JPS59104723A - Cassette type magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To reduce audio noises by moving a shielding plate which is rotatably supported by a fixed magnetic head to a place between the magnetic head and a cylinder to cut off the route through which the audio noise signal is given to the head. CONSTITUTION:The 1st link 18 revolves clockwise, and an angle 17 is pulled in the opposite direction to the loading direction of a rotary lever 8 by the link 18 when the loading of the angle 17 is completed. As a result, a shielding plate 12 is rotated counterclockwise around a support shaft 16 and against the energizing force of a spring 21. Then the upper surface of a magnetic head 7 touches the lower surface part 12b of the plate 12, and at the same time the tip folded part 12c of the plate 12 is moved up to a position where the part 12c covers a magnetic tape 2 having contact with the head 7. In this case, the part 12c can cut off an input route A of the audio noises given from a rotary magnet 14.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a cassette-type magnetic recording and reproducing apparatus that draws out a magnetic tape from a tape cassette during recording or reproduction to form a predetermined tape running path that comes into contact with a magnetic head. be.

Conventional configuration and its problems Figure 1 is a schematic diagram showing the tape drive system 1 of a conventional cassette-type magnetic recording machine, and Figure 2 shows the rotary lever mounted on the fixed magnetic head of the same machine. FIG. 3 is a side view showing the positional relationship between a portion of the magnetic head and a rotating magnetic head device. 11d is a rotating magnetic head drum (hereinafter referred to as a cylinder), and 2 is a magnetic tape which is pulled out from the tape cassette by the tape drawer guide posts 3, 4, 6.6 and wound onto the cylinder 1 (referred to as the tape loading state). ) is shown. A fixed magnetic head 7 for audio and control signals is mounted on the rotary lever 8.

This rotating lever 8 is fixed to a base plate 9 at a fulcrum III.
It is freely rotatable around I110. An audio head for audio signals is built in the upper part of the fixed magnetic head 7. Further, as shown in FIG. 2, a shield plate 12 is fixed above the fixed magnetic head for blocking snow protection signals (hereinafter referred to as audio noise) of the audio signal output. Further, in front of the fixed magnetic head 7 is a cylinder 1 and a motor 13 directly connected to the cylinder 1 for driving the cylinder 1. Furthermore, there is a rotor magnet 14 on the inner periphery of this motor 13, and the magnetic force for rotating the motor and the signal for controlling the rotation of the motor are provided by magnetization.

The operation and problems of the conventional cassette type magnetic recording/reproducing apparatus constructed as described above will be explained below.

As shown in FIG. 1, the tape 2 is connected to the dashed line 3'.

Guide posts located at 4', d, e') 3
, 4°6.6 is pulled out from the cassette 16 by being moved to the position indicated by the solid line, and wound around the cylinder 1 equipped with a rotating head (tape loading).
In conjunction with this movement, the rotating reno (-8 rotates around the fulcrum shaft 1o fixed to the base plate 9 from position P shown in the dashed line in the figure to position 8 shown in the same solid line.) do not have,
The fixed magnetic head 7 mounted on the rotary head (-8) moves from position 1 shown by the dashed line to position 7 shown by the solid line.

After this tape loading is completed, an audio signal is transmitted to the magnetic tape 2 in contact with the fixed magnetic throat 7 by the audio head 11 built in the magnetic head 7.

At this time, the distance between the fixed magnetic head 7 and the cylinder 1 becomes shorter, and the magnetization signal of the rotor magnet 14 becomes audio noise, which passes through the transmission path shown by the dashed line in FIG. There was a problem that it was input to 11. As mentioned above, the shield plate 12 is fixed to the upper part of the fixed magnetic head 7, and in order to secure a space for the tape 2 to come into contact with the magnetic head 7 after loading the tape, this shield plate 12 prevents audio noise from occurring. It was impossible to completely cut off the transmission route. Furthermore, in FIG. 1, during tape loading, the guide posts l-3, 4, 5, and 6 are located at positions 3' and
Positions 3.4.5 shown by solid lines from 4', 5', 6/
．． The fixed magnetic head 7 and the cylinder 1 move through the path B shown by the dashed line and the mechanism for moving the guide post 3 p 4 t 5 6 exists around the path B. There was a problem in that it was extremely difficult to install a shield plate between the two to block out audio noise.

However, in recent years, magnetic recording and reproducing devices such as audio equipment and video tape recorders have become smaller and lighter, and cassette holders have become smaller.
Accordingly, the distance between the fixed magnetic head 7 and the cylinder 1 needs to be further shortened, and the situation is becoming more likely to cause audio noise. On the other hand, it is naturally necessary to improve the performance of the device compared to conventional devices.

Purpose of the Invention The present invention eliminates such problems, and aims to provide a cassette-type magnetic recording and reproducing device that significantly reduces audio noise and at the same time reduces the size and weight of the device. .

Structure of the Invention The magnetic recording/reproducing device of the present invention includes a fixed magnetic head,
In conjunction with the operation of a rotary lever rotatably supported on the board, a shield plate rotatably supported on a fixed magnetic head is moved between the magnetic head and the cylinder after tape loading, and the audio Audio noise is reduced by completely blocking the path through which noise signals are input to the magnetic head.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 3, 4, and 5. FIG. 3 is a plan view showing a schematic configuration of a part of the rotating lever mounted on the magnetic head of a cassette-type magnetic recording/reproducing apparatus according to an embodiment of the present invention; FIG. 4 is a side view of the same, and FIG. The figure is a schematic side view showing the positional relationship between a part of the magnetic head tower-mounted rotary lever and the cylinder of the device when loading is completed. Note that the same components as those in the conventional example described above are given the same numbers and their explanations are omitted.

The fixed magnetic head fixed to the rotating lever 8 has a support shaft 1.
6 is fixed. Reference numeral 12 denotes a shield plate whose tip portion is bent into a 5-shape, and is rotatable about a support shaft 16 as a fulcrum. An angle 17 is still rotatably connected to the shield plate 12 by a pin 17a, and this angle 17 is rotatably connected to the first link 18 by a pin 182L. Furthermore, this first link 1
8 is rotatably connected to a second link 19 by a pin 19a, and this second ring 19 is rotatably supported around a support 20 fixed to the base plate 9 as a fulcrum.

Further, the shield plate 12 is connected to the rotary lever 8 by the spring 21.
As shown in FIG. 4 above, it is urged to rotate clockwise about the support shaft 16.

A stopper 22 for regulating the movement of the second link 19 is fixed to the column 20, and a stopper pin 23 for regulating the rotation of the shield plate 12 is fixed to the magnetic head 7.

The operation of the magnetic recording/reproducing apparatus of this embodiment configured as described above will be described below.

In Fig. 3, all the states at the time of unloading are dashed dot lines,
The state at the time of completion of loading is shown entirely by solid lines. First, when the magnetic tape 2 is loaded by the tape drawer guide post, the rotating lever 8 is rotated clockwise around the fulcrum shaft 1o from the position indicated by the dashed line to the position 8 indicated by the solid line by an interlocking mechanism (not shown), and the A magnetic head 7 comes into contact with the tape 2. Due to the operation of the rotation lever 8 during this loading, the second link 19 tries to rotate counterclockwise around the support 2o, but at a position where the stopper 22 and the side of the second link 19 contact each other. , rotation of the second link 19 is restricted. Further, the first link 18 rotates clockwise, and the angle 17 is pulled in the opposite direction to the loading direction of the rotary lever 8 by the first link 18 when loading is completed. Therefore, shield plate 1
2 is rotated counterclockwise about the support shaft 16 against the biasing force of the spring 21. The shield plate 12 is the support shaft 16
When rotated counterclockwise about the fulcrum, the upper surface of the magnetic head 7 and the lower surface portion 12b of the shield plate 12 come into contact, and the shield portion 12 at the tip of the shield plate 12 is bent.
0 moves to a position where it covers the magnetic tape 2 in contact with the magnetic head 7. At this time, the shield section 120 can block the input path Af of the audio noise signal from the rotor magnet 14.

Next, during unloading, the rotating lever 8 rotates counterclockwise about the fulcrum shaft 10, so that the shield plate 12 shown in FIG. It is released and returns to position 12 in FIG. 4 due to the biasing force of the spring 21.

However, the force that attempts to rotate the shield plate 12 counterclockwise during loading is applied by the spring 21 to the shield plate 12.
f: Greater than the force trying to rotate clockwise. Further, it is necessary to appropriately time the tape loading operation and the rotation lever 8 operation.

As described above, according to this embodiment, the shield plate 12 including the shield portion 120i rotates between the position covering the front surface of the magnetic head 7 and the position opening the front surface of the magnetic head 7, and the rotating lever 8 In conjunction with the operation of , it is possible to move the input path Ai of the audio noise signal from the rotor magnets 1 to 17 to a position where it is blocked each time the chip 2 is loaded, thereby making it possible to prevent the transmission of the audio noise signal. Become. Furthermore, when loading the tape,
Since the shield part 120 of the shield plate 12 can be placed in the space where the magnetic tape 2 comes into contact with the magnetic head 7, there is little waste of space. In addition, the shielding effect of the shield plate 12 can be achieved using other shielding methods, such as a method of attaching a shield member around the magnetic head 7 to absorb audio noise signals, or a method of attaching a shield case to the outer periphery of the rotor magnet 14. The structure of the shield member can be easily made smaller and lighter than the above.

Effects of the Invention As described above, in the magnetic recording/reproducing apparatus of the present invention, the shield plate having the shield portion works in conjunction with the tape loading operation to cover the front surface of the magnetic head and to open the front surface of the magnetic head. By rotating the tape guide to the desired position, it is possible to reduce audio noise, and the space for tape loading where the tape guide for tape drawer moves can be used as a shield. Since it is possible to effectively reduce audio noise using a simple shield member and a simple mechanism, it is also possible to reduce the size and weight of the magnetic recording/reproducing device.

[Brief explanation of drawings]

Fig. 1 is a schematic plan view showing the tape running system of a conventional cassette-type magnetic recording/reproducing device, and Fig. 2 shows the positional relationship between a part of the rotary lever mounted on the magnetic head and the rotary head drum device of the device. 3 is a side view, and FIG. 3 is a plan view schematically showing the structure of a part of the rotating lever mounted on the magnetic head of a cassette-type magnetic recording/reproducing apparatus according to an embodiment of the present invention; FIG. 4 is a side view of the same; 5
The figure is a schematic side view showing the entire positional relationship between a part of the magnetic head mounting rotary lever and the cylinder of the same apparatus when tape loading is completed. 1...Cylinder, 2...Magnetic tape,
3,4゜5.6... Guide post 1-17...
...Magnetic head, 8... Rotating lever, 9...
... Board, 1o... Fulcrum shaft, 11...
Audio head, 1.2, 12 &... Shield plate, 13... Motor, 14... Rotor magnet, 15... Cassette holder, 16...
...Spindle, 17...Angle, 18.1
9...link, 18a, 19a...pin,
20. Mountain... Support, 21... Spring, 22...
・・・S I-y par, 23...S1゛Bullet pin. Name of agent: Toshio Nakao, Physician, and one other person Figure 1

Claims (1)

[Claims] A rotary cylinder on which a rotary head is mounted, a tape loading means for pulling out a magnetic tape into a tape force center and winding it around the rotary head, and a rotary cylinder rotatably supported on a substrate and on which a fixed magnetic head is mounted. a rotating lever; a magnetic head moving means for moving the fixed magnetic head back from the magnetic tape traveling path during tape loading and moving the fixed magnetic head to a position where it comes into contact with the magnetic tape after tape loading; moving a movably supported shield plate in conjunction with the magnetic head moving means to retreat from the magnetic tape running path during tape loading;
A cassette-type magnetic recording/reproducing apparatus characterized by comprising a shield plate moving means for moving between the magnetic tape brought into contact with the fixed magnetic head and the rotary cylinder after tape loading is completed.