JPH0114996Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a dirt removal device for a rotary head of a VTR, and more particularly to a dirt removal device for a magnetic head that automatically removes dirt and keeps the head in a clean state at all times.

In a VTR, contamination of the magnetic head (adhesion of magnetic powder, etc. peeled off from the tape) affects both reproduction and recording, making it impossible to obtain good images. Therefore, in order to maintain constant performance of the VTR, it is necessary to clean the head periodically, and conventionally this was done manually by using a special cleaner rod moistened with a cleaning liquid such as alcohol. However, the magnetic head has low mechanical strength, and there is a risk that the head will be damaged during cleaning. Furthermore, in experiments conducted by the inventor, dirt on the magnetic head affects recording and reproduction for a cumulative period of several hours to several tens of hours, and it is necessary to remove dirt (cleaning) quite frequently. It was desired that dirt be removed automatically.

The present invention has been devised in view of the above points, and is intended to automatically remove dirt from a magnetic head. Before explaining the present invention, the state in which dirt adheres to the magnetic head will be explained with reference to FIGS. 1 and 2. FIG. 1 is a schematic partial plan view showing the state of contact between the magnetic head and the tape. The magnetic head 1 attached to a rotating disk (not shown) and the tape 3 are in contact with each other near the gap 2 of the magnetic head 1, and portions 4 and 4' form a gap that does not come into contact with the tape 3. Assuming that the magnetic head is rotating in the direction of the arrow in the figure,
The dirt 5 adheres to the gap 4 as shown in FIG. 2, and it is known that the accumulation of this dirt causes problems in signal reproduction and recording. In view of this, the aim of the present invention is to remove dirt from the magnetic head by bringing the tape into contact with the portion 4 of the magnetic head 1 when the tape comes into contact with the magnetic head other than during recording or reproduction.

Embodiments of the present invention will be described below with reference to FIGS. 3 to 6. FIG. 3 is a schematic plan view of the rotating disk showing the stationary state and the magnetic head dirt removal state;
The figure is a schematic plan view showing the contact between the tape 3 and the magnetic head 1 in a state where the magnetic head dirt is removed, FIG. 5 is a schematic plan view showing the rotating disk in a steady rotation state, and FIG. FIG. 3 is a schematic cross-sectional view showing the contact between the arm 7 and the stopper 11 in a rotating state.

In FIG. 3, reference number 6 is a magnetic head fixing base that supports the magnetic head 1, and is fixed to the magnetic head mounting portion 7a of an L-shaped plate-shaped arm 7 that can rotate on a rotary disk 10 about a spindle 8. It is fixed at an angle (it is a very small angle, but it is schematically drawn in the figure). The arm 7 is divided into a light head mounting part 7a and a heavy centrifugal force utilizing part 7b, with the supported part as the boundary, and the centrifugal force utilizing part 7b is connected to a spring 9.
It is urged to come into contact with the regulating protrusion 12 on the rotary disk 10, which is the first regulating means.

When the rotary disk 10 is stationary, and the steady rotation (1800 rotations/min) has not been reached, and the centrifugal force acting on the centrifugal force utilizing portion 7b of the arm 7 is smaller than the biasing force of the spring 1, the arm 7 and the magnetic head 1 is the third
The state shown in the figure, that is, the first regulation position is reached. Therefore, until the number of rotations of the rotary disk reaches a certain value, the tape 3 and the magnetic head 1 come into contact as shown in FIG. Therefore, dirt on the dirt-adhered portion 4 of the magnetic head is removed by sliding contact with the tape 3.

During playback and recording, when the rotary disk 10 reaches steady rotation and the centrifugal force acting on the centrifugal force utilizing portion 7b of the arm 7 becomes greater than the biasing force of the spring 9, the arm 7 closes the rotary disk 10, which is the second regulating means. It rotates in the opposite direction to the rotational direction of the rotary disk until it is regulated by the upper regulating protrusion 11 and assumes the second regulating position.
In this state (the state shown in FIG. 5), the rotation angle of the arm 7 is equal to the horizontal inclination angle of the magnetic head 1, so the magnetic head 1 correctly rotates the tape 3 in the state shown in FIG.
Normal recording and playback can be performed because it is in contact with the The contact between the regulating protrusion 11 and the L-shaped arm 7 is achieved by attaching the magnetic head of the L-shaped arm 7, which has a partially triangular cross section so as to fit into the V-shaped groove of the regulating protrusion 11, as shown in FIG. By means of the portion 7a, not only the horizontal position but also the height position of the magnetic head can be accurately regulated, and there is no problem in recording and reproducing.

In the above embodiment, dirt is removed using the very short time it takes for the rotational speed of the rotary disk 10 to return to normal, but when the VTR moves from stop mode to recording or playback mode, In this case, the dirt on the magnetic head 10 can be sufficiently removed by performing the conditions shown in FIG. In addition, if you want to remove dirt reliably, when fast forwarding or rewinding,
It is also possible to specially slow down the rotational speed of the rotary disk 10 to remove dirt during fast forward and rewind modes.

As described above, according to the present invention, it is possible to realize a dirt removal device that can automatically remove dirt from a magnetic head and obtain good images with a always clean head, which is useful.

[Brief explanation of the drawing]

The drawings are all schematic; FIGS. 1 and 2 are plan views showing the contact between the tape and the magnetic head, and FIGS. 3 to 6 relate to the embodiment, and FIG. 3 shows the magnetic head. 4 is a plan view showing the contact between the tape and the magnetic head in the state shown in FIG. 3; FIG. 5 is a partial plan view showing the rotary disk in a steady rotation state; FIG. 6 is a schematic cross-sectional view showing the contact between the arm 7 and the regulating protrusion 11. Explanation of main drawing numbers, 1...Magnetic head, 2...Gap, 3...Magnetic tape, 6...Magnetic head fixing base, 7...L-shaped plate arm, 8...Spindle, 9
... Spring, 10 ... Rotating disk (rotating body), 1
1, 12...Restriction protrusion (first and second restriction means).

Claims (1)

[Scope of utility model registration request] a rotating body, an arm that is rotatably supported on the rotating body and includes a magnetic head mounting portion and a centrifugal force utilizing portion heavier than the magnetic head mounting portion, sandwiching the supported portion; and the arm is placed in a first regulation position. a first regulating means for regulating the arm; a second regulating means for regulating the arm in a second regulating position; and a biasing means for biasing the magnetic head so as to properly contact the tape when the arm is in the second regulation position due to the centrifugal force acting on the centrifugal force utilizing section due to the rotation of the rotating body. A dirt removal device for a magnetic head, characterized in that it is fixed to a head mounting part.