Patent ID: 12260885

DETAILED DESCRIPTION

According to one embodiment, a disk device includes a first conversion device, a second conversion device, an optical waveguide, a first component, and a second component. The first conversion device emits light corresponding to an electric signal. The second conversion device generates an electric signal corresponding to incident light. The optical waveguide includes a first end joined to the first conversion device, and a second end joined to the second conversion device, the optical waveguide that transmits light emitted from the first conversion device to the second conversion device. The first component is electrically connected to the first conversion device. The second component is electrically connected to the second conversion device, the second component that communicates with the first component through the first conversion device, the optical waveguide, and the second conversion device.

First Embodiment

Hereinbelow, a first embodiment will be described with reference toFIGS.1to6. Note that, in the present specification, components according to embodiments and descriptions of the components may be described in a plurality of expressions. The components and the descriptions thereof are illustrative only and are not limited by the expressions in the present specification. The components can also be identified by different names from those in the present specification. Also, the components can also be described by different expressions from those in the present specification.

FIG.1is an exemplary perspective view illustrating a hard disk drive (HDD)10according to the first embodiment. The HDD10is incorporated in an electronic device1, for example, and constitutes a part of the electronic device1. In other words, the electronic device1includes the HDD10.

The HDD10is an example of a disk device, and may also be referred to as a storage device or a magnetic disk device. Examples of the electronic device1include various computers such as a personal computer, a supercomputer, a server, a television receiver, and a game machine, and devices such as an external hard drive (external HDD).

FIG.2is an exemplary perspective view illustrating the HDD10according to the first embodiment in an exploded manner. As illustrated inFIG.2, the HDD10includes a chassis11, a plurality of magnetic disks12, a spindle motor13, a clamp spring14, a plurality of magnetic heads15, an actuator assembly16, a voice coil motor (VCM)17, a ramp loading mechanism18, and a flexible printed circuit board (FPC)19. The magnetic disk12is an example of a recording medium. The actuator assembly16is an example of an actuator. The FPC19is an example of a first flexible printed circuit board.

The chassis11includes a base21, an inner cover22, and an outer cover23. The base21is a bottomed container and includes a bottom wall25and sidewalls26. The bottom wall25is an example of a first wall. The bottom wall25has substantially a rectangular (quadrangular) plate shape. The sidewalls26protrude from the outer edge of the bottom wall25. The bottom wall25and the sidewalls26are integrally made of, for example, a metal material such as an aluminum alloy.

The inner cover22and the outer cover23are made of, for example, a metal material such as an aluminum alloy. The inner cover22is attached to the end of the sidewalls26with, for example, screws. The outer cover23covers the inner cover22and is airtightly secured to the end of the sidewall26by, for example, welding.

The chassis11has an internal space S. The internal space S is formed (defined or sectioned) by the base21and the inner cover22. According to the present embodiment the internal space S of the chassis11is airtightly sealed to prevent or reduce a flow of gas between the internal space S and the outside of the chassis11.

The chassis11accommodates various components including the magnetic disks12, the spindle motor13, the clamp spring14, the magnetic heads15, the actuator assembly16, the voice coil motor17, the ramp loading mechanism18, and the FPC19in the internal space S. The internal space S and the various components housed in the internal space S are covered with the bottom wall25and the sidewalls26of the base21and the inner cover22.

The inner cover22is provided with a vent22a. The outer cover23is provided with a vent23a. After the components are attached to the inside of the base21, and the inner cover22and the outer cover23are attached to the base21, the air is removed from the internal space S through the vents22aand23a. Further, the internal space S is filled with a gas different from the air.

Examples of the gas with which the internal space S is filled include a low density gas lower in density than the air and an inert gas having low reactivity. For example, the internal space S is filled with helium. The internal space S may be filled with another fluid. Alternatively, the internal space S may be maintained in a vacuum state, at low pressure close to the vacuum state, or at negative pressure lower than atmospheric pressure.

The vent23aof the outer cover23is closed by a seal28. The seal28is made of, for example, metal or synthetic resin. The seal28airtightly seals the vent23aand prevents the gas from leaking from the internal space S through the vent23a.

Each magnetic disk12is, for example, a disk including a magnetic recording layer on at least one of the upper surface and the lower surface thereof. The diameter of the magnetic disk12is, for example, 3.5 inches, but is not limited to this example.

The spindle motor13supports and rotates the magnetic disks12stacked on each other with spacing. The clamp spring14holds the magnetic disks12on the hub of the spindle motor13.

The magnetic heads15record and reproduce information on and from the recording layers of the magnetic disks12. In other words, the magnetic heads15read and write information from and to the magnetic disks12. The magnetic heads15are supported by the actuator assembly16.

The actuator assembly16is rotatably supported by a support shaft31spaced away from the magnetic disks12. The VCM17rotates the actuator assembly16to place the actuator assembly16at a desired position. When the magnetic head15moves to the outermost periphery of the magnetic disk12due to rotation of the actuator assembly16by means of the VCM17, the ramp loading mechanism18holds the magnetic head15at an unloading position away from the magnetic disk12.

The actuator assembly16includes an actuator block35, a plurality of arms36, and a plurality of head suspension assemblies37. The head suspension assembly37can also be referred to as a head gimbal assembly (HGA).

The actuator block35is rotatably supported by the support shaft31via a bearing, for example. The arms36protrude from the actuator block35in a direction substantially orthogonal to the support shaft31. Note that the actuator assembly16may be divided, and the arms36may protrude from the actuator blocks35, respectively.

The arms36are spaced from each other in a direction in which the support shaft31extends. Each of the arms36has a plate shape that can enter a gap between the adjacent magnetic disks12. The arms36extend substantially in parallel.

The actuator block35and the arms36are integrally made of, for example, aluminum. Note that the material of the actuator block35and the arms36is not limited to this example.

The actuator block35is provided with a protrusion on which a voice coil of the VCM17is placed. The VCM17includes a pair of yokes, a voice coil placed between the yokes, and a magnet set on the yoke.

The head suspension assemblies37are attached to the tip ends of the corresponding arms36and protrude from the arms36. As a result, the head suspension assemblies37are spaced from each other in the direction in which the support shaft31extends.

Each head suspension assembly37includes a base plate41, a load beam42, and a flexure43. The magnetic heads15are attached to the corresponding head suspension assemblies37.

The base plate41and the load beam42are made of, for example, stainless steel. Note that the material of the base plate41and the load beam42is not limited to this example. The base plate41is attached to the tip end of the arm36. The load beam42has a plate shape thinner in thickness than the base plate41. The load beam42is attached to the tip end of the base plate41and protrudes from the base plate41.

The flexure43has an elongated strip shape. Note that the shape of the flexure43is not limited to this example. The flexure43is a layered plate including a metal plate (underlayer) made of stainless steel or the like, an insulating layer formed on the metal plate, a conductive layer formed on the insulating layer and constituting a plurality of interconnections (interconnect pattern), and a protective layer (insulating layer) covering the conductive layer.

The flexure43includes, at one end, a displaceable gimbal (elastic support) located above the load beam42. The magnetic head15is mounted on the gimbal. The other end of the flexure43is connected to the FPC19. As a result, the FPC19is electrically connected to the magnetic head15via the interconnections of the flexure43.

The VCM17rotates the actuator assembly16, thereby moving the magnetic head15mounted on the gimbal of the actuator assembly16around the support shaft31. That is, the actuator assembly16and the VCM17move the magnetic head15.

FIG.3is an exemplary perspective view illustrating the HDD10according to the first embodiment in an exploded manner from a different direction from that inFIG.2. As illustrated inFIG.3, the HDD10further includes a printed circuit board (PCB)50. The PCB50is placed outside the bottom wall25of the base21.

The PCB50includes a printed wiring board (PWB)51and a plurality of components mounted on the PWB51. Examples of the PWB51includes a rigid board such as a glass epoxy board, a multilayer board, and a build-up board. The PWB51is attached to the outside of the bottom wall25. In other words, the PWB51is attached to the outside of the chassis11. The PWB51is attached to the bottom wall25by, for example, screwing or snap-fitting with hooks.

FIG.4is an exemplary block diagram illustrating a configuration of the HDD10according to the first embodiment. As illustrated inFIG.4, the PCB50further includes an interface (I/F) connector52, a controller53, a servo controller54, and a relay connector55. The controller53is an example of a first component or a second component.

The I/F connector52, the controller53, the servo controller54, and the relay connector55are mounted on the PWB51. In addition, various memories such as a RAM, a ROM, and a buffer memory, a coil, a capacitor, and other electronic components are further mounted on the PWB51.

The I/F connector52is a connector conforming to an interface standard such as Serial ATA, and is connected to an I/F connector1aof the electronic device1. Accordingly, the PWB51is electrically connected to a processor1bof the electronic device1. The processor1bis, for example, a central processing unit (CPU), and controls the entire electronic device1.

The HDD10is supplied with electric power and receives access commands (control signals) such as a write command and a read command and various kinds of data from the electronic device1through the I/F connector52. The HDD10also transmits various kinds of data to the electronic device1through the I/F connector52. In this manner, the HDD10performs wired communications with the electronic device1through the I/F connector52. Note that the HDD10may be able to perform wireless communications with the electronic device1.

The controller53includes, for example, a read/write channel (RWC), a hard disk controller (HDC), and a processor. The controller53may be one component, or may be a collective term for the RWC, the HDC, and the processor, which are independent from each other. The controller53performs control of the HDD10as a whole.

The servo controller54drives the spindle motor13and the VCM17. The relay connector55is used, for example, for communicating with and supplying electric power to various components arranged in the internal space S.

As illustrated inFIG.3, the HDD10further includes a relay FPC59. The spindle motor13is electrically connected to the servo controller54of the PCB50through the relay FPC59. The spindle motor13receives a drive signal from the servo controller54and is supplied with electric power from the PCB50via the relay FPC59.

The relay FPC59is located in the vicinity of the spindle motor13, and extends from the internal space S to the outside of the chassis11through a hole penetrating the bottom wall25of the base21. The hole is sealed with, for example, synthetic resin.

The FPC19illustrated inFIG.2is elastically deformable and includes, for example, a conductive layer, an insulating layer, and an adhesive layer stacked on one another. The conductive layer is made of, for example, conductive metal such as copper. The insulating layer is made of, for example, insulating synthetic resin such as polyimide.

On the FPC19, a preamplifier61and a relay connector62are mounted. The preamplifier61and the relay connector62are located in the internal space S of the chassis11. The preamplifier61is an example of the first component or the second component. The preamplifier61is also an example of an amplifier.

The preamplifier61is electrically connected to the magnetic head15through the flexure43. Note that the preamplifier61may be mounted on the flexure43. The preamplifier61amplifies and outputs an input electric signal, for example.

The relay connector62is supplied with electric power via the relay connector55of the PWB51. In the present embodiment, the magnetic head15and the preamplifier61operate by means of electric power supplied via the relay connector62.

The HDD10further includes a relay FPC70and two relay connectors71and72. The relay FPC70is an example of a first flexible printed circuit board or a second flexible printed circuit board. The relay connector71is an example of a first connector. The relay connector72is an example of a second connector.

As with the FPC19, the relay FPC70is elastically deformable and includes, for example, a conductive layer, an insulating layer, and an adhesive layer stacked on one another. Note that the relay FPC70may be structured differently from the FPC19.

The relay FPC70is attached to the bottom wall25of the chassis11. The relay connectors71and72are disposed on the relay FPC70. The relay connector71is located outside the chassis11. The relay connector71is connected to the relay connector55of the PCB50. The relay connector72is located in the internal space S of the chassis11. The relay connector72is connected to the relay connector62of the FPC19.

The processor1bof the electronic device1and the controller53of the PCB50outside the chassis11communicate (transmit and receive data from and to) with the magnetic head15and the preamplifier61inside the chassis11via the relay connectors55,62,71, and72and the relay FPC70. Note that in the present embodiment the term “communication” refers to transmission and reception of information between independent elements. Thus, the processor1b, the controller53, the magnetic head15, and the preamplifier61do not perform various kinds of control such as signal conversion for communication. The processor1b, the controller53, the magnetic head15, and the preamplifier61have a relationship that when one outputs a signal, the other receives a signal corresponding to the signal.

Hereinbelow, the structure of the HDD10according to the present embodiment will be described in detail.FIG.5is an exemplary cross-sectional view schematically illustrating a part of the HDD10according to the first embodiment along line F5-F5inFIG.3. As illustrated inFIG.5, the bottom wall25of the base21includes an inner surface25aand an outer surface25b.

The inner surface25afaces the inside of the chassis11. The inner surface25aforms (defines or sections) a part of the internal space S of the chassis11. In other words, the inner surface25afaces the internal space S. The inner surface25afaces various components arranged in the internal space S, such as the FPC19.

The outer surface25bis opposite the inner surface25aand faces the outside of the chassis11. The outer surface25bfaces the PCB50with a space. Note that the outer surface25band the PCB50may be in contact with each other.

The bottom wall25is provided with a slit25c. The slit25cis an example of a first through hole. The slit25cpenetrates the bottom wall25and opens to the inner surface25aand the outer surface25b. In other words, the slit25callows the internal space S and the outside of the chassis11to be in communication with each other.

FIG.6is an exemplary plan view schematically illustrating the bottom wall25and the relay FPC70according to the first embodiment. As illustrated inFIG.6, the slit25cis, for example, a substantially rectangular (quadrangular) hole. Note that the shape of the slit25cis not limited to this example.

As illustrated inFIG.2, the FPC19includes a first portion19a, a second portion19b, and a third portion19c. The first portion19ais located at one end of the FPC19. The second portion19bis located at the other end of the FPC19.

The first portion19ais attached to the actuator block35of the actuator assembly16with, for example, screws. The first portion19ais electrically connected to the flexure43.

The second portion19bis attached to the bottom wall25of the chassis11with, for example, screws. As illustrated inFIG.5, the second portion19bof the FPC19extends approximately along the inner surface25aof the bottom wall25.

As illustrated inFIG.2, the third portion19cis located between the first portion19aand the second portion19b. The third portion19chas substantially a strip shape and has flexibility. For example, along with the rotation of the actuator assembly16, the first portion19aand the second portion19bmove relative to each other, and the third portion19cbends to absorb their relative movement.

As illustrated inFIG.5, the FPC19further includes a front surface19d. The front surface19dis one surface of the FPC19. The first portion19a, the second portion19b, and the third portion19cof the FPC19all partially have the front surface19d.

In the second portion19b, the front surface19dfaces the inner surface25aof the bottom wall25. Note that the front surface19dmay partially be in contact with the inner surface25aof the bottom wall25. The relay connector62protrudes from the front surface19din the second portion19b.

The PWB51includes an inner surface51a. The inner surface51afaces the outer surface25bof the bottom wall25with a space. The inner surface51acovers the slit25cof the bottom wall25. The inner surface51afurther faces the front surface19dof the FPC19through the slit25c. The relay connector55protrudes from the inner surface51a.

The relay FPC70includes an external portion75, an internal portion76, and an intermediate portion77. Each of the external portion75, the internal portion76, and the intermediate portion77is a part of the relay FPC70. The external portion75, the internal portion76, and the intermediate portion77are arranged in a direction in which the relay FPC70extends.

The external portion75forms one end of the relay FPC70, for example. The external portion75is located outside the chassis11. The external portion75extends along the outer surface25bof the bottom wall25, for example. Note that the external portion75is not limited to this example.

The internal portion76forms the other end of the relay FPC70, for example. The internal portion76is located in the internal space S of the chassis11. The internal portion76extends along the inner surface25aof the bottom wall25, for example. Note that the internal portion76is not limited to this example.

The intermediate portion77extends or connects between the external portion75and the internal portion76. The intermediate portion77passes through the slit25c. The external portion75extends from an end of the intermediate portion77located outside the chassis11. The internal portion76extends from an end of the intermediate portion77located inside the chassis11. In this manner, the relay FPC70extends across the inside and the outside of the chassis11.

The external portion75includes an inner surface75aand an outer surface75b. The inner surface75afaces the outer surface25bof the chassis11. The outer surface75bis opposite the inner surface75a. The outer surface75bfaces the inner surface51aof the PWB51with a space. The relay connector71protrudes from the outer surface75bof the external portion75.

The internal portion76includes an inner surface76aand an outer surface76b. The inner surface76afaces the inner surface25aof the chassis11. The outer surface76bis opposite the inner surface76a. The outer surface76bfaces the front surface19dof the FPC19with a space. The relay connector72protrudes from the outer surface76bof the internal portion76.

The relay FPC70is secured to the bottom wall25with adhesive78. The adhesive78secures the inner surface75aof the external portion75to the outer surface25bof the bottom wall25, and secures the inner surface76aof the internal portion76to the inner surface25aof the bottom wall25. Further, the adhesive78fills the gap between the intermediate portion77and the inner surface of the slit25c. The adhesive78contains, for example, a metal filler to be able to prevent gas from passing through the adhesive78. Thereby, the adhesive78works to airtightly seal the slit25c.

The HDD10further includes a communication unit80. The communication unit80performs optical communications between two components. In the present embodiment, the communication unit80performs optical communications between the controller53outside the chassis11and the preamplifier61inside the chassis11. The communication unit80includes two conversion devices81and82and an optical waveguide83. The communication unit80may include a plurality of optical waveguides83. Each of the conversion devices81and82is an example of a first conversion device or a second conversion device.

Each of the conversion devices81and82includes, for example, a light source, a light receiving element, and a conversion IC. In each of the conversion devices81and82according to the present embodiment, the light source, the light receiving element, and the conversion IC are integrally formed. Note that the light source, the light receiving element, and the conversion IC of each of the conversion devices81and82may be mutually independent components.

The light source of each of the conversion devices81and82is, for example, a laser diode (LD) or a light emitting diode (LED). The light receiving element is, for example, a photodiode or a phototransistor. For example, the conversion IC causes the light source to emit light corresponding to an input electric signal, and outputs an electric signal corresponding to light incident on the light receiving element. The conversion IC may perform multiplexing. That is, each of the conversion devices81and82emits light corresponding to an electric signal and generates an electric signal corresponding to incident light. Note that one of the conversion devices81and82may include a light source to emit light, and the other may include a light receiving element to generate an electric signal.

The conversion device81is mounted on the PWB51. The conversion device81is electrically connected to the controller53through an interconnection on the PWB51. Note that other components may be interposed in the interconnection between the conversion device81and the controller53.

The conversion device82is mounted on the FPC19. The conversion device82is electrically connected to the preamplifier61through an interconnection on the FPC19. Note that other components may be interposed in the interconnections between the conversion device82and the preamplifier61.

The optical waveguide83includes, for example, a transparent core layer and a cladding layer surrounding the core layer. The refractive index of the core layer and the refractive index of the cladding layer are different from each other. Thus, the optical waveguide83totally reflects and transmits light incident on the core layer at the interface between the core layer and the cladding layer. Note that the optical waveguide83is not limited to this example.

The optical waveguide83is in the form of a sheet or a rod and placed inside a board such as the FPC19and the PWB51. Note that the optical waveguide83is not limited to this example. The optical waveguide83of a rod form can be referred to as an optical fiber.

The optical waveguide83includes two ends83aand83b. Each of the ends83aand83bis an example of a first end or a second end. One end83ais joined to the conversion device81. The other end83bis joined to the conversion device82.

In the present embodiment, the term “join” refers to attaching the two components to each other for fixation. For example, the ends83aand83bare directly attached to the conversion devices81and82or indirectly attached thereto via other components. The ends83aand83band the conversion devices81and82are attached to each other for fixation, and thereby restricted from relatively moving.

For example, in the optical waveguide83light is incident from one of the ends83aand83band exits from the other of the ends83aand83b. That is, the optical waveguide83serves to transmit light emitted from one of the conversion devices81and82to the other.

The single optical waveguide83or a plurality of optical waveguides included in the optical waveguide83may connect between the conversion device81and the conversion device82. In the optical waveguide83including a plurality of optical waveguides, the optical waveguides are joined to each other with, for example, a connector. As a result, the optical waveguide83can transmit light between the ends83aand83bas a whole.

In the present embodiment, the optical waveguide83includes a first optical waveguide91, a second optical waveguide92, a third optical waveguide93, a fourth optical waveguide94, a fifth optical waveguide95, a sixth optical waveguide96, and a seventh optical waveguide97. Note that the optical waveguide83is not limited to this example.

The first optical waveguide91is included in the PWB51, for example. Note that the first optical waveguide91may be an independent component from the PWB51. The first optical waveguide91includes the end83aof the optical waveguide83. Thus, the first optical waveguide91is joined to the conversion device81. Further, the first optical waveguide91is joined to the relay connector55of the PCB50.

For example, the first optical waveguide91is included in one of the layers of the PWB51. The first optical waveguide91is covered with an insulating layer forming the inner surface51aof the PWB51except for both the ends thereof, for example. The end83aincluded in the first optical waveguide91is exposed by an opening in the insulating layer and faces the light source and the light receiving element of the conversion device81. The conversion device81is secured to the PWB51by soldering, for example. Thus, the end83ais indirectly secured to the conversion device81via the PWB51and the solder. The end83ais not limited to this example, and may be directly joined to the conversion device81, for example.

The second optical waveguide92is included in the FPC19, for example. Note that the second optical waveguide92may be an independent component from the FPC19. The second optical waveguide92has flexibility. Thus, the second optical waveguide92can bend as the FPC19bends.

The second optical waveguide92includes the end83bof the optical waveguide83. That is, the second optical waveguide92is joined to the conversion device82. Further, the second optical waveguide92is joined to the relay connector62mounted on the FPC19.

For example, the second optical waveguide92is included in one of the layers of the FPC19. The second optical waveguide92is covered with an insulating layer forming the front surface19dof the FPC19except for both the ends thereof, for example. The end83bincluded in the second optical waveguide92is exposed by an opening in the insulating layer and faces the light source and the light receiving element of the conversion device82. The conversion device82is secured to the FPC19by soldering, for example. Thus, the end83bis indirectly secured to the conversion device82via the FPC19and the solder. The end83bis not limited to this example, and may be directly joined to the conversion device82, for example.

The third optical waveguide93is included in the relay FPC70. For example, the third optical waveguide93is included in one of the layers of the relay FPC70. The third optical waveguide93includes an outer terminal93a, an inner terminal93b, and an extension93c.

The outer terminal93ais located on the outer surface75bof the external portion75of the relay FPC70. The inner terminal93bis located on the outer surface76bof the internal portion76. For example, the outer terminal93aand the inner terminal93bare exposed by openings in the insulating layer of the relay FPC70forming the outer surfaces75band76b. The extension93cextends across the external portion75, the internal portion76, and the intermediate portion77, and connects the outer terminal93aand the inner terminal93b.

The first to third optical waveguides91to93are formed, for example, by forming a core layer and a cladding layer on a desired part of a layer of a board by etching. As a result, the first to third optical waveguides91to93can be formed in the same or similar process as an interconnect pattern on a general PWB or a general FPC. Note that the first to third optical waveguides91to93may be formed in other methods.

The fourth optical waveguide94is included in the relay connector55. The fourth optical waveguide94is attached to the relay connector55which is in the form of a plug or a socket made of synthetic resin or another material, for example.

One end of the fourth optical waveguide94is joined to the first optical waveguide91. For example, the relay connector55is secured to the inner surface51aof the PWB51with screws or adhesive. That is, one end of the fourth optical waveguide94is indirectly secured to the first optical waveguide91via the relay connector55, the screws or the adhesive, and the PWB51. The fourth optical waveguide94is not limited to this example, and may be directly joined to the first optical waveguide91, for example.

For example, light emitted from the end of the fourth optical waveguide94is reflected by the end of the first optical waveguide91and bends at about 90°, and is transmitted by the first optical waveguide91. Through the first optical waveguide91, light is reflected by the end and bends at about 90°, and enters the end of the fourth optical waveguide94.

The fifth optical waveguide95is included in the relay connector62. The fifth optical waveguide95is attached to the relay connector62which is in the form of a plug or a socket made of synthetic resin or another material, for example.

One end of the fifth optical waveguide95is joined to the second optical waveguide92. For example, the relay connector62is secured to the front surface19dof the FPC19with screws or adhesive. That is, one end of the fifth optical waveguide95is indirectly secured to the second optical waveguide92via the relay connector62, the screws or the adhesive, and the FPC19. The fifth optical waveguide95is not limited to this example, and may be directly joined to the second optical waveguide92, for example.

For example, light emitted from the end of the fifth optical waveguide95is reflected by the end of the second optical waveguide92and bends at about 90°, and is transmitted by the second optical waveguide92. Through the second optical waveguide92, light is reflected by the end and bends at about 90°, and enters the end of the fifth optical waveguide95.

The sixth optical waveguide96is included in the relay connector71. The sixth optical waveguide96is attached to the relay connector71which is in the form of a plug or a socket made of synthetic resin or another material, for example.

One end of the sixth optical waveguide96is joined to the outer terminal93aof the third optical waveguide93. For example, the relay connector71is secured to the outer surface75bof the external portion75with screws or adhesive. Thus, one end of the sixth optical waveguide96is indirectly secured to the third optical waveguide93via the relay connector71, the screw or the adhesive, and the relay FPC70. The sixth optical waveguide96is not limited to this example, and may be directly joined to the third optical waveguide93, for example.

For example, light emitted from the end of the sixth optical waveguide96is reflected by the outer terminal93aand bends at about 90°, and is transmitted by the third optical waveguide93. Through the third optical waveguide93, light is reflected by the outer terminal93aand bends at about 90°, and enters the end of the sixth optical waveguide96.

By connecting the relay connectors55and71to each other, the fourth optical waveguide94and the sixth optical waveguide96are joined to each other via the relay connectors55and71. As a result, the fourth optical waveguide94and the sixth optical waveguide96can transmit light to each other.

The seventh optical waveguide97is included in the relay connector72. The seventh optical waveguide97is attached to the relay connector72which is in the form of a plug or a socket made of synthetic resin or another material, for example.

One end of the seventh optical waveguide97is joined to the inner terminal93bof the third optical waveguide93. For example, the relay connector72is secured to the outer surface76bof the internal portion76with screws or adhesive. Thus, one end of the seventh optical waveguide97is indirectly secured to the third optical waveguide93via the relay connector72, the screws or the adhesive, and the relay FPC70. The seventh optical waveguide97is not limited to this example, and may be directly joined to the third optical waveguide93.

For example, light emitted from the end of the seventh optical waveguide97is reflected by the inner terminal93band bends at about 90° and is transmitted by the third optical waveguide93. Through the third optical waveguide93, light is reflected by the inner terminal93band bends at about 90°, and enters the end of the seventh optical waveguide97.

By connecting the relay connectors62and72to each other, the fifth optical waveguide95and the seventh optical waveguide97are joined to each other via the relay connectors62and72. As a result, the fifth optical waveguide95and the seventh optical waveguide97can transmit light to each other.

In the communication unit80, the conversion devices81and82convert an electric signal into an optical signal, transmit the optical signal through the optical waveguide83, and convert an optical signal into an electric signal. As a result, the communication unit80can perform wired communications through the optical waveguide83using the optical signal.

The conversion devices81and82convert and generate signals in compliance with a common communication method, for example. Further, the light sources of the conversion devices81and82emit light having a frequency that can be detected by the corresponding light receiving elements. Note that the conversion devices81and82may emit infrared rays or ultraviolet rays in addition to or in place of visible light.

The controller53and the preamplifier61communicate with each other via the communication unit80. In the present embodiment, the communication unit80transmits an electric signal (read signal) representing data read from the magnetic disk12and an electric signal (write signal) representing data to be written between the controller53and the preamplifier61.

For example, at the time of reading data, the preamplifier61amplifies and outputs an electric signal (read signal) representing the data read from the magnetic disk12by the magnetic head15. The communication unit80supplies the read signal amplified by the preamplifier61to the RWC of the controller53.

Further, the preamplifier61amplifies an electric signal (write signal) representing data to be written supplied from the RWC of the controller53through the communication unit80. The preamplifier61supplies the write signal to the magnetic head15.

Meanwhile, the HDC of the controller53performs control of transmission and reception of data with respect to the electronic device1through the I/F connector52, control of a buffer memory, and error correction to read data, for example.

The RWC of the controller53receives and modulates data to be written from the HDC and supplies the data to the preamplifier61through the communication unit80, for example. Further, the RWC receives a signal read from the magnetic disk12from the preamplifier61through the communication unit80and demodulates the signal as digital data to output the digital data to the HDC.

The processor of the controller53is, for example, a CPU. The processor performs control of the HDD10as a whole in accordance with, for example, firmware prestored in the ROM and the magnetic disk12. For example, the processor loads the firmware into the RAM from the ROM and the magnetic disk12, and executes control of the magnetic head15, the servo controller54, the preamplifier61, the conversion devices81and82, the RWC, the HDC, and other components in accordance with the loaded firmware.

The HDD10further includes an energizer100. The energizer100is an example of a second conductor. The energizer100electrically connects two or more components to each other. In the present embodiment, the energizer100electrically connects the PCB50outside the chassis11and the magnetic head15and the preamplifier61inside the chassis11.

The energizer100includes conductive layers101,102, and103and pins104,105,106, and107. The conductive layer103is an example of a first conductor. The conductive layers101,102, and103and the pins104,105,106, and107are made of a conducive material such as copper.

The conductive layer101is included in the PWB51. The conductive layer101electrically connects the electronic components mounted on the PWB51to each other. For example, the conductive layer101electrically connects the I/F connector52, the controller53, the servo controller54, and the conversion device81to the relay connector55.

The conductive layer102is included in the FPC19. The conductive layer102electrically connects the relay connector62to the conversion device82, for example. Further, the conductive layer102electrically connects the relay connector62to the flexure43. As a result, the relay connector62is electrically connected to the magnetic head15via the conductive layer102and the flexure43.

The conductive layer103is included in the relay FPC70. The conductive layer103includes an outer terminal103aand an inner terminal103billustrated inFIG.5, and an extension103cillustrated inFIG.6. As illustrated inFIG.5, the outer terminal103ais placed in the external portion75of the relay FPC70. The inner terminal103bis placed in the internal portion76. The extension103cextends across the external portion75, the internal portion76, and the intermediate portion77, and connects the outer terminal103aand the inner terminal103b.

The pin104is provided in the relay connector55and connected to the conductive layer101. The pin105is provided in the relay connector62and connected to the conductive layer102. The pin106is provided in the relay connector71and connected to the outer terminal103aof the conductive layer103. The pin107is provided in the relay connector72and connected to the inner terminal103bof the conductive layer103. As a result, the conductive layer103electrically connects the pins106and107in the relay connectors71and72.

The relay connectors55and71are connected to each other and the pins104and106are thereby electrically connected to each other. The relay connectors62and72are connected to each other and the pins105and107are thereby electrically connected to each other. As a result, the energizer100electrically connects the FPC19outside the chassis11and the magnetic head15and the preamplifier61inside the chassis11.

The magnetic head15and the preamplifier61are supplied with electric power from the electronic device1through the energizer100and the I/F connector52. In other words, the magnetic head15, the preamplifier61, and the conversion devices81and82are supplied with electric power from the PCB50through the relay connectors55,62,71, and72. Note that the energizer100may include a plurality of interconnections for grounding or control, in addition to the ones for electric power supply. In addition, the energizer100may include interconnections for data communications between the components mounted on the FPC19and the PCB50.

Hereinbelow, an example of the operation of the HDD10according to the present embodiment will be described. For example, in a writing operation, the processor1bof the electronic device1inFIG.4inputs a write command and data to be written into the controller53via the I/F connectors1aand52. In accordance with the write command, the RWC of the controller53inputs a write signal corresponding to the data to be written into the conversion device81of the communication unit80.

The conversion IC of the conversion device81converts the input write signal into a drive signal and outputs the drive signal to the light source. The light source of the conversion device81emits light corresponding to the drive signal to the end83aof the optical waveguide83. In other words, the conversion device81emits light corresponding to an electric signal (write signal) representing information to be written to the magnetic disk12by the magnetic head15.

The optical waveguide83transmits incident light from the end83ato the end83b. The optical waveguide83emits the light from the end83bto the light receiving element of the conversion device82. That is, in the optical waveguide83, the light is incident on the end83alocated outside the chassis11and exits from the end83blocated inside the chassis11.

In response to incidence of light, the light receiving element of the conversion device82outputs an output signal corresponding to the light to the conversion IC. The conversion IC of the conversion device82converts or restores the output signal into a write signal and outputs the write signal to the preamplifier61. In other words, the conversion device82generates an electric signal (write signal) representing information to be written to the magnetic disk12by the magnetic head15, corresponding to the light emitted from the conversion device81.

The preamplifier61amplifies the write signal and outputs the write signal to the magnetic head15. The magnetic head15writes data to be written included in the write signal to the recording layer of the magnetic disk12.

Further, the controller53inFIG.4controls various components such as the VCM17in accordance with the write command. For example, the servo controller54controls the VCM17under the control of the controller53. The servo controller54outputs a signal to the VCM17through the energizer100, for example. Note that the servo controller54may output a signal to the VCM17through the communication unit80.

In a reading operation, the processor1bof the electronic device1inputs a read command into the controller53via the I/F connectors1aand52. The controller53causes the magnetic head15to read data from the recording layer of the magnetic disk12following the read command.

The magnetic head15reads intended data, and the preamplifier61amplifies a read signal corresponding to the read data and outputs the amplified read signal to the conversion IC of the conversion device82. The conversion IC of the conversion device82converts the input read signal into a drive signal and outputs the drive signal to the light source. The light source of the conversion device82emits light corresponding to the drive signal to the end83bof the optical waveguide83. In other words, the conversion device82emits light corresponding to an electric signal (read signal) representing information read from the magnetic disk12by the magnetic head15.

The optical waveguide83transmits the incident light from the end83bto the end83a. The optical waveguide83emits the light from the end83ato the light receiving element of the conversion device81. That is, in the optical waveguide83the light is incident on the end83blocated inside the chassis11and exits from the end83alocated outside the chassis11.

In response to incidence of light, the light receiving element of the conversion device81outputs an output signal corresponding to the light to the conversion IC. The conversion IC of the conversion device81converts or restores the output signal into a read signal and outputs the read signal to the controller53. In this manner, the conversion device81generates an electric signal (read signal) representing information read from the magnetic disk12by the magnetic head15, corresponding to the light emitted from the conversion device82.

The RWC of the controller53demodulates the read signal and outputs data to be read included in the read signal to the electronic device1through the I/F connectors1aand52. As a result, the electronic device1acquires the data read from the magnetic disk12.

As described above, in the present embodiment, the controller53, the conversion device81, and the end83aof the optical waveguide83are located outside the chassis11while the preamplifier61, the conversion device82, and the end83bof the optical waveguide83are located inside the chassis11. The controller53outside the chassis11and the preamplifier61inside the chassis11communicate with each other through the conversion devices81and82and the optical waveguide83.

In the operation of the HDD10described above, the preamplifier61inside the chassis11and the controller53outside the chassis11mutually transmit and receive data through wired communications by means of the communication unit80using an optical signal. The magnetic head15, the VCM17, and the FPC19inside the chassis11are supplied with electric power through the energizer100. For this reason, the relay connectors55,62,71, and72are provided with the pins104to107for electric power supply but can omit pins for data transmission and reception.

The relay connectors55,62,71, and72may be provided with the pins for data transmission and reception. In this case, the FPC19and the PWB51can mutually transmit and receive data partially through wired communications by means of the communication unit80using an optical signal and partially through wired communications using an electric signal via the relay connectors55,62,71, and72. For example, a small amount of data can be transmitted and received through wired communications using an electric signal via the relay connectors55,62,71, and72.

In the HDD10according to the first embodiment described above, the conversion device81emits light corresponding to an electric signal. The conversion device82generates an electric signal corresponding to incident light. The optical waveguide83includes the end83ajoined to the conversion device81and the end83bjoined to the conversion device82, and transmits the light emitted from the conversion device81to the conversion device82. The controller53is electrically connected to the conversion device81. The preamplifier61is electrically connected to the conversion device82, and communicates with the controller53through the conversion device81, the optical waveguide83, and the conversion device82. That is, the controller53and the preamplifier61transmit data by means of optical communications. The optical communications excels in transmission capacity (bit rate) than electrical communications. Thus, the HDD10can improve the transmission capacity and reduce the number of interconnections in comparison with the data transmission by means of the electrical communications. For example, the controller53outside the chassis11and the preamplifier61inside the chassis11transmit data to each other by means of the optical communications, which makes it possible to reduce the number of interconnections between the outside and the inside of the chassis11. As a result, in the HDD10it is made possible, for example, to decrease the size of the slit25cthat allows the communication between the inside and the outside of the chassis11, and reduce a leakage of the gas from the chassis11through the slit25c.

Conventionally, for example, a relay board may close a hole penetrating the bottom wall25, and be provided with a connector for communications between the inside and the outside of the chassis11. As the storage capacity of the HDD10increases, the number of pins (interconnects) of the connector may increase, which may cause an increase in size of the connector. A larger-size connector may lead to increasing the relay board in size, which may cause gas leakage through narrow holes in the relay board or adhesive applied between the chassis11and the relay board. This may further lead to degrading the positioning accuracy of the connector and increasing the design cost for designing a new, larger-size connector. To the contrary, the HDD10according to the present embodiment can reduce the number of interconnections as described above. Thus, the HDD10enables, for example, downsizing or omission of the relay board and the connector, and can avoid a gas leakage, a decrease in positioning accuracy between components, and an increase in design cost.

The magnetic head15is located inside the chassis11and is configured to read and write information from and to the magnetic disk12. The conversion device81emits light corresponding to an electric signal (write signal) representing information to be written to the magnetic disk12by the magnetic head15. Also, the conversion device82emits light corresponding to an electric signal (read signal) representing information read from the magnetic disk12by the magnetic head15. The conversion device82generates a write signal corresponding to light emitted from the conversion device81. Also, the conversion device81generates a read signal corresponding to light emitted from the conversion device82. That is, the HDD10uses optical communications in transmission of a write signal or a read signal. As a result, the HDD10can increase the access speed, for example.

At least a part of the optical waveguide83has flexibility. This can improve the degree of freedom in designing the HDD10. For example, by the bent optical waveguide83extending between the conversion devices81and82, it becomes unnecessary to dispose the light sources and the light receiving elements of the conversion devices81and82to face each other.

At least a part of the optical waveguide83is included in the relay FPC70. This can improve the degree of freedom in designing the HDD10. For example, the relay FPC70can transmit light and electric signals and supply electric power through the optical waveguide83and the conductive layer103included in the relay FPC70.

The conversion device81, the end83a, and the controller53are located outside the chassis11. The conversion device82, the end83b, and the preamplifier61are located inside the chassis11. Thus, the controller53outside the chassis11and the preamplifier61inside the chassis11transmit data by means of optical communications, which makes it possible to decrease the number of interconnections between the outside and the inside of the chassis11. As a result, in the HDD10, for example, it is possible to decrease the size of the slit25cthat allows the inside and the outside of the chassis11to be in communication, and reduce a leakage of gas from the chassis11through the slit25c.

The relay FPC70includes the external portion75located outside the chassis11, the internal portion76located inside the chassis11, and the intermediate portion77passing through the slit25cin the chassis11and extending between the external portion75and the internal portion76. At least a part of the optical waveguide83is included in the relay FPC70. As a result, the HDD10can dispense with a relay board, and decrease the size of the slit25c. The HDD10can thus reduce a leakage of gas from inside the chassis11, for example. Further, the HDD10can avoid a decrease in positioning accuracy between components and an increase in design cost.

The conductive layer103is included in the relay FPC70. The conductive layer103includes the outer terminal103alocated in the external portion75, the inner terminal103blocated in the internal portion76, and the extension103cconnecting the outer terminal103aand the inner terminal103b. As a result, the controller53outside the chassis11can optically communicate with the preamplifier61inside the chassis11through the optical waveguide83of the relay FPC70, and can supply electric power to the preamplifier61through the conductive layer103of the relay FPC70. Thereby, the components inside the chassis11can be stably supplied with electric power through the conductive layer103.

Second Embodiment

Hereinbelow, a second embodiment will be described with reference toFIG.7. Note that, in the following description of a plurality of embodiments, components having similar functions to those of the components already described are labeled with the same reference numerals as those of the components already described, and the description thereof may be omitted. In addition, the plurality of components labeled with the same reference numerals are not necessarily common in terms of all of the functions and properties, but may have different functions and properties in accordance with each of the embodiments.

FIG.7is an exemplary plan view schematically illustrating the FPC19according to the second embodiment. As illustrated inFIG.7, in the second embodiment, the preamplifier61is provided in the second portion19bof the FPC19. Note that the preamplifier61may be provided in the third portion19c.

The second portion19bis larger than the first portion19a. In general, as the storage capacity of the HDD10increases, the number of the preamplifiers61or the size of the preamplifier61and the number of interconnections connected to the preamplifiers61increase, for example. By implementing the preamplifier61on the relatively large second portion19b, the interconnections in the FPC19can be designed easily.

Further, in the second embodiment, the HDD10includes a communication unit110. Similarly to the communication unit80, the communication unit110optically performs communication between two components. The communication unit110performs communication between the preamplifier61and the magnetic head15. The preamplifier61and the magnetic head15are examples of a first component or a second component in the second embodiment.

The communication unit110includes two conversion devices111and112and an optical waveguide113. The communication unit110may include a plurality of optical waveguides113. Each of the conversion devices111and112is an example of a first conversion device or a second conversion device.

Similarly to the conversion devices81and82, each of the conversion devices111and112includes a light source, a light receiving element, and a conversion IC. Therefore, each of the conversion devices111and112emits light corresponding to an electric signal and generates an electric signal corresponding to incident light. Note that the conversion device111and112may be different from the conversion devices81and82.

Each of the conversion devices111and112is mounted on the FPC19. The conversion device111is electrically connected to the relay connector62and the conversion device82through interconnections of the FPC19. The conversion device112is electrically connected to the flexure43through interconnections of the FPC19. Therefore, the conversion device112is electrically connected to the magnetic head15through the flexure43.

Similarly to the optical waveguide83, the optical waveguide113totally reflects and transmits light incident on the core layer at a boundary surface between the core layer and the cladding layer. The optical waveguide113is provided in the FPC19and has flexibility. Note that the optical waveguide113may be different from the optical waveguide83.

The optical waveguide113has two ends113aand113b. Each of the ends113aand113bis an example of a first end or a second end. One end113ais joined to the conversion device111. The other end113bis joined to the conversion device112.

The optical waveguide113transmits light emitted from one of the conversion devices111and112to the other. The single optical waveguide113or a plurality of optical waveguides included in the optical waveguide113may be connected between the conversion device111and the conversion device112.

In the communication unit110, the conversion devices111and112convert an electric signal into an optical signal, transmit the optical signal through the optical waveguide113, and convert an optical signal into an electric signal. As a result, the communication unit110can perform wired communication of the optical signal through the optical waveguide113.

The preamplifier61and the magnetic head15communicate with each other via the communication unit110described above. In the present embodiment, the communication unit110transmits a read signal and a write signal between the preamplifier61and the magnetic head15.

In a writing operation, the write signal output from the controller53is input into the preamplifier61through the communication unit80. Note that, in the HDD10according to the second embodiment, the communication unit80may be omitted, and the write signal may be input into the preamplifier61through the energizer100.

The preamplifier61amplifies the write signal and inputs the amplified write signal to the conversion device111of the communication unit110. The conversion device111emits light corresponding to the write signal toward the end113aof the optical waveguide113.

The optical waveguide113transmits the light incident on the end113ato the end113b. The optical waveguide113emits the light from the end113btoward the light receiving element of the conversion device112.

For example, as the actuator assembly16rotates, the optical waveguide113provided in the FPC19flexes. However, even in a case in which the optical waveguide113flexes together with the FPC19, the optical waveguide113can transmit the light from the conversion device111to the conversion device112.

When the light is incident on the light receiving element of the conversion device112, the conversion device112generates a write signal corresponding to the light emitted from the conversion device111. The conversion device112outputs the write signal to the magnetic head15through the flexure43. The magnetic head15writes data to be written included in the write signal in the recording layer of the magnetic disk12.

On the other hand, in a reading operation, when the magnetic head15reads data to be read, the magnetic head15outputs a read signal to the conversion device112through the flexure43. The conversion device112emits light corresponding to the read signal toward the end113bof the optical waveguide113.

The optical waveguide113transmits the light incident on the end113bto the end113a. The optical waveguide113emits the light from the end113atoward the light receiving element of the conversion device111.

When the light is incident on the light receiving element of the conversion device111, the conversion device111generates a read signal corresponding to the light emitted from the conversion device112. The conversion device111outputs the read signal to the preamplifier61through interconnections of the FPC19. The preamplifier61amplifies the read signal and outputs the amplified read signal to the controller53through, for example, the communication unit80.

In the HDD10according to the second embodiment described above, at least a part of the optical waveguide113has flexibility. This can improve the degree of freedom in designing the HDD10. For example, the optical waveguide113can bend as the chassis11and the actuator assembly16move relative to each other.

At least a part of the optical waveguide113is included in the FPC19. This can improve the degree of freedom in designing the HDD10. For example, the FPC19can transmit light and electric signals and supply electric power through the optical waveguide113and the interconnections provided in the FPC19.

The FPC19includes the first portion19aattached to the actuator assembly16, the second portion19battached to the chassis11, and the flexible third portion19clocated between the first portion19aand the second portion19b. The preamplifier61is placed in the second portion19bor the third portion19c. The size of the first portion19aattached to the actuator assembly16is limited by the size of the actuator assembly16. This may cause, for example, difficulty in mounting the preamplifier61on the first portion19aand providing the first portion19awith interconnections to the preamplifier61. However, the sizes of the second portion19band the third portion19care not limited by the size of the actuator assembly16. This leads to improving the degree of freedom in placing the preamplifier61on the FPC19and improving the degree of freedom in designing the HDD10. Meanwhile, disposing the preamplifier61on the second portion19bor the third portion19cresults in elongating the distance between the preamplifier61and the magnetic head15. However, in the present embodiment, the preamplifier61and the magnetic head15transmit data by means of optical communications. The optical communications cause less data loss due to distance than electrical communications. As a result, the HDD10can prevent occurrence of data loss in communications between the preamplifier61and the magnetic head15irrespective of a longer distance between the preamplifier61and the magnetic head15.

Third Embodiment

Hereinbelow, a third embodiment will be described with reference toFIG.8.FIG.8is an exemplary cross-sectional view schematically illustrating a part of the HDD10according to the third embodiment. As illustrated inFIG.8, in the third embodiment, a through hole25dis provided in the bottom wall25instead of the slit25c. The through hole25dis an example of a second through hole.

The through hole25dpenetrates the bottom wall25and opens at the inner surface25aand the outer surface25b. In other words, the through hole25dallows the internal space S and the outside of the chassis11to be connected with each other. The through hole25dis, for example, a substantially rectangular (quadrangular) hole. Note that the shape of the through hole25dis not limited to this example.

The HDD10according to the third embodiment includes a relay board120instead of the relay FPC70. The relay board120is an example of a second wall. The relay board120is, for example, a substantially quadrangular plate made of an insulator such as synthetic resin and ceramics. Note that the relay board120is not limited to this example. The relay board120includes an inner surface120aand an outer surface120b.

The inner surface120ais a substantially flat surface facing the inside of the chassis11. The inner surface120aforms (defines or sections) a part of the internal space S inside the chassis11. The inner surface120afaces a component located in the internal space S, such as the FPC19.

The outer surface120bis a substantially flat surface located on the opposite side of the inner surface120aand facing the outside of the chassis11. The area of the outer surface120bis larger than the opening area of the through hole25d. The outer surface120bcovers the through hole25dfrom the inside of the chassis11. A part of the outer surface120bfaces the inner surface25aof the bottom wall25. Another part of the outer surface120bis exposed to the outside of the chassis11through the through hole25dand faces the inner surface51aof the PWB51through the through hole25d.

For example, adhesive121is provided between the inner surface25aof the bottom wall25and the outer surface120bof the relay board120facing each other. The adhesive121secures the inner surface25aof bottom wall25and the outer surface120bof the relay board120to each other. The adhesive121has a metal filler mixed therein, for example, which can suppress passage of gas through the adhesive121.

The adhesive121is provided along the edge of the through hole25dand closes the gap between the inner surface25aof the bottom wall25and the outer surface120bof the relay board120over the entire circumference. As a result, the relay board120airtightly closes the through hole25d. Note that the relay board120may be secured to the bottom wall25by other means such as solder.

In the third embodiment, the relay connectors71and72are provided on the relay board120. The relay connector71protrudes from the outer surface120bof the relay board120and is located outside the chassis11. The relay connector72protrudes from the inner surface120aof the relay board120and is located in the internal space S inside the chassis11.

The relay connector71passes through the through hole25d. Therefore, the sixth optical waveguide96and the pin106provided in the relay connector71pass through the through hole25d. Note that the sixth optical waveguide96and the pin106may be housed in the through hole25dwithout passing through the through hole25d. However, the optical waveguide83including the sixth optical waveguide96passes through the through hole25d, and is provided from the inside of the chassis11to the outside of the chassis11. Also, the energizer100including the pin106passes through the through hole25d, and is provided from the inside of the chassis11to the outside of the chassis11.

In the third embodiment, the communication unit80includes an eighth optical waveguide125instead of the third optical waveguide93. The eighth optical waveguide125is secured in the relay board120in a state of passing through the relay board120.

For example, the eighth optical waveguide125is formed substantially in a rod shape. The eighth optical waveguide125passes through a hole provided in the relay board120and is secured in the relay board120with synthetic resin or adhesive. Note that the eighth optical waveguide125is not limited to this example.

One end of the eighth optical waveguide125is joined to the sixth optical waveguide96. For example, the relay connector71is secured to the outer surface120bof the relay board120. Therefore, the eighth optical waveguide125is indirectly secured to the sixth optical waveguide96via the relay board120and the relay connector71. The eighth optical waveguide125is not limited to this example, and may be directly joined to the sixth optical waveguide96, for example.

The other end of the eighth optical waveguide125is joined to the seventh optical waveguide97. For example, the relay connector72is secured to the inner surface120aof the relay board120. Therefore, the eighth optical waveguide125is indirectly secured to the seventh optical waveguide97via the relay board120and the relay connector72. The eighth optical waveguide125is not limited to this example, and may be directly joined to the seventh optical waveguide97, for example.

In the third embodiment, the energizer100includes a through conductor126instead of the conductive layer103. The through conductor126includes, for example, a via. The through conductor126penetrates the relay board120and is connected to the pins106and107.

In the HDD10according to the third embodiment described above, a part of the optical waveguide83is included in the relay connector71located outside the chassis11and the relay connector72located inside the chassis11. The chassis11includes the bottom wall25provided with the through hole25d. The optical waveguide83passes through the through hole25d. That is, in the optical waveguide83, a connection structure using the connectors is provided between the conversion device81and the conversion device82. Thereby, the optical waveguide83can easily and communicably connect the conversion devices81and82apart from each other inside and outside the chassis11using the relay connectors71and72, as compared with the single optical waveguide83directly joined to the conversion device81and the conversion device82.

The energizer100passes through the through hole25d. A part of the energizer100is included in the relay connector71and the relay connector72. As a result, the components outside the chassis11can optically communicate with the components inside the chassis11through the relay connector71and the relay connector72via the optical waveguide83, and can supply electric power thereto via the energizer100. As a result, the components inside the chassis11can be supplied with electric power through the relay connector71and the relay connector72in a stable manner.

The relay board120closes the through hole25d. The relay connector71located outside the chassis11and the relay connector72located inside the chassis11are disposed on the relay board120. The optical waveguide83penetrates the relay board120. For example, the relay board120to which the relay connector71and the relay connector72are attached is attached to the bottom wall25. This makes it easier to attach the relay connector71and the relay connector72to the chassis11.

Fourth Embodiment

Hereinbelow, a fourth embodiment will be described with reference toFIG.9.FIG.9is an exemplary cross-sectional view schematically illustrating a part of the HDD10according to the fourth embodiment. As illustrated inFIG.9, in the HDD10according to the fourth embodiment, the relay board120is omitted from the HDD10according to the third embodiment.

The relay connector71according to the fourth embodiment includes a connection131and a penetrating portion132. The connection131protrudes from the outer surface25bof the bottom wall25and is located outside the chassis11. The connection131is connected to the relay connector55. The penetrating portion132extends from the connection131and passes through the through hole25d. A part of the penetrating portion132protrudes from the inner surface25aof the bottom wall25.

The relay connector71is secured to the bottom wall25with, for example, adhesive135. The adhesive135secures the connection131to the outer surface25bof the bottom wall25. Further, the adhesive135is filled between the penetrating portion132and the inner surface of the through hole25d. The adhesive135has a metal filler mixed therein, for example, which can suppress passage of gas through the adhesive135. Thus, the adhesive135airtightly seals the through hole25d.

The relay connector72according to the fourth embodiment is attached to the penetrating portion132of the relay connector71. For example, the relay connector72is attached to the penetrating portion132by snap-fitting. Further, the relay connector72may be secured to the inner surface25aof the bottom wall25with adhesive.

By attaching the relay connector72to the penetrating portion132, the sixth optical waveguide96provided in the relay connector71and the seventh optical waveguide97provided in the relay connector72are joined to each other. Further, the pins106and107provided in the relay connectors71and72are connected to each other.

The relay connector71according to the fourth embodiment is attached to the bottom wall25by, for example, inserting the penetrating portion132into the through hole25d. Further, the relay connector72is attached to the penetrating portion132protruding from the inner surface25aof the bottom wall25by snap-fitting. In this manner, the relay connectors71and72can be attached to the bottom wall25easily.

In the above description, the relay connector71is provided with the connection131and the penetrating portion132. However, the relay connector72may include the connection131and the penetrating portion132. In this case, the relay connector71is attached to the penetrating portion132of the relay connector72.

In the HDD10according to the fourth embodiment described above, one of the relay connectors71and72includes the connection131located outside the through hole25dand the penetrating portion132passing through the through hole25d. The other of the relay connectors71and72is attached to the penetrating portion132. As a result, the HDD10can dispense with the relay board120, and decrease the size of the through hole25d, for example. The HDD10can thus avoid a leakage of gas from inside the chassis11through the through hole25d.

In the first to fourth embodiments described above, the optical waveguide83extends across the inside and the outside of the chassis11while the optical waveguide113is placed inside the chassis11. The HDD10is not limited to this example, and may include an optical waveguide outside the chassis11. For example, the HDD10may include an optical waveguide in the PWB51.

According to at least one of the embodiments described above, a disk device includes a first conversion device, a second conversion device, an optical waveguide, a first component, and a second component. The first conversion device emits light corresponding to an electric signal. The second conversion device generates an electric signal corresponding to incident light. The optical waveguide includes a first end joined to the first conversion device and a second end joined to the second conversion device, and transmits light emitted from the first conversion device to the second conversion device. The first component is electrically connected to the first conversion device. The second component is electrically connected to the second conversion device, and communicates with the first component through the first conversion device, the optical waveguide, and the second conversion device. That is, the first component and the second component transmit data by means of optical communications. The optical communications excel in transmission capacity (bit rate) than electrical communications. Thus, the disk device can improve the transmission capacity and reduce the number of interconnections than data transmission by means of electric-signal communications. For example, components inside and outside a chassis transmit data to each other by means of the optical communications, thereby reducing the number of interconnections between the outside and the inside of the chassis. As a result, for example, it is possible for the disk device to decrease the size of a through hole that allows the inside and the outside of the chassis to be in communication and decrease the size of a wall that closes the through hole, reducing a leakage of gas from inside the chassis through the through hole and the wall.

In the above description, wards “suppress” and “prevent” are defined as, for example, to prevent the occurrence of an event, an effect, or an influence, or to reduce the degree of the event, the effect, or the influence. Also, in the above description, wards “limit” and “restrict” are defined as, for example, to prevent movement or rotation, or to allow movement or rotation within a predetermined range and to prevent movement or rotation beyond the predetermined range.

While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.