JPS6353601B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a turntable device for a record player, and its purpose is to effectively prevent unnecessary resonance of a record disc placed on a turntable and driven to rotate. Our objective is to provide an excellent turntable device that can perform the following functions.

In general, turntable devices for record players have a heavy turntable body attached to the turntable shaft in order to obtain smooth rotation performance, and a turntable sheet is provided on the top of the turntable body on which the record disc is placed. It was composed. However, since the record disc placed on the turntable is usually a vinyl chloride disc with a thickness of about 1 to 2 mm, unnecessary resonance occurs under strong sound pressure from the speakers when playing back the information recorded on the record disc. It is a thing,
The drawback was that it degraded the playback quality. In order to prevent the deterioration of playback sound quality caused by such unnecessary resonance, stabilizers and other devices that place weights on the record disc are known, but they do not allow the record disc itself to be in complete contact with the turntable. However, there was a problem in that it was difficult to prevent unnecessary resonance and eliminate deterioration in reproduced sound quality.

The present invention eliminates such conventional drawbacks, and the present invention will be described below with reference to drawings of embodiments.

FIG. 1 shows an embodiment of the present invention. In the figure, 1 is a record player main body, and an insulator 4 is provided on the bottom surface of the record player main body. A pick-up arm device 3 is mounted on the top surface of the record player main body 1.
and a turntable device 2 are provided. A record disc 5 is placed on the upper surface of the turntable device 2. The turntable device 2 is rotatably driven by being attached to a turntable shaft 7 driven by a motor (not shown), and a turntable sheet 6 is provided on the upper surface thereof. As shown in FIG. 2, the turntable sheet 6 has a center hole 8 in its center, into which the turntable shaft 7 is inserted, and has a ring groove 9a on its upper surface, which is perpendicular to the outer diameter direction of the ring groove 9a. A suction groove part 9 for a 17 cm record disc is composed of a radial groove 9b extending from the center, and a suction groove part 10 for a 30 cm record disc is composed of a ring groove 10a and a radial groove 10b extending orthogonally to the inner diameter direction of the ring groove 10a. is provided. The suction groove section 9 for the 17 cm record disc and the suction groove section 10 for the 30 cm record disc are arranged concentrically and independently, and the radial grooves 9b and 10b correspond to each other while maintaining an angle of 45 degrees. As above ring grooves 9a, 10a
is placed between. On the other hand, the turntable sheet 6 has two grooves 11a and 11b extending in the outer radial direction to the circumferential surface on its back surface, and these grooves 1
1a and 11b are connected to the suction groove 9 for the 17 cm record disc and the suction groove 10 for the 30 cm record disc through through holes 12a and 12b, respectively. And the above turntable sheet 6
is adhered with adhesive to the upper surface of the turntable main body 2' constituting the turntable device 2,
Concave groove 11 on the back side of the turntable sheet 6
a and 11b are closed so as to form holes that are open around the turntable sheet 6. Although not shown, it goes without saying that a vacuum sealing valve is attached to the hole opened around the turntable sheet 6. Here, the turntable main body 2' is suitably made of a relatively heavy material in order to obtain smooth rotation performance, and the turntable sheet 6 is made of resin such as polyolefin, polyethylene, polypropylene, other rubber, etc. It may be made of metal, glass, ceramic, etc., but a soft material is suitable in terms of adhesion to the record.

17cm for a turntable device with this configuration.
When a record is placed and played, a compressor is supplied to the hole around the turntable sheet 6 that constitutes the suction groove 9 for a 17cm record to vacuum the suction groove 9. , 17cm
The record disc can be brought into close contact with the turntable sheet 6. When a 30cm record is placed and played, a compressor is supplied to the holes around the turntable sheet 6 that constitute the suction groove 10 for the 30cm record to vacuum the suction groove 10. This allows the record to be brought into close contact with the turntable sheet 6.

FIG. 5 shows the acoustic characteristics of a record player having a turntable sheet of the present invention. FIG. 5 shows the pickup output characteristics when a sound pressure level (SPL) of 100 dB is applied to the record player from 50 Hz to 10 KHz. Curve A shows the case of a normal rubber turntable sheet, and curve B shows the case of the vacuum-adhesive turntable sheet of this example. As is clear from FIG. 5, the player having the turntable sheet of this example has less unnecessary resonance and excellent acoustic characteristics.

In addition, in the above embodiment, the turntable sheet 6
was pasted on the top surface of the turntable body 2', but
In addition to this, the turntable sheet 6 is shown in FIG.
It goes without saying that it may be attached to a backing plate 13 made of relatively hard resin, metal, glass, ceramic, etc., as shown in FIG.

As described above, the present invention has grooves for sucking record discs on the front surface, grooves for venting air extending to the outer periphery on the back surface, and these grooves for sucking record discs and the grooves are connected to through-holes. It is equipped with a turntable sheet provided with a record suction groove section connected in series, and air is sucked from the outer periphery of the turntable sheet through the groove, so that when the record disk is brought into close contact with the turntable sheet. In addition, the air in the groove can be easily sucked from the outside, so there is no need for a special configuration for air suction on the turntable, and unnecessary resonance can be reduced under strong sound pressure from the speakers. , it is possible to obtain good reproduction sound quality.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a record player using the turntable device of the present invention, Fig. 2 is a plan view of a turntable sheet of the same device, Fig. 3 is a sectional view taken along the line A-A in Fig. 2, and Fig. The figure is a sectional view taken along the line B-B in Figure 2, Figure 5 is a comparative characteristic diagram of a record player using the same device and a conventional record player, Figure 6 is
FIG. 7 is a sectional view showing another embodiment of the same device. 2... Tartable device, 2'... Turntable body, 6... Turntable sheet, 8...
Center hole, 9...Suction groove for 17cm records, 1
0...Suction groove for 30cm records, 11a, 1
1b...Concave groove, 12a, 12b...Through hole, 13
...Backing board.

Claims (1)

[Claims] 1. Having a groove for sucking a record on the front surface, and having a groove for venting air extending to the outer periphery on the back surface,
A turntable sheet is provided with a record suction groove section in which these record suction grooves and the groove are connected through a through hole, and air is sucked from the outer periphery of the turntable sheet through the groove. A turntable device featuring: 2. The turntable device according to claim 1, wherein the turntable sheet is adhesively attached to the upper surface of the turntable body. 3 Claim 1, characterized in that the turntable sheet has a backing plate adhered to the back surface thereof.
The turntable device described in section. 4. Claims 1 or 2, characterized in that the record disc suction groove has suction grooves for a 30 cm record disc and suction grooves for a 17 cm record disc, which are arranged independently and concentrically on the surface. Or the turntable device described in item 3.