between the amount of rotation of the reel 13 in the g direction during loading and the amount of rotation of the reel 13 in the h direction for winding after loading. In the above description, it is assumed that the amount of rotation during loading and the amount of rotation after loading are the same, as shown in characteristic a in FIG. 4. However, since there is an error in the detection accuracy of the rotation amount of the reel 13 and the accuracy of the rotation drive amount of the reel 13, the rotation amount after loading is slightly larger than the rotation amount during loading, as shown in characteristic or characteristic C. , or may be less.

In this case, assuming that the reel 13 is the supply reel, by increasing the amount of rotation after loading, that is, the amount of winding, the position of the magnetic tape can be ensured from immediately before unloading to immediately after the next loading even if both of the above-mentioned inaccuracies are poor. By shifting toward the supply reel side, the end of the recording section of the magnetic tape before and after unloading and loading overlaps the front end of the next recording section, thereby preventing the occurrence of blanks. Furthermore, positional deviation after the magnetic tape is run up after loading can be reduced.

Also, if the amount of winding after loading is reduced, blanks may occur, but if the reel 13 is used as a take-up reel, the end of the previous recorded part will not be erased due to overlap of recorded parts. These relationships are reversed.

Note that in the above configuration, the means for detecting the amount of rotation of the reel 13 is not limited to the optical sensor, and it goes without saying that other means such as an MR element may be used. Also, a light brake may be applied to one or both of the reels during loading.

[Effects of the Invention] As is clear from the above description, in the magnetic recording and reproducing apparatus according to the present invention, a cassette containing a magnetic tape wound around the first and second reels is mounted, and both reels are rotated. In a possible state, the magnetic tape is pulled out from the cassette and mounted on the magnetic head section, and the mounted magnetic tape is wound up by rotating the second reel with the first reel locked. A magnetic recording and reproducing device that performs an operation of retracting a magnetic head portion into a cassette, the device comprising means for detecting the amount of rotation of the first reel during the loading operation of the magnetic tape, and immediately after the completion of the loading operation. Since the configuration includes a control means for winding the magnetic tape by rotating the first reel in the opposite direction to the mounting operation by an amount of rotation approximately equal to the amount of rotation detected by the detection means, the magnetic With a simple and inexpensive configuration that does not require detection of the tape end state when the tape is being withdrawn, it is possible to eliminate positional deviation of the mounted magnetic tape immediately before the withdrawal operation and immediately after the next loading operation. Further, an excellent effect can be obtained in that the magnetic tape is not damaged during the tape mounting operation in the tape end state.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a control system related to the present invention of a VTR according to an embodiment of the present invention, and FIG. 2 is a bottom view of the reflector in FIG.
FIG. 3 shows I! during loading by the controller in FIG. 1Jal1 procedure flowchart, FIG. 4 is a diagram showing the relationship between the amount of rotation of the reel before and after loading according to the present invention, and FIGS. 5 and 6 schematically show the unloading state and loading completion state of the magnetic tape, respectively. FIG. 7 is a schematic perspective view showing detection of a tape end state in an unloaded state in a conventional VTR. 5... Reel stand 6... Reflector plate 7... Optical sensor 8... Reel motor 9... Operation section
10...Controller 11...Cassette 12.
...Magnetic tape 13.14...Reel 15...
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Claims (1)

[Claims] 1) loading a cassette containing a magnetic tape wound around a first and second reel, turning both reels into a rotatable state, pulling out the magnetic tape from the cassette, and loading it onto the magnetic head section; A magnetic recording and reproducing device that winds up a loaded magnetic tape and withdraws it from a magnetic head section into a cassette by rotating a second reel with a first reel locked, the magnetic recording and reproducing device comprising: means for detecting the amount of rotation of the first reel during tape loading operation; and means for rotating the first reel by an amount of rotation approximately equal to the amount of rotation detected by the detection means immediately after the completion of the loading operation. 1. A magnetic recording and reproducing device comprising a control means for winding a magnetic tape by rotating it in a direction opposite to that during rack operation.