Abstract:
A disk player has a tray capable of moving in and out of a player body. A driving unit moves the tray. A lift unit selectively engages or disengages the driving unit and raises a turntable receiving a disk loaded by the tray thereon. A spindle motor rotates the turntable. A damping unit reduces loads and impacts during movement of the lift unit.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit under 35 U.S.C. § 119(a) of Korean Patent Application No. 2005-4990 filed on Jan. 19, 2005, in the Korean Intellectual Property Office, the entire disclosure of which is hereby incorporated by reference. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a disk player. More particularly, the present invention relates to a disk player that smoothly loads and unloads disks while reducing loads and impacts associated with movement of the lifting unit. 
   2. Description of the Related Art 
   Generally, a disk player records and reproduces information on a disk such as an optical disk. Examples of disk players include CD-ROM drivers, video disk apparatuses, digital audio disk apparatuses, and DVD players. 
   The disk player has therein a disk tray moving in and out of the body. The disk tray has a receiving part for receiving a disk or a disk cartridge. A lower portion of the disk tray has a rack gear spaced a certain distance in a direction of loading. 
   The rack gear is engaged with a tray gear in the body to move in a direction of loading or unloading according to a driving direction of a driving motor. 
   The body includes a turntable seating in the tray for receiving a loaded disk, a chucking unit for chucking the disk seated in the turntable, a spindle motor for rotating both the turntable and the disk, and an optical pick up for recording and reproducing information on the rotating disk. 
   The chucking unit is fixed at an upper portion of the body. A lift unit raises the turntable, the spindle motor, and the optical pick up to chuck the loaded disk between the turntable and the chucking unit. 
   The lift unit includes a lift plate liftable in the body, and a cam slider that slides in the body to move a lift lever. The cam slider has a rack gear selectively engaged with a driving gear rotated by power of the driving motor. The cam slider moves by interference of the disk tray during loading of the disk such that the rack gear of the cam slider moves in connection with the driving gear. Accordingly, the lift plate can ascend in association with the cam slider. When unloading the disk tray, an opposite order of the above process is made to lower the lift plate. 
   The lift plate is heavy due to having many elements, such as the spindle motor, the turn table, and the optical pick-up. A large load is exerted when raising the heavy lift plate, and noise is generated due to sudden descending. 
   Accordingly, a need exists for an improved disk player that reduces loads and impacts during movement of the lifting unit. 
   SUMMARY OF THE INVENTION 
   An aspect of the present invention is to provide a disk player with an improved structure that smoothly performs loading and unloading of a disk. 
   A disk player includes a tray capable of moving in and out of a player body, a driving unit moving the tray, a lifting unit selectively engaged or disengaged with the driving unit and raising a turntable that receives a disk loaded by the tray and a spindle motor rotating the turntable, and a damping unit reducing a load and impact during movement of the lifting unit. 
   The driving unit includes a first rack gear formed at a lower portion of the tray, a tray gear rotatably formed in the player body to engage the first rack gear, and a driving motor for driving the tray gear. 
   The lifting unit may include a pivot plate supporting the spindle motor and the turntable and rotatably formed in the player body, a cam slider provided in the player body for reciprocal sliding movement that causes the pivot plate to ascend or descend according to a direction of movement thereof, a driving gear formed in the player body to rotate by power of the driving motor, and a second rack gear formed in the cam slider and engaged and disengaged with the driving gear according to the position of the cam slider. 
   The cam slider may move in association with the tray so that the second rack gear and the driving gear may be engaged and disengaged with each other. 
   The cam slider may have at a top surface an interference protrusion, and the tray may have a cam rail for guiding the interference protrusion to be driven. 
   The pivot plate may have one or more cam protrusions, and the cam slider may have a cam slit in which the cam protrusions are received in and are guided along. 
   The tray gear and the driving gear may be coaxially formed. 
   The damping unit may include an elastic member connected with the lifting unit. 
   The elastic member may connect the lifting unit and the player body to provide the lifting unit with an elastic support in the raising direction, and a reaction force for descending. 
   The damping unit may include an elastic member urging the cam slider in a moving direction of the cam slider corresponding to a raising direction of the pivot plate. 
   The elastic member may include a coiled spring. 
   Other objects, advantages and salient features of the present invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the present invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other aspects, features and advantages of the present invention will be more apparent from the following detailed description taken with reference to the accompanying drawings, in which: 
       FIG. 1  is a top plan view of a disk player according to an exemplary embodiment of the present invention; 
       FIG. 2  is a transverse elevational view in partial cross section of a disk player according to an exemplary embodiment of the present invention; 
       FIGS. 3A and 3B  are transverse elevational views in partial cross section of a disk player according to an exemplary embodiment of the present invention; 
       FIGS. 4A and 4B  are schematic views illustrating the status of a cam slider when a tray is unloaded; 
       FIGS. 5A and 5B  are views of the status of the second rack gear engaged with the driving gear as a tray is moved to a loading position by a certain distance; and 
       FIGS. 6A and 6B  are views of the status of the second rack gear when the loaded tray is completely moved to one side with the cam slider. 
   

   Throughout the drawings, like reference numerals will be understood to refer to like parts, components and structures. 
   DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
   Exemplary embodiments of the present invention are described in detail with reference to the annexed drawings. In the following description, detailed descriptions of known functions and configurations incorporated herein are omitted for conciseness and clarity. 
   Referring to  FIGS. 1 ,  2 , and  3 A, a disk player according to an exemplary embodiment of the present invention includes a body  10 , a tray  20  capable of loading and unloading in and out of the body  10 , a driving unit  30  moving the tray  20 , a spindle motor  61 , a turntable  63 , a lifting unit  40  raising the spindle motor  61  and the turntable  63 , and a damping unit  50 . 
   The tray  20  has a receiving part  21  for receiving a disk or a disk cartridge. The tray  20  moves in loading direction A and unloading direction B to move in and out of the body  10 . 
   The driving unit  30  includes a first rack gear  31  of a certain length disposed at a lower portion of the tray  20 , a tray gear  32  engaged with the first rack gear  31 , and a driving motor  33 . 
   The first rack gear  31  is preferably integrally formed with the tray  20 . The tray gear  32  is rotatably formed in the body  10 , and moves in association with the first rack gear  31  according to rotation directions to move the tray  20 . 
   The driving motor  33  transmits power via the power transmission unit  34  to the tray gear  32 , and rotates in both directions. The power transmission unit  34  includes a driving pulley  35  on a rotating axis of the driving motor  33 , a driven pulley  36 , a belt  37 , and an idle gear  38 . The belt  37  connects the driving pulley  35  and the driven pulley  36 . A pulley gear  36   a  formed coaxially with the driven puller  36  is engaged with the idle gear  38 . The power transmission unit  34  may be implemented with various examples. 
   As shown in  FIGS. 3A ,  3 B and  4 A, the lifting unit  40  includes a pivot plate  41  pivotable up and down in the body  10 , a cam slider  43  provided in the body  10  to reciprocally move in association with the pivot plate  41 , a second rack gear  45  engaged with the cam slider  43 , and a driving gear  47  rotating by power supplied by the driving motor  33  and selectively engaged with the second rack gear  45 . 
   The pivot plate  41  includes a spindle motor  61  and an optical pick-up (not shown). The spindle motor  61  pivotably supports a turntable  63  receiving a disk loaded by the tray  20 . A hinge  41   a  rotatably supports an end of the pivot plate  41  in the body  10 . A plurality of cam protrusions  41   b  are formed at the other end of the pivot plate  41  that engage the cam slider  43 . 
   The cam slider  43  is reciprocably formed in a direction C substantially perpendicular to a moving direction of the tray  20  in the body  10 , that is, substantially perpendicular to the directions A and B indicated by the arrows in  FIG. 1 . As shown in  FIGS. 4A and 4B , the cam slider  43  includes a vertical wall  43   a  with a plurality of cam slits S engaged with the cam protrusion  41   b  and a horizontal wall  43   b  substantially perpendicular to the vertical wall  43   a . The pair of cam slits S take on the same configuration of sloping upwardly or downwardly. As the cam slider  42  moves in the direction C, the cam protrusions  41   b  move relatively along the cam slits S so that the pivot plate  41  ascends and descends. A plurality of interference protrusions  43   c  and  43   d  protrude from a top surface of the horizontal wall  43   b . The interference protrusions  43   c  and  43   d  are formed in each position to interfere with cam rails  23  and  24  at a bottom surface of the tray  20 . 
   The cam rail  23  includes a first rail portion  23   a  substantially parallel with directions of loading and unloading A and B, a second rail portion  23   b  in a direction substantially perpendicular to the first rail  23   a , and a slope rail  23   c  connecting the two rails  23   a  and  23   b  and inclining with respect to the two rails  23   a  and  23   b.    
   Another cam rail  24  includes a rail portion  24   a  substantially parallel with the second rail  23   b , and a slope rail  24   b . The interference protrusions  43   c  and  43   d  are guided by each of the slope rails  23   c  and  24   b  such that the second rack gear  45  and the driving gear  47  may be engaged and disengaged. 
   The second rack gear  45  is formed integrally with the horizontal wall  43   b  by a certain length. The second rack gear  45  moves in engagement with the driving gear  47  or stops in disengagement therefrom as the cam slider  43  moves under the interference with the movement of the tray  20 . 
   The driving gear  47  may be formed coaxially or integrally with the tray gear  32 . The driving gear  47  may have a gear ratio substantially similar to that of the tray gear  32 . 
   The damping unit  50  may include an elastic member  51  elastically urging the cam slider  43  in a direction indicated by arrow C 1  in  FIGS. 4B and 5B . The elastic member  51  may be a coiled tension spring. As shown in  FIG. 4B , a first end of the elastic member  51  is connected with a locking protrusion  11  in the body  10 . A second end of the elastic member  51  is connected with a locking protrusion  43   e  at a bottom surface of the horizontal wall  43   b  of the cam slider  43 . 
   As the cam slider  43  moves in the C 1  direction to raise the pivot plate  41 , a load exerted on the driving motor  31  is reduced due to elastic restoration of the elastic member  51 . As the cam slider  43  moves in the C 2  direction to lower the pivot plate  41 , quick movement and collision of the cam slider  43  is substantially prevented due to tension of the elastic member  51 . The elastic member  51  functions as a damper, which reduces impacts caused by gravity of the pivot plate  41 . 
   In the disk player with the above structure, operations of the cam slider  43 , when the tray  20  is loaded and unloaded, are explained in detail with reference to  FIGS. 4A to 6B . 
     FIGS. 4A and 4B  are views of the position of the tray  20  before being loaded. The cam protrusions  41   b  of the pivot plate  41  are located at a lower portion of the cam slit S. The second rack gear  45  is not engaged with the driving gear  47 . Under this circumstance, a disk on the tray  20  moves in the A direction during loading. As shown in  FIGS. 5A and 5B , the interference protrusions  43   c  and  43   d  of the cam slider  43  are guided by the rail portions  23   c  and  24   b  to move in the direction C 1 . Accordingly, the second rack gear  45  is engaged with the driving gear  47  such that the cam slider  43  moves in the direction C 1  by power of the driving motor  33 . 
   As shown in  FIGS. 6A and 6B , the cam slider  43  moves in the direction C 1 . A cam pin  41   b  of the pivot plate  41  is guided along the slope of the cam slit S to ascend. At this time, a large load may be exerted on the driving motor  33  due to gravity applied on the pivot plate  41 . However, according to an exemplary embodiment, the elastic member  51  elastically urges, or pulls, the cam slider  43  in the direction C 1  such that the cam slider  43  may be easily moved. 
   When unloading the tray  20 , the members  41  and  43  operate substantially oppositely to the aforementioned operations. Accordingly, the cam slider  43  moves again in the direction C 2  so that the cam pin  41   b  descends along the cam slit S and the pivot plate  41  descends. As the elastic member  51  pulls the cam slider  43  in the direction C 1 , quick movement of the cam slider  43  is substantially prevented due to the weight of the pivot plate  41 . Accordingly, the cam slider  43  is prevented from colliding with the other members when returning, such that noise or damage may be suppressed. 
   As described above, the disk player according to exemplary embodiments of the present invention includes a damping unit urging the cam slider  43  to one side so that the driving load may be reduced for moving the cam slider  43  to raise the pivot plate  41 . 
   Additionally, the damping unit may suppress the quick returning of the cam slider  41  due to the weight of the pivot plate  41  when the cam slider  43  is moved to lower the pivot plate  41 . Therefore, noise or damage by collision may be reduced. 
   While the invention has been shown and described with reference to certain embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.