JPH0749631Y2 - Rotating head type magnetic recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a rotary head type magnetic recording / reproducing apparatus capable of recording / reproducing using a cassette tape having a large tape load.

[Prior Art] FIG. 6 is a block diagram of a conventional rotary head type magnetic recording / reproducing apparatus disclosed in, for example, Japanese Utility Model Publication No. 58-24280, showing a tape path system after setting a cassette tape. is there.

In the figure, (1) is a supply reel, (2) is a magnetic tape as a recording medium, (3a) to (3d) are tape running guides, (4) is a tape tension control guide, and (5) is a tape. The contact pressure of the guide (4) for controlling the tape tension, the spring (6) for giving an initial tension to the magnetic tape (2), and the elastic body (11) brought into contact with the supply reel (1) by the syon arm. According to the size of the supply reel (1)
It has a holding part (7) that engages one end of a belt (10) that gives a variable rotational load to, and can freely rotate in a tension reduction direction (8a) and a tension increase direction (8b) around (9) as a rotation center. Is configured.

(12) is a rotary drum carrying a magnetic head (not shown), (13) is a guide member for moving the guide roller (14) and the like to wind the tape around the rotary drum (12). (15) is a fixed head for tape speed detection,
(16) is a magnetic tape (2) between the capstan (17)
Pinch roller that drives the tape running,
(18) is a tape take-up reel, (19a) and (19b) are reel brake arms, and (20a) and (20b) are attached to the tips of the arms (19a) and (19b). It is a brake shoe that slides with 1) and (18).

FIG. 7 shows a general form in which the cassette (100) on which the magnetic tape (2) is wound is inserted into a rotary head type magnetic recording / reproducing apparatus (101). In the figure, (102) is a cassette. The insertion direction (103) is the cassette insertion opening of the rotary head type magnetic recording / reproducing apparatus (101).

Next, the operation of the above configuration will be described.

The cassette (100) is a rotating head type magnetic recording / reproducing device (10
When the magnetic tape (2) is inserted from the insertion opening (103) of (1), the magnetic tape (2) is pulled out from the cassette (100) and wound around the rotary drum (12). FIG. 6 shows the setting state in which the tape is loaded.

Next, the magnetic tape (2) starts running in response to a recording (REC) or reproduction (PLAY) mode instruction. The operation of the tension arm (5) at this time will be described with reference to the detailed view of the tension arm (5) shown in FIG.

The magnetic tape (2) is wound around the tape tension control guide (4) at a winding angle of 2θ and has a tension of T. The vertical line of the force with the rotation center axis (9) of the tension arm (5) is l2, and the force by the spring (6) is
F1, perpendicular to the rotation center axis (9) is l1, supply reel (1)
Letting F3 be the force of the belt (10) that gives a rotational load to, and l3 is the perpendicular to the rotation center axis (9), the following balance equation is established.

F1 x l1 = l2 x 2 Tcosθ + F3 x l3 (1) That is, when the tension T increases, the force balance shown in the above equation (1) is lost and the tension arm (5)
Rotates in the direction (8b) for reducing the rotational load of the supply reel (1) to balance. At this time, F3 is getting smaller. Then, the tape tension T is lowered as the rotation load of the supply reel (1) is reduced. When the tape tension T is lowered, the tension arm (5) is rotated in the direction (8a) in which the rotational load is increased in order to balance the forces in order to balance the forces. At this time, F3 increases because the winding force of the belt (10) around the supply reel (1) increases.

The closed loop system as described above is configured.

In addition to this, there is a method of driving the supply reel (1) by a direct drive type motor without using the belt (10). This method is a method in which the rotation amount of the tension arm (5) is detected and a control voltage corresponding to the detected amount is applied to the motor, but the basic concept is the same as the belt type.

Therefore, when the cassette tape load increases,
In the equation (1), the tension arm (5) rotates in the direction (8b) in which F1 and T increase and F3 decreases. That is, as shown in FIG. 9, the tension control range exists. When the cassette tape load increases, the belt force F3 decreases, and there is a tension arm rotation angle φ3 that finally becomes zero. Then, the tape tension T is in condition to balance with the force F1 by the spring (6), and when the rotation angle of the tension arm is φ3 or more,
The increase in tension occurs rapidly. If it is shown by a formula, it becomes the following formula.

F1 × l1 = l2 × 2T cosθ (2) [Problems to be solved by the invention] Since the conventional rotary head type magnetic recording / reproducing apparatus is configured as described above, the tape tension control is performed. For the time being, I naturally set a limit on the cassette tape load. Therefore, when a cassette with a cassette tape load higher than the set value is set, the tape tension cannot be kept constant as described above, leading to problems such as head protection, tape protection, and stable contact between head and tape. Atsuta In particular, there was a problem that the damage to the tape and head when the tension became large was great.

The present invention was made to solve the above problems, and when a cassette with a cassette tape load higher than the setting is inserted, the tape inside the cassette can be automatically rewound. An object of the present invention is to provide a rotary head type magnetic recording / reproducing apparatus capable of reducing the load.

[Means for Solving the Problems] A rotary head type magnetic recording / reproducing apparatus according to the present invention is provided with a tape tension detecting means for detecting the tension of a magnetic tape, and when the detected value is equal to or more than a set value, the tape is run. It is characterized in that the tape in the cassette is rewound by stopping the operation and shifting to the fast-forward or rewind mode.

[Operation] According to the present invention, when the tape tension when the cassette tape is inserted and the recording / reproducing operation is performed is equal to or more than the set value, the tape tension detection means outputs the fast forward or rewind mode. Then, the tape in the cassette is rewound so that the tape and the head are not damaged by the excessive tension.

[Embodiment of the Invention] An embodiment of the invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a rotary head type magnetic recording / reproducing apparatus according to an embodiment of the present invention, showing a tape path system in which a cassette tape is set. In FIG. 1, it is the same as the conventional example shown in FIG. The same reference numerals are given to the configurations, and the description thereof will be omitted.

In FIG. 1, (40) is a detection plate projected from the tension arm (5), and (41) is an optical sensor for detecting the tape tension with the rotation angle of the tension arm (5). (60) is an amplifier for amplifying the output of the optical sensor (41), and (61) is a comparator for comparing the detection tension level (detection value) by the optical sensor (41) with a set level (set value). If the detection tension level is below the set level, the tape running mode (62) is continued, and if it is above the set level, the tape is rewound in the cassette by moving to the fast forward or rewind mode (63). Perform.

The detection plate (4
The detailed positional relationship between the optical sensor (41) and the optical sensor (41) is as shown in FIG. 3, in which (42) is a light emitting unit and (4).
3) is a light receiving part, and when the detection plate (40) is inserted between them, the optical sensor (41) performs a detection operation.

Next, the operation of the above configuration will be described with reference to the flow chart of FIG.

When the cassette tape with a large load is set and the tape running is started and the tension arm (5) rotates out of the tension control, the optical sensor (41) performs a detection operation to fast-forward the magnetic tape (2) or After switching to the rewind mode, rewinding the tape in the cassette, setting to the original position (abnormality detection point), and continuing (rerunning) the instruction mode (PLAY / REC etc.) To take.

In the above embodiment, the optical sensor (41) and the detection plate (40) are combined as the tape tension detecting means, but as shown in FIG. 4, the Hall element (45) and the magnet (44) are combined. A combination may be used, and the same effect as that of the above embodiment can be obtained as long as the rotation angle of the tension arm (5) can be detected.

Further, in the above embodiment, the tape tension is detected by the rotation angle of the tension arm (5), but the drum drive motor (not shown), the capstan motor (not shown).
Even if the drive (load) current of the motor is detected and the motor is operated like the flow chart shown in FIG. 5, the same effect as in the above embodiment can be obtained.

[Effect of the Invention] As described above, according to the present invention, the tape tension when the cassette tape having a load equal to or higher than the set load is used is detected, and the transition to the fast-forward or rewind mode is performed. Since the tape in the cassette can be rewound, the tape load on the cassette can be reduced, and the tape and the head can be reliably prevented from being damaged or scratched.

[Brief description of drawings]

FIG. 1 is a block diagram of a rotary head type magnetic recording / reproducing apparatus according to an embodiment of the present invention, FIG. 2 is an operation flow chart of an embodiment of the present invention, and FIG. 3 is a tension arm rotation detection of the present invention. FIG. 4 is an enlarged perspective view of a portion, FIG. 4 is an enlarged side view showing tension detection means in another embodiment of the present invention, FIG. 5 is an operation flow chart showing another embodiment of the present invention, and FIG. 6 is a conventional flow chart. FIG. 7 is a block diagram showing the rotary head type magnetic recording / reproducing apparatus, FIG. 7 is a schematic explanatory view showing the insertion of the cassette into the rotary head type magnetic recording / reproducing apparatus, and FIG. 8 is a main part for explaining the operation of the tension arm. FIG. 9 is an enlarged view showing the relationship between the rotation angle of the tension arm and the tape tension. (1) …… Supply reel, (2) …… Magnetic tape, (5)
...... Tension arm, (8a), (8b) ...... Tension arm rotation direction, (9) ...... Tension arm rotation center axis, (40) ...... Detection plate, (41) ...... Optical sensor,
(100) ... Cassette, (101) ... Rotary head type magnetic recording / reproducing device. The same reference numerals in the drawings indicate the same or corresponding parts.

Continuation of the front page (56) References JP-A-58-70450 (JP, A) JP-A-52-21807 (JP, A) JP-A-51-22407 (JP, A) Actual development-Sho 51-81714 (JP , U)

Claims (1)

[Scope of utility model registration request] 1. A tape tension control guide which allows a cassette around which a magnetic tape is wound to be inserted and removed freely, and which comes into contact with a magnetic tape pulled out from the cassette when the cassette is inserted, and the tape tension control guide. A tension arm that is installed at one end and is rotatable by increasing or decreasing the tape tension, a spring that is attached to the tension arm to give initial tension to the magnetic tape, and one end that is attached to the tension arm to contact the supply reel. In a rotary head type magnetic recording / reproducing apparatus equipped with a belt for varying the contact pressure of an elastic body, by detecting a rotation angle of a tension arm, by detecting a load current of a capstan motor, or by detecting a load current of a drum motor. The magnetic tape tension is detected by either A tape tension detecting means for outputting, a comparator for comparing the detected value by the detecting means with a set value and detecting a case where the detected value is larger than the set value, and stopping the tape running at the output of the comparator to fast-forward, or A rotary head type magnetic recording / reproducing apparatus comprising: means for shifting to a rewinding mode, rewinding the tape in the cassette, and re-running from the abnormality detection point.