JPH07272226A - Magnetic head cleaning device - Google Patents

Abstract

PURPOSE:To efficiently prevent clogging of a head without damaging a magnetic head by pressing a lapping paper to a magnetic head running path by rotation of a gear train by a clogging detecting signal of a detecting device. CONSTITUTION:When a detecting device 100 detects clogging of a magnetic head, a loading motor 3 is rotated and a gear train 4 is rotated. A mode switching gear 41 being one of the gear train 4 makes a lever 5 rotate through a press lever 6, and presses a free end of the lever 5 to a head cylinder 2. A lapping paper 52 is loaded on a plane opposing to the head cylinder 2 at the free end of the lever 5, a magnetic head rotating on the head cylinder 2 is rubbed by the lapping paper 52, and made clean. When the detecting device 100 stops to issue a clogging detecting signal, the gear 41 is rotated in the reverse direction and returned to the original position. The lever 5 also is returned to the original position, the wrapping paper 52 is separated from the head cylinder 2, and cleaning of the magnetic head is completed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head cleaning device for eliminating clogging of a magnetic head of a magnetic recording / reproducing device (hereinafter referred to as VTR).

[0002]

2. Description of the Related Art Conventionally, as a measure for clogging of a magnetic head of a VTR, a clogging prevention device, a clogging detection device, and a clogging detection magnetic head cleaning device. Is being implemented.

For example, by utilizing the sliding movement of the magnetic tape leading guide, the elastic roller made of foamed resin is pressed against the head cylinder, the elastic roller is brought into contact with the rotating magnetic head, and the magnetic powder and the like adhering to the magnetic head is removed. Remove. In this case, the magnetic head is less likely to be clogged, but once clogged, this cannot be eliminated.

For example, by comparing a video signal extracted by a recording / reproducing magnetic head (hereinafter referred to as a magnetic head) and FM-modulated with a control signal extracted by a control head, there is no video signal output and a control signal output. If there is, it is judged that the magnetic head is clogged.
0-119619). In this case, it is only necessary to detect the clogging of the magnetic head.
This will bother the user.

Is for operating the cleaning mechanism (8) in response to a detection signal emitted from a clogging detection device (100) for a magnetic head shown in FIG. 4 (JP-A-63-31).
7916). The magnetic head clogging detection device (100) includes a set of magnetic heads (21) rotating on a head cylinder (2).
Among a) and (21b), one magnetic head (21a) is inspected first, and then the other magnetic head (21b) is inspected.

When the clogging confirmation signal (117) is output from the clogging confirmation signal input section (101) to the recording and reproduction timing control circuit (102), the recording and reproduction timing control circuit (102) causes the mechanism control section (102) to operate. A control signal (116a) is issued to 103). The mechanism control unit (103) sends a control signal (116) to the tape drive unit (108).
Take out e) and pull out the magnetic tape T from the cassette half. At the same time, the magnetic heads (21a) and (21b) start to rotate. At this time, the magnetic tape drive unit 108 sets the magnetic tape T
So that the magnetic heads (21a) and (21b) come into contact with each other, the magnetic tape T
Appropriate tension is applied to.

When the rotation of the magnetic heads (21a) and (21b) is stable, the magnetic head (21a) is in contact with the magnetic tape T,
From the recording / playback timing control circuit (102), connect the recording amplifier (10
The control signal (116c) is outputted to 5) and the control signal (116b) is outputted to the recording / reproducing digital signal processing circuit (104). The recording / reproducing digital signal processing circuit (104) outputs an arbitrary or fixed signal, is amplified by the recording amplifier (105), and outputs a recording signal (113).
Then, the data is written on the magnetic tape T by the magnetic head (21a).

Next, a recording / reproducing timing control circuit (10
2) outputs a control signal (116d) to the reproduction amplifier (109) and a control signal (116b) to the recording / reproduction dual signal processing circuit (104). When the magnetic head (21a) makes one revolution and comes into contact with the magnetic tape T again, the magnetic head (21a) moves to the magnetic tape (1
Read the signal recorded in 07). The read head reproduction output (114) is amplified or waveform equalized by the reproduction amplifier (109) and sent to the head output detection circuit (110) as a reproduction signal (115) to detect the head output level. Done.

The head output detecting circuit (110) judges the head output level and outputs the result to the judging section (111). The determination unit (111) determines whether or not the head is clogged based on the output of the head output detection circuit (110), and outputs the determination result to the display unit (112). The above records,
It is possible to confirm clogging of one set of magnetic heads by performing the procedure of reproduction and determination for the other magnetic head (21b) in the same manner.

As a result of checking the clogging, when it is determined that the head is clogged, the determination unit outputs a control signal (120) to the mechanism control unit (103), and the mechanism control unit (103). A cleaning mechanism operation signal is issued from the cleaning mechanism (8) to operate. Cleaning mechanism (8)
In this system, the cleaning tape (80) is wound around the head cylinder (2) and the magnetic head running on the head cylinder is brought into contact with the tape to eliminate clogging of the magnetic head.

However, the cleaning mechanism (8) has two reel stands (81) (82) for winding the cleaning tape (80) and a device (not shown) for winding the tape around the head cylinder (2). Is required, and the cleaning mechanism (8) becomes large in size. This hinders the miniaturization of VTRs, and cannot be adopted in 8mm VTRs that pursue miniaturization.

It has also been proposed to press a plate-shaped cleaning member against the head cylinder instead of the cleaning tape (80) to clean the magnetic head. In this case, the magnetic head may be damaged. It has also been proposed to increase the tension of the magnetic tape T wound around the head cylinder (2) to cause a polishing action on the magnetic head without providing a special cleaning device. In this case, the head cylinder ( The load on 2) becomes too large, causing problems such as rotation stop of the head cylinder and defective starting, and further damages the magnetic tape T. The present invention is
A magnetic head cleaning device having a simple structure and capable of eliminating clogging of the head is disclosed.

[0013]

The cleaning device of the present invention comprises:
In a VTR that rotates a plurality of magnetic heads (21) on a head cylinder (2) and records on a magnetic tape T wound around the head cylinder (2) or reproduces a signal recorded on the magnetic tape T, a magnetic head A detection device (100) for detecting clogging of (21) and a spring (56) which is pivotally supported in the vicinity of the head cylinder (2) so that it can come into contact with and separate from the magnetic head traveling path of the head cylinder (2). The end of the lever (5) is biased in a direction away from the head cylinder (2), and the lever (5)
Cushioning material (50) on the surface of the free end facing the head cylinder (2)
The wrapping paper (52) mounted via the device, and the detection device (100) which is arranged to be connected between one gear (41) and the lever (5) of the VTR mode switching gear train (4). When the gear train (4) is rotated by the clogging detection signal of the head cylinder, the wrapping paper (52) on the lever (5) is moved to the head cylinder.
It is composed of a holding rod (6) which is pressed against the magnetic head traveling path of (2).

[0014]

[Operation and effect] When the detection device (100) detects clogging of the magnetic head (21), the motor (3) rotates to rotate the gear train (4). One gear (41) of the gear train (4) rotates the lever (5) via the pressing rod (6) and presses the free end of the lever (5) against the head cylinder (2).

Head cylinder (2) at the free end of the lever (5)
A wrapping paper (52) is mounted on the surface facing the magnetic head (21) that rotates on the head cylinder (2).
Are rubbed and cleaned by the wrapping paper (52).

The wrapping paper (52) has a polishing action,
When the magnetic head (21) is strongly rubbed, the magnetic head is damaged, but in the present invention, since the wrapping paper (52) is attached to the lever (5) via the cushioning material (50), the magnetic head (21) is ) Is softly pressed, the magnetic head (21) is not damaged, and clogging of the head can be effectively eliminated.

[0017]

EXAMPLE A head cylinder (2) is arranged on a chassis (1) in an inclined manner with respect to the chassis (1).
The lever (5) is rotatably provided so as to approach the position opposite to the magnetic tape winding side of (2). A support shaft (53) for rotatably supporting the lever (5) is provided perpendicular to the chassis (1).

The free end of the lever (5) is a curved arc portion (51) along the traveling path of the magnetic head (21) of the cylinder when the free end is close to the head cylinder (2).
Is formed. An inverted L-shaped leg (5
4) is protruding downward. The arc (51) of the lever (5) is attached to the support shaft (53) by the spring (56) so that the head cylinder (2).
It is urged away from.

A wrapping paper (52) is mounted on the head cylinder (2) side surface of the arc portion (51) of the lever (5) through a cushioning material (50) such as foamed resin. The end of the cushioning material (50) is rounded and chamfered, and the wrapping paper (52) is also curved along the curvature of the chamfered portion (50a) to prevent the magnetic head (21) from being caught.

A loading motor (3) also used for mode switching is mounted on the chassis (1), and the mode switching gear (41) is connected to the loading motor (3) through a plurality of gears. In the gear train (4) including the mode switching gear (41), one gear, in the embodiment, the mode switching gear (41) and the lever (5) are connected by a holding rod (6).

The holding rod (6) has two elongated holes (61) (61), and the guide shafts (11) (11) projecting from the chassis (1) are elongated holes.
Fitting on (61), the holding rod (6) is supported so as to be linearly reciprocable in a plane parallel to the chassis (1). Presser bar
The tip (62) of (6) is in contact with the hitting piece (55) protruding laterally from the lower end of the leg (54) of the lever (5), and the base end of the pressing rod (6) bends 90 °. Forming bent pieces (63).

The mode switching gear (41) is provided with a projecting shaft (42) which can be brought into contact with the bending piece (63) of the pressing rod (6).
As is well known, when the mode switching gear (41) is rotated, a slider (not shown) is linearly moved by a cam groove formed in the gear to switch modes. In the embodiment, the magnetic tape winding mode, rewinding mode,
Replay mode, fast-forward replay mode, rewind replay mode, slow-motion replay mode, and still picture mode can be switched, but the switching is within the range where the protruding shaft (42) does not hit the work clamp (6). Is performed by rotating the gear (41).

As will be described later, the loading motor (3) is activated by the clogging detection signal of the clogging detection device (100) of the magnetic head (21), and in FIG.
1) rotates counterclockwise beyond the range of the above mode switching, and the protruding shaft (42) pushes the presser bar (6), which causes the presser bar to move.
(6) pushes the lever (5) against the spring (56). The lever (5) has its wrapping paper (52) against the spring (56).
The mounting side is rotated in the direction of pressing the head cylinder (2).

As described above, when the mode switching gear (41) rotates counterclockwise beyond the range of mode switching, the mode switching gear (41) can be maintained in the immediately preceding mode, in the embodiment, the recording or reproducing mode. ) Is included in the mode switching transmission system. Since the detection device (100) is the known device described in the conventional example, the description thereof will be omitted.

However, the detection device (100) and the magnetic head (21)
When the clogging of the gear is detected, the motor (3) rotates and the gear train
Rotate (4). One gear (41) in the gear train (4)
Rotates the lever (5) via the pressing rod (6) and presses the free end of the lever (5) against the head cylinder (2).

Head cylinder (2) at the free end of the lever (5)
A wrapping paper (52) is mounted on the surface facing the magnetic head (21) that rotates on the head cylinder (2).
Are rubbed and cleaned by the wrapping paper (52). When the detection device (100) stops issuing the clogging detection signal, the gear (41) rotates in the opposite direction to the above and returns to the original position. The lever (5) is also returned to the original position, the wrapping paper (52) is separated from the head cylinder (2), and the cleaning of the magnetic head (21) is completed.

The cleaning with the wrapping paper (52) reduces the head depth (or protrusion) of the magnetic head (21) as compared with the usual polishing with the magnetic tape T. Therefore, the cleaning period in this mode is a predetermined time. Is limited to. If the clogging is not resolved even after repeating this mode for the specified number of times, the magnetic head (21)
Is determined to have caused the detection device (100) to generate a clogging detection signal due to a cause other than clogging, such as a break in the head winding of the magnetic head (21), and no further cleaning is performed, and the magnetic head (21 ) Is protected.

The wrapping paper (52) has a polishing action,
If the magnetic head (21) is hit hard, the magnetic head will be damaged. However, in the present invention, since the wrapping paper (52) is attached to the lever (5) via the cushioning material (50), the magnetic head (21) is ) Is softly pressed, the magnetic head (21) is not damaged, and the clogging of the magnetic head can be effectively eliminated. The present invention is not limited to the configuration of the above embodiment, and various modifications can be made within the scope of the claims.

[Brief description of drawings]

FIG. 1 is a plan view of a cleaning device.

FIG. 2 is a front view of the cleaning device.

FIG. 3 is an exploded perspective view of a lever tip.

FIG. 4 is a block diagram of a detection device of a conventional cleaning device.

[Explanation of symbols]

 (1) Chassis (2) Head cylinder (21) Magnetic head (4) Gear train (41) Mode switching gear (5) Lever (50) Buffer material (52) Wrapping paper (100) Head clogging detection device

Claims (1)

[Claims] 1. A magnetic head (2) mounted on a head cylinder (2).
In a magnetic recording / reproducing apparatus for rotating 1) to record on a magnetic tape T wound around a head cylinder (2) or reproducing a signal recorded on the magnetic tape T, a detecting device for detecting clogging of a magnetic head (21). (100) and head cylinder (2)
In the vicinity of the head cylinder (2), the lever (5) is rotatably supported by the magnetic head traveling path so as to be able to come into contact with and separate from the head cylinder, and the free end is biased by the spring (56) in the direction of separating from the head cylinder (2).
And the lapping paper mounted on the surface of the lever (5) facing the head cylinder (2) at the free end through a cushioning material (50).
(52) and a gear train for mode switching of the magnetic recording / reproducing apparatus (4)
Among them, one gear (41) and the lever (5) are connected to each other, and the gear train (4) is rotated by the clogging detection signal of the detection device (100), so that the lever (5) is moved upward. Magnetic head cleaning device constituted by a holding rod (6) for pressing the wrapping paper (52) of FIG. 1 to the magnetic head traveling path of the head cylinder (2).