JPS6367243B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a linear tone arm device for use in record players.

BACKGROUND TECHNOLOGY In general, a linear tone arm device used in a record player is provided with a movable base so as to be movable on a guide rail parallel to a normal line passing through the center of rotation of the turntable, and a movable base that can be vertically interlocked with the movable base. There is also known a structure in which a tone arm is supported so as to be able to rotate, and the movable base is driven by a motor.

Problems to be Solved by the Invention However, in the conventional device, the opening angle of the tone arm with respect to the moving base (tracking error angle)
The means for detecting the tone arm and the means for adjusting the tone arm to the rest position are independent, and this has the disadvantage that it takes time and effort to adjust the rest position so that the aperture angle is zero. If the rest position is not adjusted sufficiently, the tone arm is transferred with a tracking error, resulting in a problem that the tracing performance cannot be fully demonstrated.

Means for Solving the Problems Accordingly, it is an object of the present invention to provide a linear tone arm device in which the position of the rest means can be easily adjusted to a position where the opening angle of the tone arm with respect to the moving base is zero. With the goal.

Means for Solving the Problems The linear tone arm device of the present invention includes a movable base body movable on a guide rail parallel to a normal line passing through the rotation center of the turntable, and a movable base body movable up and down and rotatable. Tone arms movably arranged in parallel and having a pick-up cartridge at the tip and a balance weight at the rear end, and a plunger with a spring that is rotatably supported by the movable base and moves the tone arm up and down. a rotary lever to which a spring urging force is applied as a resistance against the force; a lift shaft having a V-shaped concave surface in the circumferential direction screwed onto a threaded shaft provided on the rotary lever; The present invention is characterized in that the horizontal angle of the tone arm can be adjusted to be perpendicular to the normal line passing through the center of the turntable by rotating the lift shaft having the V-shaped concave surface.

Effects According to the present invention, the tracking error angle becomes zero by tightening the lift shaft to the screw shaft so that the opening angle detected by the photocoupler becomes zero, and the rest position is determined. Therefore, it is possible to adjust the tracking error angle at the same time as adjusting the rest position, making the adjustment easy and achieving sufficient tracing performance.

Embodiments Hereinafter, the present invention will be described with reference to drawings of embodiments.

1 to 4 show an embodiment of a record player using the linear tone arm device of the present invention. In the figures, 1 is the record player body, and 2 is rotatable to the player body 1 via a hinge 3. This is the lid attached to the. The record player main body 1 has a turntable shaft 5 rotated by a motor, and a turntable 6 is mounted on the turntable shaft 5.

On the other hand, a linear tone arm device 17 and a record disk holding device 18 are provided on the inner surface of the lid body 2. The linear tone arm device 17 is the first
As shown in FIG.
Support stands 22, 23 are provided on the support stands 22, 2.
Pivot bearing 2 of vertical shaft 27 provided on tone arm 26 by pivot shafts 24 and 25 provided between 3
8 and 29 so that the tone arm 26 can be pivoted in the horizontal direction, and a horizontal shaft 30 provided on the vertical shaft 27 supports the tone arm 26 so as to be movable up and down. . A plate 32 having a pointer 31 is protruded from the movable base 21, and the pointer 31 provided on the plate 32 is positioned on the axis of the tone arm 26. The movable base body 21 is provided with a plunger 33 for vertically moving the tone arm 26, and a movable rod 34 of the plunger 33 is provided with a stop portion 35 having a tapered surface 35a at its tip. The movable rod 34 of the plunger 33 is always biased by a spring 36.

The movable base body 21 is provided with a rotating lever 38 having an abutting shaft 37 that comes into contact with the tapered surface 35a of the abutting portion 35.
is pivotally attached to a rotation shaft 39 provided on the movable base 21, and also has a lift shaft 40 that abuts the lower surface of the tone arm 26. The rotary lever 38 has a torsion coil spring 41 attached to the rotary shaft 39, so that the abutment shaft 37 is connected to the abutting portion 35.
is biased by a spring in the direction of contact. Therefore, the tone arm 26 is stationary with the urging force of the rotary lever 38 and the urging force of the plunger 33 balanced, and the turntable 6
It is in a raised position away from the record disc 42 mounted on the top surface of the record disc. A lift shaft 40 provided on the rotary lever 38 is provided with a V-shaped concave surface 43 in the circumferential direction, and faces a protrusion 44 provided on the lower surface of the tone arm 26. The lift shaft 40 is a screw shaft 4 embedded in the rotation lever 38.
5 is screwed on. The protrusion 44 and the V-shaped groove 43 are provided to accurately return the tone arm 26 to the rest position, and the rest position is adjusted by adjusting the screwing depth of the lift shaft 45.

The moving base 21 has light receivers 4 facing each other.
6 and a light emitter 47 are provided, and the light receiver 4
A shutter plate 48 provided on the tone arm 26 is positioned between the tone arm 6 and the light emitter 47. Signals from the photocoupler composed of the light receiver 46, the light emitter 47, and the shutter plate 48 are transmitted when the tone arm 26 is oscillated during the performance of the tone arm 26. Used to control to maintain almost parallel relationship. A balance weight 49 is attached to one end of the tone arm 26.
A pick-up cartridge 50 is attached to the other end.

On the other hand, the rotational force of the motor 51 as a driving source for moving the tone arm 26 is generated by passing a belt 55 between a pulley 52 provided on the motor shaft and a pulley 54 provided on the shaft of the worm gear 53. A drum 57 coaxial with a gear 56 that is transmitted to the worm gear 53 and meshes with the worm gear 53.
transmitted to. The tone arm 26 is moved by connecting a connecting rod 61 provided on the movable base 21 to a rope 60 stretched between the drum 57 and the other pulleys 58, 59. Further, the tone arm 26 is configured to move approximately linearly between the rest switch 62 and the end switch 63, and its rest position is set when playing a record disc 42 with a maximum diameter of 30 cm mounted on the turntable 6. Corresponds to the starting position.

Effects of the Invention As described above, according to the present invention, a screw shaft is provided on the rotary lever which is rotatably provided on the movable base body and is stopped at the rest position by the balance of the spring biasing force, A lift shaft provided with a V-shaped concave surface was screwed onto the lift shaft, and a protrusion provided on the tone arm was dropped into the concave surface of the lift shaft, so that it was placed at a position facing the movable base and the tone arm. By tightening the lift shaft to the screw shaft so that the opening angle detected by the photocoupler is zero, the rest position can be determined and at the same time the zero position of the tracking error angle can be determined, making the adjustment very easy. This makes it easy to use and provides sufficient tracing performance.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of the linear tone arm device of the present invention, FIG. 2 is a side view of the linear tone arm device, FIG. 3 is an assembled view of main parts of the linear tone arm device, and FIG. FIG. 4 is a perspective view showing a player using a linear tone arm. 6... Turntable, 17... Linear tone arm device, 19, 20... Guide rail, 21...
...Moving base, 26...Tone arm, 33...Plunger, 36, 41...Spring, 38...Rotating lever, 45...Screw shaft, 40...Lift shaft, 4
6,47,48...photocoupler.

Claims (1)

[Claims] 1. A movable base that can move on a guide rail parallel to the normal line passing through the center of rotation of the turntable, and a movable base that is arranged in parallel to the movable base so as to be movable up and down and movable in rotation, and has a pick-up cartridge at the tip and a rear a tone arm having a balance weight at the end; rotatably supported by the movable base;
A rotary lever to which a spring biasing force is applied as a counter force against the spring biasing force of the plunger for vertically moving the tone arm, and a V-shape in the circumferential direction screwed onto a screw shaft provided on the rotary lever. a lift shaft having a concave surface; a protrusion on the lower surface of the tone arm that engages with the V-shaped concave surface; A linear tone arm device characterized in that by rotating the shaft, the tone arm can be adjusted to be perpendicular to the normal line passing through the center of the turntable.