Abstract:
The invention provides a disc device capable of offering good SATA interface performance by optimizing the placement of the SATA connector relative to the control board, solving problems concerning noise or unnecessary radiation. 
     A driver IC and DSP for executing main processing concerning disc recording or reproduction processing are installed in a main printed circuit board. A SATA connector having a power supply terminal and signal terminal is fixed to the main printed circuit board. The SATA connector is placed on the board opposite the DSP. Patterns each connecting the power supply terminal to the driver IC and connecting the signal terminal and DSP are formed on the board. The SATA connector and DSP are placed on the driver IC side relative to the central line of the board, the power supply terminal is placed on the driver IC side, and the signal terminal is placed on the DSP side.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application relates to and claims priority from Japanese Patent Application No. 2007-047851, filed on Feb. 27, 2007 the entire disclosure of which is incorporated herein by reference. 
       BACKGROUND  
       [0002]    1. Field of the Invention 
         [0003]    The invention relates generally to a disc device having a processing mechanism for executing recording or reproduction processing on a disc. 
         [0004]    2. Description of Related Art 
         [0005]    Currently, parallel ATAs (PATAs) are mainly used as interfaces for connecting a disc device to a personal computer. A PATA interface connector includes a separate power supply unit, and a separate signal unit, each of which is installed on a main printed circuit board at the back end of an optical disc device 
         [0006]    Plural control ICs are installed in a control board and contained in a disc device. A DSP for controlling an entire disc device is put at the center of the main printed circuit board. A voltage regulator IC, flash memory IC, analog front end IC (AFE) for processing pickup signals, and mechanism driver IC for rotating a disc have to be efficiently arranged around a DSP in light of efficiency in wiring patterns formed between those ICs and the DSP. 
         [0007]      FIG. 5  in JP2006-99856 A discloses an invention including plural ICs efficiently arranged on a printed circuit board. Since a motor driver is positioned at a corner opposite a power supply unit in a serial ATA interface connector via a HDC/MPC, a pattern from a power supply unit to a driver IC is formed in an X-Y direction using an end area of the main printed circuit board. 
         [0008]    JP2001-101829 A discloses a floppy disc device having an interface connector and being downsized and thinned by arranging connectors and IO terminals, which may cause noise in other components or signal crossing, as far apart as possible in a control circuit board. 
         [0009]    JP60-263370 A discloses arranging, in a floppy disc device, a recording or reproduction circuit and a motor control circuit as far apart as possible to avoid the effects of noise. 
         [0010]    Recently, serial ATA (SATA) interfaces that enable high speed serial data transfer have been used, instead of the PATAs, as interfaces for connecting optical disc devices as typified by CD or DVD devices to a personal computer. 
         [0011]    Data transfer using SATA interfaces is more susceptible to pattern impedance in a control main printed circuit board or noise caused by wires, etc., compared with data transfer using PATAs. For example, if a wiring pattern between a power supply unit in a SATA connector and a driver IC becomes long, the generated noise will affect the SATA interface performance. The same problem occurs in the case where a wiring pattern between a driver IC and a connector for a motor, or similar, driven by the driver IC is long. 
         [0012]    Arranging a power supply unit in a SATA connector and a driver IC very close to each other is conceivable, but pattern impedance problems occur if the distance from a signal unit in the SATA connector and a DSP becomes long. To solve those problems, an object of the invention is to provide a disc device capable of offering good SATA interface performance by optimizing the placement of a SATA connector with respect to a control board to solve problems concerning noise or unnecessary radiation. 
       SUMMARY  
       [0013]    To achieve the above object, the invention provides a disc device having a processing mechanism for executing recording or reproduction processing on a disc, the processing mechanism including: a control board in which a driver IC for driving a mechanism motor, and a main control IC for executing main processing concerning the disc recording or reproduction are installed; and a SATA connector having a power supply unit and a signal unit, the SATA connector being connected to the driver IC and the main control IC and provided to the control board opposite the main control IC, wherein a pattern connecting the power supply unit to the driver IC and a pattern connecting the signal unit to the main control IC are formed on the control board; and in the control board, the SATA connector and the main control IC are placed on the driver IC side relative to a line passing through the center of the control board, the power supply unit is also placed on the driver IC side, and the signal unit is placed on the main control IC side. 
         [0014]    In the disc device of the invention, plural connectors connected to the power supply unit directly or via the driver IC are placed in a concentrated manner near the driver IC on the same side as the driver IC in the control board, using both faces of the control boards. In particular, the connectors include a connector for a photosensor that detects a special pattern formed on a label side of an optical disc. 
         [0015]    The disc device of the invention also includes: a carrier mechanism having a spindle motor for rotating an optical disc, an optical pickup for executing recording or reproduction processing on the optical disc, and a carrier motor for moving the optical pickup towards or away from the center of the disc, each being fixed to a chassis; and a loading mechanism for carrying a tray that receives the optical disc into the disc device. The carrier mechanism is designed to move the optical disc carried into the disc device upwards relative to the tray to fix the optical disc to the spindle motor. A connector for the spindle motor and the photosensor connector are placed on the lower surface of the control board, and a connector for the loading mechanism is placed on the upper surface of the control board. 
         [0016]    As described above, the invention achieves provision of a disc device capable of offering good SATA interface performance by optimizing the placement of the SATA connector relative to the control board to solve problems concerning noise or unnecessary radiation. 
         [0017]    Other aspects and advantages of the invention will be apparent from the following description and the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0018]      FIG. 1  is a perspective view of the entire disc device viewed from a viewpoint in front of the disc device of the invention. 
           [0019]      FIG. 2  is a perspective view of the entire disc device viewed from a viewpoint at the back of the disc device. 
           [0020]      FIG. 3  is an exploded perspective view of main component assemblies of the disc device. 
           [0021]      FIG. 4  is a perspective view of the lower surface of the disc device viewed from a lower viewpoint in front of the disc device with the bottom plate of the case omitted. 
           [0022]      FIG. 5  is a perspective view of the lower surface of the disc device viewed from a lower viewpoint at the back of the disc device with the bottom plate of the case omitted. 
           [0023]      FIG. 6  is a bottom view of the disc device with the bottom plate of the case omitted. 
           [0024]      FIG. 7  is a bottom view of the main printed circuit board with an outline of an inter-device connection pattern added. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0025]    An embodiment of the disc device of the invention will be described below.  FIGS. 1 and 2  are perspective views of the entire disc device viewed from the front and back of the disc device respectively. The disc device  10  has, within a box-shaped case, a processing mechanism for executing recording or reproduction processing on an optical disc. The details of the processing mechanism will be described later with reference to  FIG. 3 . The box-shaped case  12  is formed by engaging a base plate  12 B with a metallic upper case  12 D formed by a top plate  12 C and a side plate  12 A that are integrally molded. The processing mechanism is provided within the case. 
         [0026]    The disc device  10  includes a front panel  14  that covers an open end in the front face of the case  12  and a tray  16  for inserting an optical disc into the disc device or ejecting a disc from the disc device. A SATA connector  50  that functions as an external I/F connector is exposed on the back face of the disc device. Reference numerals  50 A and  50 B represent a power supply terminal and a signal terminal in the SATA connector  50  respectively. After the disc device is inserted into the main body of a personal computer, the SATA connector  50  is connected to a power supply terminal and signal terminal in the personal computer. 
         [0027]      FIG. 3  is an exploded perspective view showing the main component assemblies of the disc device. The main components are assembled in the disc device in the positional relationship shown in  FIG. 3 . Reference numeral  11  represents a component called a carrier mechanism, in which an optical pickup  24  and a spindle motor  22 A for rotating a disc are fixed to a chassis  100 . 
         [0028]    The chassis  100  is supported by a case  102  of a loading mechanism  13 , which will be described later. A main printed circuit board  18  and a sub-printed circuit board  19  are also fixed to the case  102 . The processing mechanism of the invention is a collective term for the parts including the carrier mechanism  11 , the loading mechanism  13 , the main printed circuit board  18 , and the sub-printed circuit board  19 . 
         [0029]    Each of the left and right ends of the front panel  14  is provided with a small piece  32  that protrudes towards the carrier mechanism  11 . The tip of the small piece  32  has a nail that engages, inside the side plate  12 A, with a hole  35  provided on the front panel side in the side plate  12 A. 
         [0030]    The tray  16  moves, via an opening  34  in the front panel  14 , towards/away from the disc device in the direction of arrow A in  FIG. 3 . Reference numeral  13  represents the loading mechanism  13  that moves the tray  16  towards/away from the disc device. The loading mechanism  13  includes a pulley  20 C the rotation of a rotatable shaft in a loading motor  20 A is transmitted to by a belt  20 B, and a gear  20 D rotated by the pulley  20 C. The loading motor  20 A is a driving source for moving the tray towards/away from the disc device. The loading mechanism  13  also has a mechanism for swinging the front panel  14  side of the carrier mechanism  11  up and down with respect to its base end, and fixing/releasing an optical disc to/from a turntable  22 . Driving voltage is supplied to the loading motor  20 A and the mechanism for swinging the carrier mechanism  11  from the main printed circuit board  18  via the sub-printed circuit board  19 , which will be described later. 
         [0031]    The tray  16  includes a plate  16 B a disc is put on, and a front bezel panel  16 A that covers the opening  34  in the front panel  14 . Reference numeral  17  represents an opening formed in the plate  16 B. Reference numeral  22  represents the turntable in the carrier mechanism  11  that supports an optical disc to enable rotation of the optical disc. A disc is chucked between the turntable  22  and a disc clamp provided on the back face of the top plate  12 C. 
         [0032]    After a disc is put on the plate  16 B and the tray  16  is inserted into the device, the carrier mechanism  11  moves the turntable  22  upwards beyond the opening  17 , lifts the disc put on the tray  16 , and fixes the disc to the turntable  22  with the clamp on the back face of the top plate  12 C to enable rotation of the disc. The turntable  22  is rotated by the spindle motor  22 A in the carrier mechanism  11 . Reference numeral  24  represents an optical pickup unit (optical unit), which moves in the direction of arrow B in  FIG. 3  when driven by the carrier motor  25 . As described above, the carrier mechanism  11  is configured to support, with the chassis  100 , the spindle motor  22 A, the optical pickup unit  24 , and the mechanism for carrying the optical pickup unit towards or away from the center of the optical disc. The name of the “carrier mechanism” comes from the optical pickup carrying function. The optical pickup unit  24  is supported by a main shaft  104  and sub-shaft  106  and moved forward/backward along those shafts  104  and  106  by a lead screw provided on the shaft of the carrier motor  25 . 
         [0033]    A photosensor  27  for enabling a “write scribe” function is attached near the spindle motor  22 A. The write scribe function is a function for coloring and drawing patterns on a specially-treated label side of an optical disc by projecting laser light from the optical pickup to the label side. The photosensor  27  is designed to detect the patterns that are vertical stripes drawn on the label side of the optical disc and detect the position of the optical pickup in the direction of rotation of the optical disc&#39;s label side. 
         [0034]    The total area of the recording side (the lower surface seen from  FIG. 3 ) of the disc can be scanned with light beams emitted from the optical pickup  24  by controlling the turntable  22 &#39;s rotation and the optical pickup  24 &#39;s movement towards/away from the center of the disc, and this enables recording or reproduction of information. 
         [0035]    The main printed circuit board  18  includes various control ICs for controlling a driving unit for the carrier mechanism  11  and the loading mechanism  13  to achieve recording of information to an optical disc, reproduction of information, and the write scribe function. The main printed circuit board  18  is connected to the sub-printed circuit board  19 . The sub-printed circuit board is provided on the side of the front end of the optical disc device, where the front panel  14  is, relative to the main printed circuit board  18 . The sub-printed circuit board  19  is designed to control the loading mechanism  13 , e.g., controls driving of the loading motor  20 A. The sub-printed circuit board  19  has a mechanical detection switch  1   9 B for detecting the open/closed tray position to ascertain the tray  16 &#39;s open/closed status, an optical disc ejection switch  108 , and a LED  110  for indicating the disc device operation status. 
         [0036]    A connector  54  for the sub-printed circuit board  19  is provided on the upper surface  18 A of the main printed circuit board  18  at the front right side in  FIG. 3 . A connector  19 A in the sub-printed circuit board  19  and the connector  54  are connected with a flexible flat cable  52  for transmission of a control signal. 
         [0037]    Examples of installation of various control ICs in the main printed circuit board  18  will be described. Reference numerals  18 A and  18 B represent the upper and lower surfaces of the main printed circuit board  18  respectively As shown in  FIG. 3 , the SATA connector  50  is fixed to the back end of the upper surface  18 A. The SATA connector  50  functions as an external I/F connector. A single SATA connector has the power supply terminal  50 A and signal terminal  50 B, each being designed to be connected to connectors from the personal computer the disc device is inserted into. 
         [0038]    The front end of the main printed circuit board  18  has a rectangular cut portion  18 C in the middle in its width direction. A pickup connector  24 A (see  FIGS. 4 and 5 ) is provided near the cut portion  18 C in the lower surface  18 B and is connected to a flexible flat cable (FPC cable or FFC cable)  56  that can cope with the above described movement of the optical pickup unit. 
         [0039]    The flexible flat cable  56  can be freely bent. When the optical pickup unit  24  moves towards or away from the center of the optical disc, the flexible flat cable  56  bends according to the change in the relative distance between the main printed circuit board  18  and the optical pickup unit  24 . 
         [0040]      FIGS. 4 and 5  are perspective views showing the lower surface  18 B in the disc device viewed from an oblique lower viewpoint with the bottom plate  12 B of the case  12  omitted. As shown in  FIG. 4 , the SATA connector  50  fixed to the upper surface  18 A of the main printed circuit board  18  is exposed at the back end of the optical disc device. 
         [0041]      FIG. 6  is a bottom view of the disc device  10  illustrating the lower surface  18 B of the main printed circuit board  18  with the bottom plate  12 B omitted.  FIG. 7  shows the lower surface  18 B of the main printed circuit board  18  with an outline of a connection pattern between the elements added. 
         [0042]    A DSP  60  in the middle of the board, a driver IC  62 , a flash memory  64 , an AFE  66 , a regulator unit  68 , a carrier motor connector  70 , a spindle connector  72 , and a photosensor connector  74  are installed on the lower surface  18 B of the main printed circuit board  18 . As has been already described, the SATA connector  50  and the connector  54  for connection with the sub-printed circuit board  19  are installed on the upper surface  18 A of the main printed circuit board  18 . 
         [0043]    The DSP (digital signal processor)  60  is a basic IC connected to, and for controlling, the other control ICs (described later), and executing main processing for disc recording or reproduction. The DSP  60  uses a memory area in the flash memory  64  to control the carrier mechanism  11  and the loading mechanism  13  and execute main processing such as signal processing accompanying disc recording or reproduction. The DSP  60  is larger than the other ICs, and is put in the middle of the main printed circuit board  18  to best control the other ICs. 
         [0044]    The driver IC  62  is designed to supply driving voltage for drive control to the loading motor  20 A that is a driving system for the loading mechanism  13 , the spindle motor  22 A that is a driving system for the carrier mechanism  11 , and the mechanism motors such as the carrier motor  25  for the optical pickup unit  24 . 
         [0045]    The flash memory  64  is designed to temporarily store information to be recorded to the disc and information read from the disc. The AFE  66  executes processing for shaping a signal detected from a disc to convert it into a digital signal. The regulator unit  68  is designed to adjust input voltage to supply optimum voltage to each IC. The carrier motor connector  70  is connected, via the flexible flat cable  76  (see  FIG. 3 ), to the carrier motor  25  for the optical pickup. 
         [0046]    As shown in  FIG. 6 , the spindle motor connector  72  in the lower surface  18 B of the main printed circuit board  18  is connected to the spindle motor  22 A via the flexible flat cable  78 . Similarly, the photosensor connector  74  is connected to the photosensor  27  via the flexible flat cable  80 . The flexible flat cables  78  and  80  are bent at right angles in the middle and extend widthwise towards the center of the main printed circuit board  18  The flexible flat cable  78  is connected to the spindle motor  22 A, and the flexible flat cable  80  is connected to the photosensor  27  near the spindle motor  22 A. 
         [0047]    Since all electric components installed in the above described carrier mechanism  11  and loading mechanism  13  are controlled by the main printed circuit board  18 , the main printed circuit board  18  has the control ICs for controlling those electric components and connectors for connection with them. An example of installation of the control ICs, etc., on the main printed circuit board  18  will be described below according to  FIG. 7 . As has been already described, the DSP  60  is located almost at the center of the lower surface of the main printed circuit board  18 . Next, the voltage regulator  68  is installed to one side of the DSP  60 . In the example shown in  FIG. 7 , the voltage regulator  68  is installed on the right with respect to a central line CL of the main printed circuit board  18 . 
         [0048]    The flash memory  64  has many terminals to be connected to the DSP  60 , and the wiring pattern between the flash memory  64  and the DSP  60  becomes dense. Therefore, the flash memory  64  is installed on the side opposite the side where the voltage regulator  68  is installed with respect to the DSP  60 . Since the wiring pattern formed between the AFE  66  and the DSP  60  is also dense, the AFE  66  is installed on the side opposite the flash memory  64  with respect to the DSP  60 , i.e., on the same side as the regulator  68 . However, the AFE  66  is located closer to the front end of the main printed circuit board  18  than the regulator  68  to avoid the regulator  68 . Next, the driver IC  62  is installed on the side where the flash memory  64  is installed, closer to the front end of the lower surface  18 B of the main printed circuit board  18  to avoid the flash memory  64 . The connector  24 A for the optical pickup unit  24 , which has many terminals, is installed close to the front end of the lower surface  18 B of the main printed circuit board  18 , forming an almost right angle with the central line CL. The lengthwise direction of the connector  24 A is parallel to the widthwise direction of the main printed circuit board  18 . The central line CL is a central line of the main printed circuit board  18  relative to its width. 
         [0049]    The carrier motor connector  70  is provided between the flash memory  64  and the left end of the lower surface  18 B of the main printed circuit board  18 . The SATA connector  50  is installed on the upper surface  18 A of the main printed circuit board  18  at the position shown in  FIG. 7 . The SATA connector  50  is provided at the back end of the upper surface  18 A of the main printed circuit board  18 , to the side of the driver IC  62  with respect to the central line CL. The power supply terminal  50 A in the SATA connector  50  is located to the side of the driver IC  64 , and the signal terminal  50 B is located at a position facing the DSP  60  in line widthwise with the power supply terminal  50 A on the main printed circuit board  18 . 
         [0050]    By installing the SATA connector  50  at the above described position in the main printed circuit board  18 , the pattern length of the power supply pattern  120  formed between the power supply terminal  50 A and the driver IC  62  can be further shortened. Since the driver IC in particular supplies driving voltage to the driving systems, noise may occur if the pattern length between the driver IC  62  and the power supply terminal  50 A is long. 
         [0051]    Meanwhile, since the SATA connector  50  is located on the driver IC side, the pattern length of the pattern  122  formed between the power supply terminal  50 A in the SATA connector  50  and the voltage regulator  68  may become long. However, since voltage supply from the voltage regulator  68  is directed to the control ICs, the problem concerning noise is less significant compared to the driver IC. Accordingly, as shown in  FIG. 7 , the SATA connector  50  is installed on the driver IC  62  side in the upper surface  18 A of the main printed circuit board  18 . 
         [0052]    The pattern length of the pattern formed between the signal terminal  50 B in the SATA connector  50  and the DSP  60  is preferably as short as possible in order to reduce noise. To this end, the pattern  82  from the signal terminal  50 B to the DSP  60  could be shortened to its shortest length by positioning the DSP  60  at a position slightly closer to the driver IC  62  side with respect to the central line CL of the main printed circuit board  18 . In other words, the pattern  82  can be formed as a straight line along the central line CL. According to the SATA standard, the pattern impedance between the SATA signal terminal in the SATA connector and the DSP terminal has to be maintained at 100Ω±15%. The SATA standard can be complied with by forming the shortest pattern length from the SATA signal terminal to the DSP terminal as described above. 
         [0053]    The spindle motor connector  72  and the photosensor connector  74  are installed close to the driver IC  62  to face the driver IC  62  near the driver IC  62  at the front end side of the lower surface  18 B of the main printed circuit board  18 . A power supply pattern  124  is formed and connected from the power supply terminal  50 A to the photosensor connector  74 , and a power supply pattern  126  is formed and connected from the spindle motor connector  72  to the driver IC  62 . 
         [0054]    The spindle motor connector  72  is connected to an end of the flexible flat cable  78  (see  FIG. 6 ). The other end of the flexible flat cable  78  The other end of is connected to the spindle motor  22 A. The photosensor connector  74  is detachable and connected to an end of the flexible flat cable  80  (see  FIG. 6 ). The flexible flat cable  80  is connected to the photosensor  27 . 
         [0055]    By arranging the spindle motor connector  72  and the photosensor connector  74  near the driver IC  62  the patterns from the driver IC  62  to those connectors can be shortened, thereby reducing noise occurrence. 
         [0056]    Also referring to  FIG. 3 , the sub-printed circuit board connector  54  is installed on the upper surface  18 A of the main printed circuit board  18 . A voltage supply pattern is formed from the driver IC  62  to the sub-printed circuit board connector  54  using the lower surface  18 B of the main printed circuit board  18 . The sub-printed circuit board connector  54  is located facing the spindle motor connector  72  and the photosensor connecter  74  interposing the main printed circuit board  18 . As can be understood from  FIG. 7 , the sub-printed circuit board connector  54  is located at a position corresponding to an approximately intermediate point between the spindle motor connector  72  and the photosensor connector  74 . It is preferable to arrange the connectors in the board to concentrate them closer to the driver IC  62  as above, and to this end, both faces of the board may be efficiently utilized. 
         [0057]    The spindle motor connector  72  and the photosensor connector  74  are provided on the lower surface  18 B of the main printed circuit board  18  and the loading connector  54  for optical discs is provided on the upper surface  18 A of the main printed circuit board  18 , for the following reason. As described above, the carrier mechanism  11  moves, according to the loading mechanism  13  loading an optical disc, up and down in the direction along the height of the disc device. As can be understood from  FIG. 5 , the flat cables  78  and  80  respectively connected to the spindle motor connector  72  and the photosensor connector  74  also move up and down according to the carrier mechanism  11 &#39;s movement. At that moment, the flat cable  52  (see also  FIG. 3 ) that connects the sub-printed circuit board  19  to the main printed circuit board  18  is located above the flat cables  78  and  80 . Accordingly, the flat cables  78  and  80  can be prevented from accidentally touching the flat cable  52  by setting the length of the flat cables  78  and  80  so that the carrier mechanism  11  chucks an optical disc to the spindle motor  22 A, thereby preventing unintended degradation of the flat cables or connectors. 
         [0058]    All arrangements for the control ICs and connectors in the main printed circuit board explained in the above embodiment are just examples, and may be changed as appropriate. 
         [0059]    While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised that do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.