JPS60143473A - Fixing device of digital disk - Google Patents

Abstract

PURPOSE:To enable to correspond to various disks by turning on/off an electrical conduction to a motor and an electromagnet, and changing the magnitude of the conduction current by mounting/dismounting the turn table of the disk and by changing plate thickness of the disk. CONSTITUTION:When it is discriminated by a disk presence/absence discrimination circuit 19 that there is no disk 1, the power source circuit for a stater coil 15 and an electromagnetic coil 16 is opened, and the conduction current for respective coils becomes zero (i=0). On the other hand, when it is discriminated by the disk discrimination circuit 19 that there is the disk 1, the signal from a disk discrimination circuit 20 is inputted to a switching circuit 21 together wich opening of the power source circuit, and the prescribed current (i=i1) is conducted to the electromagnetic coil 16 when the disk 1 is DAD(CD). When the disk 1 is VD, higher current (i=i1, i1<i2) than that of DAD conducts to the electromagnetic coil 16, and the prescribed current (i=i2) is conducted to the stater coil 15 of a DC motor 13 by the switching circuit 21.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to processing of information signals such as audio signals and image signals.
The present invention relates to a device for fixing a digital disk on which a digitally encoded signal formed by CM (pulse code modulation) is recorded to a turntable.

PRIOR ART AND PROBLEMS Generally, a digital disk mounted on a turntable is rotated at a high speed (for example, 1800 rpm), so a device is required to securely fix it to the turntable to prevent it from slipping. be.

Conventionally, the above-mentioned fixing device has been disclosed in Japanese Patent Application Laid-Open No. 58-14382.
Some are known as described in the No. 1 gazette.

This fixing device mounts a digital disc (hereinafter referred to as a "disc") 1 horizontally to the cabinet of a player (not shown). A bearing member 3 is attached to the rotating shaft 4.
It is rotatably supported.

A turntable 5 consisting of a cylindrical main body part 61 and a flange part 52 provided on the outer periphery near the middle part of the main body part 51 for mounting the disc 1 is fitted onto the rotating shaft 4.

On the other hand, in the cabinet, a holding member 6 that presses the disc 1 against the turntable 5 and holds a disc suppressing member, which will be described later and rotates together with the turntable 5, is attached to the disc mounting surface 52a (the disc mounting surface 52a of the collar 52 of the turntable 5). It is provided so that it can move forward and backward with respect to the top surface (in Figure 1).

That is, the holding member 6 has a hollow disc shape, which is composed of a bottomed short cylindrical main body part 61 and a circular plate-like lid part 62 attached to the main body part 61 so as to close the open end of the main body part 61. The center of the outer bottom of the main body part 61 and the mounting member 7 attached to the cabinet are connected by a link 8, and the first
The disc attachment/detachment position and disc pressing position (second
It can be stopped at two positions (see figure).

A cylindrical disc pressing member 9 is attached to the holding member 6 at the lid part 6.
2 through the hole 6211, and the main body part 61
The shaft is rotatable about a shaft portion 81a protruding from the center of the inner bottom of the shaft, and is movable in the axial direction. The disk suppressing member 9 is prevented from coming off from the holding member 6 via a bottomed short cylindrical yoke 10 fitted to its inner end, and the disk 1 is fixed to the turntable 5 at its outer end. A flange portion 91 is provided to press against the flange portion 52 of.

A brushless DC motor 11 is interposed between the holding member 6 and the disc suppressing member e, and rotates together with the turntable 5 while pressing the disc 1 against the turntable 5.

That is, a ring-shaped permanent magnet 111 (hereinafter referred to as "magnet") is fixed to the inner bottom of the yoke 10.
The magnet 111 is constructed by arranging a plurality of permanent magnets magnetized in the vertical direction in FIG. 1 on the same circumference with adjacent magnetic pole faces having different polarities.

On the other hand, a circular plate-shaped printed wiring board 112 is fixed to the inner surface of the lid part 62 of the holding member 6, and the printed wiring board 112, together with the magnet 111, etc.
The plurality of coils 113 constituting the coil 1 are mounted at appropriate intervals in the circumferential direction.

The above-mentioned fixing device holds the holding member 6 at the disk attachment/detachment position shown in FIG. 1 to mount the disk 1 on the turntable 5, and then moves the holding member 6 to the disk pressing position shown in FIG. By energizing the coil 113 of the DC motor 11, the disc 1 is moved onto the turntable 5 while maintaining the gap g between the opening edge of the yoke 10 and the printed wiring board 112 as shown in FIG.
A magnetic circuit is formed in the magnet 111, the yoke 1o, and the lid 62 as shown by arrows in FIG. When the disc 1 rotates with respect to the holding member 6, the disc 1 rotates together with the turntable 5.

In FIGS. 1 and 2, reference numeral 12 denotes a pickup, which irradiates and receives a laser beam to extract a recording signal.

However, in the case of using the above fixing device, the magnet 11
Since the distance between the disk 1 and the printed wiring board 112 is constant, a disk 1 with a single thickness cannot be used;
±0.2) DAD (Digital Audio Disc) or CD (Compact Disc) and board thickness 2.5
m (±0.2) (7) In the case of VD (Hytheotism), there are problems such as having to install a spacer having a thickness equal to the difference in thickness between the flange 52 of the turntable 5 (the two sides). be.

OBJECTS OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to provide a digital disk fixing device that can be used with various types of disks.

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention includes a turntable,
Fixation of a digital disk consisting of a hollow disc-shaped holding member arranged in two pairs and a disk pressing member attached so as to be freely rotatable and movable in the axial direction. In the apparatus, an actor rotor type brushless DC motor is interposed between the holding member and the disk suppressing member, and an electromagnet capable of biasing the disk pressing member in a direction to separate from the holding member is interposed. Depending on whether a turntable is attached or not and changes in the thickness of the disc, the ON/OFF state of energization to the motor and electromagnet and the magnitude of the energizing current can be changed.

EXAMPLES Hereinafter, the present invention will be described in detail with reference to the drawings. In the following description, the same members and the like shown in FIG. 1 and FIG. 2 will be described using the same reference numerals.

FIG. 3 is a partially cutaway side view showing a first embodiment of the present invention, in which the fixing device of this embodiment is used to horizontally mount the disc 12 in the cabinet of a player (not shown).

That is, a bearing member 3 is inserted into a chassis 2 installed horizontally in a cabinet.
It rotatably supports the rotating shaft 4.

The rotating shaft 4 has a cylindrical main body 51 and the outer periphery near the middle of the main body 51 in order to mount the disk 1 thereon. = Provided flange 5
A turntable 5 consisting of 2 is fitted.

On the other hand, the cabinet is provided with a holding member 6 for holding a disk suppressing member, which will be described later, so as to be movable forward and backward relative to the disk mounting surface 52a of the collar portion 52 of the turntable 5.

The holding member 6 is provided in the shape of a hollow disc, consisting of a main body part 61 in the form of a short cylinder with a bottom, and a lid part 62 in the form of an annular plate attached to the main body part 61 so as to close the open end of the main body part 61. a clevis portion 61b protruding from the center of the outer bottom of the main body portion 61;
It is connected to the mounting member 7 attached to the cabinet by a link 8, and can freely move forward and backward with respect to the disk mounting surface 52a, and also has a disk mounting/removal position shown in FIG. It can be stopped in two positions.

The holding member 6 has a cylindrical disc pressing part and a lid part 6.
It is inserted through the hole 62m of No. 2, and is rotatable around a shaft portion 61a protruding from the center of the inner bottom of the main body portion 61, and is movable in the axial direction. The disc suppressing member 9 clamps and fixes the disc 1 together with the flange 52 of the turntable 5 via a flange 91 provided around its outer end, and constitutes a part of a DC motor to be described later. This is to prevent detachment from the holding member 6 through a short cylindrical yoke 1o with a bottom fitted to the inner end.

And between the holding member 6 and the disc suppressing member 9,
An actor rotor type brushless DC motor 13 is installed.

That is, a cylindrical permanent magnet 14 (hereinafter referred to as "magnet") is inserted into the inner circumference of the cylindrical portion 101 of the yoke 1o. The magnet 14 constitutes the DC motor 13 together with the yoke 1o and the stator coil described below, and connects a plurality of permanent magnets magnetized in the radial direction (left-right direction in FIG. 3) to adjacent magnetic poles. This is done by making the polarities of the surfaces different and arranging them on the same circumference.

On the other hand, on the inner surface of the lid part 62 of the holding member 6, a plurality of stator coils 15 that generate a radial magnetic field are installed to the magnet 1.
4 and facing each other on the inner side thereof, and are mounted at appropriate distances from each other in the circumferential direction.

Further, the inner surface of the lid portion 62 of the holding member 6 has an axial direction (
An electromagnetic coil 1B that generates a magnetic field in the vertical direction (in FIG. A short cylindrical magnetic shield 18 made of a fixed magnetic material is interposed.

The cabinet also includes a disk presence/absence determination circuit 19 for detecting whether or not the disk 1 is attached to the flange 52 of the turntable 5, and a disk detection circuit 19 for detecting whether or not the disk 1 is attached to the flange 52 of the turntable 5, and a disk detection circuit 19 for detecting the type of the disk 1, such as VD.
or DAD (CD), in other words, disc 1
Two disk discriminating circuits 20 for discriminating the size of the disk are installed as appropriate.

In addition, depending on the determination signal of the disk presence/absence determination circuit 1B,
Stator coil 15 and electromagnet coil 1 of C motor 13
ON or OFF of the energization to the electromagnetic coil 1B is selected, and the strength of the current to be energized to the electromagnetic coil 1B is selected based on the discrimination signal from the disk discrimination circuit 20.

Next, the operation of the fixing device of the above embodiment will be explained.

First, to attach the disc 1 to the turntable 5,
The holding member 6 is stopped at the disc attachment/detachment position shown in FIG.
2 on the disc mounting surface 52a.

Next, when the holding member 6 is moved to the disk suppressing position and stopped, the stator coil 15 of the DC motor 13 and the electromagnetic coil 1B are energized in accordance with the procedure shown in FIG. and the disc 1 is pressed against the flange 91 of the disc pressing member 9.
and the collar portion 52 of the turntable 5 with a predetermined pressing force, and rotates at a predetermined rotational speed.

That is, the disk presence/absence determination circuit 19 determines whether the disk 1 is
When the mL is determined, the power supply circuits for the stator coil 15 and electromagnetic coil 16 are opened, and the current flowing to each becomes zero (i=o).

On the other hand, when the disc discriminating circuit 19 determines that disc 1 is present, the power supply circuit is closed, and a signal from the disc discriminating circuit 20 is input to the switching circuit 21. A predetermined current (i=il) is applied to the electromagnetic coil 16,
Also, when the disk 1 is VD, the current is stronger than that when it is DAD (1=i□l).

<i,)m; The electromagnetic coil 16 is energized, and the switching circuit 21 causes the DC motor 1 to
A predetermined current (t"ts) is applied to the stator coil 15 of No. 3.

FIG. 5 is a half-cut side sectional view showing a second embodiment of the present invention.
The fixing device of this embodiment is similar to that of the first embodiment described above, in which the disk device surface 5 on the flange 52 of the turntable 5 is
A ring-shaped magnetic body 22 is embedded in 2a, and a flange 91 of the disk pressing member 9 facing the magnetic body 22 is embedded in the ring-shaped magnetic body 22.
5, an elastic ring-shaped rubber magnet 23 that can be attached and detached in the vertical direction is semi-embedded to reduce damage to the disk 1 and to reduce damage to the turntable 5 and the disk suppressing member 9.
Therefore, the same members, etc., as those of the first embodiment, C2, are the same as those of the first embodiment.
The same reference numerals will be used, and explanations of their configurations and functions will be omitted.

It should be noted that what is semi-embedded in the flange 91 of the disk pressing member 9 is not limited to the rubber magnet 24, but of course other plastic magnets having elasticity may be used.

Furthermore, although the fixing devices of the embodiments described above have been described for the case where the disk 1 is installed horizontally in the cabinet, they can also be applied when the disk 1 is installed vertically in the cabinet.

According to the present invention, even if the thickness of the disk changes, the disk can be reliably fixed to the turntable with a predetermined pressing force without slipping.

[Brief explanation of the drawing]

Figures 1 and 2 are side sectional views of the prior art, respectively.
The figure is a partially cutaway side view showing the first embodiment of the present invention.
Figure 4 shows the stator coil and electromagnetic 1;-1s II//7
'lnnh4^; Hill i1! +27I'NMI-1$JF
L#HI+911j It is a half-cut side view showing a second embodiment of the present invention. 1...Digital disk 2...
...Chassis 3 ...Bearing member 4 ...Rotating shaft 5 ...Turn tip 51 ...Main body Part 52...Flame part 52a...Disk mounting surface 6...Holding member 61...Body part 61a...Shaft part 61b... Clevis part 62... Lid part 62a... Hole 7... Mounting member 8... Link 9・・・・・・Disc suppression member ″e1 ・・・
...Flame part 10 ...Yoke 101 ...Cylinder part 102 ...Bottom part 11 ...DC motor 111 ...Permanent magnet 112 ...Printed wiring board 113 ...Coil 12 ...Pickup 13 ...DC motor 14 ...Permanent magnet 15 ...Stator Coil 16... Electromagnetic coil 17... Magnetic body 18... Magnetic shield 19... Disk presence/absence determination circuit 20...
... Disc discrimination circuit 21 ... Switching circuit 22 ... Magnetic body 23 ... Rubber magnet Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 15 Fig. 5

Claims (4)

[Claims] (1) A turntable on which a digital disc is mounted, a hollow disk-shaped holding member arranged in two pairs that can move forward and backward with respect to the disc mounting surface of the turntable, and a holding member that is rotatable and held in an axially movable manner. In this digital disk fixing device, a ring-shaped permanent magnet is attached to the disk suppressing member, and a stator coil is attached to the disk suppressing member to rotate the disk suppressing member with respect to the holding member. An electromagnetic coil that is positioned inside the permanent magnet and attached to the holding member, and that is positioned inside the stator coil and generates an axial magnetic field is attached to the holding member, and in conjunction with this electromagnetic coil, a disk pressing member is attached. 1. A digital disk fixing device, characterized in that a ring-shaped magnetic body is attached to a disk pressing member to urge the digital disk to be pressed. (2) The digital disk fixing device according to claim 1, wherein the stator coil and the electromagnetic coil have a cylindrical magnetic shield between them. (3) The digital disk fixing device according to claim 1, wherein the stator coil and the electromagnetic coil can be energized depending on the presence or absence of the digital disk. (4) The digital disk fixing device according to claim 1, wherein the electromagnetic coil has a variable magnitude of current applied thereto.