JPH0120481B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a linear tracking device for moving a tone arm of a record player in parallel.

As shown in FIG. 1, the relationship between the sound grooves of a record and the record needle is generally such that the sound grooves on the L side and the R side are arranged symmetrically with respect to the tip of the approximately circular stylus 1. In this case, sound reproduction distortion can be reduced most when the same stylus pressure is applied to the L and R sides. In order to reduce this playback distortion, it is necessary to always keep the tone arm with the record stylus parallel to the tangent to the arcuate sound groove of the record. This is called zero error and is considered to be the ideal state. For this reason, the so-called linear tracking system is configured so that the tone arm moves approximately parallel to the movement of the needle. Conventional examples of this system are shown in Figures 2 to 4 below. show. In FIG. 2, 2 is a motor, and 3 is a wire driven by the motor 2. An arm moving base 4 is connected to one end of the wire, and the motor moves on two parallel rails 5 and 5A. It is configured so that it can be moved by driving No. 2. A horizontal rotating shaft 6 is provided on the upper part of the arm moving base 4, and the tone arm 7 and shutter 8 are configured to rotate in conjunction with each other. Further, a sensor 9 is provided in combination with the shutter 8, and a control circuit 9A is provided which receives input from the sensor 9 and energizes or de-energizes the motor.

The tone arm 7 has a stylus pressure adjusting weight 10 attached to one end, and a cartridge 11 having a stylus 1 fixedly attached to the other end.

Next, the operation will be explained. As the needle 1 attached to the cartridge 11 moves toward the record 21 as the record is played,
When the tone arm begins to move, for example, by a distance A in the direction of arrow X above, at the same time, the tone arm also rotates in the direction of arrow X about the horizontal rotating shaft 6 as a fulcrum. When the tone arm 7 rotates to the required angle, the shutter 8 that is linked to the tone arm 7 also rotates to the required angle, so the detection signal output of the sensor 9 changes, and the motor 2 is energized through the control circuit 9A. , moves the arm moving base 4. When the arm moving base 4 moves to the distance indicated by the arrow A, the detection signal output from the sensor 9 returns to its original state, and the power supply to the motor 2 is stopped. A record is played by repeating these actions many times.

In this way, in the conventional linear tracking device of a record player, the tone arm 7 rotates and becomes oblique as the needle 1 moves. (this is called a horizontal tracking error), and the balance between the stylus pressure applied to the R and L side sound grooves is lost, as shown by the arrows in Figure 4. However, it had the disadvantage of causing playback distortion.

The present invention was made in order to eliminate the drawbacks of the conventional ones as described above, and by moving the tone arm in parallel, the horizontal tracking error angle is made zero or close to zero, thereby reducing reproduction distortion compared to the conventional one. The aim is to reduce this even further.

An embodiment of the present invention will be described below with reference to FIGS. 5 to 7. In FIG. 5, 2 is a motor, and 3 is a wire driven by the motor 2. An arm base 12 is connected to one end of the wire, and two rails 5 and 5 are arranged in parallel.
It is configured to be able to move on A by driving the motor 2. One end 1 of this arm base 12
A protrusion 14 is provided on the lower side of the arm 14, and an arm 15, which is rotatable about the protrusion 14 as a fulcrum, is suspended. A tone arm support member 16 formed in approximately the same shape as the one end portion 13 described above is provided at the lower end of this arm 15, and the arms 15 are respectively latched onto protrusions 17 provided on the tone arm support member 16. Thus, the tone arm support member 16 is suspended so as to be rotatable in a direction parallel to the rails 5, 5A. A shutter 8 is provided in a protruding manner at one end of the tone arm support member 16,
The position is detected in combination with a sensor 9 fixed to the arm base 12, and the motor 2 is controlled through a control circuit 9A. A protrusion 19 having a fulcrum 18 is provided on the lower side of the tone arm support member 16 suspended in this manner, and the tone arm 20 is attached to the surface of the record disc 21 shown in FIG. 6 using the fulcrum 18 of the protrusion 19 as a fulcrum. It is provided so as to be rotatable in the vertical direction.

Next, the operation will be explained. When playing a record, when the needle 1 attached to the tip of the tone arm 20 moves a distance A as shown in FIGS. 6 and 7, the tone arm 20 that is interlocked with the needle 1 also moves in parallel by a distance A. do. When this tone arm moves to a required distance A, the shutter 8 protruding from the tone arm support member 16 also moves in conjunction with the tone arm 20, changes the detection signal output of the sensor 9, and passes the detection signal output to the motor 2 through the control circuit 9A.
The arm base 12 moves in the direction of the arrow X. When the arm base 12 moves approximately to the distance A described above, the detection signal output of the sensor 22 returns to its original state, and the power supply to the motor 2 is stopped. A record is played by repeating these actions.

Since the present invention is configured as described above, in a linear tracking device for a record player, a base such as an arm base 12 that can be moved on rails 5, 5A arranged in a straight line by the drive of a motor 2. and the arm 1 from the base part.
The tone arm support member 16 is suspended by a suspension member such as No. 5 and is movable in a direction parallel to the rails 5 and 5A, and a shutter 8 and a sensor 9 detect the position of the tone arm support member. and control means such as a control circuit 9A for energizing or de-energizing the motor 2 in response to input from the position detecting means, and the tone arm 20 equipped with a record stylus such as the stylus 1 is connected to the tone arm 20 as described above. Projection 19 provided on tone arm support member 16
Since it is designed to rotate vertically with respect to the surface of the record, the horizontal tracking error can be reduced to zero or kept constant near zero, thereby eliminating playback distortion due to horizontal tracking error. can be reduced compared to conventional ones.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view for explaining the relationship between the sound groove of a record and a record stylus, Figs. 2 to 4 show conventional examples, Fig. 2 is a perspective view, and Fig. 3 is a perspective view. The figure is a plan view for explaining the operation.
The figure is a sectional view showing the relationship between the sound groove and the needle 1. 5 to 7 show one embodiment of the present invention, in which FIG. 5 is a perspective view, FIG. 6 is a plan view for explaining the operation, and FIG. 7 is a front view. 2...Motor, 5,5A...Rail, 8...
Shutter, 9...Sensor, 9A...Control circuit, 12...Arm base, 15...Arm, 1
6...Arm support member, 20...Tone arm.

Claims (1)

[Claims] 1 In a linear tracking device for a record player, there is a base part that can be moved on a rail arranged in a straight line by the drive of a motor, and a base part that is suspended from the base part by a hanging member and that is parallel to the rail. The tone arm support member includes a tone arm support member movable in the direction, a means for detecting the position of the tone arm support member, and a control means for energizing or de-energizing the motor in response to an input from the position detecting means. A linear tracking device for a record player, characterized in that a tone arm equipped with a record stylus is provided so as to rotate in a direction perpendicular to the record surface using a protrusion provided on the tone arm support member as a fulcrum and rotating in a direction perpendicular to the record surface. .