JPH0413770Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a rotating mechanism for a magnetic head in a reciprocating tape recorder.

(Prior art) In a reciprocating tape recorder, the magnetic track of the tape is different depending on whether the tape is running in the forward direction or in the reverse direction. It is necessary to switch. Therefore, there is a device in which the magnetic head is rotated 180 degrees in response to switching the tape running direction. The one described in Japanese Utility Model Application Publication No. 57-67250 is one of them.

(Problems to be solved by the invention) The rotation mechanism of the magnetic head in conventional reciprocating tape recorders uses a dedicated motor as a drive source for rotating the magnetic head, or a motor for rotating the magnetic head. Because a special drive mechanism was used for this, the mechanism was large.
Another problem is that when the magnetic head rotates, the magnetic head collides with a positioning stopper, and the magnetic head receives a large shock.

The purpose of this invention is to reduce the size of the mechanism by using a cam to detect the movement of the head board and the operating mode of the tape recorder, and by rotating the magnetic head using the rotational force of the cam. Another object of the present invention is to provide a rotation mechanism for a magnetic head that can reduce the shock at the end of rotation of the magnetic head.

(Means for Solving the Problems) The present invention provides a reciprocating tape recorder configured to move the head board by rotating a cam body for moving the head board according to the operation mode.
The cam body for moving the head board has a cam part for forward running of the tape and a cam part for running the tape in the reverse direction, and also integrally has a rotating cam for rotating the head when switching the running direction of the tape. The rotating cam has arcuate cam portions that share the rotation center of the cam body and have different distances from the rotation center, and a lift portion that connects the ends of these arcuate cam portions. The angular range of the arc-shaped cam portion shall be an angle corresponding to the forward direction traveling cam portion and the reverse direction traveling cam portion, respectively, and the lift portion of the rotating cam shall constitute the head rotation cam portion. It is characterized by

(Function) When the head board moving cam is rotated according to the operation mode, the head board moves. The head substrate is moved by a forward running cam when the tape is running in the forward direction, and by a reverse running cam when the tape is running in the reverse direction. When the running direction of the tape is switched, the rotating cam for rotating the head rotates together with the cam for moving the head board, and the magnetic head is rotated by the lift section that connects the arcuate cam sections with different diameters. It will be done. Even if the operating mode is switched within a range where the tape running direction remains unchanged, the rotating cam only rotates within the same arc-shaped cam portion, and the magnetic head does not rotate.

(Example) In FIGS. 1 to 3, a shaft 3 is fixed between a chassis 1 and a circuit board 2, and a gear 4 and a cam body 6 integrated with the gear 4 are rotated by the shaft 3. Possibly supported. The gear 4 is rotatably driven by a mode switching motor (not shown). The cam body 6 has a head board moving cam groove 22 for moving the head board 5 according to each operation mode of the tape recorder, and the cam groove 22 has a pin 21 fixed to the head board 5. is being dropped. Head board 5
A portion of the head support portion 7 is bent vertically to form a head support portion 7, and a horizontal bend portion 8 is further formed at the tip of the head support portion 7. A metal 33 is fitted into the head support portion 7,
The rotating shaft 11 is rotatably supported by the metal 33. The rotating shaft 11 is for rotatably supporting the magnetic head 9, and the magnetic head 9, a head mounting member 10, a pinion 12, and a collar portion 13 are integrally attached to the rotating shaft 11.

The head board 5 also has two bent parts 14, 1.
4 are formed, and these bent portions 14, 14
A rack plate 16 is mounted so as to be movable in the left-right direction using pins 27, 27 fixed to the rack plate 16 as a guide. The rack plate 16 has rack teeth 15, which mesh with the pinion 12, and the rack teeth 15 mesh with the pinion 12.
6 moves in the left-right direction, the pinion 12
is driven to rotate, and the magnetic head 9 is driven to rotate within a range of approximately 180 degrees. Rack board 1
The protruding portion 17 at the lower end of the lever 6 passes through the hole 34 of the chassis 1 and is loosely fitted into the fork portion 35 of the lever 20. The lever 20 is movable in the direction perpendicular to the plane of the paper in FIG. 1 and in the left and right directions in FIG. 2 by means of a guide pin (not shown).
0 moves, the rack plate 16 also moves. The lever 20 has a pin 19 which is dropped into a cam groove 18 formed in the gear 4 for rotating the head. Pin 19 is
Since it is moved by the cam groove 18 in a direction perpendicular to the plane of the paper in FIG. However, for the sake of clarity, the pin 19 is shown shifted in position in FIG.

The head support portion 7 of the head board 5 is provided with a pair of cut and raised pieces 23, 23.
The tips of the screws 24, 24 screwed into the screws 3, 23 are brought into contact with the main body of the head board 5, and then the screws 2
4 and 24, the inclination of the head support portion 7 with respect to the main body of the head board 5 can be adjusted.

The head mounting member 10 has a pair of abutting portions 2.
6, 36 are formed. Further, a pair of azimuth adjustment screws 25, 2 are provided at the bent portion 8 at the tip of the head support portion 7, passing through a plate spring 28 for preventing loosening.
5 are screwed together, and the tips of adjustment screws 25, 25 protruding downward from the bent portion 8 adjust the position of the head mounting member 10 according to the rotational position of the magnetic head 9.
It is adapted to come into contact with one of the contact portions 26 and 36 of. By adjusting the adjustment screws 25, 25,
Magnetic head 9 in each rotational position of magnetic head 9
The angle with respect to the tape, that is, the azimuth angle, can be adjusted.

The collar portion 13 of the pinion 12 and the rack plate 1
6 are provided with protrusions 29 and 30, respectively, and click springs 3 are attached to these protrusions 29 and 30.
Both ends of 1 are hung respectively. The elasticity of the click spring 31 urges the magnetic head 9 to rotate in each rotational position, presses the contact portions 26 and 36 of the head mounting member 10 against the azimuth adjustment screws 25 and 25, and rotates the magnetic head 9. It is designed so that it can be held in a predetermined rotational position.

Reference numerals 32 and 32 in FIG. 3 are pins provided on the chassis 1 to guide the movement of the head board 5.

FIG. 4 shows details of the cam body 6 and gear 4. Fourth
In the figure, the cam body 6 is designed to rotate integrally with the gear 4 over a range of approximately 360 degrees, and the cam body 6 is designed to rotate within a range of approximately 360 degrees.
is formed symmetrically with respect to the center line O-O passing through the center of rotation of the cam body 6, and the right side of this center line is the cam part for forward running of the tape, and the left side is the cam part for running the tape in the reverse direction. It forms the cam part. Both the forward running cam part and the reverse running cam part have a small diameter arc part, an intermediate diameter arc part, and a large diameter arc part with respect to the rotation center of the cam body 6, and a connecting part of these arc parts. The small-diameter arc portion corresponds to fast-forward and rewind modes and the stop position, the intermediate-diameter arc portion corresponds to a pause, and the large-diameter arc portion corresponds to a recording/reproducing mode. By configuring the cam groove 22 of the cam body 6 as described above, the magnetic head 9 can be kept far away from the tape in the fast forward and rewind modes and in the stop position, regardless of whether the tape is running in the forward or reverse direction. In the pause mode, the head 9 moves toward the tape and makes light contact with the tape, and in the recording/reproducing mode, the head 9 moves forward greatly so that the magnetic head can surely come into sliding contact with the tape.

A pair of cam surfaces 37, 37 for reel stand brakes are also formed on the cam body 6 and the outer peripheral surface in a symmetrical shape with respect to the line O-O, and are used to switch from fast forward or rewind mode or other operation mode to stop. When the reel is turned, a brake is applied to a reel stand (not shown) by the cam surfaces 37, 37.

Cam groove 18 for head rotation formed on gear 4
As shown in FIG. 5, the cam body 6
A large-diameter arc-shaped cam part 38 and a small-diameter arc-shaped cam part 39 are formed at positions corresponding to the forward direction running cam part and the reverse direction running cam part, respectively, with the rotation center of the cam body 6 as a common center. Further, these arcuate cam parts 38 and 39 are connected by a lift part 40. The lift section 40 corresponds to a forward/reverse switching section for the tape running direction, and when the tape running direction is switched, the lever 20 is moved by the lifting height of the lift section 40, and the movement of the lever 20 moves the rack plate 16. , pinion 12, etc., the magnetic head 9 can be rotated approximately 180 degrees. The lift portion 40 is formed in a range from the stopper position in one tape running mode to the stopper position in the opposite tape running mode, and is a cam surface whose distance from the center of rotation changes continuously. There is. Even if the operating mode is switched within the range of the tape running direction after the tape running direction is switched, the cam groove in which the pin 19 of the lever 20 is depressed is the cam portion 38 or 39, and its radius does not change. The lever 20 is stationary and the magnetic head 9 does not rotate. The positional relationship between the cam groove 18 and the cam groove 22 is as shown in FIG. The pins 19 and 21 are also rotated by 90° relative to the shaft 3.
It is engaged with each cam groove at different positions.

As shown in FIG. 1, a mode control switch contact piece 41 is fixed to the lower surface of the gear 4, and the switch contact piece 41 is formed on the circuit board 2 as shown in FIG. It is in sliding contact with the switch pattern 42. switch pattern 42
is adapted to emit a signal of an appropriate number of bits, for example, 3 bits, by the sliding contact of the contact piece 41, for each rotational position of the gear 4 corresponding to each operation mode in each tape running direction. One bit occupies an angular range of approximately 180 degrees, as shown by reference numeral 43 in FIG. 6, and is a pattern for detecting whether the tape running direction is the forward direction or the reverse direction.

The tape drive motor switching means for switching the tape running direction and tape running speed, the idler switching mechanism for driving the reel stand, etc. are located at separate positions (not shown), and the motor switching means is switched according to the designation of each operation mode. The gear 4 is rotationally driven as the idler switching mechanism and the like operate. Then, the contact piece 41 rotates together with the gear 4, and a signal is output from the switch pattern 42. Based on this signal, the operating mode is detected, and the rotational position of the gear 4 is controlled, so that the specified operating mode is achieved. It is now possible to switch.

Assume that the device is currently in a stop state and a recording/reproduction mode signal is input from this stop state. In response to the input of this signal, the gear 4 and the cam body 6 integrated therewith are rotationally driven by a mode switching motor (not shown), and the pin 21, which has fallen into the cam groove 22, is pushed by the cam groove 22, and the head board 5 is rotated. 1, the magnetic head 9 comes into sliding contact with a tape (not shown). When the gear 4 rotates together with the cam body 6 to a predetermined position corresponding to the recording/reproducing mode, it is detected by the switch pattern 42 (see FIG. 6) that the switch contact piece 41 comes into sliding contact with that the recording/reproducing position has been reached. The motor stops and the recording/reproducing position is maintained. The mode switching motor also puts the tape drive into an operating position appropriate for the recording/reproducing mode.

Assume that a reversal signal of the tape running direction is input in the recording/reproducing mode. In response to this signal, the mode switching motor rotates the cam body 6 via the gear 4, the tape recorder is temporarily brought to a stop state, and the head board 5 is moved into the cam groove 2 of the cam body 6.
The magnetic head 9 is retracted by the small diameter arc portion 2, and the magnetic head 9 is retracted largely from the tape. The gear 4 and the cam body 6 are still rotationally driven, and the pin 1 of the lever 20
9 reaches a lift portion 40 in the cam groove 18 whose distance from the center of rotation is continuously different, and this lift portion 4
With a lift of 0, the lever 20 is moved from side to side in FIG. This movement of the lever 20 causes the fork portion 35 to push the protrusion 17 at the lower end of the rack plate 16 and move the rack plate 16 from side to side.
, and the magnetic head 9 is rotated approximately 180 degrees.
The rotational position of the magnetic head 9 is determined by adjusting screws 25, 25.
The contact portion 26 or 36 of the head mounting plate 10 comes into contact with the end face of the head mounting plate 10, whereby the head mounting plate 10 is regulated at a predetermined position. The gear 4 and the cam body 6 are rotated to a position corresponding to the recording/reproducing mode and then stopped, and the pin 21 of the head board 5 is pushed by the large diameter part of the cam groove 22 to move the head board 5 forward, and the magnetic head 9
is brought into sliding contact with the tape. Further, the tape running direction is reversed and the tape is fed at a constant speed, and recording and reproduction are performed in the reverse mode.

Even if the operation mode is switched within the same tape running mode, the gear 4 only rotates within the range of the arcuate cam portion 38 or 39 of the same diameter of the cam groove 18, and the magnetic head 9 rotates. Never. On the other hand, the cam groove 22 of the cam body 6 has a different radius depending on the operating mode, and the head board 5 moves back and forth accordingly, so that the magnetic head 9 is in pressure contact with the tape or in light contact with the tape. situation,
It can be switched to a state where it is separated from the tape.

Note that the rack plate 16 may be configured as a rotatable sector gear, which is meshed with the pinion 12, and the sector gear may be rotated by movement of the lever 20. In this case, a rod-shaped spring is attached to the sector gear, the free end of this spring is engaged with the lever 20, and the movement of the lever 20 is transmitted to the sector gear via the spring, causing the sector gear to rotate. You can. Further, the cam body for moving the head board and the rotation cam for rotating the head may be provided on the front and back sides of one cam body, respectively.

In the above explanation, the terms "forward direction" and "reverse direction" refer to the same direction as the running direction of the tape when viewed from a certain running direction. "direction".

(Effects of the invention) According to the invention, the cam is used to detect the movement of the head board and the operation mode of the tape recorder, and the rotational force of the cam is used to rotate the magnetic head. It is not necessary to provide a dedicated motor for rotating the magnetic head or a complicated magnetic head rotating mechanism as in the magnetic head rotating mechanism described above, and the mechanism can be made smaller. Also,
Rotation of the magnetic head is now performed by a lift section that connects arc-shaped cam sections provided at positions corresponding to the forward direction traveling cam section and the reverse direction traveling cam section of the cam body for moving the head board. Therefore, the rotation is performed relatively slowly, and a shock at the end of rotation of the magnetic head can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a side cross-sectional view showing an embodiment of the present invention, Fig. 2 is a rear view of the same, Fig. 3 is a plan view of the same, and Fig. 4 shows the cam body for moving the head board used in the above embodiment. Plan view showing details of the rotating cam, No. 5
This figure is a plan view showing details of the rotating cam, and FIG. 6 is a plan view showing the mode control switch pattern used in the above embodiment. 5... Head board, 6... Cam body, 9... Magnetic head, 18... Cam groove for rotation, 22... Cam groove for moving the head board, 38, 39... Arc-shaped cam portion, 40... A lift part that connects the arc-shaped cam parts.

Claims (1)

[Scope of utility model registration request] In a reciprocating tape recorder configured to move the head board by rotating a cam body for moving the head board according to the operation mode, the cam body for moving the head board moves in the opposite direction to the cam part for forward running of the tape. It also has a rotating cam integrally for rotating the head when switching the running direction of the tape, and this rotating cam has a
The arc-shaped cam portions have a common center of rotation of the cam body and have different distances from the rotation center, and a lift portion that connects the ends of these arc-shaped cam portions. The angular range of is an angle corresponding to the forward direction running cam part and the reverse direction running cam part, respectively, and the lift part of the rotating cam constitutes a head rotating cam part. Head rotation mechanism.