JP2000076739A - Magnetic recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic recording/reproducing device using a slow brake capable of giving the stable braking force for friction while having a long life even at the time of intermittent recording/reproducing operation. SOLUTION: The slow brake 100 using at the time of intermittent recording/ reproducing operation is abutted on a capstan motor 40 to brake the rotation of the capstan motor 40. The braking surface 102 on the slow brake 100 is formed to have nearly the same curvature as that of the outer peripheral surface of the capstan motor 40. Thus the reliability is increased for the frictional braking to the capstan motor at the time of intermittent recording/reproducing operation without increasing the number of components or changing the constitution of the mechanism. Also, the work for exchanging the components, etc., is eliminated, then the cost is lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetic recording / reproducing apparatus, and more particularly to a magnetic recording / reproducing apparatus suitable for intermittent recording / reproducing.

[0002]

2. Description of the Related Art In an intermittent recording / reproducing mode in a conventional magnetic recording / reproducing apparatus, intermittent recording / reproducing is performed in which a magnetic tape is intermittently fed and information is recorded on the magnetic tape. In particular, when used in business applications such as a surveillance camera system, there is a high demand for recording a long video on a single cassette and searching in a short time, and the operation mode of a VTR is mainly intermittent recording / reproduction. You are in mode.
In a normal recording / reproducing mode, the capstan motor as a power source rotates at a constant speed at a predetermined speed in order to transfer the magnetic tape at a constant speed.

However, generally, in the intermittent recording / reproducing mode, the capstan motor rotates intermittently. Also, in order to further stabilize the intermittent rotation, the slow brake is always in contact with the rotating surface of the rotor on the outer periphery of the capstan motor, and the braking surface of the slow brake gives the capstan motor light friction braking. It has become.
An example of the slow brake mechanism is disclosed in Japanese Patent Application Laid-Open No. 9-223342.

[0004]

As described above, in the intermittent recording / reproducing mode, the braking surface of the slow brake always comes into contact with the rotating surface of the rotor on the outer periphery of the capstan motor.
The slow brake is configured to apply a constant pressing force. Although this pressing force is relatively small, when the frequency of use of the intermittent recording / reproducing mode increases as in a surveillance camera system, the braking surface on the slow brake starts to wear gradually, and in the case of long-term use, the wear decreases. There is a problem that the frictional braking force progresses remarkably and a predetermined friction braking force cannot be obtained. Therefore, in order to maintain the predetermined friction braking force for a long time,
Since the friction braking force must be regularly inspected and the slow brake must be replaced as necessary, additional work such as inspection work and replacement work has occurred. To give an example,
In a surveillance camera system and the like, it is necessary to replace the slow brake about twice a year, and the replacement work requires a cost, thereby increasing costs.

An object of the present invention is to provide a magnetic recording / reproducing apparatus which has a long life even during intermittent recording / reproducing without increasing the number of parts or changing the structure of a mechanism and which can provide a stable friction braking force. It is in.

[0006]

In order to achieve the above-mentioned object, the braking surface of the slow brake which comes into contact with the capstan motor is configured to have substantially the same curvature as the contact surface on the outer periphery of the capstan motor. Therefore, the contact area at the contact portion increases and the surface pressure on the braking surface generated by the slow brake pressing force decreases, so that the wear life of the slow brake braking surface can be extended.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of a magnetic recording / reproducing apparatus according to an embodiment of the present invention will be described below with reference to FIGS.

First, the configuration of a magnetic recording / reproducing apparatus according to an embodiment of the present invention in a normal recording / reproducing mode will be described with reference to FIG.

FIG. 3 shows a state in which a cassette 10 containing a magnetic tape 12 is set in a main body of a magnetic recording / reproducing apparatus.
The state where the magnetic tape 12 is loaded on the cylinder 20 is shown.

[0010] Magnetic tape 12 housed in cassette 10
The tape guides 30 and 31 are pulled out of the cassette 10 by being moved from the cassette 10 side to the cylinder 20 side as indicated by arrows A and B, and are wound around the cylinder 20 at a predetermined angle. At this time, the magnetic tape 12 is guided by the guide pins 32, 33, 34. The tension pin 35 is urged in the direction of arrow C by a tension arm (not shown), and applies a predetermined tension to the magnetic tape 12.

The cylinder 20 is supported rotatably with respect to the substrate 28. A plurality of recording / reproducing heads (not shown) are attached to the cylinder 20. When the cylinder 20 rotates in the direction of arrow D, recording tracks formed obliquely on the magnetic tape 12 using the recording / reproducing heads. And information is reproduced from this recording track. Further, at a position between the tape guide 30 and the guide pin 32, the magnetic tape 12 is in contact with the erasing head 22, so that information recorded on the magnetic tape 12 can be erased.

The magnetic tape 12 is used for the capstan motor 4.
It is sandwiched between a capstan 42 provided at the 0 axis and a pinch roller 44, and is transferred at a constant speed by the capstan motor 40 rotating at a constant speed in the direction of arrow E. At this time, the magnetic tape 12 includes guide pins 36, 37,
Guided by 38 to a predetermined position.

The capstan tree 46 is provided integrally with the capstan 42 at the axis of the capstan motor 40. The rotation of the capstan 42 is transmitted to a pulley 50 via a belt 48 hung on a capstan pulley 46. The rotation of the pulley 50 is transmitted to the T reel base 54 via the take-up gears 51 and 52 and the swing gear 53, and the magnetic tape 12 transported at a constant speed is taken up on a reel in the cassette 10.

Since the S reel stand 57 rotates in accordance with the above-described winding operation, the magnetic tape 12 is sent out from the reel in the cassette 10. At this time, the S reel base 5
Reference numeral 7 denotes a load applied by a tension band (not shown), which applies a predetermined tension to the magnetic tape 12 to be fed.

The capstan motor 40 is an epimotor in which a stator is arranged on the inner side and a rotor is arranged on the outer side of the stator. A slow brake 100 is provided near the outer peripheral surface on which the capstan motor 40 rotates. Braking surface 102 on slow brake 100
Is not in contact with the outer peripheral surface of the capstan motor 40 in the normal recording / reproducing mode, and no friction braking force is applied.

Next, the configuration of the magnetic recording / reproducing apparatus according to one embodiment of the present invention in the intermittent recording / reproducing mode will be described with reference to FIG.

FIG. 2 is similar to FIG.
Is set in the main body of the magnetic recording / reproducing apparatus, and the magnetic tape 12 is loaded on the cylinder 20. In addition, the magnetic tape 1
2 is interposed between the capstan 42 and the pinch roller 44 and is intermittently transferred by intermittent rotation of the capstan motor 40. That is, the magnetic tape 1 rotates for a predetermined time.
2 is stopped for a predetermined time after being transferred by a predetermined amount, and then the rotation operation is repeated.

In the intermittent recording / reproducing mode, the slow brake 100 is rotated in the direction of arrow F by a drive mechanism (not shown), and the braking surface 1 is rotated by a spring (not shown).
Numeral 02 is in contact with the outer peripheral surface of the capstan motor 40 and applies a predetermined friction braking force to the capstan motor 40.

The braking surface 102 on the slow brake 100 is made of felt, and is adhered and fixed to a plastic arm constituting the slow brake 100. Braking surface 1
02, the friction braking force applied to the capstan motor 40 is such a load that does not hinder the rotation of the capstan motor 40 when the capstan motor 40 is energized from the stopped state and starts to rotate. Is stopped, the load is such that the capstan motor 40 can prevent the operation of the capstan motor 40 from rotating by inertia.

With such a weak pressing force, the intermittent recording /
As in the playback mode, the braking surface 1 of the slow brake 100
02 is constantly pressed against the outer peripheral surface of the capstan motor 40, for example, the contact surface is substantially linear in the conventional braking surface 104 as shown in FIG. Since the contact area with the braking surface 104 is small, the surface pressure on the braking surface 104 increases, and the wear easily proceeds. Therefore, when the braking surface 104 is worn out due to long-time use of the intermittent recording / reproduction mode and a predetermined braking force cannot be obtained, replacement work of the slow brake 100 is required. In addition, since the slow brake 100 is mounted on the substrate 28 side, the replacement work requires time and effort.

Here, the detailed structure of the slow brake used in the present embodiment will be described with reference to FIG.

FIG. 1 shows the shape of a braking surface of a slow brake used in a magnetic recording / reproducing apparatus according to an embodiment of the present invention.

As shown in FIG. 1, in the slow brake operation state, the slow brake 100 is urged in the direction of arrow F by a spring (not shown), and the braking surface 102 contacts the outer peripheral surface of the rotor of the capstan motor 40. In contact. At this time, since the braking surface 102 has substantially the same curvature as the outer peripheral surface of the capstan motor 40, the contact area between the outer peripheral surface of the capstan motor 40 and the braking surface 102 becomes larger than before. Therefore, the surface pressure on the braking surface 102 becomes smaller than before.

Therefore, for example, if the contact area is doubled,
Since the surface pressure on the braking surface 102 is reduced to about half and the life of the braking surface 102 is doubled, the number of replacement operations, the time required for the replacement operation, and the cost required conventionally can be reduced by half.

[0025]

As described above, according to the present invention,
Without increasing the number of components or changing the structure of the mechanism, it is possible to improve the reliability with respect to the friction braking of the capstan motor during intermittent recording / reproduction. In addition, operations such as replacement of parts can be omitted, and costs can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view showing a configuration of a slow brake in one embodiment of the present invention.

FIG. 2 is a plan view showing a tape winding system during intermittent recording / reproduction.

FIG. 3 is a plan view showing a tape winding system during normal recording / reproduction.

FIG. 4 is a plan view showing a configuration of a conventional slow brake.

[Explanation of symbols]

10 cassette, 12 magnetic tape, 20 cylinder,
40 ... Capstan motor, 42 ... Capstan, 44
… Pinch roller, 46… Cap stampedry, 48…
Belt, 100: slow brake, 102: braking surface.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Takashi Watanabe 1410 Inada, Hitachinaka-shi, Ibaraki Pref. Hitachi, Ltd. Visual Information Media Division (72) Inventor Koji Ii 1410, Inada, Hitachinaka-shi, Ibaraki Stock Hitachi, Ltd. Video Information Media Division F-term (reference) 5D071 AA07 BB02 5D081 AA07 EE04 EE07

Claims (1)

[Claims] 1. A drive source for pulling out a magnetic tape from a cassette, running the magnetic tape in a state of being wound around a rotary cylinder on which a magnetic head is mounted at a predetermined angle, performing recording or reproduction, and transferring the magnetic tape. In a magnetic recording / reproducing apparatus having a capstan motor and a braking means for braking the rotation of the capstan motor, the braking means has a braking surface abutting on the capstan motor and an outer peripheral surface of the capstan motor. A magnetic recording / reproducing apparatus having substantially the same curvature.