JPH05325335A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To simplify the constitution of a device by detecting tape speed by the use of a magnetic head for detecting speed, controlling the revolving speed of a reel based on information on the tape speed, and increasing the revolving speed of the reel so that fast forwarding is performed. CONSTITUTION:In the case that a magnetic tape 3 travels in a direction shown by an arrow (a) at the time of recording/reproducing, a signal is recorded, reproduced and erased on the tape 3 by using a reproducing head 5 for detecting tape speed and a tape speed calculation circuit 12. Then, the tape speed is calculated by measuring the time from recording the signal till reproducing it. The calculated result is inputted in a control circuit 13, which arithmetically compares the detected tape speed with specified tape speed and transmits a control signal to a reel driving motor 7. The operation of a system at the time when the tape 3 travels in a direction shown by an arrow (b) is applied similarly to that at the time when the tape 3 travels in the direction shown by the arrow (a). In the case of performing the fast forwarding, the revolving speed of the reel driving motor 7 or 8 is increased and the other reel driving motor is not energized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus using a magnetic tape, and more particularly to a technique for driving the magnetic tape at a constant speed.

[0002]

2. Description of the Related Art Conventionally, in a magnetic recording / reproducing apparatus using a magnetic tape, a constant speed drive of the magnetic tape is held between the capstan and a pinch roller pressed against the capstan via the magnetic tape, and the capstan is held. It is realized by rotating at a constant speed. Further, it is necessary to wind the sent magnetic tape on a reel, but since the reel radius changes with time, the rotation speed of the reel also changes with time. Therefore, when the capstan shaft and the reel shaft are driven by one drive motor, a slip mechanism has to be included in the reel shaft drive system. In addition to driving at a constant speed, it is also necessary to have a function such as fast-forwarding of the tape, so it is necessary to switch the deceleration rate from the motor to the reel system between when the magnetic tape is fed at a constant speed and when it is fast-forwarding. A complex mechanism was needed.

[0003]

The magnetic recording / reproducing apparatus having the above structure has the following problems.
In this kind of magnetic recording / reproducing apparatus, the tape is driven at a constant speed with a so-called wow and flutter value of about 0.3% during recording and reproducing, and at the time of fast-forwarding, the tape is driven at a tape speed several to several tens of times the normal speed. There is a need to. Furthermore, if the tape is run back and forth, so-called auto-reverse, capstans, pinch rollers, etc. are required for forward and reverse, respectively, and playback,
A mechanism for switching to each mode such as fast forward and rewind is also required. Therefore, it is realized by using a complicated mechanism composed of an extremely large number of parts, and there is a limit to the weight reduction and cost reduction of the drive system. The present invention has been made in order to solve the above problems, and detects a tape speed by using a magnetic head for speed detection, and controls the number of rotations of a reel based on the information, so that the number of parts is very small. It is an object of the present invention to provide a tape running mechanism capable of realizing tape feeding at a constant speed.

[0004]

A function of sending a magnetic tape at a constant speed while ensuring a head touch between the magnetic head and the magnetic tape is obtained by detecting the traveling speed of the magnetic tape with a speed detecting magnetic head and using the information. In addition to controlling the rotation speed of the reel shaft based on this, the function of fast-forwarding the magnetic tape and the function of performing high-speed search are realized by increasing the rotation speed of the reel, for example, by increasing the number of motors opened.

[0005]

By adopting the above-mentioned means, it is sufficient that the tape speed detection means, the reel shaft drive means and the control means are provided for the feeding of the magnetic tape, and the capstan shaft which is necessary in the conventional mechanism, A pinch roller, a slip mechanism, etc. can be omitted.

[0006]

【Example】

(Embodiment 1) A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a magnetic recording / reproducing apparatus of the present invention. 1, 2 are reels, 3 are magnetic tapes,
4, 6 are magnetic heads that can be used by switching between recording and erasing for tape speed detection, 5 is a reproducing head for tape speed detection, 7 and 8 are reel drive motors for driving reel 1 and reel 2, respectively. 9 is a magnetic head for recording and reproducing information, 10 is a pressure pad, 11a,
11b is a rotary roller in the cassette, 12 is a tape speed calculation circuit for calculating the tape speed based on the control of the speed detection heads 4, 5, 6 and signals from them, and 13 is a signal of the tape speed calculation circuit 12. Based on reel drive motors 7 and 8
It is a control circuit for controlling.

First, the operation of the system when the magnetic tape 3 travels in the direction of arrow a in the drawing during recording and reproduction will be described in detail. Since the reel drive motor 8 on the supply side is not energized, the magnetic tape 3 from the reel 2 on the supply side is
It can be pulled out with almost no load. Then, as will be described in more detail later, a signal (for example, a pulse wave) is recorded on the magnetic tape 3 by using the tape speed detecting recording / erasing heads 4 and 6, the tape speed detecting reproducing head 5 and the tape speed calculating circuit 12. Recording, reproduction, and erasing are performed, and the time from recording the signal to reproduction is measured, and the tape speed is calculated. The result is input to the control circuit 13, and the control circuit 13 compares the detected tape speed with a predetermined tape speed and performs calculation, and controls the reel drive motor 7 on the winding side so that the tape speed becomes the predetermined tape speed. Send a signal. The reel drive motor 7 drives the reel 1 according to the control signal,
The magnetic tape 3 is wound around the reel 1. As a result, the magnetic tape 3 runs at a predetermined tape speed in the direction of arrow a in the figure, and the magnetic head 9 for recording and reproducing information (music, voice signal, digitized information, etc.) is pressed by the pressure pad 10. Information can be recorded or reproduced on the recorded magnetic tape 3.

On the contrary, the operation of the system when the magnetic tape 3 runs in the direction of the arrow b in the figure will be described. Similarly to the previous case, since the supply side reel drive motor 7 is not energized, the magnetic tape 3 can be pulled out from the supply side reel 1 with almost no load. Then, the tape speed is calculated using the recording / erasing heads 4 and 6 for tape speed detection, the reproducing head 5 for tape speed detection, and the tape speed calculation circuit 12 as in the case of traveling in the direction of arrow a. The result is input to the control circuit 13, and the control circuit 13 compares the detected tape speed with a predetermined tape speed and performs calculation, and controls the reel drive motor 8 on the winding side so that the tape speed becomes the predetermined tape speed. Send a signal. Reel drive motor 7
Drives the reel 2 in accordance with the control signal and winds the magnetic tape 3 onto the reel 2. Thus, the magnetic tape 3 is fed at a predetermined tape speed, and the magnetic head 9 for recording / reproducing information records / reproduces information on / from the magnetic tape 3 pressed by the pressure pad 10.

The case of performing fast-forward will be described. In the case of fast-forwarding, the number of rotations of the reel drive motor (reel drive motor 7 in the case of reel 1 and reel drive motor 8 in the case of reel 2) on the winding side is increased, and the other reel drive motor is not energized. With this, the magnetic tape 3 is fed faster than when recording or reproducing. At this time, in order to reduce the load on the reel drive motors 7 and 8 and prevent wear of the respective magnetic heads, the magnetic head 9 for information recording / reproducing and the recording, reproducing and erasing heads 4, 5, 6 for speed detection are The magnetic tape 3 may be moved to a position where it does not slide.

Next, the tape speed detection will be described in detail with reference to FIG. Figure 2 shows only the tape speed detector
It was extracted from. The tape speed detecting recording / erasing heads 4 and 6 and the reproducing head 5 record and reproduce a tape speed detecting signal on the same track of the magnetic tape 3.
Each of the tape speed detecting recording / erasing head 4, the tape speed detecting reproducing head 5, the tape speed detecting reproducing head 5, and the tape speed detecting recording / erasing head 6 has the same height in the tape width direction so that they can be erased. The head gaps are mounted at positions such that the gap distances are predetermined distances d and d ', respectively.

First, the tape speed detection when the magnetic tape 3 runs in the direction of arrow a in the figure will be described. The tape speed detecting recording / erasing head 4 is used as a recording head, and a signal (pulse wave or the like) from the tape speed calculating circuit 12 is written on the magnetic tape 3. The signal is reproduced by the tape speed detecting reproducing head 5, and the tape speed calculating circuit 1
Entered in 2. The tape speed calculation circuit 12 measures the time t from when a write signal is sent to the recording / erasing head 4 for tape speed detection to when the signal is reproduced by the reproducing head 5 for tape speed detection, and the measurement result and tape speed detection The tape speed v (= d / t) is calculated from the gap distance d between the recording / erasing head 4 and the tape speed detecting reproducing head 5.
The signal written on the magnetic tape 3 for tape speed detection is erased by using the tape speed detection recording / erasing head 6 as an erasing head.

On the contrary, when the tape runs in the direction of the arrow b in the figure, the recording / erasing head 6 for tape speed detection is used as a recording head, and a pulse wave is written on the magnetic tape 3 for reproduction for tape speed detection. It is reproduced by the head 5. The tape speed calculation circuit 12 measures the time t ′ from the time when the tape speed detection signal is recorded on the magnetic tape 3 to the time when it is reproduced, and the tape speed detection recording / erasing head 4 and the tape speed detection reproducing head 5 are measured. The tape speed v '(= d' / t ') is calculated from the gap interval d'of The signal written on the magnetic tape 3 for detecting the tape speed is erased by using the recording / erasing head 4 as an erasing head.

At this time, the tape speed detection signal is written on the magnetic tape 3 and erased, but the tape speed detection track is provided in a portion other than the information recording data track. FIG. 3 shows an example thereof. This example is for a 2-channel reciprocation of a compact cassette, and the shaded area is a data track used for recording information. The center portion of the magnetic tape has a portion not used for recording information of 660 μm. If the tape speed is detected using this portion, the information recorded in the data track will not be erased. Therefore, by matching the format of the magnetic head 9 for recording / reproducing information with the tape speed, it is possible to reproduce the information of the tape cassette recorded by using another mechanism of the conventional capstan system.
On the contrary, the information of the tape cassette recorded by the magnetic recording / reproducing apparatus can be reproduced by another mechanism of the conventional capstan system.

Further, in this embodiment, the magnetic head for tape speed detection and the magnetic head for information recording / reproduction are separately provided, but the respective heads may be integrated and used. FIG. 4 shows an example thereof. FIG. 4 is a view of the magnetic tape sliding surface of the integrated magnetic head as viewed from the magnetic tape side.

In FIG. 4A, reference numerals 30 and 31 respectively denote a recording / reproducing gap for information recording / reproducing, an erasing gap 32, and 32.
Reference numerals 33 are a recording / erasing gap and a reproducing gap for speed detection, respectively. This example is a fixed type auto-reverse-compatible head, and the gap used for information recording / reproduction and the recording / erasing gap for speed detection are switched between recording and erasing depending on the running direction of the magnetic tape. That is, when the magnetic tape runs in the direction of the arrow a in the figure, the recording / reproducing gap 30a and the erasing gap 31 are used for information recording / reproducing.
a is used, 32a is used as a recording gap, 33 is a reproducing gap, and 32b is an erasing gap for speed detection. On the contrary, when the magnetic tape runs in the direction of the arrow b in the figure, the recording / reproducing gap 30b and the erasing gap 31b are used for information recording / reproducing, and the recording gap 32b is used for speed detection.
33 is used as a reproducing gap and 32a is used as an erasing gap.

Reference numerals 34, 35 and 36 in FIG. 4B denote recording, reproducing and erasing gaps for recording and reproducing information, respectively.
Reference numerals 7, 38 and 39 are speed detection recording, reproducing and erasing gaps, respectively. This example is a rotary type auto-reverse compatible head, and the head base 40 is rotated and used in accordance with the running direction of the magnetic tape. The state shown in this figure is a case where the magnetic tape runs in the direction of arrow a in the figure, and conversely, when the magnetic tape runs in the direction of arrow b in the figure, the head base 40 is moved 180 in the direction of arrow c in the figure. The magnetic tape is rotated once, and the same gap as that when the magnetic tape runs in the direction of arrow a in the figure is used for each.

From the reel drive motors 7, 8 to the reels 1, 2
The drive force is transmitted to the reel drive motors 7 and 8 by connecting a hub clutch attached to the tip of the output shaft of the reel drive motors 7 and 8 and a reel hub at the center of the reels 1 and 2.
FIG. 5 shows the connected state. 5A is a front view and FIG. 5B is a perspective view. Reference numeral 14 is a reel hub, 15 is a hub clutch, and 16 is a reel shaft. Hub clutch 15
Is fixed to the reel shaft 16, and when the reel shaft 16 is driven by the reel drive motor, the hub clutch 15 also rotates together with the reel shaft 16.

As shown in the drawing, the claw portion 1 of the hub clutch 15
5a has side surfaces gradually increasing outward in the radial direction in a wedge shape, and when rotated in the direction of the arrow in the drawing, the side surfaces of the three claw portions 15a are the side surfaces 14b of the three pins 14a of the reel hub 14. Press to fix the reel hub 14 in the tape winding direction while aligning the center of rotation with the hub clutch 15. Since the reel hub 14 is fixed only in the winding direction, it is easy to load and unload the tape cassette (not shown) in the magnetic recording / reproducing apparatus.

Here, the reel hub 14 and the hub clutch 1
If there is play between 5, the tape speed control system has the open loop characteristic shown in FIG. A resonance point due to the looseness of the reel hub 14 and the hub clutch 15 appears, and the servo characteristics are deteriorated. When the connection between the hub clutch and the reel hub is strengthened as in the present embodiment, the open loop characteristics of the tape speed control system show a high frequency resonance due to rattling of the hub clutch and reel hub as shown in FIG. It is possible to improve the servo characteristics by moving to the side. In other words, in order to suppress the influence of the backlash of the hub clutch and the reel hub, the connection between the hub clutch on the magnetic tape winding side and the reel hub may be strengthened as shown in this embodiment.

(Embodiment 2) Next, another embodiment having the same construction as that of Embodiment 1 but different in the connecting method between the hub clutch and the reel hub will be described with reference to the drawing only in the connecting portion between the hub clutch and the reel hub.

The shape of the hub clutch is shown in FIG. 8, and an explanatory view of the connection between the hub clutch and the reel hub is shown in FIG. The hub clutch 18 is provided with a pinching portion 18a of the pin portion 14a of the reel hub 14, and is made of an elastic material such as rubber or resin. When a tape cassette (not shown) is loaded in the magnetic recording / reproducing device and the hub clutch 18 is inserted into the reel hub 14 (FIG. 9A), the reel hub 14 is inserted.
The pin portion 14a hits the inclined surface 18b of the hub clutch 18, is guided by the holding portion 18a (FIG. 9B), and is held by the holding portion 18a by its elastic force. The connection between the hub clutch 18 and the reel hub 14 is hard in the reel rotation direction and weak in the reel rotation axis direction (FIG. 9C), so that the tape cassette (not shown) can be connected to the magnetic recording / reproducing device. Easy to put on and take off.

(Embodiment 3) Another embodiment will be described with reference to the drawings, which is different from the embodiment 2 only in the method of connecting the hub clutch and the reel hub.

FIG. 10 shows the shape of the hub clutch. The hub clutch 19 has a triangular pin fixing base 19b on a cylindrical clutch base 19a. 11A and 11B are a perspective view and a side sectional view, respectively, in a state where the hub clutch 19 is inserted into the reel hub 14. Reel hub 14
The pin 14a of the clutch base 19a and the pin fixing base 1
9b, the hub fixing plate 20 provided on the cassette holder (not shown) of the magnetic recording / reproducing apparatus is provided on the opposite side of the hub clutch 19 so as not to be lifted from the clutch base 19b. Is inserted into the hub clutch insertion hole of the tape cassette, and the pin portion 14a is pressed against the clutch base 19a. The reel hub 14 is now fixed to the hub clutch 19. The hub fixing plate 20 is attached to the cassette holder so as to rotate together with the reel hub 14 and the hub clutch 19.

When the tape cassette is detached from the magnetic recording / reproducing apparatus, the tape cassette and the cassette holder move together, and the holding of the hub clutch 19 and the hub fixing plate 20 is released.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIG. In this embodiment, the speed detection method is realized by a method different from the above. The first
The same parts as those in the above embodiment are designated by the same reference numerals. Like the first embodiment, the tape wound around the reels 1 and 2 is configured to be driven in the a or b direction, and the magnetic tape 3 is pressed against the information recording / reproducing magnetic head 9 by the pressure pad 10. Then, the information is recorded and reproduced.

When recording and reproducing information, the following operations are performed. That is, the speed detection roller 50 that is in contact with the magnetic tape rotates with the movement of the tape 3, and has a rotation speed proportional to the tape speed. The speed detection roller 50 has a so-called FG (frequency).
The speed detector circuit 51 outputs a signal having a frequency proportional to the rotation speed, and the speed detection circuit 51 obtains the speed signal. The speed detection circuit 51 is f in this embodiment.
It is composed of a / v converter and outputs a voltage proportional to the frequency. In this embodiment, this is the tape speed information. This tape speed information is guided to the control circuit 13, and a tape speed detected by the control circuit 13 is compared and calculated to drive the reel drive motor 7 or 8 so that the tape speed becomes constant. The reel drive motor 7 is driven when the tape traveling direction is a, and the reel drive motor 8 is driven when the tape traveling direction is b. In this way, the tape running speed is controlled to a predetermined low constant speed during recording and reproducing of information.

The operation of fast-forwarding the tape is similar to that of the first embodiment.

(Fifth Embodiment) Next, a fifth embodiment of the present invention will be described with reference to FIG. The same parts as those in the above embodiment are designated by the same reference numerals. Like the fourth embodiment, the tape wound around the reels 1 and 2 is configured to be driven in the a or b direction, and the magnetic tape 3 is pressed against the information recording / reproducing magnetic head 9 by the pressure pad 10. Then, the information is recorded and reproduced. Here, first, the case where the tape running direction is a will be described.

When recording and reproducing information, the following operations are performed. That is, the speed detecting roller 52 contacted with the magnetic tape rotates with the movement of the tape 3 as in the second embodiment, and has a rotation speed proportional to the tape speed. A so-called FG is used for the speed detection roller 52.
(Frequency generator) is provided, and a signal 52a having a frequency proportional to the rotation speed is output and guided to the speed detection circuit 60. On the other hand, the reel 1 which is the winding side reel is provided with a reel rotation detection sensor 61, and detects the rotation speed of the reel. In this embodiment, a signal 61a having a frequency proportional to the rotation speed of the reel is output and guided to the speed detection circuit 60. Here, the frequency resolution of the speed detection roller 52 is relatively low as described later,
It does not need to have a band higher than the servo band.

The speed detecting circuit 60 operates as follows. That is, the frequency signal 61a proportional to the rotation speed of the reel is f / v converted to obtain speed information. The resolution (frequency) of this speed information is higher than that of 52a,
Since the value is higher than the tracking frequency of this control system,
The speed information in the high frequency range of this control system is given. On the other hand, the information 52a from the speed detecting roller 52 is similarly f / v converted by the speed detecting circuit 60 to give tape speed information. Here, the information 52a from the roller 52 has a lower resolution than the information 61a from the reel. Therefore, the information on the band required for the control system is not satisfied by itself, but the information on the low frequency range is the information from the reel 6
Higher accuracy than 1a. This is because the roller 52 rotates directly in contact with the tape, so that on average (at low frequencies) the correct tape speed is always detected.

On the other hand, in the information 61a from the reel, even if the tape speed is constant, the number of reel revolutions changes according to the winding radius of the tape (inversely proportional to the winding radius), so the tape speed is correct on average (at low frequencies). While not shown, at high frequencies (so-called wow and flutter area), tape speed changes are shown.

The tape speed is calculated by extracting the low frequency component of the speed information from the signal 52a with a low pass filter, extracting the high frequency component of the speed information from the signal 61a with a high pass filter, and adding them. Is configured.

In the following, the speed error is detected and calculated by the control circuit 13 and the reel drive motor 7 is driven to control the drive of the reel 1 as in the fourth embodiment.

When the traveling direction is b, the number of take-up reels is 2, so 62 is used as the reel rotation detection sensor, 62a is used as information on the number of reel rotations, and the drive motor is 8 as described above. The same operation as is performed.

Since the speed detecting roller 52 is constituted as described above, it is sufficient that the speed detecting roller 52 is lower than the speed detecting roller 50 in terms of accuracy, and for example, it is simple and outputs only one pulse per one rotation. Since it may be one, it can be inexpensive.

Hereinafter, the fast-forwarding and the like are the same as those in the first embodiment.

(Embodiment 6) Another embodiment of the construction of Embodiment 1 except for the reel drive system will be described with reference to the drawings. FIG. 14 shows a reel drive system using a worm gear. 17 is a reel shaft, 21 and 22 are worm wheels,
Reference numeral 23 is a worm gear, 24 is a reel drive motor, 25 is a motor chassis supporting the worm gear and the reel drive motor, 26 is a pressurizing spring for pressing the worm gear against the worm wheel, 27 is a pressurizing spring fixing pin provided in the mechanical chassis, 28 Is an interference arm for switching the driven reel, and 29 is a switching mechanism for driving the interference arm 28. FIG. 15 shows a side view of the worm gear and the worm wheel. The worm wheel 21 has a hub clutch portion 21a, which is integrated with the hub clutch.
The worm wheel 22 also has a hub clutch portion 22a.

The worm gear 23 is a reel drive motor 24.
Is press-fitted to the output shaft 24a. Reel drive motor 2
4 and the worm gear 23 are supported by a motor chassis 25, and the motor chassis 25 is supported so as to be swingable around a shaft 25a that is erected on the mechanical chassis. The pressure spring 26 is provided between the pressure spring fixing pin 25b on the motor chassis 25 and the pressure spring fixing pin 27 on the mechanical chassis.
The motor chassis 25 is pressed so that the worm gear 23 meshes with the worm wheel 21. Since the worm wheel 22 is not connected to the drive system, it can freely rotate around the reel shaft 17. The worm wheel 21 is driven by driving the reel drive motor 24, and the magnetic tape is sent from the reel on the worm wheel 22 side to the reel on the worm wheel 21 side at a constant speed. At this time, if the number of rotations of the reel drive motor 24 is increased, a fast-forward state is set.

By operating the interference arm 28 in the direction of the arrow in the drawing by the switching mechanism 28, the motor chassis 25 rotates about the rotary shaft 25a, and the pressurizing spring 26 causes the motor chassis 25 to move the worm gear 23 to the worm wheel 22. Pressurize to mesh with. Worm wheel 2
Since 1 is not connected to the drive system, it can freely rotate around the reel shaft 17. By rotating the reel driving motor 24 in the reverse direction and driving the worm wheel 22, the reel on the worm wheel 21 side is moved to the worm wheel 2 side.
The magnetic tape is sent to the reel on the second side at a constant speed. If the number of rotations of the reel drive motor 24 is increased, fast-forwarding can be performed.

As described above, the constant speed feeding and the fast feeding of the magnetic tape can be performed bidirectionally.

When the worm gear is used, a large reduction ratio can be obtained by one-step deceleration, the number of rotations of the motor can be increased as compared with the direct drive, and the motor can be used near the number of rotations where the efficiency of the motor is good, so that power consumption can be reduced. Further, since the motor rotation speed increases, the influence of ripple can be moved to a high frequency region. Furthermore, since the worm gear and the worm wheel can be in a state of always meshing,
Wow and flutter due to meshing of teeth when using spur gears can be reduced.

A drive mechanism similar to this is used in the second embodiment.
It goes without saying that it may be applied to 3.

(Embodiment 7) Similar to Embodiment 6, another embodiment of the structure of Embodiment 1 except for the reel drive system will be described with reference to the drawings. 16 and 17 show the configuration of the reel drive system. Reference numeral 17 is a reel shaft, 40 and 41 are drive wheels, 42 is a reel drive motor, 43 is a motor chassis supporting the reel drive motor, 44 is a pressurizing spring for pressing the reel drive motor against a disc-shaped plate, and 45 is a mechanical chassis. Is a pressurizing spring fixing pin provided at, 46 is a switching mechanism for switching the reel to be driven, and 47 is an interference arm for performing the switching operation.

As shown in FIG. 10, drive wheels 40, 4
Reference numeral 1 is a disk-shaped plate, and rubber 48 is adhesively fixed to the side surface thereof, and is integral with the hub clutch portions 40a and 41a. On the side surface of the drive wheel 41, the output shaft 42a of the reel drive motor 42 is pressed against the rubber 48 by the pressurizing force of the pressurizing spring 44. With this, the driving force of the reel drive motor 42 is
It is transmitted from the rubber 48 to the drive wheel 41. When the drive wheel 41 is driven by the reel drive motor 42,
The magnetic tape is sent at a constant speed from the reel on the drive wheel 40 side to the reel on the drive wheel 41 side. Further, fast-forwarding can be performed by increasing the rotation speed of the reel drive motor 42.

When the interference arm 47 is driven in the direction of the arrow in the drawing by the switching mechanism 46, the motor chassis 43 rotates about the rotation shaft 43a, and the pressurizing spring 44 causes the output shaft 42a of the reel drive motor 42 to move to the drive wheel 40. Is pressed by. Since the drive wheel 41 is not connected to the drive system, it can freely rotate around the reel shaft 17. When the drive wheel 40 is driven by the reel drive motor 42 whose rotation direction is reversed, the magnetic tape is sent from the reel on the drive wheel 41 side to the reel on the drive wheel 40 side at a constant speed. Further, fast-forwarding can be performed by increasing the rotation speed of the reel drive motor.

In this drive method, a large reduction ratio can be obtained by deceleration of one stage, the rotation speed of the reel drive motor can be increased as compared with the direct drive, and the motor can be used in the vicinity of the rotation speed where the motor efficiency is high, so that the power consumption is small. it can. Further, since the motor speed increases, it is possible to move the ripple to a region where the frequency is high. In addition, since the motor output shaft is applied to the rubber on the side of the drive wheel to transmit power, wow caused by tooth meshing when using gears
No flutter component is generated.

Further, in the present embodiment, the drive wheels 40, 4
Although the rubber 48 is provided on the outer peripheral portion of No. 1, it may be replaced with a material having high rigidity.

A drive mechanism similar to this is used in the second embodiment.
It goes without saying that it may be applied to 3.

Although the examples have been shown by giving several kinds of examples as described above, the present invention is not limited to these examples, and may be, for example, each of the above-mentioned constitutions as long as the requirements of the present invention are satisfied. It is also possible to realize by combining elements.

[0050]

According to the present invention, the tape speed of the magnetic tape is detected by the speed detecting means, the motor is controlled based on the information, and the reel is driven to realize the tape feeding at a constant speed. In addition, in order to realize fast-forwarding by increasing the rotation speed of the reel by a simple method,
It is possible to provide a tape running mechanism that does not require a capstan, a pinch roller, a slip mechanism, etc., has a simple device configuration, and has an extremely small number of parts.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a magnetic recording / reproducing apparatus according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a tape speed detection unit according to the first embodiment of this invention.

FIG. 3 is a compact cassette track format.

FIG. 4 is an arrangement example of a speed detecting head according to the first embodiment of the present invention.

FIG. 5 is an explanatory view of the connection between the reel hub and the hub clutch of the first embodiment of the present invention.

FIG. 6 is an open loop characteristic (with play) of the tape speed control system according to the first embodiment of the present invention.

FIG. 7 is an open loop characteristic (without play) of the tape speed control system of the first embodiment of the present invention.

FIG. 8 is a perspective view of a hub clutch according to a second embodiment of the present invention.

FIG. 9 is an explanatory view of the connection between the reel hub and the hub clutch of the second embodiment of the present invention.

FIG. 10 is a perspective view of a hub clutch according to a third embodiment of the present invention.

FIG. 11 is an explanatory view of the connection between the reel hub and the hub clutch of the third embodiment of the present invention.

FIG. 12 is a configuration diagram of a magnetic recording / reproducing apparatus according to a fourth embodiment of the present invention.

FIG. 13 is a configuration diagram of a magnetic recording / reproducing apparatus according to a fifth embodiment of the present invention.

FIG. 14 is a reduction mechanism using a worm gear according to a sixth embodiment of the present invention.

FIG. 15 is a side view of a worm gear according to a sixth embodiment of the present invention.

FIG. 16 is a reduction mechanism using a drive wheel according to a seventh embodiment of the present invention.

FIG. 17 is a side view of a drive wheel according to a seventh embodiment of the present invention.

[Explanation of symbols]

 1, 2 reels 3 magnetic tape 4, 6 tape speed detection recording / erasing head 5 tape speed detection reproducing head 7, 8 reel drive motor 9 information recording / reproducing magnetic head 10 pad 11 cassette inner roller 12 tape speed calculation circuit 13 Control circuit 14 Reel hub 15, 18, 19 Hub clutch 16 Reel shaft 17 Reel shaft 20 Hub fixing plate 21, 22 Worm wheel 23 Worm gear 24 Reel drive motor 25 Motor chassis 26 Pressure spring 28 Interference arm 29 Switching mechanism 30 For information recording / reproducing Recording / playback gap 31 Information recording / playback erase gap 32 Speed detection write / erase gap 33 Speed detection playback gap 34 Information recording / playback recording gap 35 Information recording / playback playback gap 36 Information recording / playback The eraser 37 Recording gap for speed detection 38 Playback gap for speed detection 39 Erasing gap for speed detection 40, 41 Drive wheel 42 Reel drive motor 43 Motor chassis 44 Pressurizing spring 45 Pressurizing spring fixing pin 46 Switching mechanism 47 Interfering arm 50 speed detection roller 51 speed detection circuit 52 speed detection roller 60 speed detection circuit 61, 62 reel rotation detection sensor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akito Yoshimoto 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka

Claims (13)

[Claims] 1. A magnetic recording / reproducing apparatus for recording / reproducing information on / from a magnetic tape with a magnetic head, comprising tape speed detecting means for detecting a tape speed and reel driving means for driving a reel on which the magnetic tape is wound. The magnetic tape is moved at a constant speed by controlling the reel driving means based on the tape speed information detected by the tape speed detecting means, and information is recorded and reproduced by a magnetic head for recording and reproducing information. A magnetic recording / reproducing apparatus, characterized in that when the magnetic tape is fast forwarded, the reel driving means increases the number of rotations of the reel. 2. A magnetic recording / reproducing apparatus according to claim 1, wherein a pressure pad in a tape cassette is used as a means for pressing the magnetic tape against the information recording / reproducing magnetic head or the magnetic gap. .. 3. A tape speed detecting recording head or recording gap is provided on the upstream side in the running direction of the magnetic tape, and a tape speed detecting reproducing head or reproducing gap is provided on the downstream side at a predetermined distance from each other. A speed detection signal is recorded on the magnetic tape with a recording head or a recording gap, the time until the reproducing head for reproducing the tape speed or the reproducing gap detects the signal is measured, and the tape speed is calculated based on the distance / time calculation. Claim 1 characterized in that it is provided with a tape speed detecting means for detecting.
The magnetic recording / reproducing apparatus according to the item 2 or item 2. 4. The tape speed detecting means is configured to detect or measure the tape speed by contacting or winding a magnetic tape around a rotatable roller and detecting the rotational speed of the roller which rotates as the tape moves. The magnetic recording / reproducing apparatus according to claim 2, wherein 5. Both reel rotation speed information for detecting the rotation speed of a reel on which a tape is wound and rotation speed information of a roller that rotates when a magnetic tape comes into contact with a rotatable roller or the winding tape moves. 3. A magnetic recording / reproducing apparatus according to claim 1, further comprising a tape speed detecting means for detecting a tape speed by using the. 6. A magnetic head or magnetic gap for speed detection signal recording, speed detection signal reproduction and speed detection signal erasing from the upstream side in the direction of travel of the magnetic tape so that speed detection signals can be recorded, reproduced and erased on the same track. Are arranged in this order, and the speed detection signal recorded by the speed detection signal recording head or the recording gap is erased by the speed detection erasing head or the erasing gap on the downstream side of the speed detecting reproducing head or the reproducing gap. The magnetic recording / reproducing apparatus according to claim 1, 2, or 3. 7. The magnetic recording / reproducing apparatus according to claim 6, wherein the tape speed detecting recording head, the reproducing head and the erasing head are incorporated in an information recording / reproducing magnetic head. 8. The tape take-up reel shaft as a reel driving means is directly driven by a motor, as claimed in claim 1, claim 2, claim 3, claim 4, claim 5, claim 5. The magnetic recording / reproducing apparatus according to item 6 or 7. 9. A reel take-up means for driving a tape take-up reel shaft by a motor through a speed reduction mechanism, according to claim 1, claim 2, claim 3, claim 4, claim 4. The magnetic recording / reproducing apparatus according to item 5, 6, or 7. 10. The magnetic recording / reproducing apparatus according to claim 9, wherein a worm gear is used as the deceleration mechanism. 11. The magnetic recording / reproducing apparatus according to claim 9, wherein the driving force of the motor is frictionally transmitted to the disk-shaped member attached to the tape take-up reel shaft to reduce the speed. 12. A bidirectional traveling can be performed by switching a reel to be driven, Claims 1, 2, 3, 4, 5 and 6,
The magnetic recording / reproducing apparatus according to item 6, item 7, item 8, item 9, item 10, or item 11. 13. A hub clutch for fixing the take-up reel hub only in the tape winding rotation direction when the winding reel is rotated in the tape winding direction. The first term, the second term,
The magnetic recording / reproducing apparatus according to the third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh or twelfth item.