JPS6047205A - Record disc sucking device - Google Patents

Abstract

PURPOSE:To allow a record disc to be played while being sucked firmly by placing a sealed sheet between a turntable and the record disc and utilizing the sucking operation of the sealed sheet and the depressing operation of a stabilizer so as to correct a warp of the record disc with a warp. CONSTITUTION:The sealed sheet 4 is set onto the turntable 1 ahead the start of record playing and the record disc 3 is placed onto the sheet 4, an outer seal 9 is allowed to contact closely to the outer circumference of the record disc 3 so as to form an air chamber 12 between the record disc 3 and the sheet 4. When a stabilizer 5 is placed on the upper face of the center part of the record disc 3 via a center spindle 2, a ring seal 14 is allowed to contact closely onto the record disc 3 so as to form an air chamber 15 between the record disc 3 and the stabilizer 5, allowing the record disc 3 to be sucked and fixed firmly onto the sealed sheet 14. Thus, even if there is a more or less warp in the record disc 3, the warp is corrected by the suction of the sealed sheet 4 and the close mounting of the stabilizer 5.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a record adsorption device that can firmly adsorb a record to be played and place it on a turntable of a record reproducing device.

The raw material for vinyl records is vinyl chloride, which is soft and sensitive to heat, so some warping may occur during manufacturing.
Also, during use, the product may become deformed depending on the storage conditions. The low-frequency noise generated by the warping of a record has a frequency of about 5 Hz or less, and although it is inaudible to the ear, it causes cross-modulation distortion and impairs sound quality. It is also known that, as another problem, the radiated sound pressure from the speakers induces minute vibrations in the record, which causes ripple noise. Many of these problems are
This problem can be solved by firmly fixing the record on the turntable. Considering this point, it is possible to form a negative pressure chamber inside the turntable and use the negative pressure to attract the record. Proposed. However, this requires significant design changes to the turntable itself, resulting in a complex and expensive structure.

Therefore, an object of the present invention is to enable a record disc to be played on to be removably placed on an existing turntable while being firmly sucked and fixed. a sheet with a seal that is interposed between the record and the record to create an air chamber between them, a stabilizer that is placed on the record to create an air chamber between the record, and a stabilizer that is placed on the record to create an air chamber between the two. It is an object of the present invention to provide a record adsorption device characterized in that a negative pressure source and a stabilizer, each of which can be placed under negative pressure, are connected via an airtight rotary joint.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a side view showing the state in which the record adsorption device of the present invention is used. a donut-shaped sheet 4 with a sticker, a stabilizer 5 placed on the non-recording surface at the center of the record 3 via the center spindle 2 of the turntable 1, and a vacuum (not shown) between the stabilizer 5 and the It is composed of a joint arm 6 that connects to a negative pressure source such as a pump.

As shown in FIGS. 2 and 3, the sealed sheet 4 is provided with an inner seal 8 on the inner surface of the center hole 7 that is in close contact with the center spindle 2, and on the outer periphery of the inner seal 8 that is in close contact with the center spindle 2. An outer seal 9 that can be brought into close contact with the outer periphery is provided around the periphery. Further, a circular recess 10 concentric with the center hole 7 is formed on the upper surface of the central portion of the sealed sheet 4, and at least two or more radial slits 11 connected to the circular recess 10 are formed. In this case, the material of the sealing sheet 4 is generally made of materials used for turntables or turntable sheets 1-, such as ceramic, glass, metals such as aluminum alloys and copper alloys, or rubber. If formed, the inner seal 8 and outer seal 9 can be integrally formed.

The outer seal 9 is made of a flexible material such as neoprene rubber, and is made of a flexible material such as neoprene rubber.
As shown in the figure, an annular base 9 formed to fit strongly into an annular groove 4a provided around the seam 1-4.
a, and a thin flange 9b formed to extend outward from the upper end of the base portion 9a at a slight upward angle.

In this case, the outer periphery of the flange 9b is normally located above the upper surface of the sheet 4, is in close contact with the outer periphery of the record 3 including the group guard 3a, and there is no air between the flange 9b and the record 3. A chamber 12 is formed. Further, the inner seal 8 is similarly made of a flexible material such as neoprene rubber.

As shown in FIGS. 1 and 5, the stabilizer 5 has a center hole 13 in its center into which the center spindle 2 is inserted, and is provided around the outer periphery of the lower surface of the stabilizer 5 to hold the record disc 3. It is provided with an annular seal 14 that can be brought into close contact with the top surface. An air chamber 15 is formed between the record disc 3 and the stabilizer 5 by the annular seal 14.

In addition, the center hole]3 has a slot groove 16 as shown in FIG.
．． The IE3 is soaked in acid, and the air chambers 12, 1.5 are communicated with a negative pressure source via the grooves 16.16.

On the other hand, a truncated conical recess 17 whose upper end expands is formed in the upper part of the center hole 13 of the stabilizer 5.
A rotary joint portion 19 is fitted into this recess 17 via a rubber backing 1'8.

The stabilizer 5 and the joint arm 6 are connected airtightly and rotatably via the rotary joint portion 19. In this case, as shown in FIG. 5, for example, in the rotary joint part 19, the center shaft 21 of the joint arm rod is inserted from above into a chamber 19b formed with a thrust receiving plate 20 on the lower surface of the rotary joint base 19a. At the same time, the tip of the center shaft 21 is brought into point contact with a ball 22 disposed within the chamber 19b, thereby smoothing the rotation of the stabilizer 5 relative to the joint arm 6. In addition, by attaching a sheet-shaped rubber backing 23 with a backing presser 24 above the chamber 19b, the stabilizer 5 and the joint arm 6 can be attached.
Airtightness is maintained. In this case, the last receiving plate 20 has a communication hole 20a that communicates the center hole 13 and the chamber 19b.

20a is bored. Further, a large-diameter head 21a is formed at the tip of the center shaft 21, and the large-diameter head 21a prevents the joint arm 6 from being accidentally pulled out from the rotary joint portion 19. Further, a negative pressure passage 25 formed in the joint arm 6 and the center shaft 21
The negative pressure passage 25 is bent outward at the large diameter head 21a to ensure communication with the chamber 19b.

FIG. 7 shows another embodiment of the rotary joint portion 19, in which a center shaft 21 protruding into the rotary joint base 19a is connected to a permanent magnet 26 and a magnet 26 disposed at a vertically symmetrical position with respect to the permanent magnet 26. This is a case in which the pole piece 27 is supported by a bearing consisting of a pair of magnetic pole pieces 27 and 27, and a magnetic fluid 29 is sealed in each of the annular grooves 28 provided on the inner peripheral surface of the magnetic pole piece 27. Note that 30 is a backing that maintains the air-water tightness of the annular groove 28, and 31 is an O-ring provided around the outer periphery of the magnetic pole piece 27. Further, 21b is a large-diameter part provided on the center shaft 21 to prevent removal, 32 is a presser piece for preventing removal, and 33 is a communication hole that communicates the center hole 13 with the negative pressure passage 25. It is.

FIG. 8 shows yet another embodiment of the rotary joint portion 19, in which O-rings 31 are arranged on the outer peripheral surface of the center shaft 21 that protrudes into the single-rotation joint base 19a to maintain airtightness. This is the case when the following is done.

Note that in the embodiments shown in FIGS. 7 and 8, if the diameter of the center shaft 21 is made thinner, the effect on rotation accuracy can be almost ignored; however, in this case, the tip of the center shaft 21 is formed into an arc shape. By doing so, rotation accuracy can be further improved.

On the other hand, as shown in FIGS. 1 and 9, the base of the joint arm 6 is pivotable in the vertical direction with, for example, a pivot 35 at the upper end of a support leg 34 disposed on the outside of the turntable 1. The support leg 34 is rotatably supported in the horizontal direction by a thrust bearing 36 disposed on the record player. Therefore, the joint arm 6 is movable horizontally and vertically. Note that 37 is a negative pressure pipe that connects the negative pressure passage 25 of the joint arm 6 and a negative pressure source.

Next, the operation of the record disc suction device of the present invention will be explained.

Prior to the start of record performance, a sheet 4 with a sticker is set on a turntable l. And record 3
When placed on the sheet 4 using the center spindle 2 as a guide, the outer seal 9 provided around the outer periphery of the sheet 4 comes into close contact with the outer periphery of the record 3, creating an air chamber between the record 3 and the sheet 4. 12 is formed. Next, the stabilizer 5 is attached to the record 3 via the center spindle 2.
When the stabilizer 5 is placed on the upper surface of the center, the annular seal 14 of the stabilizer 5 comes into close contact with the record 3, and an air chamber 15 is formed between the record 3 and the stabilizer 5. and,
When the vacuum pump (not shown) is activated, the negative pressure passage 25 provided in the joint arm 6 and the center shaft 21. Chamber 19b, communication hole 20a and slot groove 16 of center hole 13
The air chamber 15 becomes negative pressure through the air chamber 15, and the circular recess 10 and the radial slits 11...
The pressure inside the air chamber 12 is also reduced through the air chamber 12, resulting in a negative pressure state. Therefore, the record 3 is firmly suctioned and fixed onto the sticker sheet 4, and the stabilizer 5 is placed tightly on the record 3, so even if there is some warpage inside the record 3, 1 is also straightened by the adsorption of the sealed sheet 4 and the close placement of the stabilizer 5. Even if the turntable 1 is rotated in this state, the stabilizer 5 rotates freely relative to the joint arm 6 and center shaft 21, so the record 3 can be fixed by suction for a long period of time. Highly faithful reproduced sound can be obtained without cross-modulation distortion due to warping or ripple noise due to radiated sound pressure from the speaker.

To remove the record 3 at the end of the performance, etc.
The negative pressure source side is opened to the atmosphere and air is introduced into the air chambers 12 and 15 to release the adsorption state due to the negative pressure. Then, the record 3 is removed from the turntable 1 by displacing the joint arm 6 in the vertical and horizontal directions.

As explained above, according to the record adsorption device of the present invention, it can be easily set on an existing turntable in a removable manner, and the adsorption action of the sheet with a sticker and the suppression action of the stabilizer can be easily set. This means that even if a record has a warp, it can be played while being firmly suctioned to correct the warp, which eliminates cross-modulation distortion caused by the warp of the record and rumble noise caused by the sound pressure radiated from the speakers. It is possible to obtain high-fidelity playback sound without any generation of noise. Also, sheets with stickers.

Stabilizers, joint arms, and the like have simple structures and are suitable for mass production, so they can provide excellent effects such as being cost-effective, so their utility value is significant.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the usage state of the record disc suction device of the present invention, FIG. 2 is a plan view of the sheet with a seal in the present invention, and FIG. 3 is a sectional view taken along the line ■-■ in FIG. Fourth
The figure is an enlarged sectional view of the main part of the outer seal, FIG. 5 is a sectional view showing an example of the rotating joint part of the stabilizer and joint arm in the present invention, and FIG.
7 and 8 are sectional views showing other embodiments of the rotary joint portion, respectively, and FIG. 9 is a sectional view showing an example of the overall structure of the present invention. In the figure, 4 is a seat with a seal, 5 is a stabilizer, 6 is a joint arm, 7 is a center hole, 8 is an inner seal, 9
1 is an outer seal, 10 is a circular recess, 11 is a radial slit, 12.1'5 is an air chamber, 13 is a center hole, 14 is an annular seal, 16 is a slotted groove, 19 is a rotary joint part, and 20 is a thrust receiver. plate, 20a is a communication hole, 21 is a center shaft, 2
1b is a large diameter head, 22 is a ball, 23 is a rubber backing, 24 is a backing holder, 25 is a negative pressure passage, 26 is a permanent magnet, 27 is a magnetic pole piece, 29 is a magnetic body, 33 is an O-ring, 34 is a Support leg, 35 is a pivot, 36 is a thrust bearing, 3
7 is a negative pressure pipe. Patent applicant: Audio-Technica Co., Ltd. Agent: Patent attorney: Takuya Ohara

Claims (1)

[Claims] It has a donut shape that is inserted between the turntable of a record playback device and the record being played, and has an inner seal on its inner periphery that comes into close contact with the center spindle of the turntable, and a record on its outer periphery. a sheet with a seal having an outer seal that can come into close contact with the outer periphery of the record; a stabilizer that is placed in the center of the record through the center spindle and has an annular seal provided around the outer periphery of the record; , a joint arm that connects the stabilizer and a negative pressure source that can create a negative pressure in the space between the sealed sheet and the record disc and the space between the record disc and the stabilizer; A record adsorption device, which is disposed horizontally and vertically displaceably on the outside of the table, and is connected to the input stabilizer via an airtight rotary joint at its free end. Device.