Patent Publication Number: US-2005120362-A1

Title: Disk drive having unit for preventing falling-off of traverse unit

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a disk drive having a unit for preventing falling-off of a traverse unit.  
      2. Related Art  
      In a disk drive using a tray for conveying a disk, the disk placed on the tray is carried in with the tray to a reproduction position, at which a traverse unit moves upward and the disk is mounted on a turntable and then damped. Conversely, when a reproduced disk is removed, the traverse unit is moved downward, thereby the disk mounted on the turntable is placed on the tray and then carried out with the tray.  
      Basic movement of such a tray-type disk drive is described according to drawings. As shown in a side cross-sectional view in  FIG. 8 ( a ), a traverse unit  2  inclines downward in a condition after a tray  1  has been carried out. When a disk is placed on the tray  1  and carried in into the drive, the traverse unit  2  moves upward and the disk is mounted on a turntable  3 , and then pinched and damped by a damper  4  (see  FIG. 8 ( b )).  
      The traverse unit  2  is attached to a frame  5 , and a traverse holder moves up and down with a rear end as the fulcrum. The traverse unit  2  is provided with the turntable  3  and an optical pickup, and then attached to the frame. That is, the traverse unit  2  is configured in a way that it is obliquely inserted into a space formed in the frame  5 , stably supported by a holding mechanism, and does not rattle.  
      A boss  2   a  is provided at an end of the traverse unit  2 , the boss  2   a  fits into a cam groove of a slide cam body  6 , and the slide cam body  6  slides left and right (slides in a depth direction on  FIG. 8 ( a ) and  FIG. 8 ( b )), thereby the traverse unit  2  moves up and down.  
      In “Disk Recording or Playback Device and Method for Assembling the Device” according to JP-A-2003-196951, in order to improve workability in attaching a mechanism deck (traverse unit) and correctly move the mechanism deck up and down even if shock is applied externally, the mechanism deck, which has a turntable for rotating a disk and vertically moves in cooperation with a slide body, has a sub-chassis attached with the turntable and a frame (traverse holder) that fits into the slide body and supports the sub-chassis. In the chassis (body frame), a holding mechanism is provided, which vertically swingably supports the frame in a position fitted into the slide body through a space between a damper support plate and the chassis. From the frame, a protrusive shaft, which is supported by the holding mechanism and regulates vertical rattle of the frame, is outwardly provided, and the protrusive shaft has a projection for preventing lateral rattle of the frame.  
      According to the configuration, since the mechanism deck can be attached to the chassis with the damper support plate being attached to the chassis, the workability is improved. In addition, since the protrusive shaft is supported by the holding mechanism and thus the vertical rattle is regulated, the mechanism deck does not fall out from the slide body and the chassis even if shock is externally applied. Therefore, the mechanism deck can be correctly moved up and down.  
      However, in the connection between the frame (traverse holder) and the chassis (body frame), since a large opening is formed in the chassis to form a regulating part, strength of the chassis is lowered, resulting in reduction in reliability of products. In addition, since a through-hole for a space into which the protrusive shaft enters is formed in a sidewall of the chassis, a slide core die is necessary for forming a receiving part of the traverse holder in a die for molding the chassis (body frame) of a disk drive in addition to a two-face die of a cavity die and core die, and therefore the die becomes complicated. Since the projection formed on the protrusive shaft of the frame attached to the chassis is formed at a fixed angle with respect to a horizontal face in consideration with assemble workability, the die for the frame (traverse holder) also becomes complicated.  
      In this way, the conventional disk drive has problems as above. Issues to be solved by the invention are these problems, and an object of the invention is to provide a disk drive in which the strength in the connection between the traverse holder and the body frame is improved, and reliability is high so that the attached traverse unit does not fall off. Furthermore, another object of the invention is to provide a disk drive, which allows a pattern of the die for molding the frame and the traverse holder to be simplified.  
     SUMMARY OF THE INVENTION  
      The disk drive having a unit for preventing falling-off of the traverse unit according to the invention is configured to include a traverse unit having a traverse chassis attached with a component such as a turntable and optical pickup, a traverse holder holding a front end of the traverse chassis, a body frame for mounting the traverse unit, and a laterally movable slide cam body disposed at a front side of the traverse unit, a rear end of the traverse chassis being connected to the body frame via an elastic ring; wherein the traverse holder is formed from a front holding the front end of the traverse chassis and both support arms extending rearward from both ends of the front, the front has a boss protruding forward and freely fits into a cam groove in the slide cam body, and each of the support arms is integrally provided with an upwardly protruded vertical-rib and its end and base have a protrusive shaft and a guide boss, which are protruded outward, respectively; on both sidewalls of the body frame, vertical guide grooves into which guide bosses on the support arms fit, guide ribs drooping parallel via spaces into which the vertical ribs fit, and horizontal support ribs for rotatably pinching the protrusive shafts on the traverse holder between them and the guide ribs are integrally molded using a resin material; the protrusive shafts on the traverse holder are pinched by the guide ribs and both the horizontal support ribs, thereby the shafts become pivots of rotation of the traverse holder, the vertical ribs on the support arms are fitted into spaces between the guide ribs, thereby a lateral position of the traverse unit is regulated, and the guide bosses are freely fitted into the vertical guide grooves and the boss protruded from the front is freely fitted into the cam groove on the slide cam body, thereby vertical movement of the traverse unit is regulated.  
      According to such a configuration, the traverse unit can be inserted into the body frame from an underside portion of the body frame and mounted therein; and the protrusive shafts on the traverse holder are rotatably pinched by both the horizontal support ribs and the guide ribs, thereby become pivots of rotation of the traverse holder without rattle; the vertical ribs on the support arms are fitted into the space between the guide ribs, thereby a lateral position of the traverse unit is regulated; and the guide bosses are freely fitted into the vertical guide grooves and the boss protruded from the front is freely fitted into the cam grooves of the slide cam body, thereby vertical movement of the traverse unit is regulated. Therefore, the traverse unit does not fall off from the frame. In addition, the supporting, horizontal support ribs and the guide ribs are integrally molded with the body frame, similarly, the vertical guide grooves into which the guide bosses are freely fitted are integrally molded with the body frame, thereby high strength can be obtained.  
      The horizontal support rib formed on one sidewall may be configured in a way that a back-and-forth long-hole into which the protrusive shaft fits is formed at a position facing to the guide rib and thus the rib is formed as a lower edge of the long hole, and the horizontal support rib on the other sidewall may be configured in a way that it is protruded inwardly from a lower end of the sidewall, and an insertion into which one of the protrusive shafts can be inserted is formed adjacently to the horizontal support rib.  
      The horizontal support rib and the guide rib on the other sidewall can be integrally molded into an overhang inwardly overhanging from the sidewall. The guide rib may comprise a high guide-rib-part having a longer drooping length, a shorter, low guide-rib-part, and an inclined guide-rib-part connecting between the high and low guide-rib parts.  
      According to the disk drive of the invention, in the case that the traverse unit is attached to the body frame, when it is obliquely inserted from a bottom side of the body frame to an inner space of the body frame, the protrusive shafts on the traverse holder are placed and supported on the horizontal support ribs formed on the body frame, and their upper sides contact to the guide ribs, in addition, the lateral position is regulated because the vertical ribs on the support arms fit into the spaces between the guide ribs, and thus the traverse unit is supported without rattle. Furthermore, the guide bosses on the traverse unit freely fit into the vertical guide grooves formed on the body frame, thereby the traverse unit stably moves up and down, and does not fall off from the frame.  
      The horizontal support ribs, guide ribs, and vertical guide grooves are integrally molded with the body frame using a resin material, therefore strength is high. Furthermore, when the horizontal support ribs, guide ribs, and vertical guide grooves are integrally molded with the body frame, a slide core mold is not necessary, and they can be produced only by a combination of upper and lower molds, therefore the die is easily produced. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING  
       FIG. 1  is a plan view showing an internal structure in a carrying-out condition of a tray in a disk drive according to an embodiment of the invention;  
       FIG. 2  is a plan view showing an internal structure in a carrying-in condition of the tray in the disk drive;  
      FIGS.  3 ( a ),  3 ( b ) and  3 ( c ) are a plan view, front view and right side view showing a traverse unit of the disk drive, respectively;  
       FIG. 4  is a bottom view showing a condition where the traverse unit is attached to a body frame;  
       FIG. 5  is a perspective view showing the body frame from a bottom side;  
       FIG. 6  is a side view showing a relation between a long hole in a sidewall of the frame and a guide rib;  
       FIG. 7  is a longitudinal section view showing a condition where the traverse unit is held in a holding mechanism provided on the sidewall of the body frame;  
       FIG. 8 ( a ) is a side cross-sectional view showing a carrying-out condition of a tray for explaining basic movement of a tray-type disk drive, and  FIG. 8 ( b ) is a side cross-sectional view showing a carrying-in condition of the tray. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENT  
       FIG. 1  shows an internal structure of a disk drive according to an embodiment of the invention, which has a body frame  10  integrally molded using a resin material, a traverse unit  11  arranged in the frame, and a tray  12  in a carrying-out condition. A circular, shallow groove is formed on a top of the tray  12 , and a disk fits into the groove to be set. A tray rack  13  is provided in a back-and-forth direction at a bottom side of the tray  12 , and a tray conveyance gear  13   a  engages with the tray rack  13 . The tray conveyance gear  13   a  is rotationally driven by a feed motor  14 , and the rotation of the tray conveyance gear  13   a  allows the tray  12  to advance or back a defined distance between a disk replacement position and a disk reproduction position.  
      Furthermore, an approximately L-shaped tray-guide-groove  15  is provided along the tray rack  13  on a bottom side of the tray  12 . The tray guide groove  15  comprises a longitudinal guide groove  15   a  extending parallel to the tray rack  13 , a lateral guide groove  15   b  perpendicular to the tray rack  13 , and a corner guide groove  15   c  formed between the longitudinal guide groove  15   a  and the lateral guide groove  15   b . In addition, a curved-portion  15   d  having a small curvature is provided at a rear end of the longitudinal guide groove  15   a.    
      A laterally movable slide cam body  16  is disposed at a front side of the traverse unit  11  in the body frame  10 , and a cam rod boss  16   a  is jutted out on the slide cam body  16 . The cam rod boss  16   a  freely fits into the tray guide groove  15 . When the tray  12  advances toward the disk replacement position and the cam rod boss  16   a  freely fitting into the longitudinal guide groove  15   a  reaches the curved portion  15   d , the tray  12  stops. When the tray  12  backs and the cam rod boss  16   a  freely fitting into the longitudinal guide groove  15   a  reaches the corner guide groove  15   c , the tray  12  stops. That is, the cam rod boss  16   a  moves along the tray guide groove  15 , and the slide cam body  16  also moves along the tray guide groove  15 .  
      When the tray  12  backs and the cam rod boss  16   a  reaches the corner guide groove  15   c  of the tray guide groove  15 , as shown in  FIG. 2 , the slide cam body  16  moves left, and the tray conveyance gear  13   a  disengaged from the tray rack  13  engages with a slide cam body rack  16   b  provided at an end of the slide cam body  16 . Then, as the tray conveyance gear  13   a  continues to rotate, the cam rod boss  16   a  slides along the lateral guide groove  15   b , thereby the slide cam body rack  16   b  is fed right and the slide cam body  16  moves right.  
      In a condition where the disk placed on the tray is in the disk reproduction position after the tray has backed, when the traverse unit  11  moves up, the disk is mounted on the turntable and damped by the damper. Then, an optical pickup moves with the rotation of the disk and recording or reproduction is performed.  
      The traverse unit  11 , as shown in FIGS.  3 ( a ),  3 ( b ) and  3 ( c ), comprises a traverse chassis  17  and a traverse holder  18 , and the traverse chassis  17  is connected to the traverse holder  18  via elastic rings  19 ,  19 . The traverse holder  18  is formed in an approximately U shape having a front  20  and both support arms  21 ,  21 . A boss  20   a  protrudes to a front side in a center of the front  20 , a protrusive shaft  21  a protrudes outwardly from each of ends of the support arms  21 , and a guide boss  21   b  protrudes outwardly from each of bases of the support arms  21 .  
      The traverse chassis  17  is attached with the turntable and the optical pickup (not shown), and the traverse unit  11  configured in this manner is mounted on the body frame  10  of the disk drive.  FIG. 4  shows the condition from a bottom side of the unit, where the traverse unit  11  is mounted on the body frame  10 . A rear end of the traverse chassis  17  of the traverse unit  11  is connected to the body frame  10  via the elastic rings  19 , and both protrusive shafts  21   a ,  21   a  and the guide bosses  21   b ,  21   b  on the traverse holder  18  are supported by the body frame  10  as described later.  
      The boss  20   a  provided on the front  20  of the traverse holder  18  fits into a stepwise cam groove (not shown) provided in the slide cam body  16 , and the traverse unit  11  moves up and down by left-and-right movement of the slide. In this case, the protrusive shafts  21   a ,  21   a  work as base shafts or pivots for the vertical movement of the traverse unit  11 , and the guide bosses  21   b ,  21   b  slide vertically along the vertical guide grooves.  
      In the body frame  10  mounted with the traverse unit  11 , as shown in  FIG. 5 , a holding mechanism and a vertical guide groove  23   a  are formed so that the traverse unit  11  can be inserted obliquely from its bottom side into an inner space  22  and mounted therein. One end side of the holding mechanism is configured in a way that a long hole  25  into which the protrusive shaft  21   a  fits is formed in a sidewall  24   a  of the body frame, and guide ribs  27   a ,  27   a  are formed against the sidewall  24   a  at a position of the long hole  25  with a predetermined interval. Here, a horizontal support rib  29   a  is formed at a lower side (upper side on  FIG. 5 ) of the long hole  25 .  
      The guide ribs  27   a ,  27   a  rise from a base  26   a  extending inwardly from the sidewall  24   a , and are parallel to each other. Each guide rib  27   a  comprises a high guide-rib-part  28   a , low guide-rib-part  28   b , and an inclined guide-rib-part  28   c , which are different in height. Accordingly, height formed within the long hole  25  and the horizontal support rib  29   a  varies such that it is minimum at the high guide-rib-part  28   a  and maximum at the low guide-rib-part  28   b  (see  FIG. 6 ). The protrusive shaft  21   a  provided in the traverse holder  18  forming the traverse unit fits into a low-guide-rib  28   b  side of the long hole  25 , and then moves to a high-guide-rib  28   a  side to be positioned.  
      On the other hand, an overhang  30  that largely overhangs to the inside is provided on a sidewall  24   b  at the other side, and an inwardly protruded horizontal-support-rib  29   b  is formed on the overhang  30 . Similarly as the sidewall  24   a  side, a base  26   b  protrudes from the overhang  30 , and guide ribs  27   b ,  27   b  rise from the base  26   b . Although there is no hole provided in the overhang side, an insertion  31  is formed by cutting off the horizontal support rib  29   b.    
      When the traverse unit is mounted, one protrusive shaft  21   a  is inserted into the low guide-rib-part  28   b  side of the long hole  25 , and the other protrusive shaft  21   a  is fitted into the insertion  31 . Both protrusive shafts  21   a ,  21   a  are moved along the guide ribs  27   a ,  27   a , and can be fitted into spaces between the high guide-rib-parts  28   a  and the horizontal support ribs  29   a ,  29   b  without rattle. On the other hand, the guide bosses  21   b ,  21   b  on the traverse holder  18  are freely fitted into the vertical guide grooves  23   a ,  23   a  formed along the vertical guides  23 , 23 .  
       FIG. 7  shows a condition where the traverse unit  11  is positioned and held by the holding mechanism provided on the sidewalls  24   a ,  24   b  of the body frame. That is, both protrusive shafts  21   a ,  21   a  on the traverse holder  18  fit into spaces between the horizontal support ribs  29   a ,  29   b  on the sidewalls  24   a ,  24   b  of the body frame and the guide ribs  27   a ,  27   b  respectively, thereby vertical positioning is carried out. Vertical ribs  21   c  protrude from respective support arms  21  having protrusive shafts  21   a  at their ends, and the vertical ribs  21   c  are fitted into respective spaces  27   c  formed between both guide ribs  27   a ,  27   a  and between the ribs  27   b ,  27   b , thereby a lateral position is regulated. In addition, the guide bosses  21   b ,  21   b  are fitted into the vertical guide grooves  23   a ,  23   a  respectively, thereby the position of the disk drive is regulated in the back-and-forth direction (slide direction of the tray), and therefore the traverse unit  11  does not fall off from the body frame  10 .  
      The horizontal support rib  29   a  can be formed, rather than through forming the long hole  25 , in an inwardly protruded mode from the sidewall  24   a  similarly as in the horizontal support rib  29   b  formed on the other sidewall  24   b . In this case, an insertion is provided similarly as the insertion  31  provided adjacently to the horizontal support rib  29   b . In any mode, the vertical rib fits into the space between the guide ribs and thus the lateral positioning is performed, thereby the traverse unit is supported without rattle, and the advantages can be similarly obtained.  
      The front boss  20   a  on the traverse holder  18  freely fits into the slide cam body groove, and the slide cam body  16  slides left and right, thereby the boss  20   a  vertically moves, at the same time the traverse unit  11  moves up and down.