JPS58111151A - Record detecting device - Google Patents

Abstract

PURPOSE:To obtain a small-sized device optically detecting intermusic of a record with less load to an arm by using one end of a pair of optical fibers fitted to the arm as a detecting terminal and coupling the other end with a light emitting element and a photodetector. CONSTITUTION:A pair of optical fibers 6 are fitted to an arm 5 for a player; one end of the optical fibers 6 is arranged so as to be opposed to a record disc at a position close to a record detecting part 8 to use the terminal as a detecting terminal and the other end is coupled with the light emitting element 1 and the photodetector 2. It is preferable to attach a lens 9 to the detecting terminal part of said optical fibers 6. In a device for detecting intermusic by using the difference of reflected light between the intramusic and intermusic of the record disc, the size and weight of the device can be reduced and a load to the arm can be also reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is characterized in that a pair of optical fibers is attached to a player arm, one end of the original fiber is installed near a record detection section facing the surface of the record to serve as a detection end, and the other end emits light. The present invention relates to a record detecting device configured to be coupled to an element and a light receiving element.

Conventionally, in order to optically detect the song gaps on a record, as shown in the schematic cross-sectional view of Fig. 1, a light emitting element 1 and a
An optical coupling device in which a light-receiving element 2 is integrated into a housing case 3 is seen into the cartridge portion at the tip of the arm. In this method, there are restrictions on downsizing the detection unit itself due to the size of the light emitting element 1 and the light receiving element 2, and the weight of the light emitting element and the light receiving element places a heavy burden on the arm, and the record stylus There were many problems and it was difficult to install it near the

The present invention eliminates such problems and proposes a record detection device using a source fiber that is lightweight and has a high degree of freedom in installation.

Hereinafter, the configuration of a record detection device using an optical fiber according to the present invention will be explained with reference to the drawings.

FIG. 2 shows an embodiment of the record detecting device of the present invention.The record detecting device of the present invention includes a light emitting element 1, a light receiving element 2, a cartridge portion 4, an arm 6, a multicore plastic fiber bundle 6. The plastic 77.47 bundle 6 is freely bent within the metal sleeve 7, and one end thereof is placed near the record stylus 8 to serve as a detection end. At the other end, the same glass fiber bundle 6 is branched into two, which are coupled to a light emitting element 1 and a light receiving element 2, respectively.

Light from the light emitting element 1 is irradiated onto the record via the plastic fiber bundle 6. On the record surface, the reflectance of the irradiated light is rounded between the curved surface portion and the inter-track portion, so the reflected light is utilized, and this reflected light is made to enter the light receiving element 2 via the plastic fiber bundle 6. According to the record detecting device of the present invention, there is no need to attach the light emitting element 1 and the light receiving element 2 to the cartridge section 4 at the tip of the arm 6, and only one end of the plastic fiber bundle 6 needs to be installed. The light emitting element 1 and the light receiving element 2 are attached to the circuit section of the player, and light is transmitted via the plastic fiber bundle 6.

Since the record detecting device of the present invention uses the original fiber itself in the detecting section, it can be easily installed in an arm or cartridge where space is limited. In addition, unlike conventional optical coupling devices, it does not require an opening, so it has excellent dustproof properties, and the light weight of the fiber reduces the burden placed on the arm. According to such a record detection device, it becomes possible to accurately detect the intervals between songs, and automatic song selection becomes easy. moreover,
When a lens 9 is attached to the detection end of the plastic fiber bundle 6, the detection resolution and 87N ratio can be increased due to the light condensing effect.

FIG. 3 shows an embodiment in which a record detecting device is constructed using two sets of single-core or multi-core plastic fibers.

Fiber 1 on the light emitting element side that transmits light from the light emitting element 1
The fiber 11 on the light-receiving element side that transmits the reflected light from the light and the record to the light-receiving element 2 is also independent on the detection end side.
I don't want it to be installed near the record needle 8 of the cartridge 4 via the arm 6. The S/N ratio can be most preferably increased by setting the opposing angle θ of the tips of the two sets of fibers to 30 to 6o0. Note that the above-mentioned opposing angle θ depends on the distance from the detection end of the fiber to the record disc.
It is preferable to change it appropriately within the range of ~60'.

Although the above explanation is an example using a plastic fiber, the same effect can be obtained by using a multicomponent glass fiber, a quartz fiber, or the like as the fiber.

[Brief explanation of the drawing]

Fig. 1 is a schematic sectional view of an optical system used in a conventional track interval detection device, Fig. 2 is a schematic diagram of the main part of a record detection device according to an embodiment of the present invention, and Fig. 3 is a diagram showing an optical system using two sets of fibers. FIG. 3 is a configuration diagram of main parts of another embodiment of the present invention. 1. Light emitting element, 2 mmam+a light receiving element, 36. . *aaaam housing case, 4, cartridge, 6, arm, 6 amuses
Plastic Phino (,7,,,,, Metal slip, 8 ****am record needle, 961119.Lens, 10,,,,,,, Phino on the light emitting element side (,11,
, , , fiber on the photodetector side.

Claims (2)

[Claims] (1) A pair of optical fibers was attached to the player arm, one end of the optical fiber was installed near the record detection section facing the record surface to serve as the detection end, and the other end was connected to the light emitting element and the light receiving element. A record detection device characterized by: (2) The record detection device according to claim 1, characterized in that a lens is installed at the detection end of the optical fiber.