This application claims priority from, and incorporates by reference the entire disclosure of, Japanese Patent Applications
1. Field of the Invention
The present invention relates to a clamp mechanism for a disk-shaped recording medium and a reproducing apparatus for the recording medium and, more particularly, to a clamp mechanism for a disk-shaped recording medium that is used to clamp the disk-shaped recording medium onto a turntable for reproduction/recording (reproduction or recording) and a reproducing apparatus, for the disk-shaped recording medium, that is equipped with the clamp mechanism. Here, it is to be understood that the clamp mechanism comprises a clamper for rotatably holding the disk-shaped recording medium on the turntable, a clamper holder for holding the clamper, and a disk clamp portion formed integrally with the turntable and adapted to engage with the clamper.
2. Description of the Related Art
There are a wide variety of disk-shaped recording media, typical examples including the CD (Compact Disc) and the MD (MiniDisc) for recording musical pieces such as music and songs and the DVD (Digital Versatile Disc) for recording video. Of these types of disks, the CD and the DVD are of the same disk size; therefore, the disk-shaped recording medium here will be described by taking the CD as an example.
Usually, a disk-shaped recording medium (hereinafter sometimes simply called a disk) such as a CD is inserted in a disk player forming part of an audio system or the like, and played back to present musical pieces to the user for listening. In this case, if the disk player has a built-in automatic disk changer, a plurality of disks can be set in the changer, and musical pieces can be presented to the user for listening by automatically selecting and playing back the disks one at a time in the desired sequence.
To play back music from the disk on such a disk player (the procedure is the same for the case of recording), it is essential that the disk player be equipped with some means for correctly clamping the disk on the turntable for rotation. The means that plays an important part in the disk player is the disk clamp mechanism which rotatably clamps the disk on the turntable.
Known disk players include, for example, the one disclosed in Japanese Unexamined Patent Publication No. H06-203447. In the disk player disclosed in Japanese Unexamined Patent Publication No. H06-203447, the clamp mechanism for clamping the disk comprises the earlier mentioned clamper, the damper holder, and the disk clamp portion formed integrally with the turntable. In the clamped condition, this disk clamp portion is positioned inside the clamper.
The disk placed on a moving table is clamped between the turntable and the clamper, and is rotated by a spindle motor. The turntable and the damper are mounted on a common unit. This unit is mounted to a chassis via a spring. When the moving table moves from outside the apparatus to inside the apparatus (when inserting the disk), or from inside the apparatus to outside the apparatus (when ejecting the disk), the unit is located in a lower position, and when the moving table is drawn into the apparatus, the unit moves into an upper position where the turntable holds the disk thereon.
In the invention disclosed in Japanese
Unexamined Patent Publication No. H06-203447, it is described that, as the turntable moves up and down, the moving table need not be provided with a means for moving the disk up and down; as a result, the moving table can be made thin in construction, and the overall size of the disk player can thus be reduced.
However, when mounting the thus constructed disk player, for example, in a vehicle, the disk player is usually installed in that portion of an instrument panel (dash panel) that is located between the driver's seat and the front passenger seat in the vehicle. As the space for mounting such automotive apparatus in a vehicle is extremely limited, severe size limitations are imposed on automotive apparatuses designed for mounting in a vehicle's dashboard (such apparatuses are called in-dash type apparatuses). Furthermore, as, traditionally, radio receivers and cassette players are installed as automotive audio apparatuses, the disk player, as a latecomer, must be further reduced in size, and the size reduction achieved by the disk player according to the invention disclosed in Japanese Unexamined Patent Publication No. H06-203447 has not been sufficient.
It is an object of the present invention to achieve a significant reduction in the size of a clamp mechanism for clamping a disk onto a turntable, and it is also an object of the invention to achieve a reduction in the overall size of a reproducing apparatus through the size reduction of the clamp mechanism. It is a further object of the present invention to provide a clamp mechanism having a construction such that the damper of the clamp mechanism does not easily come off its position even when subjected to external forces.
The invention that achieves the above objects can be implemented in the following modes.
According to a first mode, there is provided a clamp mechanism for a disk-shaped recording medium comprising: a turntable for rotating the disk-shaped recording medium; a damper capable of being clamped onto the turntable; and a damper holder having a projecting part for holding the damper in rotatable fashion, wherein the damper holder is attached to the damper by inserting at least a portion of the projecting part into a space formed within the clamper.
According to a second mode, there is provided a clamp mechanism for a disk-shaped recording medium, comprising: a turntable for mounting thereon the disk-shaped recording medium; a damper capable of being clamped onto the turntable; and a damper holder having a projecting part for holding the damper in rotatable fashion, wherein the damper has an elastically deformable movable piece as well as a space formed within the clamper, and the damper holder is attached to the damper by inserting at least a portion of the projecting part into the space.
According to a third mode, there is provided a reproducing apparatus for a disk-shaped recording medium, comprising: a turntable for mounting thereon the disk-shaped recording medium; a damper capable of being clamped onto the turntable; and a damper holder having a projecting part for holding the damper in rotatable fashion, wherein the damper holder is attached to the damper by inserting at least a portion of the projecting part into a space formed within the clamper.
In one preferred embodiment of the clamp mechanism for the disk-shaped recording medium according to the second mode, the projecting part is provided at an end thereof with a flange having an outer diameter to be accommodated in the space, the chamber portion is provided with at least two engaging protrusions for preventing the flange from coming out of the space, and one of the engaging protrusions is an end portion of a movable piece, wherein the flange is pushed into the space in the chamber portion by causing the movable piece to deform, and the damper holder is attached to the damper by allowing the movable piece to return to a position where the movable piece was originally located before being deformed.
In another preferred embodiment of the clamp mechanism for the disk-shaped recording medium according to the second mode, the projecting part is provided at an end thereof with a flange having an outer diameter to be accommodated in the space, the chamber portion includes a cut-out portion formed by cutting out a portion of a sidewall thereof along a length just enough to allow the flange to pass through, at least one engaging protrusion for preventing the flange from coming out of the space is provided on a sidewall of an opening formed to expose the chamber space at a side thereof facing the damper holder, and the cut-out portion and a portion of the damper that faces the sidewall of the chamber portion is provided with an engaging member that closes the cut-out portion.
Preferably, in this case, in the portion of the damper that faces the sidewall of the chamber portion, a first engaging hole is provided at a position facing the cut-out portion and second and third engaging holes are provided at positions equally distanced from the first engaging hole, and the engaging member is constructed from elastically deformable members comprising a head that serves the same function as the engaging protrusion for a main body, two arms, and one leg, wherein the head is inserted into the cut-out portion, the arms are inserted into the second and third engaging holes, and the leg is inserted into the first engaging hole. Here, the arms should be curved along the same direction as the direction along which the portion of the damper that faces the sidewall of the chamber portion is curved.
According to the present invention, the following effects are achieved.
(1) The damper supporter which protruded outside the damper in the prior art is constructed as a clamper mounting shaft that can be accommodated into the space formed within the clamper. As a result, the vertical height of the disk player is reduced, achieving a reduction in the overall size of the disk player.
(2) Further, as will be described later, as the damper portion containing the space can also be used for aligning the center with the turntable, the need for the prior art clamper tooth is eliminated.
(3) Furthermore, the need for the prior art damper pressing portion is also eliminated.
(4) In a free condition in which the disk is not yet mounted on the turntable, vibration noise tends to occur due to vibrations; such vibration noise is suppressed by the construction of the invention in which the damper mounting shaft is held fixed by the movable piece.
(5) In a clamped condition in which the disk is mounted on the turntable, the movable piece is easily disengageable from the damper mounting shaft, and thus the friction occurring between the damper and the damper mounting shaft during the rotation of the disk D can be reduced to nearly zero.
The present invention will be more clearly understood from the description as set forth below with reference to the accompanying drawings, wherein:
Before describing the preferred embodiments of the present invention, the construction of a prior art clamp mechanism for a disk-shaped recording medium and the construction of a disk player as a reproducing apparatus for the recording medium will be described with reference to FIGS. 1 to 3.
The disk D placed on a moving table 101 is clamped between the turntable T and the clamper 2, and is rotated by a spindle motor M. The turntable T and the damper 2 are mounted on a common unit 102. This unit 102 is mounted to a chassis 102 via a spring 104. When the moving table 101 moves from outside the apparatus to inside the apparatus (when inserting the disk), or from inside the apparatus to outside the apparatus (when ejecting the disk), the unit 102 is located in the position lower than the position shown, and when the moving table 101 is drawn into the apparatus, the unit 102 moves into the position shown in the diagram where the turntable T holds the disk D thereon.
In the prior art disk player disclosed in Japanese Unexamined Patent Publication No. H06-203447, as the turntable T moves up and down, the moving table 101 need not be provided with a means for moving the disk up and down. As a result, in the prior art disk player disclosed in Japanese Unexamined Patent Publication No. H06-203447, the moving table 101 can be made thin in construction, and the overall size of the disk player can thus be reduced.
However, in the case of an automotive apparatus designed for mounting inside an automotive cabin, since the space for mounting the disk player is extremely limited, there is a need to further reduce the size of the disk player. Among the various factors that may contribute to the size reduction of the disk player, the present invention focuses attention on the clamp mechanism 1 to achieve the size reduction.
First, the conventional clamp mechanism employed in the prior art will be described with reference to
The clamper 2 has a disk-like shape, and is provided at its center with a mounting shaft 51 formed in protruding fashion. The mounting shaft 51 is passed through a hole 56 formed through the clamper holder 3, and a flange-like clamper supporter 52 having an outer diameter larger than the through hole 56 is attached to a free end of the mounting shaft 51. The damper 2 is supported in the clamper holder 3 in rotatable fashion by means of the mounting shaft 51 and the clamper supporter 52. The damper holder 3 has a clamper pressing portion 53 for pressing the end of the mounting shaft 51. A recessed portion 57 having a ring-shaped damper tooth 54 at its center is formed in the surface of the damper 2 that faces the turntable T.
On the other hand, the turntable T is mounted on a rotating shaft A which rotates with the rotation of the spindle motor M, and the turntable T is thus rotated by the spindle motor M. The disk clamp portion 4 which engages with the clamper 2 is provided on the side of the turntable T that faces the damper 2. The disk clamp portion 4 is shaped so that at least its end portion engages in the recessed portion 57 formed on the damper 2, and is formed with a disk clamp groove 55 in which the damper tooth 54 formed on the damper 2 is engaged.
When playing back (or recording on) the disk D, the clamp mechanism 1 changes from the free condition of
Here, as is apparent from
In view of this, the present invention aims to reduce the size of the disk player by reducing the vertical height of the disk player, in particular, by reducing the vertical height of the clamp mechanism 1. That is, the present invention aims to reduce the vertical height H of the clamp mechanism 1 shown in
Before describing the construction of the clamp mechanism 1 of the present invention, a description will be given of the construction of a disk player 40 equipped with the clamp mechanism 1 of the present invention. It is assumed that the disk player 40 hereinafter described has a built-in automatic disk changer 10 (hereinafter simply called the disk changer 10).
The swing arm 63 is constructed so that it turns by being driven by the driving unit 67, and comprises two major components, a frame 60 and a clamp arm (clamper holder) 3. A turntable T for rotating a disk is provided on an end portion of the frame 60, while an optical head 36 and a guideway 35 along which the optical head 36 moves are provided in the center portion of the frame 60. The base of the clamp arm 3 is attached to the frame 60 by way of a rotating shaft, and a damper 2 for clamping the disk is rotatably attached to an end portion of the clamp arm 3. The end portion of the clamp arm 3 is turned toward the frame 60, causing the damper 2 to clamp the disk firmly onto the turntable T.
The vertical position of the swing arm 63 in the disk player 40 does not change and remains constant. Accordingly, in order to allow the swing arm 63 to clamp a desired one of the disks held in the stocker 64, the stocker 64 is split in the vertical direction of the apparatus and moves. The stocker 64 comprises a single stocker base and a plurality of movable stockers as movable trays mounted thereon, each movable stocker being capable of holding one disk. The stocker 64 moves up and down inside the apparatus by means of the stocker lift mechanism 65. In order to allow the swing arm 63 to remove a desired one of the disks held in the stocker 64, the movable stockers forming the stocker 64 can be split vertically at a desired position by means of a stocker splitting mechanism 66.
Further, a disk pushing mechanism 61 for pushing out a selected one of the disks held in the stocker 64 is provided in the casing of the disk changer 40 behind the stocker 64 comprising the plurality of movable stockers. The height of the disk pushing mechanism 61 from the bottom surface of the disk changer 40 is fixed, and the stocker 64 is moved up and down so that the disk in the movable stocker located at a prescribed position can be pushed out by the disk pushing mechanism 61 and ejected through a disk insert/eject slot 62 of the disk changer 40.
Next, the operation of the disk changer 10 in the disk player 40 shown in
When the disk 2-3 is placed on the turntable T, the disk 2-3 is clamped by the damper 2 as shown in
After that, the turntable T is further moved in the direction in which the disk 2-3 is being withdrawn, and comes to rest at the playback position shown in
When the disk 2-3 is stored in the movable stocker 4-3, the damper 2 moves up to free the disk 2-3 on the turntable T, and the clamp mechanism comprising the turntable T and the damper 2 moves back to the position where it does not interfere with the disk D held in the stocker, as shown in
As described above, in the case of the autochanger 10 built into the disk player 40, the clamp mechanism comprising the turntable T and the damper 2 is moved into the space provided between the disks D divided into the upper and lower stacks; therefore, if the vertical height of the clamp mechanism is large, the space provided between the disks D to accommodate the clamp mechanism becomes large, increasing the vertical dimension of the disk player 40. That is, in the case of an automotive disk player to be mounted in a limited space and used to play back many disks, it is important to be able to play back the disk in a confined space allowed for the splitting of the stocker, and therefore, reducing the thickness of the disk clamp mechanism is essential for reducing the overall size of the disk player.
As shown, in the present invention, a space 5 is formed within the damper 2 so that the flange portion 6F provided at the end of the damper mounting shaft 6, which corresponds to the damper supporter 52 shown in
As shown in
The peripheral portion 8 has a ring-shaped flat surface when viewed from the turntable T, and in the clamped condition in which the disk D is clamped by the clamper 2, this peripheral portion 8 presses the disk D from above to prevent the disk D from flipping out during playback/recording. Further, since it is desirable that, in the clamped condition the chamber portion 7 engaged deeper into the recessed groove portion 9 of the disk clamp portion 4, a height difference d is provided between the top face of the chamber portion 7 and the surface of the peripheral portion 8.
In the present invention, as the clamper 2 has the chamber portion 7 where the space 5 is formed and, in the clamped condition, the chamber portion 7 engages into the recessed groove portion 9 of the disk clamp portion 4, the maximum height h of the clamp mechanism 1 as measured from the disk D in the clamped condition is smaller than the height H of the same portion shown in
To achieve this, the chamber portion 7 of the damper 2 is formed so as to be engageable with the recessed groove portion 9 of the disk clamp portion 4 by leaving a slight gap therebetween so that the center of rotation of the damper 2 substantially coincides with the center of rotation of the turntable T. In this case, the circumferential edge of at least one of the opposing surfaces of the chamber portion 7 and the recessed groove portion 9 is tapered in order to enable the chamber portion 7 to engage smoothly into the recessed groove portion 9. This will be explained with reference to
Here, the circumferential edges of the chamber portion 7 and the recessed groove portion 9 may take any suitable shape, such as a rectangle, hexagon, or circle, when viewed from the top, as long as they are similar to each other, but in the embodiment of the present invention, the edges are circular in shape because the damper 2 and the disk clamp portion 4 are both circular in shape when viewed from the top.
In this case, as shown in
Here, the inner diameter of the through hole 30 must be made smaller than the outer diameter of the flange portion 6F of the damper mounting shaft 6 positioned within the space 5. The reason is that the flange portion 6F must be prevented from coming out through the hole 30 when the damper holder 3 disengages the damper 2 from the disk clamp portion 4. However, when the inner diameter of the through hole 30 is made smaller than the outer diameter of the flange portion 6F, the flange portion 6F formed at the end of the damper mounting shaft 6 of the damper 2 cannot be inserted into the space 5 in the chamber portion 7 during assembling at the factory, unless some ingenious means is devised.
In view of this, in the present invention, the through hole 30 is formed in the following way. First, a fitting portion 20 (to be described in detail with reference to
At this time, play is formed between the fitting portion 20 and the damper mounting shaft 6, as shown in
There is therefore a need to provide a fastening means for fastening the damper mounting shaft 6 to the damper 2 to prevent generation of such vibration noise. The fastening means, however, must be made so that the damper mounting shaft 6 can be unfastened from the clamper 2 when playing back or recording on a disk. The reason is that, if the damper mounting shaft 6 remained fastened to the damper 2 during disk playback/recording, the disk D cannot be rotated freely.
In view of the above situation, the movable piece 21 of the present embodiment is made to elastically press the damper mounting shaft 6 and fix it in place in the free condition in which the disk D is not clamped by the damper 2, while on the other hand, in the clamped condition in which the disk D is clamped by the damper 2, the movable piece 21 is disengaged and moved away from the damper mounting shaft 6 (see
Further, a protrusion is formed on the bottom surface of the recessed groove portion 9 (as will be described in detail with reference to
In
Of the three pieces, the movable piece 21 as a whole is formed from a large long U-shaped thin piece so as to be elastically deformable, as described above. The end portion of the thus formed movable piece 21 can be substantially displaced in directions indicated by a double-headed arrow P. Accordingly, when the flange portion 6F of the clamper mounting shaft 6 is being pushed into the space 5 (at the time of assembling), the movable piece 21 is displaced and spread outwardly from the center, creating a space through which the damper mounting shaft 6 and the flange portion 6F thereof can be completely pushed into the space 5. When the flange portion 6F is completely pushed into the space 5, the movable piece 21 returns to its original shape. The small circle drawn in the center of the space 5 in
Accordingly, the hemispherical protrusion (small circle) and its surrounding area shown in each of
From the above description, it can be understood that the clamper mounting shaft 6 and the flange portion 6F thereof can be easily fitted into the space 5 in the chamber portion 7 in snap-fit fashion. In this case, when the disk D is not loaded (the free condition), if there is play between the clamper mounting shaft 6 and the fitting portion 20 as shown in
On the other hand, referring to
In the above noncontacting rotation (
Accordingly, in the embodiment of the present invention, a protrusion 41 formed in a substantially semispherical shape is provided at the center of the bottom surface of the chamber portion 7, as shown in Figures 11A and 11B. To correspond with this, a recess 42 for accepting the protrusion 41 therein to achieve positioning when the damper mounting shaft 6 and the flange portion 6F thereof are placed into the space 5 is formed at the center of the bottom surface of the end portion of the damper mounting shaft 6.
Thus, the damper 2 (and hence, the disk D) is allowed to rotate stably without any friction and without being displaced off-center.
On the other hand, in the embodiment shown in
Furthermore, the outer circumferential face and the bottom surface of the chamber 7 located near the position directly below the end 21A of the movable piece 21 are cut out along a predetermined length to provide a cut-out portion 7C. The inner diameter of the space 5 is made larger than the diameter of the flange portion 6F provided at the end of the damper mounting shaft 6, but the horizontal width of the cut-out portion 7C is made slightly smaller than the diameter of the flange portion 6F. On the other hand, the damper mounting shaft 6 rigidly attached to the end portion of the damper holder 3 is provided, at its end, with the flange portion 6F and, at its base, with a mounting portion 6T which is attached to the damper holder 3 by swaging or like means.
To attach the damper 2 to the end portion of the damper holder 3, the movable piece 21 is pressed to deform downward by the flange portion 6F of the damper mounting shaft 6 attached to the end portion of the damper holder 3 and, with the cut-out portion 7C of the chamber portion 7 exposed, the flange portion 6F is placed against the cut-out portion 7C and then pushed in the direction of the space 5, causing the chamber portion 7 to deform; in this way, the flange portion 6F is pushed through the cut-out portion 7C into the space 5 in the chamber portion 7. After pushing the flange portion 6F into the space 5, the movable piece 21 deformed under the flange portion 6F is then deformed outwardly so as to ride over the outer circumference of the flange portion 6F, thus positioning the end portion 21A of the movable piece 21 above the flange portion 6F, that is, the moving piece 21 thus returns to its original position.
The resulting condition is shown in
When clamping the disk, the protrusion 41 formed in protruding fashion on the bottom surface of the chamber portion 7 is engaged into the recess 42 formed in the end portion of the damper mounting shaft 6 to achieve positioning, as in the embodiment described with reference to
The damper main body 2A is formed from an elastically deformable synthetic resin, as in the foregoing embodiment. As can be seen from
A portion of the sidewall of the chamber portion 7 is cut out to form a cut-out portion 7C, and a circular through hole 30 is formed in the ceiling of the chamber portion 7, i.e., in the fitting portion 20. The outer circumferential portion of the through hole 30 that is adjacent to the cut-out portion 7C is cut out to form a guide hole 34. Further, the through hole 30 is provided, at positions equally distanced to the right and left from the guide groove 34, with a first fixed piece 22 and a second fixed piece 23 as engaging protrusions protruding toward the space 5 in the through hole 30.
On the other hand, the outer circumferential portion of the ring-shaped groove 26 formed between the chamber portion 7 and the disk pressing portion 24 is provided with a first engaging hole 25C at a position that faces the cut-out portion 7C of the chamber portion 7, and also with second and third engaging holes 25L and 25R at positions equally distanced from the first engaging hole 25C. Further, the protrusion 41 is formed on the bottom surface of the space 5 in the chamber portion 7, as in the embodiment described with reference to
Next, the structure of the engaging piece 2B attached to the damper main body 2A will be described. The engaging piece 2B also is formed from an elastically deformable synthetic resin.
The engaging piece 2B is attached to the engaging holes 25C, 25L, and 25R provided in the damper main body 2A, and comprises, as shown in
To attach the damper main body 2A to the end portion of the damper holder 3, the flange portion 6F of the damper mounting shaft 6 attached to the end portion of the damper holder 3 is pushed along the guide groove 34 in the through hole 30 of the damper main body 2A obliquely into the space 5, as shown in
The resulting condition is shown in
The condition shown in
Next, by causing the tapered face of the leg 16C to slide along the sloped face of the ring-shaped groove, the leg 16C is inserted into the engaging hole 25C of the damper main body 2A. At this time, the arms 15L and 15R flex to facilitate the insertion of the leg 16C into the engaging hole 25C of the damper main body 2A. In this way, the head 14 is inserted into the engaging hole 25C of the damper main body 2A, the arm 15L is inserted into the engaging hole 25L of the damper main body 2A, the arm 15R is inserted into the engaging hole 25R of the damper main body 2A, and the leg 16C is inserted into the engaging hole 25C of the damper main body 2A, resulting in the condition shown in
In this condition, the damper 2 with the engaging piece 2B attached to the damper main body 2A is fitted onto the damper mounting shaft 6 by leaving play between them. That is, the damper 2 is allowed to move in the horizontal direction, relative to the damper mounting shaft 6, within a range equal to the difference between the outer diameter of the damper mounting shaft 6 and the diameter of the virtual circle K defined by the ends of the first and second fixed pieces 22 and 23 and the end of the head 14 of the engaging piece. Further, as the diameter of the virtual circle K defined by the ends of the first and second fixed pieces 22 and 23 and the end of the head 14 is smaller than the diameter of the flange portion 6F placed in the space 5, the damper 2 is prevented from being disengaged from the clamper mounting shaft 6.
If any of the forward, backward, leftward, and rightward external forces indicated by open arrows F, B, L, and R is applied to the clamper 2 of this embodiment, the leg 16C of the engaging piece 2B resists the forward, leftward, and rightward external forces indicated by the open arrows F, L, and R, while the arms 15L and 15R resist the backward external force indicated by the open arrow B, so that the engaging piece 2B does not easily come off the damper main body 2A. Further, as shown in the cross-sectional view of
In this embodiment also, when clamping the disk, the protrusion 41 formed in protruding fashion on the bottom surface of the chamber portion 7 shown in
Number | Date | Country | Kind |
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2004-060893 | Mar 2004 | JP | national |
2005-015174 | Jan 2005 | JP | national |