JPH0124723Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to an improvement of an optical sensor for automatic song interval detection molded in the pickup portion of a tone arm of a record player.

(Prior Art) Generally, the optical sensor section 3 in the tone arm 1 is located in the pickup section 2 at the tip of the tone arm 1 as shown in FIG. 4B, and is molded as shown in FIG. 4C, which is a partial cross-sectional view. has been done. FIG. 4A is a cross-sectional view of the optical sensor section 3, and is a cross-sectional view along αα, which passes through a line perpendicular to the longitudinal direction of the tone arm 1 and connecting the centers of the light emitter 7 and the light receiver 8. be. As shown here, the optical sensor unit 3 has a frame 6 inside a housing 5, and a light emitter 7 and a light receiver 8 are arranged in this frame 6, and the light emitted by the light emitter 7 is directed onto the record disc. It is configured so that it is reflected on a line through which the tip of the needle passes and is detected by a photoreceptor 8.
However, due to component precision and assembly precision, this optical sensor 3 may be misaligned or tilted when the frame 6 is attached to the cartridge. The amount of light received by the photoreceptor 8 decreases at the center of the area, and the detection ability decreases, so there is a risk of malfunction. Furthermore, depending on the degree of misalignment, light may be reflected on the line through which the needle tip passes and cannot be detected, making it impossible to obtain the correct lowering position of the needle tip. In this case, since it does not have a function to adjust the angle of the frame 6, it cannot be corrected once it is installed. Therefore, the frequency of occurrence of defective products during mass production is high, posing a major obstacle in quality control.

(Purpose of the invention) The purpose of the invention is to eliminate the above-mentioned drawbacks and to make it possible to correct the descent position of the needle tip by adjusting with a simple operation the deviation of the descent position of the needle tip due to the deviation or inclination of the optical sensor section 3. optical sensor 3
Our goal is to provide the following.

(Example) A first example of the optical sensor 3 according to the present invention is described below.
This will be explained based on the diagram. The same parts as those in the conventional example are given the same reference numerals and explanations are omitted. First, FIG. 1 is a cross-sectional view of the optical sensor section 3 of FIG. be. The light emitting body 7 and the light receiving body 8 in the figure are placed within the frame 6, and the light emitting part and the light receiving part are arranged so that the light emitted from the light emitter 7 is reflected by the record surface and enters the light receiving body 8. The photoreceptors 8 are arranged and fixed in parallel at positions where the output is maximum. In addition, in order to prevent malfunction, the slits 6a and 6 are formed in the light receiving direction of the photoreceptor 8 and by the extension of the frame 6.
b is formed. Barrier 6 between the two slits
a, and is configured to prevent malfunctions due to the light from the light emitting section directly entering the light receiving section. The frame 6 has a surface for fixing the light emitter 7 and the light receiver 8, and a pair of walls perpendicular to this surface and facing each other along the longitudinal direction of the tone arm 1, and is movable within the housing 5. It is located in The housing 5 is molded to wrap around the frame 6, with one wall 5
A leaf spring 9 is fixed on the inside of A by a known method, and contacts the outer wall surface of one of the opposing walls of the frame 6 to urge the frame 6 rightward in the figure. The housing 5 also has a protrusion 5D near the top of the inner surface of the wall 5B opposite to the inner surface of the wall 5A, and a hole 5C penetrating near the bottom of the inner surface of the wall 5B. A screw 11 is screwed into the hole 5C,
By adjusting the degree of screwing, the frame 6 is swung about the protrusion 5D as a fulcrum to adjust the misalignment.

FIG. 3 is a diagram showing the position and state of the optical sensor section 3. For example, FIG. The light is reflected at the point of contact with the center line X of the cartridge passing through the needle tip, and is received through the trajectory of the reflected light. On the other hand, if there is an angular shift in the frame 6 as shown in Figure B, the emitted light A will be reflected at the reflection point Y on the board 12, and the center of the light will travel above C. In this case, the reflected light that actually enters the photoreceptor 8 is b, and the light is received at a position away from the center of the reflected light, so the amount of received light decreases. Moreover, a distance T deviates between the center line Or, even if it is the selected song, the performance may start from the middle. In such a case, in the present invention, by making the screw 11 in Fig. 1 deeper or shallower,
By swinging the lower part of the frame 6 to the upper left with D as the center, the inclination of the light emitter 7 and the light receiver 8 can be changed, and the center line X and the reflection point Y can be made on the same line, eliminating the misalignment distance T. It is something that can be done.

Next, as shown in FIG. 2, a screw 13 similar to the screw 11 is provided for the projection 5D in FIG.
This is the device shown in FIG. 1 with an additional adjustment function. For example, even after making adjustments based on the explanation in Figure 1, the reflection point Y with respect to the center line X is parallel to the center line X on the board surface 12, as shown in Figure 3 C. In the case where a shift occurs due to the movement, the present invention is capable of correcting the shift T by moving the frame 6 in parallel while adjusting the screws 13 and 11 in FIG. In the embodiment, the leaf spring 9 is used as the biasing means, but the invention is not limited to this, as long as it can be used as the biasing means. Also, the protrusion 5D and the screw 11
The number of screws 13 is also described using the minimum necessary number, and is not limited to the number shown in the figure.

(Effect of the invention) As described above, the optical sensor according to the present invention is equipped with a means for adjusting the deviation and inclination of the optical sensor section 3, so that the needle tip caused by the deviation and inclination can be easily adjusted. It is now possible to correct deviations in the lowering position of the machine, and during mass production, adjustments can be made in the subsequent process, standardizing variations in quality caused by poor parts precision and assembly precision, and reducing the number of defective products. can be lowered. On the other hand, if the needle tip descending position becomes misaligned due to misalignment or inclination, the user can easily correct it.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an optical sensor showing an embodiment, Fig. 2 is a sectional view showing another embodiment, and Figs. 3 A, B, and C schematically show the position and state of the optical sensor section. FIG. 4A is a sectional view of a conventional optical sensor, FIG. 4B is a perspective view of a tone arm, and FIG. 4C is a partial sectional view of a pickup section. 1: Tone arm, 2: Pickup, 3: Optical sensor, 4: Cantilever, 5: Housing, 6: Frame, 7: Emitter, 8: Photoreceptor,
9: Leaf spring, 10: Leaf spring fixture, 11: Screw, 12: Record surface, 13: Screw.

Claims (1)

[Scope of utility model registration request] In the optical sensor of a record player, which has the function of detecting the interval between songs using the light reflected from the record and setting the lowering position of the tone arm, 2.
a frame having a housing having two opposing walls, a frame having a light emitter and a photoreceptor and having a wall within the housing and opposite the walls; and the frame on one wall of the housing. An optical sensor comprising: means for urging; and means for adjusting the position of the frame against the urging force of the urging means.