JPS58158074A - Size detector for record disk - Google Patents

Abstract

PURPOSE:To detect the size of record disk without touching, by using a reflective type sensor for a detection part and utilizing light reflected from the record disk. CONSTITUTION:For example, when a 17cm record disk 4 is placed on the top surface of a rubber sheet 2, light from the light emitting diode of the reflective type sensor 9 for detection of 17cm record disk illuminates the reverse surface of the record disk 4 through transmission holes 1a and 2a, and its reflected light is inputted to a phototransistor to detect the presence of the record disk 4. The outputs of sensors 9, 10, and 11, at that time, are operated logically to decide that the 17cm record disk 4 is mounted on the rubber sheet 2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a record size detecting device for a fully automatic record player, which detects the size of a record using reflective light from the record using a reflective 7-hole cover. This has a simple configuration and allows size detection to be performed without damaging the record.

Conventionally, fully automatic 7" rakes have been equipped with a device that automatically detects the size of a record.

FIG. 1 shows an example of such a conventional record size detection device. In Fig. 1, 1 is a turntable, 2 is a rubber band placed on it), 3 is a turntable shaft, 4 is a record, 5 (5a, 5b,
5a) is 17(m record detection mechanism, 6(6a, 6b
, 6a) and 7 (7a, 7b, 7a) are 25cIrL and 30(m record disc detection @ mechanism, 8 is a magnetic sensing element such as a Hall IC that is a part of each record disc detection mechanism 5a, 6a7c) This is the board to be attached.

In the record size detection device configured as described above, when the 17cIrL record 4 is placed on the rubber sheet 2, the 17c1rL record size detection mechanism 5 detects that the record 4 is placed on the detection bin 6a. When the magnet 5b attached to the lower part of the detection bottle 6a approaches the magnetic sensing element 60, the Hall IC
The magnetically sensitive elements 60 are activated, and the remaining magnetically sensitive elements 60 and 70 are not activated. As a result, the record placed on the rubber sheet 2 is determined to be a 17-year record. A 30σ record is placed on rubber sheet 2.
Similarly, the 17crIL record detection mechanism 6 and the 26cIn/3acm record detection mechanism 6 and 7
is activated in arrow 1 and detected as a 3ocr/L record.

However, in such a detection device, since the detection bins 5b, 6b, and 7bf are pressed with the eye 2 of the record 4, there is a drawback that the record is inevitably scratched, and moreover, the record disc size detection mechanism 5 and 6 is unavoidably damaged.・The drawback was that 7 itself was extremely complex.

The present invention provides a record disc size detection device configured to overcome all of these conventional drawbacks.

An embodiment of the present invention will be described below with reference to FIGS. 2, 3, and 2.
In FIG. 3, parts having the same functions as those in FIG. 1 are denoted by the same reference numerals, and their explanation will be omitted.

9 is a reflective sensor for detecting 17 record discs, 9a is a light emitting diode which is a part of it, sb is a phototransistor which is also a part of 7, 10 and 11 are 25
(m and 30 (m) are reflection type sensors for detecting record discs. These are also configured similarly to sensor 9. On the other hand, the turntable 1 and rubber sheet 2 are placed at different positions depending on the size of the record. Specifically, within a radius of 8.6α from the rotation center of the turntable 1 and the rubber sheet 2.

The radius is thicker than 8.50 m (12.5 (within a range smaller than m, the radius is thicker than 12.5 cIrL and 15 cIrL)
The original transmission holes 1a, 1b, 1 respectively within a smaller range
a.

2a, 2b, and 2a are provided. These transmission holes 1a to 1a and 2a to 2a are provided at mutually coincident positions, and the 5 reflection type sensors 9°10.11 are
They are arranged on the locus of movement of each of the transmission holes 1a to 1a and 2a to 2°.

Figure 4 shows reflective sensors 9, 1o, and 9 for record detection.
the sensor 9 for the distance l from 11 to the reflective surface 1;
10. Phototransistor 9b, 1 which is the light receiving part of 11
It shows the relationship between the charge draining blades 0b and 11b.

When the 170 record disc 4 is placed on the top surface of the rubber sheet 2 as shown in FIG.
Reflective sensor 90 for detecting a 7cm record The light from the source diode 9a passes through the transmission holes 1a+2a and illuminates the bottom surface of the record 4, and the reflected light is manually applied to the phototransistor 9b to detect the absence of a 40M record. Light emitting diode 10a*1 of each of the 26 CIIL and 3acnl record disc detection reflective sensors 1o and 11
Since the source from 1a is not reflected by the record 4, it is transmitted through the transparent hole 1b of the tar/table 1 and the rubber sheet 2.

The light passes through 1a, 2b, and 2a and is not received by the phototransistor. Valley sensor 9°10.1 at this time
By performing all logic operations on the outputs of 1, it is determined whether the 17-year record 4 is placed on the rubber sheet 2 or not. 2
5cIrL and 30cIrL records are also judged in the same way.

Here, each record detection reflective sensor 9 @
10 and 11 are the distances to the bottom surface of the record 4 as shown in FIG. 3. Even if one side of the turntable 1, that is, a part other than the transmission hole, is irradiated with the light from the light emitting diode, if the original current of the phototransistor (Ipl in Fig. 4) is made extremely small, the transmission hole can be Erroneous detection due to rotation can be prevented. To do this, for example, it is necessary to prevent the reflected light from the bottom surface of the turntable from being received by the phototransistor, or to
A sheet or the like with low light reflectance may be attached to the lower surface of the lower surface other than the transmission hole.

With this configuration, it is possible to detect the size of the record disc without contacting the record disc 4, and at the same time, it can be realized with a simple configuration since a complicated mechanism would be unreliable.

As described above, the present invention uses a reflective sensor in the detection section and uses reflected light from the record to detect the size of the record without contacting the record, which can damage the record. Since there is no fear, the detection section itself is simple, and all of these can be placed on the turntable F side, the entire device can be significantly simplified.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional record size detection device, Section 21 and Fig. 3 are sectional views showing a record size detection device according to an embodiment of the present invention, and Fig. 4 is a reflective photocoupler output. FIG. 3 is a characteristic diagram showing the relationship between distance and distance. 1...Turntable, 1a-10...
・Light transmission hole, 2...Rubber sheet% 2"~2C
.....Light transmission hole, 3..Turntable shaft, 4..17 my record, 8..
... Board, 9-11 ... Reflective sensor. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2

Claims (1)

[Claims] Light transmission holes 'ffi located at positions according to the size of the record
! a turntable, a rubber sheet placed on the turntable and having an original transmission hole at a position facing the transmitted light; A reflection type photocoupler is provided, and the source from the photocoupler is irradiated through the transmission hole to the F side of the record placed on the rubber sheet, and the reflected light of -f: is reflected from the above-mentioned A record size detection device that detects the size of a record by receiving light using the photo force 1 arm.