JP2007200474A - Optical pickup device and optical disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lower-profile optical pickup device ensured in rigidity and a lower-profile optical disk device mounted with the optical pickup device. <P>SOLUTION: The optical pickup device is equipped with; an optical system provided with an objective lens 4 for focusing laser beams emitted from a laser light source 3 on an optical disk; an actuator 15 for driving the objective lens 4; and a carriage 2 with the optical system and the actuator 15 arranged inside, the carriage 2 equipped with a flat plate-shaped extension base 2c outside the carriage 2, wherein the top face of the extension base 2c is provided at a position lower than the top face of the carriage 2 and the lower face of the extension base 2c is provided at a position higher than the lower face of the carriage 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical pickup device used in an optical disk device, and more particularly to an optical pickup device and an optical disk device used in a thin optical disk device mounted on a notebook personal computer.

  Conventionally, especially notebook personal computers have been reduced in thickness, and optical disc apparatuses mounted thereon have been required to be reduced in thickness. In order to reduce the thickness of the optical disk device, it is essential to reduce the thickness of the optical pickup device that emits laser light to the optical disk and records and reproduces information.

  FIG. 9 is a block diagram of a conventional optical pickup device, and FIG. 10 is a cross-sectional view taken along line AA of FIG. The carriage 102 forms the framework of the optical pickup device 101. In order to reduce the thickness of the optical pickup device 101, the thickness of the carriage 102 is 4.2 mm. The carriage 102 includes an optical system region 102a, an actuator region 102b, and an extended base 102c. Various optical components are arranged in the optical system region 102a directly or via an attachment member. The optical components arranged in the optical system region include a laser light source 103 that emits laser light, light receiving sensors 105 and 106 that receive the laser light emitted from the laser light source 103, and the objective lens 103 that receives the laser light emitted from the laser light source. And an optical element 107, a collimating lens 108, and a beam splitter 109 that lead to the light receiving sensors 105 and 106. An actuator 111 is disposed in the actuator region 102b. The actuator 111 drives the objective lens 104 that condenses the laser light emitted from the laser light source 103 onto the optical disk. A hologram element 110 is also disposed on the actuator 111.

  Further, as shown in FIG. 10, the extension base 102c is provided outside the actuator region 102b, and a through hole 102d is formed at the center. A flat portion 102e is provided on the upper surface side of the through-hole 102d. A first flexible printed circuit board (hereinafter referred to as a first FPC) 112 that connects the flat portion 102e from the outside to the connection portion 115 and a first flexible printed circuit board 112 that connects from the connection portion 115 to the actuator 111 are provided. 2 A connecting portion 115 for connecting a flexible printed circuit board (hereinafter referred to as a second FPC) 113 is disposed. The connecting portion 115 is connected with solder 114. The solder 114 is disposed on the opposite side of the flat portion 102e via the first FPC 112 and the second FPC 113.

  A flat portion 102g is provided on the lower surface side of the through hole 102c, and a space portion 102f is provided across the flat portion 102g. A connecting portion 115 for connecting the first FPC 112 connected from the outside to the connecting portion 115 and the second FPC 113 connected from the connecting portion 115 to the light receiving sensor 105 is disposed on the flat portion 102g. The connecting portion 115 is connected with solder 114. The solder 114 is disposed so as to be stored in the space portion 102f. The distance between the flat portion 102e and the flat portion 102g, that is, the thickness of the extended base 102c is 2.0 mm.

  Further, the extension base 102 c is covered with a cover 116. The cover 116 is a sheet metal and presses the first FPC 112 and the second FPC 113 on the lower surface side by the elastic force of the material. At this time, since the connection portion 115 on the lower surface side is in the space portion 102f, the cover 116 and the solder 114 are not electrically connected. Further, since the space between the upper surface of the solder 114 and the cover 116 is ensured, the cover 116 and the solder 114 are not electrically connected.

In Patent Document 1, FIG. 4 shows that the first FPC 112 and the second FPC 113 are connected by an extension base 102c provided outside the optical system region 102a and the actuator region 102b. The upper surface side of the extension base 102 c is cut to such an extent that the arranged connecting portion 115 does not protrude from the upper surface side of the optical pickup device 101.
JP 2005-276263 A

  However, in order to further reduce the thickness of the optical pickup device, it is necessary to reduce the thickness of the carriage. In order to reduce the thickness of the carriage in the conventional carriage structure, the thickness of the extension base must be reduced. On the other hand, it is necessary to ensure the strength of the extension base after ensuring the solder height of the connecting portion that does not conduct with the surroundings. For this reason, there is a limit to reducing the thickness of the optical pickup device. Moreover, if a necessary connection part is provided on one side of the extension base as shown in (Patent Document 1), a large area is required. When the area of the extension base increases, the extension base cannot be accommodated in one place and needs to be dispersed in a plurality of places. However, if the extension base is dispersed in a state where the carriage is thin, the rigidity of the entire carriage becomes weak, and there is a problem that it cannot be used.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described conventional problems, and to provide a thinner optical pickup device and optical disc device while ensuring rigidity.

  To achieve the above object, the present invention provides an optical system including an objective lens for condensing laser light emitted from a laser light source onto an optical disc, an actuator for driving the objective lens, the optical system, and the actuator. A carriage that is disposed on the inner side, and the carriage has a flat plate shape having an upper surface provided outside the carriage at a position lower than the upper surface of the carriage and a lower surface provided at a position higher than the lower surface of the carriage. An optical pickup device comprising an extended base of

  The extension base is flat and the connection parts can be arranged on both the upper and lower surfaces.

  In the optical pickup device and the optical disk device of the present invention, the extension base of the carriage is formed in a flat plate shape so that the connection portions can be arranged on both the upper surface and the lower surface. Therefore, the thickness of the optical pickup device can be reduced while ensuring rigidity.

  According to a first aspect of the present invention, there is provided an optical system including an objective lens that condenses laser light emitted from a laser light source onto an optical disc, an actuator that drives the objective lens, and a carriage that arranges the optical system and the actuator inside. The carriage is an optical pickup device provided with an extended base in which the upper surface is provided at a position lower than the upper surface of the carriage on the outer side of the carriage and the lower surface is provided at a position higher than the lower surface of the carriage.

  The extension base is flat and the connection parts can be arranged on both the upper and lower surfaces. Therefore, the thickness of the optical pickup device can be reduced while ensuring rigidity.

  According to a second aspect of the present invention, in the first aspect of the invention, the first flexible printed circuit board connecting at least from the outside to the connection portion and a second flexible printed circuit board connecting from the connection portion to the predetermined part are provided, and the connection portion Is an optical pickup device arranged on at least one of the upper surface or the lower surface of the extension base.

  A third aspect of the present invention is the optical pickup device according to the first aspect of the present invention, wherein the carriage has a thickness of 3.5 mm or less.

  By reducing the thickness of the carriage, an optical pickup device having a thinner thickness can be realized, and the thickness of the optical disk device can be further reduced.

  A fourth aspect of the present invention is the optical pickup device according to the first aspect, wherein the extension base has a thickness of 0.2 mm or more and 1.5 mm or less.

  If the thickness of the extension base is 0.2 mm or more, the strength of the extension base can be secured. Moreover, if it is 1.5 mm or less, the space | interval of a connection part and the cover of an optical pick-up apparatus can be ensured.

  A fifth aspect of the present invention is the optical pickup device according to the first aspect of the present invention, wherein the carriage is recessed in a substantially circular shape on the outer side opposite to the extension base.

  When the optical pickup device moves to the innermost circumference, the spindle motor rotates along the substantially circularly recessed portion. Therefore, the space efficiency of the optical disk device is improved.

  The invention of claim 6 is the optical pickup device according to claim 2, wherein the predetermined component is an actuator.

  Since the second FPC is connected to the actuator body and the actuator is assembled separately, and the completed actuator can be incorporated into the carriage, the assembly work of the optical pickup device is facilitated.

  A seventh aspect of the invention is the optical pickup device according to the second aspect of the invention, wherein the predetermined component is a light receiving sensor that receives the laser light emitted from the laser light source and reflected from the optical disk.

  Since the second FPC can be connected to the light receiving sensor in advance and the components including the light receiving sensor are assembled and then assembled into the carriage, the assembly work of the optical pickup device is facilitated.

  The invention according to claim 8 is the optical pickup device according to claim 2, wherein the predetermined component is a light receiving sensor that receives part of the laser light emitted from the laser light source.

  Since the second FPC can be connected to the light receiving sensor in advance and then incorporated into the carriage, the optical pickup device can be easily assembled.

  A ninth aspect of the invention is the optical pickup device according to the second aspect of the invention, wherein the first flexible printed circuit board connects from the outside to the laser light source.

  The optical pickup device can be assembled without unnecessarily increasing the number of second FPCs or increasing the area of the extension base that is required accordingly.

  A tenth aspect of the present invention is the optical pickup device according to the first aspect of the present invention, wherein the outer edge portion of the projection from the upper surface of the extension base has a substantially right angle.

  Even when the optical pickup device moves to the outermost periphery of the optical disk device, the corner portion comes to the corner portion of the optical disk device, so that the space efficiency can be improved.

  According to an eleventh aspect of the present invention, in the second aspect of the present invention, the connection between the first flexible printed board and the second flexible printed board is an optical pickup device using solder.

  The thickness of the connecting portion can be reduced.

  The invention of claim 12 is the invention of claim 2, wherein at least one of the first flexible printed circuit board and the second flexible printed circuit board is provided with a variable resistor, and the variable resistor is provided on an upper surface or a lower surface of the extension base. Optical pickup device.

  The variable resistor has a thickness that cannot be ignored, and the thickness of the optical pickup device can be reduced by arranging the variable resistor on the extension base together with the connection portion.

  The invention of claim 13 is the invention of claim 2, wherein at least one of the first flexible printed circuit board and the second flexible printed circuit board includes an electronic component portion in which electronic components are concentrated and the thickness of the carriage is outside the carriage. The electronic component area is an optical pickup device that includes an electronic component area having a thickness smaller than the thickness of the electronic component area.

  It is not necessary to arrange the electronic component on the upper surface side or the lower surface side of the optical system region so as not to block the path of the laser beam, and it is possible to prevent the optical pickup device from becoming thick.

  A fourteenth aspect of the present invention is the optical pickup device according to the thirteenth aspect of the present invention, wherein the extension base and the electronic component region are provided adjacent to each other.

  It is not directly related to the recording and reproducing characteristics of the optical pickup device, and the strength of the main part of the optical pickup device can be secured by adjoining the thin region, and good recording and reproducing characteristics can be obtained.

  A fifteenth aspect of the invention is the optical pickup device according to the second aspect of the invention, wherein the cover covers at least the upper surface side of the extension base, and an insulating member is provided between the connection portion and the surface facing the connection portion of the cover. .

  It is possible to prevent direct contact between the solder soldered to the connection portion and the cover.

  A sixteenth aspect of the invention is the optical pickup device according to the second aspect of the invention, wherein the cover covers at least the lower surface side of the extension base, and an insulating member is provided between the connection portion and the surface facing the connection portion of the cover. .

  It is possible to prevent direct contact between the solder soldered to the connection portion and the cover.

  According to a seventeenth aspect of the present invention, in the second aspect of the invention, a light having a cover that covers a non-conductive portion of at least one connection portion of the first flexible printed circuit board or the second flexible printed circuit board disposed on the lower surface of the extension base. It is a pickup device.

  It is possible to prevent direct contact between the solder soldered to the connection portion and the cover.

  According to an eighteenth aspect of the present invention, there is provided an optical system including an objective lens that condenses laser light emitted from a laser light source onto an optical disc, an actuator that drives the objective lens, and a carriage that arranges the optical system and the actuator inside. And the carriage includes an optical pickup device including an extended base provided with an upper surface provided at a position lower than the upper surface of the carriage and provided with a lower surface at a position higher than the lower surface of the carriage. This is an optical disc device.

  Since the extension base is flat and the connection portions can be arranged on both the upper surface and the lower surface, the optical pickup device capable of reducing the thickness while securing rigidity is mounted. Therefore, an extremely thin optical disk device can be obtained.

(Embodiment 1)
The first embodiment will be described with reference to the drawings. FIG. 1A is a top view of the optical pickup device according to the first embodiment, and FIG. 1B is a bottom view. The cover is removed. The first FPC (flexible printed circuit board) 20 is indicated by a broken line. The upper surface is a surface on the same side as the objective lens 4, and the lower surface is a surface opposite to the objective lens 4. The optical pickup device 1 is configured by attaching various components directly or via an attachment member to a carriage 2 forming a skeleton. The components attached to the carriage 2 are a laser light source 3 that emits laser light, light receiving sensors 5 and 6 that receive the laser light emitted from the laser light source 3, and a laser light emitted from the laser light source 3 is condensed on an optical disk. There is an objective lens 4. Further, a diffraction element 7 as a light guide member for guiding laser light emitted from the laser light source 3 to the objective lens 4 and the light receiving sensors 5 and 6, a beam splitter 8, a mirror 9, a collimator lens 10, a wave plate 11, and an angle conversion prism. 12, a rising prism 13, and an astigmatism lens 14. The laser light source 3, the light receiving sensors 5 and 6, the objective lens 4, and the light guide member are collectively referred to as an optical system. The optical system is disposed inside the carriage 2. An actuator 15 that mounts and drives the objective lens 4 is fixed inside the carriage 2. Further, the laser source 3, the diffraction element 7, the beam splitter 8, the astigmatism lens 14, and the light receiving sensor 5 are attached to the coupling base 16 and fixed to the carriage 2 as a laser module 17.

  Further, the connecting portion 22 of the first FPC 20 and the second FPC 21 is disposed on the extended base 2 c of the carriage 2. The first FPC 20 is an FPC that connects the outside to the connection unit 22. The second FPC 21 includes three actuators FPC 23 that connects the connecting portion 22 to the actuator 15, a sensor FPC 24 that connects the connecting portion 22 to the light receiving sensor 5, and a monitor FPC 25 that connects the connecting portion 22 to the light receiving sensor 6.

  2A is a perspective configuration diagram from the top surface of the carriage according to the first embodiment, and FIG. 2B is a perspective configuration diagram from the bottom surface. The carriage 2 is formed of an alloy material such as Zn alloy or Mg alloy, or a hard resin material. In the first embodiment, it is necessary to make the optical pickup device 1 thin, and for this purpose, the carriage 2 must also be thin. It is desirable to use an alloy material that can ensure rigidity even when the carriage 2 is thin. The carriage 2 includes an optical system region 2a having an opening and an actuator region 2b adjacent to each other. A laser module 25 is attached inside the opening of the optical system region 2a. In addition, an attachment portion is provided so that each light guide member and the light receiving sensor 6 can be attached with high accuracy in position and angle. The actuator region 2b is provided with an opening in which the actuator 15 is fixed.

  Further, one outer side of the optical system region 2a and the actuator region 2b was provided with an outer edge portion recessed in a substantially circular shape. When the optical pickup device 1 moves to the innermost circumference, a spindle motor (not shown) rotates along this circular portion. Therefore, the space efficiency of the optical disk device is improved. On the opposite outer side, an electronic component region 2d is provided adjacent to the optical system region 2a. The electronic component region 2 d has a flat plate shape with the lower surface provided at a position higher than the lower surface of the carriage 2. An electronic component part is provided on the lower surface portion of the electronic component region 2d to concentrate the electronic component on at least one of the first FPC 20 or the second FPC 21. In the first embodiment, the electronic component portion 20f is provided in the first FPC 20.

  An extension base 2c is provided outside the optical system region 2a and the actuator region 2b adjacent to the electronic component region 2d. The extension base 2 c has a flat plate shape in which the upper surface is provided at a position lower than the upper surface of the carriage 2 and the lower surface is provided at a position higher than the lower surface of the carriage 2. Further, the outer edge portion of the projection from the upper surface of the extension base 2c has a substantially right angle. This is to improve the space efficiency by making the corners come to the corners of the optical disk device even when the optical pickup device 1 of the first embodiment moves to the outermost periphery of the optical disk device. Further, the strength of the main part of the optical pickup device 1 can be ensured by adjoining the electronic component region 2d having a small thickness and the extension base 2c without being directly related to the recording and reproduction characteristics of the optical pickup device 1. And good recording and reproduction characteristics can be obtained.

  The thickness of the carriage 2 is the difference between the highest position and the lowest position in the thickness direction of the carriage 2 and is 3.5 mm or less. This is to reduce the thickness of the carriage 2 in order to aim for an ultra-thin optical disk device. If the strength can be secured, the thickness is desirably 3.0 mm or less. In the first embodiment, it is 2.6 mm. The thickness of the extension base 2c is the thickness of the flat plate portion excluding the small protrusions 2e, and is set to 0.2 mm or more and 1.5 mm or less. If it is less than 0.2 mm, it is difficult to ensure the strength of the extension base 2c. Conversely, if it exceeds 1.5 mm, the difference in thickness between the optical system region 2a and the actuator region 2b is reduced, and when the connection portion 22 is disposed, a space between the connection portion 22 and the cover (not shown) is secured. This is because it becomes difficult to do. Therefore, if the thickness of the extension base 2c is 0.4 mm or more and 1.0 mm or less, it is desirable that the strength of the extension base 2c can be sufficiently secured and the distance between the connection portion 22 and the cover can be sufficiently secured. In this Embodiment 1, it was set to 0.55 mm. In addition, the optical system region 2a and the actuator region 2b having a large opening are not provided with a thin portion as much as possible such as the extension base 2c, and the thin portion is an extension outside the optical system region 2a and the actuator region 2b. It was concentrated on the base 2c and the electronic component area 2d. Therefore, the reduction in rigidity of the optical system region 2a and the actuator region 2b, which are important in the laser beam path, by reducing the thickness of the carriage 2 is minimized. Therefore, stable recording / reproducing characteristics could be obtained.

  The extended base 2c was provided with some small protrusions 2e. By positioning a small hole corresponding to the FPC and allowing the small protrusion 2e to pass through the small hole when the connecting portion 22 is disposed, the FPC can be positioned accurately.

  The laser light source 3 is a two-wavelength semiconductor laser light source that emits a laser beam for DVD and a laser beam for CD, and is a so-called frame laser light source in which a light emitting element is fixed via a submount arranged on a frame. The laser light source 3 is arranged so that the emitted laser light becomes P-polarized light.

  The diffraction element 7 transmits the laser beam for DVD as it is, diffracts the laser beam for CD and diffracts it, transmits the laser beam for CD, and diffracts the laser beam for DVD. In combination with a diffraction grating for DVDs.

  The beam splitter 8 is made of optical glass or optical plastic and has an inclined surface inside. A polarization separation film is formed on the inclined surface. The polarization separation film transmits most of the P-polarized laser light and reflects a part thereof, and totally reflects the S-polarized laser light.

  The mirror 9 is for bending the optical path in order to make the optical system compact. A total reflection film is formed on the surface of the mirror 9.

  The collimating lens 10 is a lens for making the laser light emitted from the laser light source 3 and diverging light substantially parallel. The collimating lens 10 is made of optical glass or optical plastic.

  The wave plate 11 converts the polarization of the laser light emitted from the laser light source 3 that is P-polarized light into circularly polarized light, and converts the laser light that is circularly polarized light reflected by the optical disk into S-polarized light. The wave plate 11 is set to have a refractive index and a thickness so as to act on both the DVD laser beam and the CD laser beam.

  The angle conversion prism 12 optimizes the angle of the laser beam incident on the rising prism 13 to reduce the thickness of the rising prism 13 as much as possible. An angle is given in a direction perpendicular to the angle.

  The rising prism 13 is disposed immediately below the objective lens 4 and is a prism for raising laser light in a direction perpendicular to the optical disk.

  The objective lens 4 is a lens that condenses the laser light emitted from the laser light source 3 so as to be focused on the recording surface of the optical disk. CD and DVD have different focal positions, and the objective lens 4 is a bifocal lens. The objective lens 4 is made of optical glass or optical plastic.

  Optical discs are CD, CD-ROM, CD-R / RW for DVD, DVDROM, DVD ± R / RW, DVD-RAM for DVD, etc. All CD and DVD are recorded except for read-only media. Can also be played back. In the first embodiment, the CD and the DVD are used, but not only the combination thereof but also the combination with a so-called BD (Blu-ray Disc), HD DVD (High Definition DVD) or the like does not lose generality.

  The astigmatism lens 14 is a lens for giving astigmatism to the laser light reflected by the optical disk in order to perform focus control by the astigmatism method. The astigmatism lens 14 is made of optical glass or optical plastic.

  The light receiving sensor 5 receives the laser light emitted from the laser light source 3 and reflected by the optical disk, converts the laser light into an electrical signal such as a tracking control signal, a focus control signal, and an RF signal and outputs the electrical signal.

  The light receiving sensor 6 receives the laser light emitted from the laser light source 3 and reflected and separated by the beam splitter 8, converts the light amount into an electric signal, and outputs it. The electric signal is used for controlling the amount of laser light emitted from the laser light source 3.

  Both DVD and CD laser beams emitted from the laser light source 3 are diffracted and separated by the diffraction element 7 and enter the beam splitter 8. When the separated laser light is incident on the light receiving sensor 5, it is converted into an electrical signal for tracking control. A part of the laser light is reflected by the polarization separation film on the inclined surface of the beam splitter 8, enters the light receiving sensor 6, and is converted into an electric signal for controlling the amount of light. Most of the transmitted laser light is reflected by the mirror 9 and enters the collimating lens 10. The collimating lens 10 converts the divergent light into substantially parallel light and enters the wave plate 11. The laser light incident on the wave plate 11 is converted from P-polarized linearly polarized light to circularly polarized light, enters the angle conversion prism 12, changes the optical path slightly, and enters the rising prism 13. The direction of the laser light incident on the rising prism 13 is changed in a direction substantially perpendicular to the optical disk and is incident on the objective lens 4, and the objective lens 4 is converted from substantially parallel light into focused light and incident on the optical disk. The laser beam incident on the optical disc is focused on the recording surface of the optical disc.

  The laser beam reflected by the recording surface of the optical disk passes through the objective lens 4, the rising prism 13, the angle conversion prism 12, the wave plate 11, and the collimator lens 10, is reflected by the mirror 9, and enters the beam splitter 8. The objective lens 4 converts the divergent light into substantially parallel light. The wave plate 11 converts the circularly polarized light to the linearly polarized light going forward from the circularly polarized light, that is, S-polarized light. The collimating lens 10 converts substantially parallel light into focused light. The laser light incident on the beam splitter 8 is totally reflected by the polarization separation film and enters the astigmatism lens 14. The laser beam given astigmatism by the astigmatism lens 14 enters the light receiving sensor 5 and is converted into an electric signal for focus control. Further, the light quantity of at least a part of the laser light incident on the light receiving sensor 5 is converted into an electrical signal for RF signal.

  FIG. 3A is an overall configuration diagram of the first FPC according to the first embodiment, and FIG. 3B is a configuration diagram of a connection portion. The first FPC 20 is greatly curved and has a terminal portion 20g for connecting to an external connector (not shown) on one end side. On the other end side, the first FPC 20 has a connecting portion 20a to the actuator FPC 23, a connecting portion 20b to the sensor FPC 24, and a connecting portion 20c to the monitor FPC 25. The connection part 20b and the connection part 20c are substantially integral. Moreover, it has the connection part 20e for connecting with the laser light source 3. FIG. By connecting the laser light source 3 to the first FPC 20, the optical pickup device 1 can be assembled without unnecessarily increasing the number of the second FPCs 21 or increasing the area of the extension base 2c that is necessary accordingly. . Furthermore, it has a variable resistor portion 20d for mounting the variable resistor 26, and an electronic component portion 20f for mounting an electronic component 27 such as a resistor or a capacitor. A driver IC 28 for driving the laser light source 3 is also mounted on the electronic component unit 20f. The connecting portion 20a includes two small through holes 20h and a window portion 20i, and a solder land 20j is exposed in the window portion 20i. The connecting portion 20b includes a small through hole 20k and a large through hole 20l, and a solder land 20m is provided at the edge of the through hole 20l. The connecting portion 20c has a small through hole 20n, and a solder land 20o is provided on the outer edge portion. The variable resistor portion 20d includes a through hole 20p and a solder land 20q. A variable resistor 26 is fixed to the solder land 20q.

  4A is a configuration diagram of the actuator FPC of the second FPC according to the first embodiment, FIG. 4B is a configuration diagram of the sensor FPC, and FIG. 4C is a configuration diagram of the monitor FPC. The actuator FPC 23 has a connection part 23a connected to the actuator 15 at one end and a connection part 23b connected to the connection part 20a of the first FPC 20 at the other end. The connecting portion 23b includes two small through holes 23c and a solder land 23d, and a reinforcing plate is provided on the back side. The sensor FPC 24 has a connection portion 24a connected to the light receiving sensor 5 at one end and a connection portion 24b connected to the connection portion 20b of the first FPC 20. The connecting portion 24b includes two small through holes 24c and solder lands 24d, and a reinforcing plate is provided on the back side. The monitor FPC 25 has a connection part 25 a connected to the light receiving sensor 6 and a connection part 25 b connected to the connection part 20 c of the first FPC 20. The connecting portion 25b includes two small through holes 25c and a solder land 25d, and a reinforcing plate is provided on the back side. The connection portion 22 includes a connection portion between the connection portion 20a and the connection portion 23b, a connection portion between the connection portion 20b and the connection portion 24b, and a connection portion between the connection portion 20c and the connection portion 25b.

  As shown in FIG. 1, the first FPC 20 is connected to the laser light source 3 by a connecting portion 20e when the laser module 17 is attached to the carriage 2, the connecting portion 20a is the upper surface side of the extension base 2c, and the connection portions 20b and 20c are extension bases. It arrange | positions at the carriage 2 so that it may become the lower surface side of 2c. Further, the variable resistor portion 20c on which the variable resistor 26 is previously mounted is disposed on the carriage 2 so as to be on the upper surface side of the extension base 2c. On the other hand, among the second FPCs 21, the actuator FPC 23 is connected to the actuator 15 at the connection part 23a when the actuator 15 is assembled in advance, and the connection part 23b is on the upper surface side of the extension base 2c when the actuator 15 is attached to the carriage 2. It is arranged on the carriage 2 as described above. Since the actuator 15 is assembled separately, the optical pickup device 1 can be easily assembled. The sensor FPC 24 is connected to the light receiving sensor 5 at the connecting portion 24a when the laser module 17 is assembled in advance, and the carriage 2 so that the connecting portion 24b is on the lower surface side of the extension base 2c when the laser module 17 is attached to the carriage 2. Placed in. Since the laser module 17 is assembled separately, the optical pickup device 1 can be easily assembled. The monitor FPC 25 is connected to the light receiving sensor 6 in advance by the connecting portion 25a, and is arranged on the carriage 2 so that the connecting portion 25b is on the lower surface side of the extension base 2c when the light receiving sensor 6 is attached to the carriage 2. Since the light receiving sensor 6 and the monitor FPC 25 are separately connected, there is an effect that the optical pickup device 1 can be easily assembled.

  The connection portion 20a of the first FPC 20 and the connection portion 23b of the actuator FPC 23 are sequentially stacked on the upper surface side of the extension base 2c of the carriage 2. At this time, the predetermined small protrusion 2e penetrates the through hole 20h and the through hole 23c. The solder lands 20j and the solder lands 23d are oriented so as not to face the carriage 2. Then, the solder lands 23 d of the actuator FPC 23 are arranged adjacent to each other on the solder lands 20 j of the first FPC 20. The first FPC 20 and the actuator FPC 23 are connected by soldering the corresponding solder lands 20j and the solder lands 23d. The portions other than the soldering between the carriage 2 and the connection portion 23b and between the connection portion 23b and the connection portion 20a may be fixed with an adhesive or a double-sided tape as necessary.

  Similarly, the connection part 24b of the sensor FPC 24 and the connection part 20b of the first FPC 20 and the connection part 25b of the monitor FPC 25 and the connection part 20c of the first FPC 20 are also arranged and connected on the lower surface side of the extension base 2c of the carriage 2. At that time, the first FPC 20 is overlaid on the sensor FPC 24 and the monitor FPC 25. Further, at that time, the connecting portion 20b and the connecting portion 20c are substantially integrated as described above, so that it is efficient to perform the work simultaneously. The solder land 24d of the sensor FPC 24 is exposed from the through hole 20l of the connection portion 20b of the first FPC 20, and is adjacent to the solder land 20m. Further, the solder land 25d of the monitor FPC 25 is adjacent to the solder land 20o at the outer edge portion of the connection portion 20c of the first FPC 20. Solder lands 20j, 20m, 20o, 23d, 24d, and 25d that are required to have a thickness not facing the carriage 2 are disposed on both sides of the flat extension base 2c, so that it is wasted in the thickness direction of the optical pickup device 1. Space is eliminated and the thickness of the optical pickup device 1 can be reduced. Soldering is a connection method that does not use a connector or the like, and the overall thickness can be reduced.

  For connection between the first FPC 20 and the second FPC 21, for example, solder lands 20j of the first FPC 20 and solder lands 23d of the actuator FPC 23 may be opposed to each other, cream solder may be disposed therebetween, and thermocompression bonding may be performed. Similarly, solder lands 20m of the first FPC 20, the solder lands 24d of the sensor FPC 24, the solder lands 20o of the first FPC 20 and the solder lands 25d of the monitor FPC 25 are opposed to each other, and cream solder is disposed therebetween and thermocompression bonded. . The overall thickness can be made thinner than normal soldering.

  Further, the variable resistor portion 20d of the first FPC 20 is disposed on the upper surface side of the extension base 2c. The variable resistor 26 is for setting in advance so that the amount of laser light emitted to the optical disc becomes a predetermined value, and is necessary when the optical pickup device 1 is manufactured. One variable resistor 26 is provided for each of the DVD and the CD. You may fix between the carriage 2 and the variable resistor part 20d with an adhesive, a double-sided tape, etc. as needed. The variable resistor 26 has a thickness that cannot be ignored. By arranging the variable resistor 26 on the extension base 2c together with the connection portion 22, the thickness of the optical pickup device 1 can be reduced.

  The electronic component part 20 f of the first FPC 20 is arranged so as to be on the lower surface side of the electronic component region 2 d of the carriage 2. The electronic component 27 including the driver IC 28 is oriented so as not to face the carriage 2. You may fix between the carriage 2 and the electronic component part 20f with an adhesive, a double-sided tape, etc. as needed. The electronic components 27 are arranged in a concentrated manner in the electronic component area 2d. For this reason, it is not necessary to arrange the electronic component 27 on the upper surface side or the lower surface side of the optical system region 2a so as not to block the path of the laser beam, and the thickness of the optical pickup device 1 can be prevented from increasing.

  5A is a top view of the optical pickup device to which the cover according to the first embodiment is attached, FIG. 5B is a bottom view, and FIG. 6A is a cross-sectional view taken along line AA in FIGS. 5A and 5B. FIG. 4B is a cross-sectional view taken along line AA when a cover that covers the lower surface side is disposed. The covers 29, 30, and 31 are all made of sheet metal, and are fixed to the carriage 2 with several claws or screws.

  The cover 29 mainly covers the optical system region 2a and the electronic component region 2d on the upper surface side so that the optical system is exposed and is not touched by a general user, and the appearance quality is improved.

  The cover 30 mainly covers the actuator region 2b and the extension base 2c on the upper surface side, but has an opening, and a part of the actuator 15 including the objective lens 4 is exposed from the opening. Part of the actuator 15 including the objective lens 4 is exposed because it is necessary for emitting laser light from the objective lens 4 to irradiate the optical disk. It is covered with a cover 30 in order to prevent it and improve the appearance quality. Since solder obtained by soldering the solder lands 20j and the solder lands 23d is exposed on the surface of the connection portion 22 between the first FPC 20 and the actuator FPC 23, an insulating member is provided between the connection portion 22 and the back surface of the cover 30. 32 is arranged to prevent direct contact between the connecting portion 22 and the cover 30. If the distance between the connecting portion 22 and the cover 30 can be sufficiently secured, the insulating member 32 need not be disposed. The material of the insulating member 32 may be a general insulating material such as polyethylene terephthalate or polyimide.

  The cover 31 mainly covers the electronic component region 2d and the extended base 2c on the lower surface side. The cover 31 is for pressing the first FPC 20 and the second FPC 21 to prevent the first FPC 20 and the second FPC 21 from floating with respect to the carriage 2. In the extended base 2c, the cover 31 is a non-conductive portion of the connection portion 22 except for the solder obtained by soldering the solder lands 20m and the solder lands 24d and the solder obtained by soldering the solder lands 20o and the solder lands 25d. Holding the FPC part. That is, the cover 31 presses only the portion where the sensor FPC 24, which is the second FPC 21, and the first FPC 20 overlap and the portion where the monitor FPC 25 and the first FPC 20 overlap, thereby preventing direct contact between the cover 31 and the solder soldered. . Since the solder soldered and the cover 31 do not overlap at the same time, the thickness of the optical pickup device 1 can be reduced by the thickness of the cover 31 with respect to the case of overlapping. Although the soldered solder is exposed, since it is on the lower surface side opposite to the objective lens 4, it is hardly visible to general users, and the influence on the appearance quality is small.

  As shown in FIG. 6B, if there is a design margin, the cover 31 is covered up to the soldered portion as in the case of the cover 30, and the space between the soldered solder and the cover 31 is covered. An insulating member 32 may be disposed on the surface. If there is a margin, the insulating member 32 may not be disposed. By covering the cover 31 up to the soldered portion, it is possible to prevent the first FPC 20 and the second FPC 21 from floating with respect to the carriage 2 more reliably.

  As shown in FIG. 6A, the extended base 2 c has an upper surface provided outside the carriage 2 at a position lower than the upper surface of the carriage 2, and a lower surface provided at a position higher than the lower surface of the carriage 2. . Therefore, the connection part 22 can be arranged not only on the upper surface side but also on the lower surface side in the extension base 2c, and the connection part 22 is efficiently and thinly arranged without increasing the area of the extension base 2c and reducing the strength. be able to. Moreover, since the extension base 2c is flat, it is easy to maintain strength even if it is thin. Further, since the connection portion 22 on the upper surface side and the connection portion 22 on the lower surface side are arranged back to back, it is not necessary to allow for an unnecessary margin in the thickness direction, and the thickness of the carriage 2 can be reduced. . One of the unnecessary margins in the thickness direction is a gap between the cover 30 on the upper surface side and the solder that is soldered, and the minimum margin can be provided by arranging the insulating member 32. Further, since the lower surface side cover 31 does not need to cover the solder that has been soldered, the gap between the cover 31 and the solder that is one of the unnecessary margins in the thickness direction is equal to the height of the lowermost surface of the carriage 2 and the solder. It can be replaced by the difference in the height of the applied solder. Therefore, the thickness of the optical pickup device 1 can be further reduced.

  Further, a heat conductive member may be connected between the front surface of the driver IC 28 shown in FIG. Although the driver IC 28 is likely to generate heat, the heat generated in the cover 31 is transmitted through the heat transfer member and is released into the air or the like, so that the temperature of the driver IC 28 can be suppressed from rising. Examples of the heat conductive member include heat release grease such as silicon grease and heat release sheet such as graphite sheet.

  In the first embodiment, the actuator FPC 23, the sensor FPC 24, the connection portion 22 between the monitor FPC 25 and the first FPC 20, and the variable resistor 26 are arranged on the extension base 2c. However, it is not limited to that. At least one of the actuator FPC 23, the sensor FPC 24, and the monitor FPC 25 may be disposed in another location such as the electronic component area 2d, or may be abolished and directly connected from the first FPC 20 to each predetermined component. Conversely, for example, an FPC connecting the connection portion 22 to the laser light source 3 may be set, and the connection portion 22 may be disposed on the extension base 2c. Further, the variable resistor 26 may be disposed in the electronic component region 2d, for example.

  In the first embodiment, the connection portion 20e for connecting to the laser light source 3 is provided in the first FPC 20, but the present invention is not limited to this. A second FPC 21 to be newly connected to the laser light source 3 may be set, and an electronic component unit for mounting an electronic component including the driver IC 28 may be provided on the second FPC 21. Further, the variable resistor 26 may be provided in the second FPC 21. Although the number of connecting portions 22 increases, the first FPC 20 and the laser light source 3 can be handled separately, and the manufacture becomes easy.

  As described above, in the optical pickup device 1 according to the first embodiment, the extension base 2c of the carriage 2 has a flat plate shape so that the connection portions 22 can be disposed on both the upper surface and the lower surface. Therefore, the thickness of the optical pickup device 1 can be reduced while ensuring rigidity.

(Embodiment 2)
The second embodiment will be described with reference to the drawings. The second embodiment is an optical disk device provided with the optical pickup device described in the first embodiment. FIG. 7A is a configuration top view of the optical pickup module of the second embodiment, and FIG. 7B is a bottom view. FIG. 8 is a block diagram of the optical disk apparatus according to the second embodiment.

  In FIG. 7, the drive mechanism of the optical disk device 50 that includes a rotation drive unit that rotates the optical disk and a moving unit that moves the optical pickup device 1 closer to or away from the rotation drive unit is referred to as an optical pickup module 40. The base 41 forms a framework of the optical pickup module 40, and the optical pickup module 40 is configured by arranging each component directly or indirectly on the base 41.

  The rotation drive unit includes a spindle motor 42 having a turntable 42a on which an optical disk is placed. The spindle motor 42 is fixed to the base 41. The spindle motor 42 generates a rotational driving force that rotates the optical disk.

  The moving unit includes a feed motor 43, a screw shaft 44, and guide shafts 45 and 46. The feed motor 43 is fixed to the base 41. The feed motor 43 generates a rotational driving force necessary for the optical pickup device 1 to move between the inner periphery and the outer periphery of the optical disc. A stepping motor, a DC motor, or the like is used as the feed motor 43. The screw shaft 44 has a groove formed in a spiral shape, and is connected to the feed motor 43 directly or through several stages of gears. In the second embodiment, the feed motor 43 is connected through several stages of gears. The guide shafts 45 and 46 are fixed to the base 41 via support members at both ends. The guide shafts 45 and 46 support the optical pickup device 1 so as to be movable. The optical pickup device 1 includes a rack 47 having guide teeth that mesh with the grooves of the screw shaft 44. Since the rack 47 converts the rotational driving force of the feed motor 43 transmitted to the screw shaft 44 into a linear driving force, the optical pickup device 1 can move between the inner periphery and the outer periphery of the optical disc.

  The rotation driving unit is not limited to the configuration described in the second embodiment as long as it can rotate the optical disk at a predetermined rotation speed. The moving unit is not limited to the configuration described in the second embodiment as long as it can move the optical pickup device 1 to a predetermined position between the inner periphery and the outer periphery of the optical disc.

  The optical pickup device 1 has the structure shown in FIG. 5 to which covers 29, 30, and 31 are attached. As described in the first embodiment, the objective lens 4 is exposed. The optical pickup device 1 is thin and can handle all recording and reproduction of CDs and DVDs. The optical pickup device 1 performs at least one of recording and reproduction of information on the optical disk, and emits laser light toward the optical disk for that purpose. The inclination of the guide shafts 45 and 46 is adjusted by an adjustment mechanism that constitutes a support member so that the laser light emitted from the optical pickup device 1 is incident on the optical disk at a right angle.

  The first FPC 20 electrically connects the main body of the optical pickup device 1 and the main body of the optical pickup module 40. The first FPC 20 is a conductive wire for supplying electric power to the optical pickup device 1 from the main body side of the optical pickup module 40 and sending an electric signal, and an electric signal from the optical pickup device 1 to the main body side of the optical pickup module 40. It is also a conductive wire for sending. As described in the first embodiment, the optical pickup device 1 is further connected to the actuator FPC 23, the sensor FPC 24, and the monitor FPC 25 as the second FPC 21, or directly connected to the first FPC 20, as described in the first embodiment. It ’s ridiculous.

  The cover 48 has an opening to expose a part including the objective lens 4 of the optical pickup device 1 and the turntable 42 a of the spindle motor 42. Further, in the case of the second embodiment, the feed motor 43 and the guide shaft 46 are also exposed so that the thickness of the optical pickup module 40 is reduced.

  In FIG. 8, a casing 51 is configured by combining an upper casing 51a and a lower casing 51b and fixing them together using screws or the like. The tray 52 is provided in the casing 51 so as to freely appear and disappear. The tray 52 arranges the optical pickup module 40 from the lower surface side. The bezel 53 is provided on the front end surface of the tray 52, and is configured to close the entrance / exit of the tray 52 when the tray 52 is stored in the housing 51. The bezel 53 is provided with an eject switch 54, and when the eject switch 54 is pressed, the engagement between the housing 51 and the tray 52 is released, and the tray 52 can be brought into and out of the housing 51. The rails 55 are slidably attached to both sides of the tray 52 and the casing 51, respectively. A circuit board (not shown) is provided inside the casing 51 and the tray 52, and a signal processing system IC, a power supply circuit, and the like are mounted thereon. The external connector 56 is connected to a power / signal line provided in an electronic device such as a computer. Then, power is supplied into the optical disc apparatus 50 via the external connector 56, an external electric signal is guided into the optical disc apparatus 50, or an electric signal generated by the optical disc apparatus 50 is sent to an electronic device or the like. To do.

  As described above, the optical disk device 50 according to the second embodiment includes the optical pickup device 1 that is thinner and secures rigidity, and can handle all recording and reproduction of CDs and DVDs. Further, the optical disc device 50 itself is also focused so as to be thin. Therefore, the optical disk device 50 according to the second embodiment is thin and can support all recording and reproduction of CDs and DVDs.

  As described above, the objective lens driving device of the present invention is mounted on an optical pickup device and used for a thin optical disk device. The optical disk apparatus of the present invention is particularly preferably mounted on a thin notebook personal computer.

(A) Top view of the optical pickup device of the first embodiment, (b) Bottom view (A) Perspective configuration diagram from the top surface of the carriage of the first embodiment, (b) Perspective configuration diagram from the bottom surface (A) Overall configuration diagram of first FPC according to the first embodiment, (b) Configuration diagram of connection part (A) Configuration diagram of actuator FPC of second FPC of Embodiment 1, (b) Configuration diagram of sensor FPC, (c) Configuration diagram of monitor FPC (A) Top view of the optical pickup device to which the cover of Embodiment 1 is attached, (b) Bottom view (A) AA sectional view of FIGS. 5 (a) and 5 (b), (b) AA sectional view when a cover covering the lower surface side is arranged. (A) Configuration top view of optical pickup module according to Embodiment 2, (b) Bottom view Configuration diagram of optical disc apparatus of Embodiment 2 Configuration of conventional optical pickup device AA sectional view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical pick-up apparatus 2 Carriage 2a Optical system area | region 2b Actuator area | region 2c Extension base 2d Electronic component area | region 2e Small protrusion 3 Laser light source 4 Objective lens 5, 6 Light receiving sensor 7 Diffraction element 8 Beam splitter 9 Mirror 10 Collimating lens 11 Wave plate 12 Angle Conversion prism 13 Rising prism 14 Astigmatism lens 15 Actuator 16 Coupling base 17 Laser module 20 First FPC
20a, 20b, 20c, 20e Connection part 20d Variable resistor part 20f Electronic component part 20g Terminal part 20h, 20k, 20l, 20n, 20p Through hole 20i Window part 20j, 20m, 20o, 20q Solder land 21 2nd FPC
22 Connection 23 Actuator FPC
23a, 23b Connection portion 23c Through hole 23d Solder land 24 Sensor FPC
24a, 24b Connection portion 24c Through hole 24d Solder land 25 Monitor FPC
25a, 25b Connection portion 25c Through hole 25d Solder land 26 Variable resistor 27 Electronic component 28 Driver IC
29, 30, 31 Cover 32 Insulating member 40 Optical pickup module 41 Base 42 Spindle motor 42a Turntable 43 Feed motor 44 Screw shaft 45, 46 Guide shaft 47 Rack 48 Cover 50 Optical disk device 51 Housing 51a Upper housing 51b Lower housing 52 Tray 53 Bezel 54 Eject switch 55 Rail 56 External connector

Claims (18)

An optical system including an objective lens that condenses laser light emitted from a laser light source on an optical disc, an actuator that drives the objective lens, and a carriage that disposes the optical system and the actuator inside. The carriage includes a flat plate-like extension base having an upper surface provided outside the carriage at a position lower than the upper surface of the carriage and a lower surface provided at a position higher than the lower surface of the carriage. Optical pickup device. A first flexible printed circuit board connecting from the outside to at least the connection part; and a second flexible printed circuit board connecting from the connection part to a predetermined part, wherein the connection part is at least one of an upper surface or a lower surface of the extension base. The optical pickup device according to claim 1, wherein 2. The optical pickup device according to claim 1, wherein the thickness of the carriage is 3.5 mm or less. The optical pickup device according to claim 1, wherein the extension base has a thickness of 0.2 mm to 1.5 mm. 2. The optical pickup device according to claim 1, wherein the carriage has a substantially circular outer side opposite to the extended base. The optical pickup device according to claim 2, wherein the predetermined component is the actuator. 3. The optical pickup device according to claim 2, wherein the predetermined component is a light receiving sensor that receives laser light emitted from the laser light source and reflected from the optical disk. 3. The optical pickup device according to claim 2, wherein the predetermined component is a light receiving sensor that receives part of the laser light emitted from the laser light source. 3. The optical pickup device according to claim 2, wherein the first flexible printed circuit board is connected from the outside to the laser light source. 2. The optical pickup device according to claim 1, wherein an outer edge portion of the projection from the upper surface of the extension base has a substantially right angle. 3. The optical pickup device according to claim 2, wherein the first flexible printed circuit board and the second flexible printed circuit board are connected with solder. The variable resistor is disposed on at least one of the first flexible printed circuit board and the second flexible printed circuit board, and the variable resistor is disposed on an upper surface or a lower surface of the extension base. Optical pickup device. At least one of the first flexible printed circuit board or the second flexible printed circuit board includes an electronic component part that concentrates and arranges electronic components, and an electronic component region having a thickness smaller than the thickness of the carriage is formed outside the carriage. The optical pickup device according to claim 2, wherein the electronic component unit is disposed in the electronic component region. 14. The optical pickup device according to claim 13, wherein the extension base and the electronic component region are provided adjacent to each other. The optical pickup device according to claim 2, further comprising: a cover that covers at least the upper surface side of the extension base; and an insulating member between the surface of the cover that faces the connection portion and the connection portion. The optical pickup device according to claim 2, further comprising: a cover that covers at least a lower surface side of the extension base; and an insulating member between the surface of the cover that faces the connection portion and the connection portion. 3. The optical pickup according to claim 2, further comprising a cover that covers a non-conductive portion of at least one connection portion of the first flexible printed circuit board or the second flexible printed circuit board disposed on a lower surface of the extension base. apparatus. An optical system including an objective lens that condenses laser light emitted from a laser light source on an optical disc, an actuator that drives the objective lens, and a carriage that disposes the optical system and the actuator inside. The carriage includes an optical pickup device including a flat plate-like extension base having an upper surface provided outside the carriage at a position lower than the upper surface of the carriage and a lower surface provided at a position higher than the lower surface of the carriage. An optical disc device characterized by that.

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