Abstract:
A flexible cable and a disk drive with a flexible cable are provided. The disk drive includes a main base, a pickup base installed on the main base and provided with parts for recording and reproducing of signals on and from a disk, including an optical pickup linearly movable within a predetermined region, a board fixedly installed on a side of the main base and configured to control driving of the parts, including the optical pickup, and a flexible cable. The flexible cable includes a folded portion formed at a portion of a flexible cable main body so as to cause both ends of the flexible cable main body to extend in the same direction, wherein ends of the flexible cable connect to the optical pickup and the board at opposite positions, respectively, so as to transmit signals therebetween. With this structure, it is possible to efficiently use inner space of the disk drive.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates to a disk drive, and more particularly, to a flexible cable for electrically connecting a movable optical pickup to a fixed board in a disk drive. 
   2. Background of the Related Art 
     FIG. 1  is a schematic plan view of a related art disk drive.  FIGS. 2A and 2B  are schematic sectional views of a flexible cable used for connecting an optical pickup to a main board in the related art disk drive. 
   Referring to  FIGS. 1-2B , a main base  1  forms a frame of the disk drive. The main base  1  includes a main board  2  on which a variety of parts for controlling the driving of the disk drive are installed. The main base  1  has a generally rectangular hole  2 A at a center thereof, and a pickup base  3  is installed in the hole. The pickup base  3  is supported on the main base  1  at a rear end thereof by vibration-proof members  5  made, for example, of elastic material and configured to absorb vibrations and noises. 
   A spindle motor  7  configured to rotate a disk is positioned on the pickup base  3 . A disk is seated on a turntable  8  which is provided at a top end of the spindle motor  7  and which is configured to be rotated by the spindle motor  7 . An optical pickup  9  is installed on the pickup base  3  and is guided along guide shafts  10 . The optical pickup  9  records or reads out signals by irradiating a signal-recording surface of the disk with light. The optical pickup  9  is driven by a sled motor (not shown) to move along the guide shafts  10 . 
   An electrical connection between the optical pickup  9 , which moves along the guide shafts  10 , and the main board  2  is established by a flexible cable  11 , generally referred to as a “FFC” (Flexible Flat Cable), as shown in  FIGS. 2A-2B . The flexible cable  11  is flexible such that it can be freely bent to a certain extent. One end of the flexible cable  11  is connected to the main board  2  by a connector  11   c  and the other end thereof is connected to the optical pickup  9  so as to transmit signals between the main board  2  and the optical pickup  9 . 
   A front end of the pickup base  3  is supported on a lift base  12 . The lift base  12  is installed so that a front end thereof can be pivoted on a shaft  13  that functions as a center of rotation. Vibration-proof members  5 ′ are interposed between the lift base  12  and the pickup base  3  to support the pickup base  3  on the lift base  12  and prevent transmission of vibrations and noises. 
   In the related art disk drive described above, the optical pickup  9  records signals on the disk or reproduces recorded signals while moving along the guide shafts  10  by means of a driving force from the sled motor (not shown). The flexible cable  11  is used for transmitting signals between the optical pickup  9  and the main board  2 . Since the flexible cable  11  can be freely bent to a certain extent, as described above, it may be installed to be bent and protrude toward a side opposite to the optical pickup  9  with respect to the connector  11   c , as shown in  FIG. 2A . Further, when the optical pickup  9  moves toward the turntable  8 , the flexible cable is pulled by the optical pickup  9 , as shown in  FIG. 2B . 
   However, there is the following problem in the related art disk drive described above. The flexible cable  11  is installed to protrude toward a side opposite to the optical pickup  9  with respect to the connector  11   c  for connection to the main board  2 , making a connection between the main board  2  and the optical pickup  9 . As the flexible cable  11  is installed as such, it is not possible to install other parts in a region A (see  FIGS. 2A-2B ) opposite to the optical pickup  9  with respect to the connector  11   c . Therefore, there is the disadvantage that a length of a portion of the disk drive behind the optical pickup  9  relatively increases. 
   SUMMARY OF THE INVENTION 
   An object of the invention is to solve at least one or more of the above problems and/or disadvantages in a whole or in part and to provide at least the advantages described hereinafter. 
   In order to achieve at least the above objects, in whole or in part, and in accordance with the purposes of the invention, as embodied and broadly described, there is provided a flexible cable according to an embodiment of the invention comprising a flexible cable main body having one end configured to connect to a first part and the other end configured to connect to a second part on a side opposite to the first part and configured to transmit signals between the first and second parts, wherein at least one of the first and second parts is movable, and a folded portion formed by folding a portion of the cable main body so that two opposing faces are in contact with each other. 
   To further achieve at least the above objects, in whole or in part, and in accordance with the purposes of the invention, as embodied and broadly described, there is provided a flexible cable according to an embodiment of the invention comprising a first end configured to be connected to a first part and a second end configured to be connected to a second part so as to transmit signals between the first and second parts, at least one of the first and second parts being movable, and a folded portion formed by folding a portion of the flexible cable, wherein the folded portion does not deviate from vertical alignment with the first part. 
   To further achieve at least the above objects, in whole or in part, and in accordance with the purposes of the invention, as embodied and broadly described, there is provided a flexible cable according to an embodiment of the invention comprising a first end configured to be connected to a first part and a second end configured to be connected to a second part so as to transmit signals between the first and second parts, at least one of the first and second parts being movable, and at least one curved portion formed by folding a portion of the flexible cable, wherein a vertex of the curved portion does not deviate from vertical alignment with the first part. 
   To further achieve at least the above objects, in whole or in part and in accordance with the purposed of the invention, as embodied and broadly described, there is provided a disk drive according to an embodiment of the invention comprising a main base, a pickup base installed on the main base and provided with parts for recording and reproducing signals on and from a disk, including an optical pickup linearly movable within a predetermined region, a board fixedly installed on a side of the main base and configured to control driving of the parts including the optical pickup, and a flexible cable having a folded portion formed by folding a portion of a flexible cable main body, wherein two strips of cable extend from the folded portion in the same direction and are connected, respectively, to the optical pickup and the board so as to transmit signals therebetween. 
   Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be realized and attained as particularly pointed out in the appended claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be described in detail with reference to the following drawings in which like reference numerals refer to like elements wherein: 
       FIG. 1  is a schematic plan view of a related art disk drive; 
       FIGS. 2A and 2B  are schematic sectional views of a flexible cable used for connecting an optical pickup to a main board in the related art disk drive; 
       FIG. 3  is a schematic sectional view a disk drive with a flexible cable according to an embodiment of the invention; 
       FIG. 4  is a schematic sectional view showing a state in which an optical pickup has moved toward an inner circumference of a disk in accordance with an embodiment of the invention; 
       FIG. 5  is a schematic sectional view of a disk drive with a flexible cable according to another embodiment of the invention; 
       FIG. 6  is a schematic sectional view of a flexible cable according to an embodiment of the invention; 
       FIG. 7  is a schematic sectional view of a flexible cable according to another embodiment of the invention; 
       FIG. 8A  is a schematic exploded perspective view of a flexible cable according to another embodiment of the invention; 
       FIG. 8B  is a schematic sectional view of the flexible cable of  FIG. 8A ; and 
       FIG. 9  is a schematic sectional view of a flexible cable according to yet another embodiment of the invention. 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     FIG. 3  is a schematic sectional view of a disk drive according to an embodiment of the invention.  FIG. 4  shows a state in which an optical pickup has moved toward an inner circumference of a disk in accordance with an embodiment of the invention. 
   Referring to  FIGS. 3 and 4 , a main base  30  forms a frame of the disk drive. A main board  32  is installed at a side of the main base  30 . The main board  32  is not necessarily installed on the main base  30  and may be installed at a separate location. A variety of parts for controlling the driving of the disk drive are installed on the main board  32 . 
   A pickup base  40  is installed on the main base  30 . The pickup base  40  is provided with a variety of parts for recording signals and reproducing recorded signals on and from a disk D, as discussed below. A spindle motor  42  is installed on the pickup base  40 , and a turntable  43  is mounted on a rotational shaft of the spindle motor  42 . A disk D is seated on the turntable so as to be rotated therewith. 
   A tray  60  is installed on the main base  30 . The tray  60  is installed so as to be movable inside and outside of the main base  30 , and thus, functions to move the disk D between a loading position and an unloading position. The tray  60  has a disk-seating portion  62  configured for seating the disk D thereon. 
   A pickup window  45  having a predetermined area is formed in a center of the pickup base  40 . An optical pickup  46  is installed in an area of the pickup window  45  so as to be movable along guide shafts  47  by an additional driving source (not shown). The guide shafts  47  are installed on the pickup base  40  and movably support both lateral ends of the optical pickup  46 . The optical pickup  46  functions to record signals or reproduce recorded signals by irradiating a signal-recording surface of the disk D with light. 
   The optical pickup  46  and the main board  32  are connected using a flexible cable  50 . A cable main body  51  is formed of a flexible material. One end of the cable main body  51  is connected to the optical pickup  46  and the other end is connected to the main board  32  by a connector  33 . The cable main body  51  has a straight portion  51   p , and a curved portion  51   r  having a predetermined curvature and which can be elastically deformed to allow changes in the curvature due to the movement of the optical pickup  46 . 
   The cable main body  51  is divided into the straight portion  51   p  and the curved portion  51   r  by a folded portion  53 . However, in practice, the curved portion  51   r  may not be formed upon manufacture of the flexible cable  50  but may be formed when the optical pickup  46  and the main board  32  are connected to each other using the flexible cable  50 . In other words, the shape of the flexible cable  50  shown in the figures can be made when one end portion (straight portion  51   p ) of the flexible cable main body  51  is bent at the folded portion  53  and is connected to the optical pickup  46 , and the other end portion, which becomes the curved portion  51   r , is connected to the connector  33 . 
   It can be seen from the figures that an end of the folded portion  53  is vertically aligned with and placed into the connector  33 . In the embodiment of  FIG. 3 , the end of the folded portion  53  does not deviate from vertical alignment with the connector  33 , as shown in  FIG. 3 , prior to movement of the optical pickup  46 . In the embodiment of  FIG. 3 , the end of the folded portion  53  is positioned adjacent to the optical pickup rather than the connector  33  with the curved portion extending therebetween. 
   As the optical pickup  46  moves when the disk drive is driven, the folded portion  53  is repeatedly subjected to forces causing a portion of the folded portion  53  to be unfolded, as shown in  FIG. 4 . However, the folded portion  53  may include an additional provision for continuously maintaining the folded state of the cable main body  51 , which will be described further herein below. 
     FIG. 5  shows another embodiment of the disk drive according to the invention. In this embodiment, the straight portion  51   p  of the cable main body  51  is connected to the connector  33  mounted on the main board  32 , and the curved portion  51   r  is connected to the optical pickup  46 . In such a case, even though the curved portion  51   r  of the cable main body  51  slightly protrudes toward a side opposite to the optical pickup  46  with respect to the connector  33 , it is possible to relatively save some space in the disk drive over a conventional disk drive. In this embodiment, a vertex of the curved portion  51   r  does not deviate from vertical alignment with the connector  33 , as shown in  FIG. 5 , prior to movement of the optical pickup  46 . Further, in the embodiment of  FIG. 5 , the vertex of the curved portion  51   r  is positioned adjacent the optical pickup  46  rather than the connector  33 . 
     FIGS. 6 to 9  shows a variety of embodiments of the flexible cable according to the invention.  FIG. 6  shows that an adhesive member  56  may be used to maintain the folded state of the folded portion  53  of the cable main body  51 . The adhesive member  56  may be placed between contact portions of the straight portion  51   p  and the curved portion  51   r  on one or both sides of the folded portion  53  of the cable main body  51 . Upon manufacture of the flexible cable  50 , after the folded portion  53  is formed, the adhesive member  56  may then be placed between the straight portion  51   p  and the curved portion  51   r  to maintain the folded state. Examples of an adhesive member  56  include, but are not limited to, two-sided tapes or silicon materials. Other means of maintaining the folded sate of the folded portion  53  may also be provided. 
   Another embodiment of the flexible cable is shown in  FIG. 7  according to the invention and will be explained below. In this embodiment, a reinforcement folded-plate  156  may be used to maintain the folded state of the folded portion  53  of the cable main body  51 . The reinforcement folded-plate  156  may be attached to both sides of the folded portion  53 . The reinforcement folded-plate  156  is configured to maintain the shape of the folded portion  53  of the cable main body  51  using the shape of the reinforcement folded-plate itself. Referring to  FIG. 7 , the folded portion  53  of the cable main body  51  is placed between folded opposing portions of the reinforcement folded-plate  156 . Alternatively, the reinforcement folded-plate  156  may be placed between the straight portion  51   p  and the curved portion  51   r  of the cable main body  51 . 
   The reinforcement folded-plate  156  may be made of, for example, synthetic resin or metal. It is possible to form the reinforcement folded-plate  156  in the desired shape during manufacture of the reinforcement folded-plate  156 . Alternatively, it is also possible to form the reinforcement folded-plate in the desired shape by bringing a preform into contact with the folded portion  53  and folding, i.e. plastically deforming, the preform. 
     FIGS. 8A and 8B  show a further embodiment of the flexible cable according to the invention. In this embodiment, a folding clip  256  is used to maintain the folded state of the folded portion  53  of the cable main body  51 . The folding clip  256  may be in the shape of a flat hexahedron and may be formed with an insertion slot  257  into which a predetermined length of the folded portion  53  of the cable main body  51  is inserted. Other shapes for the folding clip may also be appropriate. According to this embodiment, the folded portion  53  may be first formed in the cable main body  51  and then may be inserted into the insertion slot  257  of the folding clip  256 , thereby maintaining the folded state of the folded portion  53 , as shown in  FIG. 8B . 
     FIG. 9  shows a still further embodiment of the flexible cable according to the invention. A tape  356  is used to maintain the folded state of the folded portion  53  of the cable main body  51 . In this embodiment, the tape  356  is used to wrap the straight portion  51   p  and the curved portion  51   r  on both sides of the folded portion  53  of the cable main body  51 . The tape  356  is configured to maintain the folded state of the folded portion  53  by wrapping the straight portion  51   p  and the curved portion  51   r  together. 
   Hereinafter, operations of the flexible cable and the disc drive with the flexible cable in accordance with embodiments of the invention will be explained herein below with reference to the embodiments of  FIGS. 3-4 . 
   When a disk D is loaded into the disk drive and an operating signal is input, the disk D seated on the turntable  43  is rotated by the spindle motor  42  and the optical pickup  46  moves along the guide shafts  47  in a radial direction of the disk D so that signals can be recorded or reproduced. 
   The transmission of signals between the optical pickup  46  moving along the guide shafts  47  and the main board  32  are exchanged through the flexible cable  50 . Examples of signals transmitted through the flexible cable  50  may include signals for operations of the optical pickup  46 , signals to be recorded on the disk D, signals to be reproduced from the disk D, etc. 
     FIG. 3  shows a state in which the optical pickup  46  is positioned adjacent an outer circumference of the disk D, while  FIG. 4  shows a state in which the optical pickup  46  is adjacent to a center of the disk D. It is noted that the straight portion  51   p  is not deformed and only the curved portion  51   r  is deformed as the optical pickup  46  moves along the guide shafts  10 . 
   That is, in the state of  FIG. 3 , the curved portion  51   r  takes the shape of an arch having a relatively long radius of curvature. On the other hand, in the state of  FIG. 4 , a portion of the curved portion  51   r  takes the shape of an arch having a relatively small radius of curvature and the remainder thereof approximates to a straight line. That is, as the optical pickup  46  moves from the outer circumference to the inner circumference of the disk D, the curved portion  51   r  is elastically deformed so that the radius of curvature of the section of the curved portion  51   r  becomes small and the remainder thereof approximately takes the shape of a straight line. When the optical pickup  46  moves in the opposite direction, the curved portion  51   r  is restored to the original arched state, that is, the state of  FIG. 3 . 
   The invention provides at least the following advantages. 
   As described above, the flexible cable  50  does not protrude into a region A beyond the connector  33  when the optical pickup  46  is operated. Accordingly, the region A outside the connector  33  may be used as a space for installation of additional parts. 
   Further, since a space needed for installation of a flexible cable electrically connecting an optical pickup, which is a relatively movable part, to a fixed main board is minimized, it is possible to make the disk drive light, thin, and simple. 
   Also, even though a folded portion formed in the flexible cable is repeatedly subjected to forces as the optical pickup is operated, the folded portion is not unfolded due to the structure for maintaining the folded state of the folded portion. Thus, the durability of a product with the flexible cable is enhanced. 
   Further, the variety of embodiments for maintaining the folded state of the folded portion  51  of the flexible cable  50  described herein may be properly selected according to various conditions, such as design conditions of the disk drive. Although in certain circumstances the best performance can be obtained when the folding clip  256  is used, the folding clip  256  may not be suitable for, for example, a light, thin, and/or simple disk drive due to the thickness of the folding clip. In such a case, use of the adhesive member  56  or tape  356  may be more appropriate, improving workability, and making the disk drive light, thin, and simple. 
   The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the invention. The present teaching can be readily applied to other types of apparatuses. The description of the invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures.