JPS623462A - Reflecting type sensor for music selecting record player - Google Patents

Abstract

PURPOSE:To eliminate the change of a photodetecting quantity due to the change of a reflecting surface distance and to improve the inter-music space detecting accuracy and the reliability by providing an irradiating port or a photodetecting port having a shielding part which can adjust irradiating luminous energy by the reflecting surface distance. CONSTITUTION:A reflecting type sensor 4 has the irradiating port of the light emitting diode and the photodetecting port 9 of the photo transistor. Here, when respective reflecting surface distances are A, B and C, the positions 12A, 12B and 12C are obtained in which the light of the light emitting diode passes an irradiating port 8 to combine the focus at the distances. In order to eliminate the change of the photodetecting quantity of the photo transistor in respective reflecting surface distances A, B and C, the shielding part having shielding dimensions 14A, 14B and 14C corresponding to respective reflecting distances A, B and C is provided at the irradiating port. The shielding part is formed to an object shape. By such a constitution, the inter-music detecting accuracy and the reliability can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a reflective sensor for a music selection record player that dramatically improves the music selection performance and reliability of the music selection record player.

BACKGROUND OF THE INVENTION In recent years, record players with excellent operability and music selection functionality have become mainstream. Therefore, the reflection type sensor of the music selection record player should be one with high selection accuracy such as 5-track bass and less sound groove drop, and the sensor output due to warping or distortion of the record itself and the installation of the reflection sensor itself due to height positional deviation etc. There is a need for highly reliable sensors that are not affected by voltage changes.

An example of the reflective sensor of the conventional music selection record player mentioned above will be described below with reference to the drawings.

Fig. 5 shows an overall diagram showing the positional relationship between the reflective sensor of the music selection record player and the record, and Fig. 6 (a) and (b) show the reflective type of the conventional music selection record player in Fig. 6. A cross-sectional view of the sensor and a plan view from below, where 1 is a record, 2 is a record center, and 3 is a top view of the sensor.
4 is a reflection type sensor of the music selection record player, which is attached to the arm. 5
6 is a light emitting diode for illuminating the record surface, 6 is a phototransistor for receiving the reflected light of the light irradiated onto the record surface from the light emitting diode 5, and 7 is a light emitting diode for accommodating the light emitting diode 5 and phototransistor 6. A resin case, 8 is an irradiation port that irradiates the record with light from a light emitting diode 5 provided in the resin case 7, and 9 is a phototransistor 6 that directs light reflected from the record surface provided in the resin case.
This is a light receiving port for receiving light. Incidentally, the light emitting diode 5 and the phototransistor 6 are constituted by chip components.

The operation of the conventional reflective sensor of the music selection record player configured as described above will be described below.

First, the reflective sensor 4 is the record center 2 of the record 1.
When moving in the direction of Since the intermediate portion 3 is a flat portion, light is specularly reflected and is received by the phototransistor 6 through the light receiving aperture 9.

Since the amount of light received in the sound groove portion is small due to diffuse reflection, and the amount of light received is large in the five-track interval portion 3 due to regular reflection, recognition between songs can be performed.

Problems to be Solved by the Invention However, in the above configuration, the light emitting diode 5
Since the irradiation port 8 that irradiates the light from the reflective surface has a perfect rectangular shape, the distance characteristics of the reflective sensor (the change in the amount of received light with respect to the change in the distance between the sensor and the reflective surface) are as shown in Fig. 2. A very large peak appears when the distance is small, and as the distance increases, the amount of light received decreases.
If the distance changes by about ±1ff due to warping or distortion of the record, sensor height position deviation, etc. due to the reflective surface distance of a normal music selection record player, the amount of light received will also change greatly, and the detection angle between the five songs will change. It had a big problem with reliability.

In view of the above-mentioned problems, the present invention provides a reflective sensor for a record player for song selection that has high accuracy and reliability in song selection, with almost no change in the amount of light received by the phototransistor even when the reflective surface distance changes by approximately ±1n. It is.

Means for Solving the Problems In order to solve the above problems, the reflective sensor of the music selection record player of the present invention includes a light emitting diode, a phototransistor, a resin case, and the amount of light received changes depending on the length of the distance between the reflective surfaces. It is equipped with an irradiation port or a light receiving port that has a shielding part that can adjust the amount of irradiation light to prevent it from occurring.

Effect The present invention provides an output near the peak of the distance characteristic of a conventional reflective sensor by providing an irradiation port or a light receiving port with a plate that can adjust the amount of irradiated light depending on the distance of the reflective surface as described above. As a result, there is almost no change in the amount of light received even when the reflective surface distance changes due to warping of the record, greatly increasing the accuracy and reliability of detecting between songs. This is something that can be done.

Embodiment Hereinafter, a reflective sensor for a music selection record player according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 3 is a dimensional drawing of the reflective sensor according to the present invention, and FIG. 1 is a bottom view of the reflective sensor according to the first embodiment using the present invention, and the names of each part are the same as those in FIG. 5. They are indicated by the same reference numerals. Figure 4 is a relationship diagram for determining the shielding dimensions of the light emitting diode's irradiation aperture, where 8.9 is the light emitting diode's irradiation aperture and the phototransistor's light receiving aperture, 10 is the reflective surface, and 11 is the sensor and the reflective surface. 10 is the reflective surface distance between 10, 12 is the position where the light that focuses at each reflective surface distance 11 passes through the irradiation port 8, 13 is the distance characteristic of the conventional reflective sensor, 14 is each reflective surface distance of distance characteristic 13 FIG. 4 is a diagram showing the blocking ratio for suppressing and flattening the output at .

The function of the reflective sensor of the music selection record player configured as above will be explained below with reference to FIGS. 3 and 4.

First, with reference to FIG. 4, a method of determining the shield size of the irradiation port of the light emitting diode will be explained.

In FIG. 4(a), if the distances between the reflective surfaces are A, B, and C, the position at which the light from the light emitting diode passes through the irradiation port 8 to be focused is 12 mm.

12B and 12G, and the continuous attack ratio to suppress the output of distance characteristic 13 is 14 from Figure 4(b)! L.

14b, 140, and the shielding dimensions 14mm, 14B, and 14G as shown in Fig. 3 are determined as (repeat dimension) = (irradiation port @g) x rate) / (received light amount), and the successive part is The one formed into a symmetrical shape is shown in FIG.

As described above, according to this embodiment, the distance characteristic of the reflective sensor can be made into a flat curve by repeatedly firing a part of the light emitting diode irradiation port, and the reflective surface distance due to warping of the record surface etc. The amount of light received by the phototransistor can be made to hardly change with respect to changes in .

In the first embodiment, instead of the irradiation port 8, the light receiving port 9 of the phototransistor may be repeatedly bombarded at the same rate as above.

Effects of the Invention As described above, the present invention makes it possible to forcibly make the distance characteristic of a reflective sensor into a flat curve by repeatedly hitting the irradiation port of the light emitting diode at a certain rate, and thereby making it possible to forcibly make the distance characteristic of the reflective sensor into a flat curve. The reflective surface distance may be ±1H due to warping or distortion of the record surface or due to height positional deviation when mounting the sensor itself.
Even if the amount of light is changed, the amount of light received by the phototransistor hardly changes, and it is possible to realize a reflection type sensor for a record player that has high accuracy in song selection and is highly reliable.

[Brief explanation of the drawing]

Fig. 1 is a bottom view of the reflective sensor according to the embodiment of the present invention, Fig. 2 is a distance-light reception characteristic diagram of the conventional example and the embodiment of the present invention, and Fig. 3 is a continuous attack of the reflective sensor of the present invention. Dimension diagram, Figure 4 (IL), (b) is a sectional view and characteristic diagram showing the relationship for determining the continuous attack dimensions, Figure 5 is a top view of the reflective sensor of the song selection record player and the record,
FIGS. 6(a) and 6(b) are a sectional view and a bottom view of a conventional reflective sensor. 1...Record, 2...Record center, 3...Between songs, 4...Reflective sensor, 6...Light emitting diode , 6...
・Phototransistor, 7... Resin case, 8.
...Irradiation port, 9...Light receiving port, 10...
...Reflecting surface, 11...Reflecting surface distance, 12...
...Irradiation light passing position, 13...Distance characteristics,
14... Consecutive attack rate. Name of agent: Patent attorney Toshio Nakao and 1 other person7-
1'r Yoke Mata 8-Ichikasuchiguchi 2nd figure Jin direction distance Isho tθm]

Claims (1)

[Claims] A light emitting diode for illuminating the record surface, a phototransistor for receiving reflected light from the record surface, a resin case for housing the light emitting diode and phototransistor, and a light emitting diode opened in the resin case. It has an irradiation port on the side and a rectangular light receiving port on the phototransistor side. A reflection type sensor for a music selection record player characterized by forming a part.