JPH02223055A - Both-side performance disk player - Google Patents

Abstract

PURPOSE:To smoothly execute the alignment of a set of circular substrates to a turn table and to sufficiently isolate a disk now being performed from outside vibration by constituting a pressing force addition means of an attracting force generation means which attracts a pressing member toward the turn table. CONSTITUTION:A position change-over holding means A which decides the position of a second aligning member 38 at an insertion possible position where it can be inserted in the central hole of the circular substrate 23a or an insertion impossible position where it cannot be inserted according to the movement of a supporting member 31 between a first clamping position and a second clamping position is provided. Therefore, disk pressing force which is added to the disk at the respective aligning time of a set of circular substrates forming the disk 23 is almost equally made small. Thus, the respective circular substrates are made easy to move in the radius direction thereof and the alignment of both circular substrates is always and smoothly executed. Besides, since the supporting member 31 is not brought into contact with the pressing members 32 and 41 when the disk is clamped, the disk now being performed is isolated from the outside vibration.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a double-sided disc player for playing both sides of an information recording disc (hereinafter simply referred to as a disc) consisting of a pair of circular substrates each having a signal recording layer.

BACKGROUND ART There is already known a double-sided disc player that is provided with two pickups corresponding to each signal recording layer of a pair of circular substrates forming a disc, and plays both signal recording layers without reversing the disc. It is being In such a double-sided disc player, when a pair of circular substrates that form a disc are connected to each other with an offset of e in the radial direction, in order to smoothly perform performances on both signal recording layers of both circular substrates, Both circular substrates must be individually centered with respect to the turntable.

FIG. 14 shows a disk clamp mechanism, which is an important part of a conventional double-sided disc player, which performs a performance by centering each of the pair of circular boards individually with respect to the turntable, and the disc clamp mechanism, which is the main part of the conventional double-sided disc player, and how the disc is moved to the turntable. and a disk centering means for centering the disk.

As shown in FIG. 14, a turntable 2 is fitted onto a spindle shaft 1 of a spindle motor and driven to rotate.
The disc 3 mounted on the disc 3 is made up of a pair of circular substrates 3a and 3b, both of which have signal recording layers, which are fixed to each other. A recess is formed in the disc support surface 2a of the turntable 1, and a first centering member 5 is provided in the recess so as to be freely retractable from the disc support surface 2a. The first centering member 5 is guided by the spindle shaft 2, is biased by a coil spring 6, and is fitted into the center hole of one circular substrate 3b of the disk 3 to center the circular substrate 3b.

A support member 7 is provided above the turntable 2 and is movable within a plane perpendicular to the disk supporting surface 2a of the turntable 2. Although not shown, the support member 7 is moved and positioned to the non-clamped position shown in FIG. 14 and the first clamped position and second clamped position shown in FIGS. 15 and 16, respectively. Positioning means are provided.

The support member 7 is provided with a pressing member which is made up of a combination of a rotating member 8 and a disk abutting member 9 and which presses the disk 3 toward the turntable 2 so as to be rotatable and movable in the rotation center axis direction. Specifically, the rotating member 8 has a columnar portion 8a and a flange portion 8b, and the columnar portion 8a is loosely fitted into an opening 7a formed in the support member 7. A ball bearing 1o is fitted into the rotating member 8 with its inner race 10a. An intermediate member 10c is fixed to the outer race 10b of the ball bearing 10, and the intermediate member 10c can come into contact with a receiving plate 11 made of a viscoelastic member attached to the lower surface of the support member 7.

A disk contacting member 9, which together with the rotating member 8 constitutes the above-mentioned pressing member and contacts the disk 3, is attached to the rotating member 8 so as to be movable in the rotation center axis direction. A coil spring 12 is interposed between the rotating member 8 and the disk abutting member 9.

A second centering member 13 that fits into the center hole of the other circular substrate 3a of the disk 3 to center the circular substrate is attached to the rotating member 8 so as to be movable in the direction of the rotation center axis of the rotating member 8. ing.

The second centering member 13 includes a claw portion 8 formed on the rotating member 8.
It is held by d. Further, a coil spring 14 is disposed between the rotating member 8 and the second centering member 13.

A pair of optical pickups 16 and 17 are arranged so as to sandwich the disk Φ 3 placed on the turntable 2, and are guided along the recording surface of the disk 3 by a guide drive means (not shown). and moved.

The operation of the double-sided performance disc player having the above configuration will be briefly explained.

First, when playing the signal recording layer of one of the circular substrates 3b of the disc 3, that is, the circular substrate that is in contact with the turntable 2, the support member 31 must be moved close to the turntable 2 from the unclamped position shown in FIG. It is moved and positioned at the first clamp position shown in FIG. As a result, the disk abutting member 9 comes into contact with the disk 3, and the coil spring 12 is compressed to generate a pressing force, and the disk 3 is pressed against the turntable 2. At the same time, the first centering member 5 engages with the center hole of the circular substrate 3b to center the circular substrate. At this time, the flange portion 8b of the rotating member 8 is separated from the support member 7, and the intermediate member 10c fixed to the outer race 10b of the ball bearing 10 is brought into contact with the receiving plate 11 on the lower surface of the support member 7 with a predetermined frictional force. come into contact with In this state, the turntable 2 is rotated, and recorded information is read by the lower optical pickup 17 shown in FIG.

Next, when playing the signal recording layer of the other circular substrate 3a, the support member 31 is brought closer to the turntable 2 and reaches the second clamping position shown in FIG. 16. Therefore, the rotating member 8 descends with respect to the disk abutting member 9 that is already in contact with the disk 3 and is in a fixed state, and the second centering member 13 held by the claw portion 8d of the rotating member 8 contracts. Due to the biasing force of the coil spring 14, the circular substrate 3
The disc 3 is inserted into the center hole of the disc 3 and is slightly displaced in the radial direction. At the same time, the cylindrical portion of the second centering member 13 comes into contact with the first centering member 5, and the first centering member 5
is removed from the center hole of the circular substrate 3b and sunk below the disk supporting surface of the turntable 2. By this operation, the circular substrate 3a is centered with respect to the turntable 2. In this state, the turntable 2 is rotated in the reverse direction, and the optical pickup 16 disposed above the disk 3 reads the recorded information on the circular substrate 3a.

In the conventional double-sided disc player mentioned above,
The upper circular board 3a that is not in contact with the turntable 2
When performing a performance, the coil spring 12, which has already been bent and is applying a certain amount of pressing force to the disc abutting member 9, is further bent. Therefore, if the disc pressing force becomes extremely large and the coefficient of friction between the disc supporting surface of the turntable 2 and the disc 3 increases due to the influence of moisture, etc., the frictional force generated between the two becomes extremely large. Therefore, even if the second centering member 13 is fitted into the center hole of the circular substrate 3a, there is a concern that the disk 3 will not shift and centering will not be achieved.

Furthermore, since the support member 7 and the ball bearing 10 are always in contact with each other when the disc is clamped, external vibrations that have an adverse effect on the performance of the disc are transmitted to the second centering member through the support member 7, the ball bearing 10, and the rotating member 8 in this order. 13 and the first centering member 5, and this may reach the disk 3, which is disadvantageous.

Furthermore, even though the ball bearing 10 is a radial type, it must be highly durable and capable of sustaining high-speed rotation for long periods of time without impairing rotational accuracy while receiving a large thrust load, which increases cost. was inviting.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and its purpose is to always smoothly center a pair of circular substrates constituting a disc with respect to a turntable, and to provide To provide a double-sided performance disc player in which a disc is sufficiently isolated from external vibrations and the cost can be reduced.

In the double-sided disc player according to the present invention, the second centering member that fits into the center hole of the circular substrate on the non-contact side with respect to the turntable is held, and the disc pressing force is applied to the pressing member that presses the disc against the turntable. The pressing force applying means includes a suction force generating means that attracts the pressing member toward the turntable, and when the support member holding the pressing member is in the unclamped position farthest from the turntable, the pressing member is When the turntable is held at a position spaced apart from the disk supporting surface, and is in the first clamp position, which is an intermediate position, and the second clamp position, which is closest to the turntable, it is not in contact with the pressing member, and the support member is Position switching holding means for positioning the second centering member between a fitable position where the second centering member can be fitted into the center hole of the circular substrate and an unfittable position where the second centering member cannot be fitted in accordance with movement between the first clamp position and the second clamp position; The disc pressing force applied to the disc during centering of each of the pair of circular substrates forming the disc is approximately equally small, and the transmission of external vibrations to the disc during performance is blocked. There is.

Embodiments Hereinafter, a double-sided disc player as an embodiment of the present invention will be described with reference to the accompanying drawings.

1 to 5 show a double-sided disc player as a first embodiment of the present invention.

As shown in FIG. 1, the turntable 21 has a base portion 21
The base body 21a is fitted onto a spindle shaft 22 of a spindle motor and driven to rotate. The disk 23 to be mounted on the turntable 21 is made up of a pair of circular substrates 23a and 23b, each having a signal recording layer, which are attached to each other so that the signal recording layer is on the inside. Note that the two sun-shaped substrates 23a and 23b are connected to each other with an offset of e in the radial direction.

A recess 2 is formed in the disc supporting surface 21c of the turntable 21.
1d is formed, and a turntable 21 is placed in the recess.
A first centering member 24 is provided so as to be freely protrusive and retractable from the disk supporting surface 21c and along the rotation center axis of the turntable. The first centering member 24 is slidably fitted onto the spindle shaft 22 and guided by the spindle shaft. The first centering member 24 has a tapered surface 24a on its outer circumference, and one of the circular substrates 23b, which is in contact with the disk supporting surface 21c of the turntable 21, is a pair of circular substrates 23a and 23b forming the disk 23. By fitting the tapered surface 24a into the center hole, the circular substrate 23b is centered with respect to the turntable 21. A coil spring 26 is interposed between the turntable 21 and the first centering member 24, which applies a bias force to the first centering member in the projecting direction.

A support member 31 is disposed above the turntable 21, and a support member 31 is provided above the turntable 21.
It is movable in the vertical direction perpendicular to 1c (arrow Z direction and the opposite direction). A disc-shaped rotating member 32 is provided in the center of the support member 31 so as to be rotatable and movable in the direction of the rotation center axis. Specifically, the rotating member 32 has a columnar part 32a and a flange part 32b, and an opening 31a formed in the support member 31.
The columnar portion 32a is loosely fitted into the columnar portion 32a. A second centering member 38 is attached to the columnar part 32b of the rotating member 32 with a screw 3.
2c.

A tapered surface 38a is formed on the outer periphery of the second centering member 38, and a pair of circular substrates 2 forming the disk 23 are connected to each other.
3a and 23b, the turntable 2 is fitted with the tapered surface 38a into the center hole of the circular substrate 23a which is on the non-contact side with respect to the disk supporting surface 21c of the turntable 21.
The circular substrate 23a is centered with respect to 1. The second centering member 38 has a cylindrical portion 38b at its center of rotation, and the center hole 38c of the cylindrical portion is located at the center of the spindle shaft 2.
2, the second centering member 38
is centered with respect to the turntable 21.

A disk contacting member 41 that directly contacts and presses the disk 23 placed on the turntable 21 is slidably attached to the cylindrical portion 38b of the second centering member 38. The disk abutting member 41 constitutes a pressing member that presses the disk 23 against the turntable 21 together with the rotating member 32 .

Near the outer periphery of the disk abutting member 41, an annular leaf spring 41a is attached at its inner periphery in a cantilevered manner, and the outer periphery, that is, the free end, of this leaf spring 41a is made of rubber or the like. A high friction member 41b is fixed. The disk abutting member 41 is composed of this leaf spring 41a and the high friction member 4.
Circular substrates 23a and 2 forming a disk 23 at 1b
It abuts near the center hole of 3b.

As shown in FIGS. 2 to 4, the disk contact member 4
For example, three cylindrical protrusions 41d are provided on the inner surface of the turntable 21 at equal intervals on a concentric circle and protrude toward the turntable 21. These cylindrical protrusions 41d are inserted into circular openings 38e formed in the main surface of the second centering member 38. An annular yoke plate 46 holding a magnet 45 is attached to the tip of each cylindrical projection 41d by screws 47.

On the other hand, the disk holding part 21b, which is a component of the turntable 21, is made of a magnetic material.
It acts as a suction force generating means for applying a disk pressing force to the pressing member by suctioning toward the pressing member. Note that the disc holding part 21b of the turntable 21 has a columnar part 21f that attracts the magnet 45, and the magnet 45 is attached to the second
It is attracted to this columnar part 21f through an opening 24b formed in the centering member 24.

A gap sheet 45a made of a non-magnetic material is attached to the attraction surface of the magnet 45, and when the magnet 45 is attracted to the columnar part 21f of the disk holding part 21b, this gap sheet 45a is attached between the magnet 45 and the columnar part 21f. A gap sheet 45a is interposed.

A bowl-shaped slider 50 is disposed between the rotating member 32 and the disk abutting member 41, and a second
It is slidably attached to the cylindrical portion 38b of the centering member 38. This slider 50 and the disk abutting member 41
A coil spring 51 is interposed between the two. Further, a coil spring 52 is interposed between the slider 50 and the second centering member 38 to press the second centering member toward the turntable 21 . The second centering member 38 is held by, for example, three claws 50a formed on the slider 50.

Specifically, as shown in FIGS. 2 and 3, the main surface of the second centering member 38 has three small rectangular openings 38f.
are formed concentrically and at equal intervals, and the claw portion 50a fits into this opening 38.

The disk abutting member 41 is formed into a bowl shape and is arranged to open toward the disk supporting surface 21c of the turntable 21. The second centering member 38 is also formed into a bowl shape as a whole, and is fitted into the disk abutting member 41 so as to be movable in the direction of the rotation center axis of the rotating member 32. Therefore, as shown in FIG. 2, the claw portion 50a that protrudes from the slider 50 and holds the second centering member 38 is inserted into the opening 41f formed in the disk abutting member 41. . With this configuration, the slider 50
The claw portion 50a also holds the disk abutting member 41 together with the second centering member 38, and the dedicated holding means for holding the disk abutting member 41 on the slider 50 is eliminated.

As shown in FIG. 5, a pair of rectangular plate-shaped moving members 71 and 72 are arranged so as to sandwich the support member 31 from the left and right sides, and in the front-rear direction (direction of arrow Y and the opposite direction).
It is capable of reciprocating motion. A total of four bottles 31b, two on each side of the left and right sides of the support member 31, are protruded, and a cam groove 71a is formed in each of the movable members 71 and 72, respectively.

Each pin is slidably engaged with 72a. Each cam/
71t71a and 72a as a whole are inclined downward (in the opposite direction of arrow 2) toward the front (in the direction of arrow Y). That is, the supporting member 31 is moved up and down by moving the moving members 71 and 72 back and forth.

Each cam groove 71a and 72a is connected to each moving member 71 and 72.
Three linear parts 71b, 71c, 7 extending in the moving direction of
1d, 72b, 72c, and 72d, and two slanted parts 71 that are continuous with each linear part and inclined with respect to the linear part.
e, 71f, 72-e, and 72f, and the cam groove as a whole is stepped. Therefore, each moving member 7
1 and 72, the support member 31 intermittently moves 2
Perform step-by-step movement.

Rack portions 71g and 72g are formed at the lower front end of each moving member 71 and 72 along the moving direction thereof, respectively. A synchronous shaft 73 is located near each moving member 71 and 72.
is rotatably provided, and a pair of gears 73a and 73b fitted to both ends of the synchronization shaft mesh with rack portions 71g and 72g of each moving member 71 and 72, respectively.

A gear 74a fitted to the output shaft of a motor 74 meshes with one gear 73a. That is, as the motor 74 rotates, the support member 31 is moved up and down.

The above-described moving members 71 and 72, the synchronized shaft 73, and the motor 74 move the support member 31 to the non-clamped position shown in FIG. Positioning means for positioning at first and second clamp positions, which will be described later, is configured.

As shown in FIGS. 1, 3, and 6, for example, three recesses 50c are formed at equal intervals in the circumferential direction on the inner circumferential surface of the slider 50 that can face the outer circumferential surface of the disk abutting member 41. ing. Further, as shown in FIGS. 1, 4, and 6, a second
Three four portions 38h are also formed on the outer peripheral surface of the centering member 38 at equal intervals in the circumferential direction. These two recesses 5°C and 38h cannot face each other when the slider 50 is in the first position shown in FIG. 1, and the slider 50 is lowered a predetermined distance toward the turntable 21 from the first position. to face each other when On the other hand, as shown in FIG. 1, FIG. 2, FIG. 4, and FIG. , an opening 41h is formed so as to be able to face each of the recesses 50c and 38h, and a spherical movable piece 54 that can engage with both the recesses 50c and 38h is arranged within this opening 41h.

The dimension indicated by el in FIG. 6, that is, the distance between the opposing surfaces of the peripheral side walls of the slider 50 and the second centering member 38, is smaller than the diameter d of the movable piece 54. Also, the distance e2 between one of the opposing surfaces of each of the peripheral side walls of the slider 50 and the second centering member 38 and the bottom surfaces of the four recesses 50c and 38h that are opposed to the one surface. and e3 are slightly larger than the diameter d of the movable piece 54. That is, due to the relative movement of the respective peripheral side walls of the slider 50 and the second centering member 38, the movable piece 5 disposed within the opening 41h of the disk abutting member 41
4 is configured to selectively engage with each of the recesses 50c and 38h by about a hemisphere.

The recesses 50c and 38h of the slider 50 and the second centering member 38 described above, the opening 41h formed in the disk abutting member 41, the movable piece 54, and the slider 50 in the direction away from the turntable 21. The second centering member 38 can be fitted into the center hole of the circular substrate 23a in accordance with the movement of the support member 31 between the first clamp position and the second clamp position by the coil springs 51 and 52 that provide the pie spacing. A position switching holding means is configured for positioning between a fittable position and a nonfittable position.

As shown in FIG. 1, a pair of optical pickups 76 and 77 are arranged to sandwich the disc 23 placed on the turntable 21 in the vertical direction, and are guided by a guide drive means (not shown). It is moved along the recording surface of the disk 23. These optical pickups 76 and 77 provide circular substrates 23a and 23b.
The recorded information of the signal recording layer is read.

Next, the operation of the double-sided disc player having the above structure will be briefly explained with reference to FIGS. 7 and 8.

First, of the pair of circular substrates 23a and 23b forming the disk 23, the disk supporting surface 2 of the turntable 21
When the signal recording layer of one of the circular substrates 23b in contact with the substrate 1c is to be played, the motor 74 shown in FIG. to the intermediate point position.

As a result, the support member 31 is moved from the unclamped position shown in FIG. 1 to be close to the turntable 21, and is positioned at the first clamped position as an intermediate position shown in FIG. 7. Note that, as shown in FIG. 1, the support member 31
When in the non-clamping position, the pressing member consisting of the rotating member 32 and the disk abutting member 41 is held at a position spaced apart from the disk supporting surface 21c of the turntable 21. As the support member 31 moves from the non-clamped position to the first clamped position, the magnet 45 attracts the disk holding portion 21b of the turntable 21, and the disk abutting member 41 is pressed against the disk 23.

At the same time, the first centering member 24 is fitted into the center hole of the circular substrate 23b, and due to its wedge action, the disc 23 is slightly shifted in the radial direction to correct its position, and the turntable 2
Centered relative to 1. Note that in this state, the support member 31 is out of contact with the above-mentioned pressing member consisting of the rotating member 32 and the disk abutting member 41. Therefore, disk 23
The pressing force applied to the magnet 45 and the disk holding part 2
Only the suction force generated between 1b is generated.

In this state, the turntable 21 is rotated forward, and the first
The optical pickup 77 on the lower side shown in the figure reads recorded information on the signal recording layer of the circular substrate 23b.

At this time, the movable piece 54 is fitted into the recess 38h of the second centering member 38, and the second centering member 38 is locked to the disk abutting member 41.

Next, when playing the signal recording layer of the other circular substrate 23a that is in a non-contact state with respect to the disk supporting surface 21C of the turntable 21, the motor 74 shown in FIG. and 72 are moved from the intermediate point position of the movement stroke to near the end point position.

Therefore, the support member 31 is brought closer to the turntable 21, and reaches the second clamp position shown by the solid line in FIG. 8 from the first clamp position shown in FIG.

At this time, the movable piece 54 is still fitted into the four parts 38h of the second centering member 38, and the second centering member 38 is locked to the disk abutting member 41 and fitted into the center hole of the circular base plate 23a. It is in a position that eight people cannot fit into. Thereafter, the motor 74 continues to rotate slightly, and the support member 31 is brought to the position shown by the two-dot chain line in FIG. As a result, the slider 50 is pushed down from the first position shown in FIG. 7 to the second position shown in FIG. 8, and the recess 50c formed in the slider 50 reaches a position into which the movable piece 54 can fit. At the same time, the second centering member 38 held by the claw portion 50a of the slider 50 is fitted into the center hole of the circular substrate 3a by the urging force of the coil spring 52 contracted by the lowering of the slider 50, and due to the wedge action. The disc 23 is slightly offset in the radial direction. At the same time, the outer peripheral portion of the second centering member 38 engages with and pushes down the first centering member 24, and the first centering member 24 is separated from the center hole of the circular substrate 23b. It sinks below the disk supporting surface 21c of the turntable 21. As the second centering member 38 descends, the movable piece 54 separates from the recess 38h of the second centering member 38 and engages with the recess 50C of the slider 50. As a result, slider 5
0 is locked to the disk abutting member 41, so the second
The centering member 38 is also fixed in a state in which it is fitted into the center hole of the circular substrate 23a. In this way, the circular substrate 23a is centered with respect to the turntable 21. Note that the pressing force applied to the disc 23 at this time is due to the attraction force generated between the magnet 45 and the disc support portion 21b, and the coil spring 5.
It is the sum of the biasing force based on the deflection of 2. However, the coil spring 52 merely acts to apply a bias upward (direction of arrow Z) to the slider 50, and its spring constant is small, and furthermore, the state shown in FIG. 8 changes from the state shown in FIG. 7. Since the disk is bent for the first time in the process of bending, the disk pressing force in this state is approximately equal to the disk pressing force in the state shown in FIG. 7, that is, when centering the other circular substrates 2 and 3b. Therefore, the disk 23 can be easily moved on the turntable 21 due to the wedge effect caused by the second centering member 38 fitting into the center hole of the circular substrate 23a.

When the circular substrate 23a is centered with respect to the turntable 21 as described above, the motor 74 is rotated slightly in reverse, and the support member 31 is returned to the second clamping position shown by the solid line in FIG. And the pressing member consisting of the disk contact member 41 is not in contact with the pressing member. Then, the turntable 21 is rotated in the reverse direction, and the other optical pickup 76 disposed above the disk 23 reads the recorded information on the signal recording layer of the circular substrate 23a.

After this, when the signal recording layer of the other circular board 23b is to be played again, the motor 74 is reversed and the support member 3
1 is raised from the second clamp position shown by the solid line in FIG. 8 to the first clamp position shown in FIG.

As the supporting member 31 rises, the rotating member 32 is pushed up, and the second centering member 38 rises and separates from the center hole of the circular substrate 23a into which it has been fitted. At the same time, the first centering member 24 is projected onto the disk supporting surface 21c of the turntable 21 by the bias applied by the coil spring 26, and again centers the circular substrate 23b. Further, as the second centering member 38 rises, the recess 38h of the second centering member reaches a position into which the movable piece 54 can fit. Then, coil spring 5
1 and 52, the slider 50 is raised, and the movable piece 54 comes out of the recess 50c of the slider 50 and engages with the recess 38h, resulting in the state shown in FIG. Thereafter, the turntable 21 is rotated forward in the same manner as described above, and the lower optical pickup 77 reads the recorded information on the signal recording layer of the circular substrate 23b.

As is clear from the above description, when the support member 31 moves from the first clamp position shown in FIG. 7 to the second clamp position shown in FIG. Once engaged with the pressing member via the slider 50.

Conversely, when moving from the second clamp position to the first clamp position, the rotating member 32, which is a component of the pressing member,
engage directly with. As described above, when playing the signal recording layers of the pair of circular substrates 23a and 23b forming the disc 23, the turntables 21 are rotated in opposite directions.

As described above, since the support member 31 engages with the pressing member when switching between the disk clamp state and the centering state for each of the circular substrates 23a and 23b, this applies a braking force to the rotation of the turntable 21. It will be in a state where it will be granted. Therefore, the turntable 21 does not continue rotating for a long time due to its inertia, but immediately stops. Therefore, the performance switching for both the Japanese-style boards 23a and 23b can be quickly performed.

FIG. 9 shows a modification of the double-sided disc player shown in FIGS. 1 to 8.

In the double-sided disc player shown in FIGS. 1 to 8, a position switching holding means consisting of a spherical movable piece 54 or the like is provided near the outer periphery of the slider 50, the disc abutting member 41, and the second centering member 38. In contrast, in this modified example, the position switching and holding means is arranged near the rotation center axis of the slider 50 or the like. With this configuration, the slider 50 can be made into a small plate-like member without having to be shaped into a bowl, thereby making it easier to downsize the player as a whole. In this modified example, the parts other than those described above are constructed in the same manner as the double-sided playing diffuser player shown in FIGS. 1 to 8, and therefore will not be described in detail.

FIG. 10 shows a double-sided disc player as a second embodiment of the present invention. The double-sided disc player is constructed in the same manner as the double-sided disc player shown in FIGS. 1 to 8 and 9 except as described below, and will not be described in detail. The same reference numerals are used for the same or corresponding parts as in the double-sided disc player shown in FIGS. 1 to 8 and 9.

As shown in FIG. 10, in the double-sided disc player, a disc contact member 4 that contacts the disc
1 is fixed to the rotating member 32 via a disc-shaped intermediate member 81 with a screw 32c. Further, a second centering member 38 that engages with and centers the circular substrate 23a is slidably attached to the disk abutting member 41.

As is particularly clear from FIG. 11, two types of locking grooves 82a and 82b each extending in the direction of the rotation center axis of the rotating member 32, for example, six grooves, are provided on the peripheral surfaces of the rotating member 32 and the intermediate member 81.
are formed at equal intervals in the circumferential direction. Three sliding pieces 83 are slidably provided in each of these locking grooves 82a and 82b.
are provided and fixed to the slider 50 at equal intervals in the circumferential direction. In addition, as shown in FIG. 11, in addition to the above-mentioned locking grooves 82a and 82b, the sliding piece 83 is arranged on the peripheral surface of the rotating member 32 and the intermediate member 81 from one locking groove 82a to the other locking groove. An introduction groove 82c is introduced into the locking groove 82b, and a locking groove 82b is introduced into the locking groove 82b.
Another introduction groove 83d into which the sliding piece 83 is introduced is formed.

Each of the above-mentioned locking grooves 82a, 82b, each introduction groove 82c,
82d and the sliding piece 83, the first
Position switching for positioning the second centering member 38 between a position where it can be fitted into the center hole of the circular substrate 23a and a position where it cannot be fitted, depending on movement between the clamp position and the second clamp position. A holding means is configured.

Next, the operation of the double-sided disc player having the above configuration will be briefly explained with reference to FIGS. 12 and 13.

First, of the pair of circular substrates 23a and 23b forming the disk 23, the disk supporting surface 2 of the turntable 21
When the signal recording layer of one of the circular substrates 23b in contact with the substrate 1c is to be played, the motor 74 shown in FIG. to the intermediate point position.

As a result, the support member 31 is moved from the non-clamped position shown in FIG. 10 to be close to the turntable 21 and positioned at the first clamped position as an intermediate position shown in FIG. 12. Note that, as shown in FIG. 10, when the support member 31 is in the unclamped position, the rotation member 32
A pressing member consisting of a disk abutting member 41 and a disk contacting member 41 is held at a position spaced apart from the disk supporting surface 21c of the turntable 21. As the support member 31 moves from the non-clamp position to the first clamp position, the magnet 45 is attracted to the disk holding portion 21b of the turntable 21, and the disk abutting member 41 is pressed against the disk 23.

At the same time, the first centering member 24 is fitted into the center hole of the circular substrate 23b, and due to its wedge action, the disc 23 is slightly shifted in the radial direction to correct its position, and the turntable 2
Centered relative to 1. Note that in this state, the support member 31 is out of contact with the above-mentioned pressing member consisting of the rotating member 32 and the disk abutting member 41. Therefore, disk 23
The pressing force applied to the magnet 45 and the disk holding part 2
Only the suction force generated between 1b is generated.

In this state, the turntable 21 is rotated forward, and the first
The optical pickup 77 on the lower side shown in the figure reads recorded information on the signal recording layer of the circular substrate 23b. At this time, the sliding piece 83 is located at the position shown by the solid line in FIG. 8, that is, at the upper end of the locking groove 82a.

Next, when playing the signal recording layer of the other circular substrate 23a that is in a non-contact state with respect to the disk supporting surface 21C of the turntable 21, the motor 74 shown in FIG. and 72 are moved from the midpoint position to the end position of the movement stroke. Therefore, the support member 31 is brought closer to the turntable 21, and reaches the second clamp position shown in FIG. 13 from the first clamp position shown in FIG. 12. At this time, sliding piece 8
3 is still at the upper end of the locking groove 82a, and the second centering member 38 is locked to the disk abutting member 50 and is in a position where it cannot fit into the center hole of the circular substrate 23a. . Thereafter, the motor 74 continues to rotate slightly, and the support member 31 is brought to the position shown by the two-dot chain line in FIG.

This causes the slider 50 to be pushed down from the first position shown in FIG. 12 to the second position shown in FIG. 13. Thereafter, the motor 74 is slightly reversed, and the support member 31 is returned to the second clamping position shown by the solid line in FIG.
It does not come into contact with the pressing member consisting of the rotating member 32 and the disk abutting member 41. Due to the movement of the support member 31, the sliding piece 83 moves from one locking groove 82a at a high position to the other locking groove 82b at a low position via the introduction groove 82c.
Insert into. ÷That is, the slider 50 has been lowered by a predetermined distance from the first position shown in FIG. 12 and positioned at the second position shown in FIG. 13. As a result, the second centering member 38 is fitted into the center hole of the circular substrate 23a by the biasing force of the coil spring 52 contracted by the descent of the slider 50, and the disk 23 is slightly displaced in the radial direction by the wedge action. . At the same time, the outer peripheral portion of the second centering member 38 is connected to the first centering member 24.
When the first centering member 24 is engaged with and pressed down, the first centering member 24 is removed from the center hole of the circular base plate 23b and sunk below the disk supporting surface 21c of the turntable 21. In this way, the circular substrate 23a is centered with respect to the turntable 21. Note that the pressing force applied to the disk 23 at this time is the sum of the attractive force generated between the magnet 45 and the disk supporting portion 21b and the urging force based on the deflection of the coil spring 52. However, the coil spring 52 merely acts to apply a bias upward (direction of arrow Z) to the slider 50, and its spring constant is small, and moreover, the state shown in FIG. 12 changes from the state shown in FIG. 13. Since the disk is bent for the first time in the process of bending, the disk pressing force in this state is approximately equal to the disk pressing force in the state shown in FIG. 12, that is, when centering the other circular substrate 23a. Therefore, the disk 23 can be easily moved on the turntable 21 due to the wedge effect caused by the second centering member 38 fitting into the center hole of the circular substrate 23a.

When the circular substrate 23a is centered with respect to the turntable 21 as described above, the turntable 21 is rotated in the opposite direction,
The other optical pickup 76 disposed above the disk 23 reads the recorded information in the signal recording layer of the circular substrate 23a.

After this, when the signal recording layer of the other circular board 23b is to be played again, the motor 74 sequentially rotates forward and backward, and the support member 31 moves from the second clamping position shown by the solid line in FIG. It is raised to the first clamp position shown in FIG. 12 through the position shown by the two-dot chain line in the figure. By this movement of the support member 31, the sliding piece 83 is fitted from the locking groove 82b at a low position, through the introduction groove 82d, into the locking groove 82a at a high position. As a result, the slider 50 is raised from the second position shown in FIG. 13 to the first position shown in FIG. 12. Therefore, the second centering member 3
8 rises and separates from the center hole of the circular substrate 23a into which it has been fitted. At the same time, the first centering member 24 is projected onto the disk supporting surface 21c of the turntable 21 by the bias applied by the coil spring 26, and the circular substrate 23b is centered again, resulting in the state shown in FIG. 12. Thereafter, the turntable 21 is rotated forward in the same manner as described above, and the lower optical pickup 77 reads the recorded information on the signal recording layer of the circular substrate 23b.

As is clear from the above description, the support member 31 moves from the first clamp position shown in FIG. 12 to the second clamp position shown in FIG.
When moving to the clamp position, the slider 50
Once engaged via . Also, when moving from the second clamp position to the first clamp position, the press member is once engaged via the slider 50. As mentioned above, when playing the signal recording layers of the pair of circular substrates 23a and 23b forming the disc 23, the turntable 2
1 are rotated in opposite directions. As described above, since the support member 31 engages with the pressing member when switching between the disk clamp state and the centering state for each of the circular substrates 23a and 23b, this applies a braking force to the rotation of the turntable 21. It will be in a state where it will be granted. Therefore, the turntable 21 does not continue rotating for a long time due to its inertia, but immediately stops. Therefore, performance switching for both circular boards 23a and 23b can be quickly performed.

In the above embodiment, two optical pickups are provided to sandwich the disc placed on the turntable, but it is possible to provide only one optical pickup and use it to correspond to the image recording surface of the disc. It may also be configured to move as appropriate.

Further, in the above embodiment, the support member 31 that supports the clamper, that is, the pressing member and attaches and detaches it to the disk on the turntable, is configured to be moved while maintaining a state parallel to the disk supporting surface of the turntable. However, the present invention is not limited to this configuration, and a configuration in which the support member 3a is swung in a plane substantially perpendicular to the disk supporting surface of the turntable may also be adopted.

Effects of the Invention As detailed above, in the double-sided disc player according to the present invention, the second disc is fitted into the center hole of the circular board on the non-contact side with respect to the turntable to center it.
A pressing force applying means for applying a disc pressing force to a pressing member that holds the centering member and presses the disc against the turntable includes a suction force generating means that attracts the pressing member toward the turntable, and the pressing member When the support member holding the support member is in the unclamped position furthest from the turntable, the pressing member is held in a position spaced apart from the disk supporting surface of the turntable, and the support member is held in the first clamped position, which is an intermediate position, and is closest to the turntable. When in the second clamp position, there is no contact with the pressing member, and as the support member moves between the first clamp position and the second clamp position, the second centering member is moved into the center hole of the circular substrate. It has a position switching holding means for positioning it between a fit-in position where it can be fitted and a position where it cannot fit.

Because of this configuration, the disk pressing forces applied to the disks when centering each of the pair of circular substrates that form the disk are approximately equally small, and as a result, each circular substrate can move easily in its radial direction, and the centering of both circular substrates can be adjusted. This allows for smooth delivery at all times.

Further, when the disc is clamped, the supporting member does not come into contact with the pressing member, so the disc being played is isolated from external vibrations, and a good playing condition is ensured.

Moreover, because of this configuration, there is no need to interpose an expensive bearing between the pressing member and the supporting member that holds it, as in conventional double-sided disc players, and costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a front view including a partial cross section of a disc clamping mechanism and a disc centering means, which are the main parts of a double-sided disc player as a first embodiment of the present invention, and FIGS. 5 is a perspective view of the disk clamp mechanism shown in FIG. 1, and FIG. 6 is a perspective view of the disk clamp mechanism shown in FIGS. 1 to 4. FIGS. 7 and 8 are detailed views of a part of the disk centering means shown in FIGS. 1 to 6, and FIG. FIG. 10 shows a modification of the double-sided disc player shown in FIGS. 8 to 8, and FIG. 10 shows a disc clamping mechanism and a disc centering means, which are the main parts of a double-sided disc player according to a second embodiment of the present invention. FIG. 11 is a detailed view of a part of the disc centering means shown in FIG. 10, and FIGS. 12 and 13 are a front view including a cross section, and FIGS. FIG. 14 is a front view including a partial cross section of the disc clamp mechanism and disc centering means, which are the main parts of a conventional double-sided disc player, and FIGS.
FIG. 3 is an explanatory diagram of the operation of the disk clamp mechanism and disk centering means shown in the figure. Explanation of symbols of main parts 21... Turntable 23... Discs 23a, 23b... Circular board 24... First centering member 31... ... Supporting member 32 ... Rotating member 38 ... Second centering member 41 ... Disc abutting member 45 ... Magnet No. 4

Claims (4)

[Claims] (1) An information recording disk consisting of a pair of circular substrates, each having a signal recording layer and a center hole, which are fixed to each other, is centered on the turntable by a disk centering means and pressed by a disk clamp mechanism to perform a performance. None, the disc clamping mechanism moves from the farthest unclamped position to the first intermediate position from the disc carrying surface of the turntable.
a support member that can move toward and away from the disk supporting surface during the period from the clamp position to the second clamp position; and positioning means for positioning the support member;
It consists of a pressing member that presses the vicinity of the center hole of the information recording disk, and a pressing force applying means that applies a disk pressing force to the pressing member, and the disk centering means is configured to press against the disk supporting surface and against the turn. a first centering member that is provided so as to be freely protrusive and retractable along the rotation center axis of the table and that can be fitted into the center hole; a bias force applying means that applies a bias force to the first centering member in a protruding direction; a second centering member that can be fitted into the center hole and is provided on the pressing member so as to be movable between a fittable position and a nonfittable position with respect to the center hole, and the second clamp of the support member; In the double-sided disc player, the second centering member is moved to a position close to the disc supporting surface and fitted into the center hole, and the first centering member is recessed from the disc supporting surface. , the pressing force applying means comprises a suction force generating means for suctioning the pressing member towards the turntable, and when the supporting member is in the non-clamping position, the pressing member is at a position separated from the disk supporting surface. and hold the first
And when it is in the second clamp position, it is out of contact with the pressing member, and according to the movement of the support member between the first clamp position and the second clamp position, the second centering member is moved to the fittable position and the second clamp position. A double-sided performance disc player characterized by having a position switching holding means for positioning the disc in a position where it cannot be inserted. (2) The double-sided performance disc player according to claim 1, wherein the support member engages with the pressing member when moving from one of the first clamp position and the second clamp position to the other. (3) Claim 1, wherein the attractive force generating means comprises a magnet and a magnetic member that are provided on one and the other of the turntable and the pressing member and attract each other.
Or the double-sided performance disc player according to 2. (4) The double-sided performance disc according to any one of claims 1 to 3, further comprising an elastic member provided in a cantilevered manner on the pressing member and pressing the information recording disc at a free end. player.