JP2006236460A - Optical pickup device and optical disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical pickup device and an optical disk device recording/reproducing many kinds of optical disks with different distance to a recording medium or different wavelengh to be used. <P>SOLUTION: The optical pickup device has a light source which emits light with first wavelength and light with wavelength longer than the first wavelength, condensing means for condensing the light from the light source and a switching means provided between the light source and the condensing means and for switching reflection and transmission of the light with the first wavelength independent of a polarizing state. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical disc apparatus that can be mounted on a portable electronic device such as a notebook personal computer or an electronic device such as a stationary personal computer, and an optical pickup device mounted on the optical disc device.

  Conventionally, there has been a technique in which a polarization state of light emitted from a laser diode is changed by a TN liquid crystal plate, and an optical path is switched according to an optical disk to be reproduced (for example, see Patent Document 1).

However, with the diversification of types of optical discs, in particular, optical discs of different types have appeared even if the wavelength used is the same.
JP-A-9-223327

  With the diversification of the types of optical discs, there has been a demand for optical pickup devices and optical disc devices that can perform recording / reproduction on optical discs having different distances to recording layers and different wavelengths to be used.

  The present invention is provided between a light source that emits light having a first wavelength and light having a wavelength longer than the first wavelength, a condensing unit that condenses light from the light source, and the light source and the condensing unit. And switching means for switching between reflection and transmission of light of the first wavelength regardless of the polarization state.

  According to the present invention, recording / reproducing can be performed on various types of optical discs having different distances to recording layers and different wavelengths to be used.

  FIG. 1 is a schematic diagram showing an optical pickup device according to an embodiment of the present invention.

  In FIG. 1, reference numeral 1 denotes a short-wavelength optical unit that emits a short-wavelength laser. Light emitted from the short-wavelength optical unit 1 has a wavelength of 400 nm to 415 nm. In this embodiment, light of about 405 nm is emitted. It was configured as follows. In general, light having the above-described laser wavelength is blue to purple. In the present embodiment, the details of the short-wavelength optical unit 1 will be described later, but a light source unit 1a that emits a short-wavelength laser, a light-receiving unit 1b for signal detection that receives light reflected from the optical disc 2, It includes a light receiving portion 1c provided to monitor the amount of light emitted from the light source portion 1a, an optical member 1d, and a holding member (not shown) that holds these constituent members in a predetermined positional relationship. Yes. The light source unit 1a is provided with a semiconductor laser element (not shown) mainly composed of GaN or GaN, and light emitted from the semiconductor laser element is incident on the optical member 1d, and the incident light Part of the light is reflected by the optical member 1d and enters the light receiving portion 1c. Although not shown, a circuit for converting light into an electric signal by the light receiving unit 1c and adjusting the intensity of light emitted from the light source unit 1a to a desired intensity based on the electric signal is provided. . Further, most of the light emitted from the light source unit 1a is guided toward the optical disc 2 through the optical member 1d. The light reflected by the optical disk 2 is incident on the light receiving unit 1b through the optical member 1d. The light receiving unit 1b converts light into an electrical signal, and generates an RF signal, a tracking error signal, a focus error signal, and the like from the electrical signal. In the optical member 1d, a hologram 1e for separating the reflected light from the optical disc 2 is provided so that a focus error signal can be obtained.

  In this embodiment, in order to reduce the size of the optical pickup device, the optical pickup device is configured as one short wavelength optical unit including the light source unit 1a, the light receiving units 1b and 1c, and the optical member 1d. At least one of 1c may be configured to be separated from the short wavelength optical unit 1 or configured as a separate unit, or the optical member 1d may be configured to be separated from the short wavelength optical unit 1 and configured as a separate unit.

  Reference numeral 3 denotes a long wavelength optical unit that emits a long wavelength laser. The light emitted from the long wavelength optical unit 3 has a wavelength of 640 nm to 800 nm, and emits a single type of light or a plurality of types of light. A plurality of light beams having wavelengths are emitted. In the present embodiment, a light beam having a wavelength of about 660 nm (red: for example for DVD) and a light beam of about 780 nm (for infrared: for example, for CD) are emitted. In the present embodiment, details of the long wavelength optical unit 3 will be described later, but a light source unit 3a that emits a long wavelength laser, a light detection unit 3b for signal detection that receives light reflected from the optical disk 2, It includes a light receiving portion 3c provided to monitor the amount of light emitted from the light source portion 3a, an optical member 3d, and a holding member (not shown) that holds these constituent members in a predetermined positional relationship. Yes. The light source unit 3a is provided with a semiconductor laser element (not shown). This semiconductor laser element is composed of a monoblock (monolithic structure), and a light flux (red) having a wavelength of about 660 nm from the monoblock element. And a light beam (infrared) of about 780 nm is emitted. In this embodiment, the monoblock element emits two light beams. However, a single block element may emit two light beams. A plurality of light beams emitted from the semiconductor laser element are incident on the optical member 3d, and a part of the incident light is reflected by the optical member 3d and enters the light receiving unit 3c. Although not shown, a circuit for converting light into an electric signal by the light receiving unit 3c and adjusting the intensity of light emitted from the light source unit 3a to a desired intensity based on the electric signal is provided. . Further, most of the light emitted from the light source unit 3a is guided toward the optical disc 2 through the optical member 3d. The light reflected by the optical disk 2 is incident on the light receiving unit 3b through the optical member 3d. The light receiving unit 3b converts light into an electrical signal, and generates an RF signal, a tracking error signal, a focus error signal, and the like from the electrical signal. The optical member 3d is provided with a hologram 3e that separates the reflected light from the optical disc 2 into a plurality of pieces and guides them to a predetermined location on the light receiving unit 3b in order to generate a focus error signal for CD. .

  In this embodiment, in order to reduce the size of the optical pickup device, the optical pickup device is configured as one long wavelength optical unit 3 including the light source unit 3a, the light receiving units 3b and 3c, and the optical member 3d. , 3c may be configured to be separated from the long wavelength optical unit 3 or may be configured as a separate unit. Alternatively, the optical member 3d may be configured to be separated from the long wavelength optical unit 3 and configured as a separate unit.

  Reference numeral 4 denotes a beam shaping lens through which light emitted from the short wavelength optical unit 1 and reflected light from the optical disk 2 pass. The beam shaping lens 4 is preferably made of glass with little deterioration due to the passage of a short wavelength laser. In the present embodiment, the beam shaping lens 4 is made of glass. However, the beam shaping lens 4 can be made of other materials as long as the material is less deteriorated by the passage of the short wavelength laser. is there. The beam shaping lens 4 is provided for the purpose of canceling the astigmatism of the short wavelength laser and the astigmatism generated in the optical path from the short wavelength optical unit 1 to the optical disc 2. For the purpose of the beam shaping lens 4, the light reflected from the optical disk 2 may be incident on the short wavelength optical unit 1 without going through the beam shaping lens 4, but the reflected light from the optical disk 2 is optically arranged. In this embodiment, the light is incident on the short wavelength optical unit 1 through the beam shaping lens 4. In the present embodiment, the beam shaping lens 4 is used so as to reduce the astigmatism of short wavelength light. However, a beam shaping prism or a beam shaping hologram may be used instead.

  Further, convex portions 4a and concave portions 4b are respectively provided at both ends of the beam shaping lens 4, and the light emitted from the short wavelength optical unit 1 is first incident on the convex portions 4a and emitted from the concave portions 4b. The shaping lens 4 is arranged.

  Reference numeral 5 denotes an optical component, and the optical component 5 is arranged at the tip of the beam shaping lens 4 on the optical path and arranged on the concave portion 4b side of the beam shaping lens 4. That is, the light emitted from the short wavelength optical unit 1 enters the optical component 5 through the beam shaping lens 4, is guided to the optical disc 2, and the light reflected from the optical disc 2 is the optical component 5 and the beam shaping lens. Then, the light enters the short wavelength optical unit 1 through 4. The optical component 5 is provided with a hologram and has at least the following functions. That is, it is a function of separating the light reflected from the optical disc 2 into a predetermined light flux so as to mainly generate a tracking error signal. As described above, the hologram 1e provided in the optical member 1d is separated into a plurality of light beams to generate a focus error signal, and the optical component 5 generates a tracking error signal into a plurality of light beams. To separate.

  As will be described in detail later, the optical component 5 may have a function of functioning as a RIM intensity correction filter that attenuates the amount of light at a substantially central portion of short-wavelength light. Further, the optical component 5 is separated into two parts, and one optical component 5 has a function of separating the light reflected from the optical disc 2 into a predetermined light beam so as to mainly generate a tracking error signal. The optical component 5 can also have a function of a RIM intensity correction filter.

  Reference numeral 6 denotes a relay lens through which long-wavelength light emitted from the long-wavelength optical unit 3 passes. The relay lens 6 is made of a transparent member such as resin or glass. The relay lens 6 is provided to efficiently guide the light emitted from the long wavelength optical unit 3 to the rear member. Further, by providing the relay lens 6, the long wavelength optical unit 3 can be arranged on the beam splitter 7 side, so that the apparatus can be reduced in size.

  A beam splitter 7 is an optical member. At least two transparent members 7b and 7c are joined in the beam splitter 7, and one inclined surface 7a is provided between the transparent members 7b and 7c. The inclined surface 7a is provided with a wavelength selection film. A wavelength selective film is directly formed on the inclined surface 7a of the transparent member 7c into which the light emitted from the short wavelength optical unit 1 enters, and resin or glass is formed on the inclined surface 7a of the transparent member 7c on which the wavelength selective film is formed. The transparent member 7b is joined via a joining material such as.

  The beam splitter 7 has a function of reflecting the short wavelength light emitted from the short wavelength optical unit 1 and transmitting the light emitted from the long wavelength optical unit 3. That is, the light emitted from the short wavelength optical unit 1 and the light emitted from the long wavelength optical unit 3 are guided in substantially the same direction.

  A collimator lens 8 is movably held. The collimator lens 8 is attached to a slider 8b, and the slider 8b is movably attached to a pair of support members 8a provided substantially in parallel. A lead screw 8c provided with a helical groove is provided so as to be substantially parallel to the support member 8a, and a protrusion entering the groove of the lead screw 8c is provided at the end of the slider 8b. A gear group 8d is coupled to the lead screw 8c, and a drive member 8e is provided in the gear group 8d. The driving force of the driving member 8e is transmitted to the lead screw 8c through the gear group 8d, and the lead screw 8c is rotated by the driving force, and as a result, the slider 8b moves along the supporting member 8a. That is, the collimator lens 8 can be moved in the direction approaching the beam splitter 7 or moved away from the beam splitter 7 depending on the difference in the driving direction and the driving speed of the driving member 8e, and the speed of the movement. Etc. can be adjusted.

  Various motors and the like are preferably used as the drive member 8e, and it is particularly preferable to use a stepping motor as the drive member 8e. That is, by adjusting the number of pulses sent to the stepping motor, the rotation amount of the lead screw 8c is determined, and as a result, the movement amount of the collimator lens 8 can be easily set.

  In this manner, by adopting a configuration in which the collimator lens 8 is brought close to or away from the beam splitter 7, the spherical aberration can be easily adjusted. That is, since the spherical aberration of the short wavelength light can be adjusted by the position of the collimator lens 8, the first recording layer provided in the short wavelength optical disc and the depth different from the first recording layer. Each of the second recording layers provided in the recording medium can be configured to effectively perform at least one of recording and reproduction.

  The collimator lens 8 is made of glass or, preferably, a short-wavelength light resin (a resin that does not deteriorate or hardly deteriorate due to a short wavelength), since long-wavelength and short-wavelength light incident from the beam splitter 7 is transmitted. . The collimator lens 8 also transmits short-wavelength or long-wavelength light reflected by the optical disk 2.

  Further, in the present embodiment, the configuration for correcting the spherical aberration of light having a short wavelength is configured such that the collimator lens 8 is moved by the driving member 8e. However, the collimator lens 8 is moved by other configurations. Alternatively, the spherical aberration of the short wavelength light may be adjusted using other means.

  Reference numeral 9 denotes a raising mirror, and the raising mirror 9 is provided with a quarter-wave member 9a that acts on short-wavelength light. As the quarter-wave member 9a, a quarter-wave plate that rotates the polarization direction of light that has passed twice (in the forward path and the return path) by approximately 90 degrees is preferably used. In the present embodiment, the quarter wavelength member 9 a is sandwiched between the rising mirrors 9. A wavelength selection film 9b is provided on the surface of the rising mirror 9 on which the light emitted from the units 1 and 3 is incident. The wavelength selection film 9b is provided so that the long wavelength light emitted from the long wavelength optical unit 3 is almost reflected. It has a function of transmitting almost all the light having a short wavelength emitted from the wavelength optical unit 1.

  Reference numeral 10 denotes an objective lens for a long wavelength laser. The objective lens 10 condenses the light reflected from the rising mirror 9 on the optical disk 2. Although the objective lens 10 is used in the present embodiment, the objective lens 10 may be composed of other condensing members such as a hologram. As a matter of course, the light reflected from the optical disk 2 passes through the objective lens 10. The objective lens 10 is made of a material such as glass or resin.

  Reference numeral 11 denotes an optical component provided between the objective lens 10 and the raising mirror 9. The optical component 11 is compatible with the optical disc 2 of DVD (light having a wavelength of approximately 660 nm) and CD (light having a wavelength of approximately 780 nm). In addition, an aperture filter for realizing a necessary numerical aperture, a polarization hologram that reacts to light having a wavelength of about 660 nm, and a quarter wavelength member (preferably a quarter wavelength plate) are provided. . The optical component 11 includes a dielectric multilayer film, a diffraction grating aperture means, and the like. A polarization hologram applies polarization to light of approximately 660 nm (separates light having a wavelength of approximately 660 nm into light for tracking error signals and focus error signals). Further, the quarter wavelength member rotates the polarization direction of the return path with respect to the forward path of light having a wavelength of approximately 660 nm and approximately 780 nm by approximately 90 degrees.

  Reference numeral 12 denotes a rising mirror that almost reflects short-wavelength light. The rising mirror 12 is provided with a reflective film.

  Reference numeral 13 denotes an objective lens, and the objective lens 13 condenses the light reflected from the rising mirror 12 on the optical disk 2. Although the objective lens 13 is used in the present embodiment, the objective lens 13 may be composed of other condensing members such as a hologram. As a matter of course, the light reflected from the optical disk 2 passes through the objective lens 13. The objective lens 13 is made of glass or resin, but when the objective lens 13 is made of resin, it is preferably made of a short-wavelength light resin (a resin that does not deteriorate or hardly deteriorate due to a short wavelength). Composed.

  Reference numeral 14 denotes an achromatic diffraction lens provided between the objective lens 13 and the raising mirror 12, and the achromatic diffraction lens 14 has a function of correcting chromatic aberration. The achromatic diffractive lens 14 is provided so as to cancel and reduce chromatic aberration caused by each optical component through which light having a short wavelength passes. The achromatic diffractive lens 14 is basically formed by forming a desired hologram on the lens, and the degree of correction of chromatic aberration can be determined by adjusting at least one of the grating pitch of the hologram and the radius of curvature of the lens. It is. The achromatic diffractive lens 14 is made of resin such as plastic or glass. In the case of using a resin or the like, the resin is preferably composed of a short-wavelength light resin (a resin that does not deteriorate or hardly deteriorate due to a short wavelength).

  The specific arrangement of the optical system configured as described above will be described below with reference to FIG.

  FIG. 2 actually shows an example in which the optical configuration shown in FIG. 1 is embodied. The shape and the like of the members shown in FIG. 1 are slightly different, but the functions are almost the same.

  Reference numeral 15 denotes a base, to which the above-described members are attached so as to be fixed or movable. The base 15 is made of a metal or metal alloy material such as zinc, zinc alloy, aluminum, aluminum alloy, titanium, or titanium alloy, and is preferably made using a die casting method or the like from the viewpoint of mass production. The base 15 is movably held by an optical pickup module as shown in FIGS.

  3 and 4, reference numeral 20 denotes a frame, to which shafts 21 and 22 arranged substantially in parallel are attached to the frame 20, and a base 15 is movably attached to the shafts 21 and 22. Further, on the opposite side of the shaft 22 from the shaft 21 side, a screw shaft 23 provided with a helical groove is attached to the frame 20 so as to be rotatable in parallel with the shafts 21 and 22. Although not shown in detail, a member provided integrally or separately on the base 15 is engaged with a groove provided on the screw shaft 23. The screw shaft 23 meshes with a gear group 24 a that is rotatably provided on the frame 20, and the gear group 24 a meshes with the feed motor 24. Accordingly, when the feed motor 24 is rotated, the gear group 24a is rotated, and the screw shaft 23 is rotated accordingly. As the screw shaft 23 is rotated, the base 15 reciprocates in the arrow direction shown in FIG. be able to. At this time, in the present embodiment, the feed motor 24 is disposed substantially parallel to the screw shaft 23. Further, the optical disk 2 is mounted on the frame 20, and a spindle motor 25 for rotating the optical disk 2 is attached by a method such as screwing or bonding.

  Further, as shown in FIG. 3, a control board 26 is provided separately from the frame 20, and the control board 26 and the base 15 are electrically joined, for example, via a flexible board 29. Further, the control board 26 is also electrically connected to the spindle motor 25 by a member not shown. The control board 26 is provided with a connector 27 for electrical connection with a control board provided in the optical disk apparatus. A flexible board or the like (not shown) is inserted into the connector 27 for electrical connection.

  Further, as shown in FIG. 4, a frame cover 30 for the purpose of protecting the member may be provided at least on the side facing the optical disk in the frame 20. A through hole 31 is provided in the frame cover 30, and at least the objective lenses 10 and 13 on the base 15 are exposed from the through hole 31, and a spindle motor 25 protrudes a predetermined amount. 3 and 4, the frame 20 is provided with an attachment portion 20a for fixing to other members, and screws or the like are inserted into the attachment portion 20a to attach the frame 20 to other members.

  In FIG. 2, a base 15 includes a short wavelength optical unit 1, a long wavelength optical unit 3, a beam shaping lens 4, an optical component 5, a relay lens 6, a beam splitter 7, a support member 8a, a lead screw 8c, and a gear group 8d. , The drive member 8e, the raising mirrors 9 and 12, etc. are bonded using an organic adhesive such as a photo-curing adhesive or an epoxy adhesive, or a metal adhesive such as solder or lead-free solder is used. Or are attached using a method such as screwing, fitting, or press-fitting.

  The lead screw 8c and the gear group 8d are rotatably attached to the base 15.

  Reference numeral 17 denotes a suspension holder. The suspension holder 17 is attached to the base 15 by various joining methods via a yoke member to be described later, and the lens holder 16 and the suspension holder 17 are coupled via a plurality of suspensions 18. The lens holder 16 is supported so as to be movable within a predetermined range with respect to the base 15. The lens holder 16 is provided with the objective lenses 10 and 13 and the optical component 11, the achromatic diffraction lens 14, and the like. When the lens holder 16 is moved, the objective lens 10 and 13 and the optical component 11 and the color are moved together with the lens holder 16. The eraser diffractive lens 14 also moves. As shown in FIG. 5, the raising mirrors 9 and 12 are attached to raised portions 15d and 15e provided on the base 15 by a photo-curing resin or an instantaneous adhesive, respectively. When the rising mirror 9 is attached to the raised portion 15d, the bonding position between the raised mirror 9 and the raised portion 15d is considered so as not to block the light transmitted through the rising mirror 9. Since the raising mirrors 9 and 12 are provided so as to be positioned below the lens holder 16, they are not shown in FIG.

  Since the rising mirror 9 is inclined with respect to the light beam emitted from the short wavelength optical unit 1 and passed through the beam splitter 7 and the collimator lens 8, the light beam coming from the short wavelength optical unit 1 The light is refracted when passing through the raising mirror 9, and moves by a distance d shown in FIG.

  As shown in FIG. 5, the objective lens 10 and the objective lens 13 having a lens axial thickness larger than that of the objective lens 10 are emitted from the short wavelength optical unit 1 and the long wavelength optical unit 3 and are beam splitter 7. The objective lens 10 and the objective lens 13 are arranged in this order along the direction in which the light passing through the collimator lens 8 travels. In other words, as shown in FIG. 6, in the lens holder 16, the objective lens 13 and the objective lens 10 are arranged in this order from the suspension holder 17 side.

  By arranging the objective lenses 10 and 13 in such a manner, even if the lens holder 16 is driven up and down, the light beam is not blocked by the objective lens 13 and the achromatic diffraction lens 14, so that the optical pickup device is thin. Can be realized.

  The configuration around the lens holder 16 will be described with reference to FIGS. FIG. 7 is a cross-sectional view taken along the line AA of FIG. 6 showing the optical pickup device in the present embodiment.

  As shown in FIG. 7, the lens holder 16 is provided with through holes 16a and 16b. The objective lenses 10 and 13 are dropped into the through holes 16a and 16b from the P1 direction shown in FIG. Fixed with adhesive. At this time, the outer peripheral portions of the objective lenses 10 and 13 come into contact with the peripheral portions of the through holes 16 a and 16 b of the lens holder 16. Further, the optical component 11 and the achromatic diffractive lens 14 are respectively inserted into the through holes 16a and 16b from the direction of the arrow P2 in FIG. 7, and are also fixed by a photo-curing adhesive or an instantaneous adhesive. Also at this time, the outer peripheral portions of the optical component 11 and the achromatic diffraction lens 14 come into contact with the peripheral portions of the through holes 16 a and 16 b of the lens holder 16.

  As shown in FIG. 6, reference numerals 33 and 34 denote focus coils, which are respectively wound in a substantially ring shape, and are provided at diagonal positions of the lens holder 16. Similarly to the focus coils 33 and 34, the tracking coils 35 and 36 are wound in a substantially ring shape, and are provided at diagonal positions different from the focus coils 33 and 34, respectively. Sub-tracking coils 37 and 38 are provided between the focus coils 33 and 34 and the lens holder 16, respectively. By providing the sub-tracking coils 37 and 38, an unnecessary inclination of the lens holder 16 generated during tracking can be suppressed. The sub-tracking coils 37 and 38 are bonded to the lens holder 16 with an organic adhesive such as a thermosetting adhesive, and then the focus coils 33 and 34 are bonded to the sub-tracking coils 37 and 38 with an adhesive or the like. In addition, for example, a method in which a joined body in which the sub-tracking coil 37 and the focus coil 33 are joined in advance may be adhered to the lens holder 16. For the bonding between these coils and the lens holder 16 or between the coils, a thermosetting adhesive is preferably used. However, bonding using a photocurable adhesive or other adhesive is also possible. It can be implemented. In addition, as long as the coil, the lens holder 16, and the coils can be reliably arranged at predetermined positions, they may be joined using other methods.

  Three suspensions 18 are provided on one side so as to sandwich the lens holder 16, and the suspension 18 elastically connects the suspension holder 17 and the lens holder 16, and at least the lens holder 16 is within a predetermined range. The suspension holder 17 can be displaced. In the present embodiment, three suspensions 18 are provided on one side, for a total of six. However, even if a larger number (for example, eight) of suspensions 18 is provided, the number of suspensions 18 (for example, four) is less than that. ) Suspension 18 may be provided. For convenience, the upper three suspensions 18 in FIG. 6 are the suspensions 18a, 18b, and 18c from the side facing the optical disc 2, and the lower three suspensions 18 in FIG. 18e and 18f. Both ends of the suspension 18 are fixed to the lens holder 16 and the suspension holder 17 by insert molding, respectively.

  Hereinafter, an example of wiring between the suspension 18 and each coil provided in the lens holder 16 will be described. That is, a current flows through each suspension provided in the lens holder 16 via the suspension 18.

  Both ends of the focus coil 33 are electrically connected to the suspensions 18a and 18b, respectively, and both ends of the focus coil 34 are electrically connected to the suspensions 18d and 18e, respectively. The tracking coil 35, the sub-tracking coil 37, the tracking coil 36, and the sub-tracking coil 38 are connected in series, and one end of each of the series connected coils is connected to the suspension 18c, and the other is connected to the suspension 18c. Connected to the suspension 18f. The ends of the coils and the suspension 18 are electrically connected to each other by a metallic bonding material such as solder or lead-free solder.

  The suspension 18 may be configured by a wire having a substantially circular cross section, a substantially elliptical shape, or a polygonal shape such as a rectangular cross section, or may be formed as a suspension 18 by processing a leaf spring. The suspension 18 is substantially C-shaped when viewed from the light emission direction of the objective lenses 10 and 13 with the suspension holder 17 facing down, and tension is applied. This makes it possible to reduce the size and resonance of the suspension 18 in the buckling direction.

  Reference numeral 32 denotes a yoke member made of Fe or an Fe alloy that can easily form a magnetic circuit, and the yoke member 32 is cut and raised by standing portions 32a, 32b, and 32c facing the respective coils provided on the lens holder 16. For example, the yoke member 32 is integrally provided. An opening 32d is provided on the lower surface of the yoke member 32, and the rising mirrors 9 and 12 fixed to the base 15 are inserted from the opening 32d. The suspension holder 17 is fixed on the yoke member 32 by a technique such as adhesion, and the yoke member 32 is also joined to the base 15 by a technique such as adhesion.

  Reference numerals 39 to 42 denote magnets provided on the yoke member 32 by a technique such as adhesion.

  The magnet 39 is attached to the standing portion 32 c and is provided to face the focus coil 33 and the sub-tracking coil 37. Further, the magnet 39 has a magnetic pole exposed on the surface facing the focus coil 33 and the sub-tracking coil 37 in the order of S pole and N pole from the bottom surface toward the objective lenses 10 and 13 in the height direction shown in FIG. Thus, the yoke member 32 is magnetized.

  In the width direction shown in FIG. 6, the magnet 40 is attached to the side opposite to the side where the magnet 39 is attached of the standing portion 32 c and is provided so as to face the tracking coil 35. In this embodiment, the standing portion 32c is formed wide in the width direction shown in FIG. 6 so as to increase the rigidity and the like of the yoke member 32. However, the standing portion 32c is divided into two, and one of them is a magnet. It is good also as a structure which attached 39 by adhesion | attachment etc. and attached the magnet 40 to the other. Further, the magnet 40 is magnetized so that the magnetic poles are exposed on the surface facing the tracking coil 35 in the order of N pole and S pole from the inside in the width direction shown in FIG. .

  The magnet 41 is attached to the standing portion 32b and is provided so as to face the tracking coil 36. In the width direction shown in FIG. 6, a magnetic pole is formed on the surface facing the tracking coil 36 in order of N pole and S pole from the inside. It is magnetized so as to be exposed and disposed on the yoke member 32.

  The magnet 42 is attached to the standing portion 32 a and is provided to face the focus coil 34 and the sub-tracking coil 38. Further, the magnet 42 has magnetic poles exposed on the surface facing the focus coil 34 and the sub-tracking coil 38 in the order of S pole and N pole from the bottom surface toward the objective lenses 10 and 13 in the height direction shown in FIG. Thus, the yoke member 32 is magnetized.

  Details of each part will be described below.

  First, the short wavelength optical unit 1 will be described with reference to FIGS. Note that FIG. 9 is illustrated so that the arrangement relationship of each part is clear, and FIG. 10 is a cross-sectional view of the actual short wavelength optical unit 1.

  At least the light source unit 1a, the light receiving unit 1b, the light receiving unit 1c, and the optical member 1d are directly or indirectly attached to the mounting unit 43. Further, the rear end portion of the placement portion 43 is attached to the holding member 44. The mounting portion 43c of the mounting portion 43 with the holding member 44 has a convex curved shape, and similarly, the mounting portion of the holding member 44 with the mounting portion 43 has a concave curved shape. The mounting portion 43 is combined with the holding member 44 and is positioned so as to have a desired positional relationship with each other by sliding the curved portions, and thereafter, a metal adhesive such as solder or an organic adhesive Fixed to each other.

  The mounting unit 43 is provided with a light source storage unit 43a that can store at least a part of the light source unit 1a. After the light source unit 1a is stored in the light source storage unit 43a, the light source unit 1a is a light source using a bonding material. It joins so that it may not drop from storage part 43a. In addition, a through hole 43b is provided in a portion facing the light emitting part of the light source part 1a so as to communicate with the light source storage part 43a, and light emitted from the light source part 1a passes through the through hole 43b and enters the optical member 1d. Led. As will be described later in detail, the optical member 1d includes at least an optical unit 46 having an inclined surface 46a and an optical unit 47 having a plurality of inclined surfaces therein. The mounting portion 43 is integrally formed with a light receiving attachment portion 48 facing the optical member 1 d, and a through hole 45 is provided in the light receiving attachment portion 48. On the opposite side of the light receiving attachment portion 48 from the optical member 1d side, the light receiving portion 1b is attached through a flexible printed circuit board 49 by a technique such as adhesion. Although the flexible printed circuit board 49 is omitted and described in FIG. 9 and FIG. 10, etc., the light receiving portion 1b is electrically connected to other members, and a through hole 49a is provided. The light from the optical member 1d is guided to the light receiving unit 1b through the through holes 45 and 49a. Further, as apparent from FIG. 10, the light receiving attachment portion 50 is integrally provided on the mounting portion 43 so as to face the light receiving attachment portion 48, and the optical member 1 d is interposed between the light receiving attachment portions 48 and 50. Be placed. Although not illustrated in the light receiving attachment portion 50, a through hole is provided, and the light receiving portion 1c is attached to the light receiving attachment portion 50 by a technique such as adhesion. Light from the optical part 46 passes through a through hole of the light receiving attachment part 50 (not shown) and enters the light receiving part 1c.

  Next, the optical parts 46 and 47 of the optical member 1d will be described in detail with reference to FIG.

  The light having a short wavelength emitted from the light emitting point of the light source unit 1a is guided to the optical unit 46 through the cover glass 51 provided in the portion serving as the light emission window of the light source unit 1a. The light incident on the flat surface 46b provided substantially parallel to the cover glass 51 of the optical unit 46 passes through the optical unit 46, and the light incident on the inclined surface 46a inclined with respect to the flat surface 46b is reflected and is shown in FIG. Is incident on a light receiving unit 1c not shown, and is used for monitoring optical output. A reflective portion such as a dielectric multilayer film or a metal film is formed on the inclined surface 46a. Most of the light passing through the optical unit 46 is guided to the optical unit 47 through the plane 46c provided substantially parallel to the plane 46b. At this time, although not shown in the drawing, a dimming filter is formed on the flat surface 46 c, and the light dimmed by the dimming filter is guided to the optical unit 47. The transmittance of the neutral density filter has various values, and the transmittance is adjusted by the spread angle of the light emitted from the light source unit 1a. That is, when the spread angle of light from the light source unit 1a is large, the transmittance of the dimming filter is low, and when the spread angle of light from the light source unit 1a is small, the transmittance of the dimming filter is increased. Configure as follows. In this way, by adjusting the transmittance of the light control filter according to the spread angle of the light from the light source unit 1a, the light output is too strong during recording or reproduction of a single-layer disc or a multilayer disc, and undesired data erasure Can be prevented. Specifically, the spread angle of light emitted from the light source unit 1a is classified in advance for each predetermined range, and a dimming filter having a different transmittance is provided for each classified light source unit 1a, so that the optical disc is And good recording / reproducing characteristics can be obtained. The dimming filter is composed of a dielectric multilayer film or a metal film, and when adjusting the transmittance, when using a dielectric multilayer film, it can be adjusted by its constituent material, film configuration or film thickness. When a metal film is used, the constituent material and thickness of the metal film can be adjusted.

  The light that has passed through the plane 46 c enters the optical unit 47. At this time, a gap having a predetermined interval is provided between the optical unit 46 and the optical unit 47. The optical part 47 has a substantially rectangular parallelepiped shape as a whole, and a light absorption film having a light absorption function is provided on a bottom surface 53 on which light from the light source part 1a is incident, except for a predetermined region. This prevents the light emitted from the light source unit 1a from entering the optical unit 47 from a place other than the predetermined portion. At least a part of the light emitted from the light source unit 1 a and passed through the optical unit 46 enters the optical unit 47 from a portion where the absorption film on the bottom surface 53 is not disposed.

  The optical unit 47 is configured by joining blocks 58 to 61 made of transparent glass or the like, and an inclined surface 54 is formed at a joint portion between the block 58 and the block 59, and between the block 59 and the block 60. An inclined surface 55 is formed, and an inclined surface 56 is formed between the block 60 and the block 61. At least inclined surfaces 54, 55, and 56 are provided inside the optical unit 47, and end portions of the inclined surfaces 54, 55, and 56 are exposed on the surface of the optical unit 47. The inclined surface 54 is provided with a first polarizing beam splitter, and the inclined surface 55 is similarly provided with a second polarizing beam splitter. The first and second polarizing beam splitters are both formed directly on the block 59, but the first polarizing beam splitter may be formed on the block 58, or the second polarizing beam splitter may be formed on the block 60. May be. Both the first and second polarization beam splitters have a function of transmitting P-polarized light (hereinafter abbreviated as P wave) and reflecting S-polarized light (hereinafter abbreviated as S wave). In addition, at least the first and second polarization beam splitters may be provided in a portion through which light mainly passes in the optical unit 47, but in the case of the present embodiment, the inclined surfaces 54, 55 was provided on the entire surface. On the inclined surface 56, a reflection film and a hologram 57 (same as the hologram 1e shown in FIG. 1) for generating astigmatism are formed.

  Light that has entered the optical unit 47 through the bottom surface of the optical unit 47 from the light source unit 1 a is an S wave, is reflected by the first polarizing beam splitter provided on the inclined surface 54, and is formed on the inclined surface 55. The light is incident on the second polarization beam splitter. As described above, the second polarizing beam splitter also reflects the S wave, so that the light incident on the second polarizing beam splitter is reflected and emitted from the upper surface 62z of the optical unit 47, and passes through the above-described members. To the optical disc 2. Further, the light reflected by the optical disk 2 is converted into a P wave by the action of the quarter wavelength member 9 a and enters the optical unit 47 again from the upper surface 62 z of the optical unit 47. At this time, the emission part of the light directed from the optical unit 47 toward the optical disk 2 and the incident part of the reflected light reflected from the optical disk 2 are substantially at the same position. Since the light reflected from the optical disk 2 and returned to the optical unit 47 is a P wave as described above, the second polarization beam splitter provided on the inclined surface 55 is transmitted and incident on the inclined surface 56. The inclined surface 56 is provided with a reflection hologram 57 that generates astigmatism, and the reflected light from the optical disc 2 is separated in a predetermined direction by the hologram 57 so that a focus error signal can be obtained. Since the light reflected by the inclined surface 56 is a P wave, it passes through the second polarizing beam splitter again, passes through the block 59, and as described above, the first polarizing beam splitter also transmits the P wave. Therefore, the light passes through the first polarizing beam splitter, passes through the block 58, is emitted to the outside of the optical unit 47, and then enters the light receiving unit 1b.

  Next, an example of the light source unit 1a will be described with reference to FIGS.

  As shown in FIGS. 12 and 13, the light source unit 1a is composed of the following members. First, a base 62 made of a metal material is provided, and concave portions 62a used for adjusting the position of the light source unit 1a and the like are provided on both short sides of the base 62. Further, through holes 62b and 62c are provided. Although not shown in the drawing, another through hole is provided in addition to the through holes 62b and 62c. A cover member 63 is joined to the base 62 by welding, soldering, or the like. A square through hole 64 is provided on the top surface of the cover member 63, and a cover glass 65 (see FIG. 11) is formed so as to close the through hole 64. The same as the cover glass 51) is attached by a technique such as adhesion. The cross section of the cover member 63 is an ellipse or an ellipse. In addition, a block 66 such as copper or a copper alloy, preferably having good thermal conductivity, is provided in a region surrounded by the base 62 and the cover member 63, and the block 66 is joined to the base 62 by welding or a metal joining material. Has been. The cross section of the block 66 has a substantially semicircular shape. A semiconductor laser element 68 is provided on a flat portion of the block 66 via a submount 67 made of a metal material. Accordingly, the submount 67 and the semiconductor laser element 68 are disposed in the region surrounded by the base 62 and the cover member 63 together with the block 66. The light emitting surface of the semiconductor laser element 68 is disposed so as to face the cover glass 65 and is emitted from the cover glass 65 to the outside. Rod-like terminals 69, 70, 71 are inserted into the through holes 62b, 62c provided in the base 62 and the other through holes, respectively, and the terminals are provided so as to maintain insulation between the base 62 and the terminals 69, 70, 71. The through holes 62b, 62c of 69, 70, 71 and the portions inserted into the other through holes are attached to the base 62 via an insulating material. The tip portions of the terminals 69, 70, 71 protrude into a region surrounded by the base 62 and the cover member 63. Although not shown, between the semiconductor laser element 68 and the terminals 69, 70, 71 by wire bonding or the like. Make electrical connections. Accordingly, power is supplied to the semiconductor laser element 68 via the terminals 69, 70, 71, and light having a short wavelength is emitted.

  As described above, the semiconductor laser element 68 is preferably a gallium nitride based semiconductor laser element in which an active layer (gallium nitride having an emission center such as In) is basically provided between p-type gallium nitride and n-type gallium nitride. Used to emit light having a wavelength of 400 nm to 415 nm. As a matter of course, other material-based semiconductor laser elements that emit other short-wavelength lasers can also be used.

  The semiconductor laser element 68 has a rectangular parallelepiped shape with a rectangular cross section, and since the long side portion of the cross sectional rectangle is joined to the submount 67, the long side 62d of the base 62 and the length of the cross sectional rectangle of the semiconductor laser element 68 are long. The side direction P is non-parallel (in the present embodiment, it intersects substantially vertically). With such a configuration, the cross section of the light emitted from the semiconductor laser element 68 can be emitted so that the major axis of the intensity distribution of the substantially elliptical radiation light and the long side 62d of the base member 62 are substantially parallel. it can. For example, as shown in FIG. 14, 72 is an axis substantially parallel to the long side 62 d of the base 62, and 74 is a light profile indicated by a line with constant intensity, which is an intensity distribution of light emitted from the semiconductor laser element 68. , 73 is a substantially elliptical long axis of the contour 74 of the emitted light. In this embodiment, as shown in FIG. 14A, the angle θ at which the axis 72 and the long axis 73 intersect is 90 degrees. Instead of the configuration, as shown in FIG. 14B and FIG. 14C, the angle θ is set not to be 90 degrees. Note that the angle θ is defined as the minimum angle at which the axis 72 and the long axis 73 intersect. That is, the angle θ is not less than 0 degrees and not more than 90 degrees. That is, as shown in FIG. 14B, the axis 72 and the long axis 73 are parallel, and as shown in FIGS. 14B to 14F, the long axis 73 and the axis 72 intersect at a predetermined angle θ. ing. At this time, the intersecting angle θ is preferably 0 ° or more and 45 ° or less, more preferably 0 ° or more and 30 ° or less, and further preferably 0 ° or more and 10 ° or less. Naturally, as shown in FIG. 14B, it is most preferable that the major axis 73 and the axis 72 are substantially parallel (the angle θ is substantially 0 degree). In the above example, the shaft 72 is parallel to the long side 62d of the base 62. However, the shaft 72 can also be defined in relation to other components as described below. That is, the axis 72 can be defined as being an axis parallel to the main surface of the mounted optical disk 2 and perpendicular to the direction of the light emitted from the cover glass 65 of the light source unit 1a. It can also be defined that the axis is perpendicular to the thickness direction of the base 15 shown and is also perpendicular to the direction of the light emitted from the cover glass 65 of the light source unit 1a, and is parallel to the bottom surface of the base 15 and also the light source unit 1a. It can also be defined that the axis is perpendicular to the direction of light emitted from the cover glass 65. Furthermore, it can also be defined as an axis perpendicular to the rotation axis of the spindle motor 25 and perpendicular to the direction of light emitted from the cover glass 65 of the light source unit 1a.

  In this way, by making the long axis of the outer ring of the light emitted from the light source unit 1a as described above, the light utilization efficiency can be increased, and the light source unit 1a having the same output can be used. For example, if the optical disk 2 can be irradiated with light having a higher output and the intensity of the light applied to the optical disk 2 is the same, the light source unit 1a having a lower output can be used.

  Hereinafter, the principle will be described in detail with reference to FIG.

  FIG. 15A shows a case where the axis 72 and the long axis 73 intersect perpendicularly, that is, a case where a vertically long oval shape is formed in the drawing. In this case, an area up to a portion having a predetermined amount of light when the light quantity at the center Q of the light outline 74 (a point where the major axis and the minor axis intersect) is 1 in the direction along the axis 72. Of light is used. That is, for example, in the present embodiment, the predetermined ratio is 0.6 (this ratio is determined depending on the specification, etc., but is generally 0.3 to 0.8). The light in the circular region 75 of the distance, that is, the circular region 75 having a diameter of L1 + L2 can be used. In this embodiment, since L1≈L2, the region of light that is substantially used is a circular region 75 having a radius of L1 or L2. In the case of FIG. 15A, since it is vertically long, in the direction of the axis 72, the distances L1 and L2 at which the light quantity from the center Q to the center Q becomes 0.6 are relatively short and can be used. There is a small amount of light. On the other hand, as in the optimum embodiment shown in FIG. 15B, the light in the region up to the portion where the light amount is a predetermined ratio is used. That is, for example, in the present embodiment, the predetermined ratio is 0.6 (this ratio is determined depending on the specification or the like, but is usually 0.3 to 0.8), and L3 and L4 from the center Q to the left and right. The light in the circular region 75 of the distance, that is, the circular region 75 having a diameter of L3 + L4 can be used. In this embodiment, since L3≈L4, the region of light that is substantially used is a circular region 75 having a radius of L3 or L4. In the case of FIG. 15B, since the light outline 74 is horizontally long, in the direction of the axis 72, the distances L3 and L4 at which the light amount from the center Q to the center Q becomes 0.6 are relatively long. Therefore, the available light amount area is very wide compared to the example of FIG. 15A, and light can be used efficiently. That is, L1 <L3 and L2 <L4.

  In the present embodiment, as described above, the configuration in which the major axis 73 of the substantially elliptical light emitted from the light source unit 1a is not perpendicular to the axis 72 but is a predetermined angle θ (including 0 degrees) is shown in FIG. 12 and 13, the long side 62 d of the base 62 is attached to the base 15 side, so that the long axis of the elliptical light emitted from the light source unit 1 a is set to the base 15 as described above. Since it can be made substantially parallel and the height of the light source unit 1a is not increased, the apparatus can be made thinner. In the optical disk apparatus of 18 mm or less, preferably 15 mm or less, more preferably 13 mm or less assumed in the present embodiment, it is very preferable to mount the light source unit 1a low in realizing these optical disk apparatuses. It can be said. Further, when the shaft 72 and the long shaft 73 are set to a predetermined angle (greater than 0 degree and less than 90 degrees), the light source unit 1a itself is rotated by a predetermined angle (in this case, the light source unit 1a is somewhat attached) Or the block 66 in the light source section 1a is rotated by a predetermined amount to be attached to the base 62, or when the semiconductor laser element 68 is attached to the block 66, the long side 62d is inclined. It can be realized by attaching.

  Next, the long wavelength optical unit 3 will be described with reference to FIG.

  The mounting unit 76 is provided with a light source holding unit 76a. The light source unit 3a is joined to the light source holding unit 76a with a bonding material such as solder, lead-free solder, or a photocurable resin. An optical member 3d is attached on the light source holding part 76a. Further, the light receiving portions 3b and 3c are attached to the mounting portion 76 with a bonding material such as a photo-curing resin so as to sandwich the optical member 3d. The light source unit 3 a covers at least a part of the lead frame 77 with a molding member 78 such as a resin, and a semiconductor laser element 79 is mounted on the lead frame 77. Terminals 77 a to 77 c are electrically connected to the lead frame 77. As described above, the semiconductor laser element 79 emits light having a wavelength of 640 nm to 800 nm, and emits a single type of light or emits a plurality of types of light. . In the present embodiment, a light beam having a wavelength of about 660 nm (red: for example for DVD) and a light beam of about 780 nm (for infrared: for example, for CD) are emitted. The semiconductor laser element 79 is a monoblock element that emits two light beams. However, a device that emits one light beam in one block may be provided on a plurality of lead frames 77.

  The optical member 3d is composed of two optical units 80 and 81, and the optical unit 80 is plate-shaped, so that unnecessary light emitted from the light source unit 3a does not reach the optical unit 81 (not shown), that is, A film for preventing stray light is formed. That is, the film for preventing stray light has an opening, and a main part of the light is guided to the optical unit 81 through the opening, and light incident on the part other than the opening is absorbed. In addition, a hologram having a wavelength selectivity that acts on CD-compatible light and hardly acts on DVD-compatible light is provided, and the CD-compatible light is separated into three beams by this hologram. The optical unit 81 is provided on the optical unit 80, and the optical unit 81 is configured by joining blocks 82 to 85 made of transparent glass or the like, and an inclined surface is formed at a joint portion between the block 82 and the block 83. 86 is formed, an inclined surface 87 is formed between the block 83 and the block 84, and an inclined surface 88 is formed between the block 84 and the block 85. At least inclined surfaces 86, 87, 88 are provided inside the optical unit 81, and ends of the inclined surfaces 86, 87, 88 are exposed on the surface of the optical unit 81.

  The inclined surface 86 is provided with at least one of a reflection film and a hologram on a part of the light transmission part so as to reflect 3 to 15% of the light emitted from the light source unit 3a, and is compatible with CD. A dielectric multilayer film is formed which transmits the P wave of the light and the DVD compatible light and reflects the S wave. The light reflected by the inclined surface 86 enters the light receiving unit 3c and is used for controlling the light output of the light source unit 3a. Further, the inclined surface 87 is provided with a dielectric multilayer film that transmits the P wave of CD-compatible light and DVD-compatible light, reflects the S wave of CD-compatible light, and transmits the S wave of DVD-compatible light. Is formed. The inclined surface 88 is provided with a dielectric multilayer film or a metal film having a reflecting action. In the present embodiment, the inclined surface 88 is provided with a reflective hologram 3e.

  When the CD-corresponding light emitted from the light source unit 3 a is incident on the optical unit 80, the stray light portion is removed and the light is separated by a hologram having wavelength selectivity, and becomes three beams on the optical disc 2. Further, when the light enters the optical unit 81 from the optical unit 80, a part of the light is reflected by the inclined surface 86 and is incident on the light receiving unit 3c. The light is incident on 83 and guided to the inclined surface 87. The light corresponding to the CD, which is a P wave, passes through the inclined surface 87, passes through the block 84, and is emitted from the upper surface of the block 84. Further, the light reflected by the optical disk 2 becomes an S wave by the action of the quarter wavelength member of the optical component 11, and is incident on the upper surface of the block 84 again and is incident on the inclined surface 87. Since the inclined surface 87 is provided with a film having a function of reflecting the S wave of CD-compatible light, the CD-compatible light reflected from the optical disc 2 is reflected and reflected by the inclined surface 88, and further blocked. Then, the light passes through 84 and enters the inclined surface 87 again. As described above, the inclined surface 87 is provided with the film for reflecting the S wave of light corresponding to the CD, so that it is reflected again by the inclined surface 87, passes through the block 84, and is guided to the light receiving unit 3 b. The light incident on the light receiving unit 3b is converted into an electric signal, and an RF signal, a tracking error signal, a focus error signal, and the like are generated. The reflected hologram 3e provided on the inclined surface 88 separates the reflected light from the optical disk 2 into a plurality of light beams, which are respectively guided to predetermined locations on the light receiving unit 3b to generate a focus error signal.

  When the DVD-compatible light emitted from the light source unit 3 a enters the optical unit 80, the stray light portion is removed and enters the optical unit 81. The hologram having wavelength selectivity provided in the optical unit 80 does not act on DVD-compatible light. When the light enters the optical unit 81 from the optical unit 80, a part of the light is reflected by the inclined surface 86 and incident on the light receiving unit 3c, and the other light passes through the inclined surface 86 and enters the block 83. Guided to face 87. On the inclined surface 87, the DVD-compatible light is a P wave, so that it passes through the block 84 and is emitted from the upper surface of the block 84. Further, the light reflected by the optical disk 2 becomes an S wave and again enters the upper surface of the block 84 and enters the inclined surface 87. Since the inclined surface 87 is provided with a film having a function of allowing the DVD-compatible light to pass through, the DVD-compatible light reflected from the optical disc 2 passes through the inclined surface 87 and further passes through the block 83 to be inclined. 86 is incident. Since the inclined surface 86 reflects S-wave light corresponding to DVD, the DVD-compatible light is reflected, passes through the block 83, and enters the inclined surface 87 again. As described above, the inclined surface 87 is compatible with DVD. Since a film through which light passes is formed, the light passes through the inclined surface 87 and is guided to the light receiving unit 3b. The light incident on the light receiving unit 3b is converted into an electric signal, and an RF signal, a tracking error signal, a focus error signal, and the like are generated.

  In FIG. 16, a round trip path of light corresponding to CD is shown.

  Next, the beam shaping lens 4 used in this embodiment will be described.

  As shown in FIG. 17, the beam shaping lens 4 includes a light transmission part 4d including a convex part 4a and a concave part 4b and a mounting part 4c provided so as to sandwich the light transmission part 4d. Although the mounting portion 4c is integrally formed in the present embodiment, the light transmitting portion 4d and the mounting portion 4c may be configured as separate members and bonded to each other with an adhesive or the like.

  As shown in FIG. 17A, short-wavelength light emitted from the short-wavelength optical unit 1 has an elliptical shape immediately before entering the beam shaping lens 4, but the convex portions 4a and the concave portions 4b By setting the curvature radius or a predetermined curved surface shape, the light becomes a substantially circular light after passing through the beam shaping lens 4. Similarly, the light reflected by the optical disk 2 or the like passes through the beam shaping lens 4 so that the circular light is converted into a substantially elliptical shape.

  Next, the optical component 5 used in this embodiment will be described with reference to FIG.

  The optical component 5 has a substantially square shape made of transparent glass or the like, and is configured by sandwiching the polarizing portion 5c and the polarizing portion 5d between the plate-like substrates 5a and 5b. The polarizing unit 5 c acts greatly on the S wave emitted from the short wavelength optical unit 1 and hardly acts on the P wave reflected by the optical disc 2. Further, the polarization unit 5 d hardly acts on the S wave emitted from the short wavelength optical unit 1, and acts largely on the P wave reflected by the optical disc 2. For the optical component 5, the light emitted from the short wavelength optical unit 1 passes through the substrate 5a, the polarizing unit 5c, the polarizing unit 5d, and the substrate 5b in this order, and the light reflected by the optical disc 2 is the substrate 5b and polarized light. It passes through the part 5d, the polarizing part 5c, and the substrate 5a in this order. As shown in FIG. 18B, the polarization portion 5c is formed with a polarization-selective hologram 5e in a substantially square shape using an optically anisotropic resin material. As shown in FIG. 18B, the hologram 5e is formed in a rectangular shape and is configured such that the end of the incident light beam diameter protrudes from the long side. Although not shown, the polarization portion 5c is configured by filling the hologram 5e with at least an optically isotropic resin. As one of the manufacturing methods, a hologram 5e is produced on a substrate 5a by a known method, and at least a gap of the hologram 5e is filled with an optically isotropic resin. As shown in FIG. 18C, on the X axis in FIG. 18B, the amount of incident light is indicated by a dotted line, and when passing through the polarizing portion 5c, the amount of light generally decreases as shown by a solid line. Further, as shown in FIG. 18 (d), the incident light quantity is indicated by a dotted line on the Y axis in FIG. 18 (b), and when passing through the polarizing portion 5c, the incident light is mainly incident as shown by the solid line. The configuration is such that a large amount of light is dropped. Thus, by dropping a portion with a large amount of light at the polarizing portion 5c, the RIM intensity (the intensity ratio of the outermost light flux with respect to the center intensity) can be increased, and short-wavelength light is condensed at a small spot on the optical disc 2. Therefore, at least one of recording / reproduction on the high-density optical disc 2 can be performed. That is, the polarization unit 5c has a function of a RIM intensity correction filter that does not act in the X-axis direction where the RIM intensity is high but acts only in the Y-axis direction where the RIM intensity is low.

  Further, in the polarizing portion 5d, a polarization selective hologram is provided on the substrate 5b, although not shown with an optically anisotropic resin material, and is configured by filling the hologram with an isotropic resin. . The hologram that constitutes a part of the polarization unit 5d has a function of separating the light reflected from the optical disc 2 into a predetermined light flux so as to mainly generate a tracking error signal.

  Further, as one of the manufacturing methods, polarizing portions 5c and 5d are formed on the substrates 5a and 5b, respectively, and the polarizing portions 5c and 5d are opposed to each other, and are bonded with an adhesive such as a resin therebetween. In this way, the optical component 5 is formed.

  Next, the relay lens 6 will be described in detail.

  Specifically, the relay lens 6 has a shape as shown in FIG. That is, a light transmitting portion 6a through which light passes substantially at least partially, a plurality of protrusions 6b provided around the light transmitting portion 6a, and preferably provided radially, and an outer angle provided with the protrusions 6b. In this embodiment, the light transmission part 6a, the protrusion 6b, and the outer ring part 6c are integrally formed. However, each part is constituted by a separate piece, and each part is formed. May be attached to each other.

  A mounting portion 15a is erected on the base 15, and a concave portion 15b having a step portion 15c is provided on the mounting portion 15a. The relay lens 6 is inserted from the insertion direction shown in FIG. The relay lens 6 is configured not to drop off to the long wavelength optical unit 3 side by the concave portion 15b provided with the step portion 15c. Although not shown, a through hole is provided in the portion of the inserted relay lens 6 that faces the light transmission portion 6a. Accordingly, as shown in FIG. 19, the light emitted from the long wavelength optical unit 3 sequentially passes through the light transmission part 6 a and the through holes provided in the attachment part 15 a and is directed toward the beam splitter 7.

  Also, an astigmatism can be corrected by an operator, an automatic adjustment device, or the like by bringing a thin pin or the like (not shown) into contact with the projection 6b and displacing the relay lens 6 by a predetermined angle. Further, since the outer ring portion 6c substantially contacts the inner wall of the recess 15b, and the outer ring portion 6c has some protrusions and recesses, but the outer shape is substantially circular, the relay lens 6 is It is held rotatably by a thin pin or the like. After correcting the astigmatism by rotating the relay lens 6 by a predetermined angle, the relay lens 6 is cured by providing an instantaneous adhesive or a photo-curable adhesive over at least the relay lens 6 and the mounting portion 15a. The attachment portion 15a is fixed. At this time, it is preferable that an adhesive is provided in the recess 15b in the mounting portion 15a. Further, an application method and an application amount of the adhesive are taken into consideration so that the adhesive is not substantially applied to the light transmitting portion 6a. It is preferable.

  Next, the beam splitter 7 will be described in detail.

  As shown in FIG. 20, the outer shape of the beam splitter 7 is configured to be a substantially rectangular parallelepiped shape or a substantially cubic shape, and is configured by joining the transparent members 7b and 7c as described above, and by joining the transparent members 7b and 7c. It has the inclined surface 7a formed. As shown in FIG. 20, the inclined surface 7a is formed at an angle of about 45 degrees with respect to the bottom surface 7f of the side surface. However, according to the specifications and the outer shape of the beam splitter 7, the inclined surface 7a has a predetermined angle. It is determined appropriately. The transparent members 7b and 7c are formed in a substantially triangular prism shape with a glass material such as BK7. As shown in FIG. 20, the inclined surface has a laminated portion 7d and a joint portion 7e.

The laminated portion 7d is configured by alternately laminating low refractive index films and high refractive index films. In this embodiment, a SiO ₂ film is used as the low refractive index film, and a Ta ₂ O ₅ film is used as the high refractive index film. It was constructed using a membrane. Moreover, each film thickness of the high refractive index film | membrane and the low refractive index film | membrane was about 10 nm-400 nm. Further, in this embodiment, preferably the surface on which the laminate section 7d of the transparent member 7c, after performing polishing and surface treatment, using a thin film forming technique such as sputtering or vapor deposition SiO2, Ta ₂ O _5, Laminated portions 7d are formed by laminating SiO ₂ , Ta ₂ O ₅ ,..., SiO ₂ , Ta ₂ O ₅ , SiO ₂ in this order. In this embodiment, 20 or more pairs of thin films of SiO ₂ film and Ta ₂ O ₅ film are stacked (preferably 35 sets or less in consideration of yield and manufacturing cost). When calculating each of the SiO ₂ film and the Ta ₂ O ₅ film as one layer, the laminated portion 7d is composed of 40 to 70 layers. Further, it is advantageous in terms of characteristics and productivity that the actual thickness of the laminated portion 7d is 2 to 10 μm.

When the stacked portion 7d is configured in this way, by adjusting the formation film thickness of each layer (in the above-described case, the SiO ₂ film and the Ta ₂ O ₅ film), light of a predetermined wavelength is transmitted and other wavelengths are transmitted. It is possible to have a function of reflecting the light. In the present embodiment, the laminated portion 7d transmits red light (light having a wavelength of approximately 660 nm) and infrared light (light having a wavelength of approximately 780 nm), and reflects short wavelength light (light having a wavelength of approximately 405 nm). The configuration.

  A joint 7e is provided between the laminated part 7d and the transmissive member 7b, and a Si-based adhesive is preferably used for the joint 7e. Si-based adhesives have the property of not easily deteriorating with respect to light having a short wavelength, and are very preferable in an optical pickup device using light having a wavelength of about 405 nm as in this embodiment. As a matter of course, the joint 7e may be made of glass or other resin material. By setting the thickness of the bonding portion 7e to 3 to 15 μm (preferably 8 to 12 μm), reliable bonding between the transparent members 7b and 7c can be realized, and productivity can be improved. Further, the feature of the present embodiment is that the light having a short wavelength is incident from the bottom side 7f side, so that the laminated portion 7d is provided on the transparent member 7c without the joint portion 7e. It can suppress that the junction part 7e deteriorates with the light of a short wavelength.

  Next, the collimator lens 8 and its driving device will be described.

  As shown in FIG. 21, a lead screw 8c, a gear group 8d, and a drive member 8e are fixed to the base 89. In the present embodiment, a stepping motor is used as the driving member 8e. A motor gear 90 is fixed to the rotation shaft of the drive member 8e. A train shaft 91 is rotatably attached to the base 89. A train gear 92 is fixed to the train shaft 91, and a motor gear 90 is engaged with the train gear 92. The base 89 is integrally provided with a pair of attachment portions 89a and 89b. One end of the screw shaft 8c is rotatably held by the attachment portion 89a, and the other end of the screw shaft 8c is attached to the attachment portion 89b. It is inserted freely. A shaft gear 93 is fixed to the end portion on the attachment portion 89b side, and the shaft gear 93 meshes with the train gear 92. That is, by the rotation of the driving member 8e, the rotational driving force is transmitted to the screw shaft 8c via the gear group 8d (motor gear 90, train gear 92, shaft gear 93).

  As described above, the driving device 94 on which the above-described members are mounted is attached to the base 15.

  As shown in FIG. 22, a slider 8 b on which a collimator lens 8 is mounted is movably attached to a pair of support members 8 a attached to the base 15. The drive device 94 is provided on the side of the support member 8a so that the screw shaft 8c of the drive device 94 and the support member 8a are substantially parallel to each other. A rack member 95 made of an elastic material such as a leaf spring is attached to the slider 8b by bonding, mechanical joining, or the like, and an end portion of the rack member 95 is a spiral groove provided in the screw shaft 8c. Are engaged. Therefore, the moving direction and speed of the slider 8b can be adjusted by the rotating direction and rotating speed of the screw shaft 8c. In the present embodiment, since the stepping motor is used for the driving member 8e, the position of the slider 8b, that is, the position of the collimator lens 8 can be determined by the number of pulses supplied to the driving member 8e.

  Although not shown, the case where at least one of recording / reproducing is performed on the optical disc 2 (having the first recording layer and the second recording layer) with the light from the short wavelength optical unit 1 and the long wavelength optical unit In the case where information is recorded / reproduced with respect to the optical disc 2 with CD-compatible light or DVD-compatible light emitted from the optical disc 2, at least a recording / reproduction operation in which the positions of the collimator lenses 8 are surely different from each other is ensured. This is a preferred form of doing one.

  Accordingly, when at least one of recording / reproducing is performed on the first recording layer of the optical disc 2 with the light from the short wavelength optical unit 1, the collimator lens 8 is positioned at the first position, and the short wavelength optical unit 1. When at least one of recording / reproducing is performed with respect to the second recording layer of the optical disc 2 by the light from the collimator lens 8, the collimator lens 8 is positioned at the second position and is compatible with the CD emitted from the long wavelength optical unit 3. When at least one of recording / reproduction with respect to the optical disk 2 is performed with light, the collimator lens 8 is positioned at the third position, and recording with respect to the optical disk 2 is performed with DVD-compatible light emitted from the long wavelength optical unit 3. / When performing at least one of reproduction, the collimator lens 8 is positioned at the fourth position. The first to fourth positions are positions of the collimator lens 8 within a range where the slider 8b can operate, and the first position and the second position are always different positions. The third position and the fourth position are at positions different from at least one of the first position and the second position, and are preferably located between the first position and the second position. At least two of the first position to the fourth position are different positions.

  An example of the operation according to the above configuration is shown.

  It is assumed that a separate sensor or the like (not shown) is provided and is located at the home position of the slider 8b by this sensor. A control member (not shown) determines, based on a signal from the outside, which wavelength of light is used for recording / reproduction, or whether recording / reproduction is performed on the first recording layer or the second recording layer. The number of pulses to be sent from the memory to the drive member 8e is read from the signal. At this time, the first to fourth positions are determined depending on which wavelength of light is used for recording / reproduction or whether recording / reproduction is performed on the first recording layer or the second recording layer. . In order to position the collimator lens 8 at each position, it is known to some extent at which time the slider 8b existing at the home position needs to be moved in which direction. By recording the number, the collimator lens 8 can be easily positioned at the optimum position (first to fourth positions). Note that the first position to the fourth position may coincide with the home position of the slider 8b. When the predetermined operation is completed, the control member causes the drive member 8e to send a pulse so as to return the slider 8b to the home position. FIG. 23 shows a state in which the collimator lens 8 and its driving device 94 are attached.

  Next, the achromatic diffraction lens 14 will be described.

  As shown in FIG. 24, the achromatic diffractive lens 14 has a light transmission part 14d and an outer ring part 14c that surrounds the outside of the light transmission part 14d, and is provided on the objective lens 13 side of the light transmission part 14d. The surface 14a is concave, and a hologram having a predetermined pitch and shape is provided on the surface 14b on the opposite side of the rising mirror 12 side. Essentially, light having a short wavelength is transmitted through the light transmitting portion 14d. In order to correct the chromatic aberration, desired chromatic aberration correction can be performed by adjusting the pitch of the hologram provided on the surface 14b. The achromatic diffraction lens 14 has a substantially circular shape, and the outer ring portion 14 c is attached to the lens holder 16. In the present embodiment, the light transmitting portion 14d and the outer ring portion 14c are integrally formed, but the light transmitting portion 14d and the outer ring portion 14c are formed as separate members. For example, the light transmitting portion 14d is provided at the center of the outer ring portion 14c. An embedded configuration may be used.

  Next, embodiments of the lens holder 16 and the suspension holder 17 will be described with reference to FIGS. 6 and 7 have substantially the same function. 25 to 28 and FIGS. 6 and 7 have substantially the same functions as described above, the members shown in FIGS. 25 to 28 are the members shown in FIGS. The shape is slightly different.

  The lens holder 16 needs to increase the resonance frequency of the lens holder 16 when performing at least one of recording / reproduction with respect to the optical disc 2 at a high speed. That is, in order to control the lens holder 16 so as to follow the surface shake of the optical disk 2 of the lens holder 16 by recording / reproducing at a high speed, the resonance frequency of the lens holder 16 is increased to be equal to or less than the resonance frequency. It is preferable to control the lens holder 16 in the region. One method for increasing the resonance frequency of the lens holder 16 is to give the lens holder 16 high rigidity. In the present embodiment, in order to give the lens holder 16 high rigidity, all or at least a part of the lens holder 16 is made of a material in which fibers are dispersed in a resin (hereinafter abbreviated as a composite material). As the resin, liquid crystal polymer, epoxy resin, polyimide resin, polyamide resin, acrylic resin, etc. are suitably used, and as the fiber, metal fiber such as carbon fiber, carbon black, copper, nickel, aluminum, stainless steel, etc. In addition, these composite fibers are preferably used. In the present embodiment, the lens holder 16 is made of a material in which carbon fibers are dispersed in a liquid crystal polymer.

  As shown in FIGS. 25 and 26, when the lens holder 16 and the suspension holder 17 are made of the above composite material, the lens holder 16 and the suspension holder 17 may have conductivity, so that they are formed on the surfaces of the suspensions 18a to 18f. An insulating film was formed. In this case, an insulating member is provided between the lens holder 16 and the various coils to be insulated, or various coils are constituted by windings in which the windings themselves are insulated. As described above, by providing the suspensions 18a to 18f with the insulating coating, the insulation between the lens holder 16 and the suspension holder 17 having conductivity is maintained. Insulated end portions 98 and 99 of the suspensions 18a to 18f are attached to the bobbin suspension receiving portions 96 and 97 provided integrally with the lens holder 16 by insert molding. The insulated ends 100 and 101 of the suspensions 18a to 18f on the suspension holder 17 side are attached to the suspension holder 17 by insert molding. Further, the tip portions 102 and 103 on the lens holder 16 side of the suspensions 18a to 18f are not provided with an insulating film, and the tip portions 102 and 103 and various coils provided on the lens holder 16 are electrically connected. Furthermore, the tip portions 104 and 105 on the suspension holder 17 side of the suspensions 18a to 18f are not provided with an insulating film, and are connected to the tip portions 104 and 105 and a flexible printed board (not shown). .

  Further, as a modification of the embodiment shown in FIGS. 25 and 26, as shown in FIGS. 27 and 28, the end portions 106 of the suspensions 18a to 18f are provided without providing an insulating film on almost all of the suspensions 18a to 18f. , 107 is provided with an insulating film, and part or all of the end portions 106, 107 (in the case of all, consideration is given so that the lens holder 16 and the suspensions 18a to 18f are not in contact) with the bobbin suspension receiving portions 96, 97. To join. In the embodiment shown in FIGS. 27 and 28, a part of the end portions 106 and 107 are joined to the bobbin suspension receiving portions 96 and 97 in order to maintain insulation. Also, the end portions 108 and 109 on the suspension holder 17 side of the suspensions 18a to 18f are provided with an insulating film, and at least the end portions 108 and 109 and the suspension holder 17 are joined. In the embodiment shown in FIGS. The end portions 108 and 109 are all joined to the suspension holder 17.

  In addition, as the above-mentioned insulating film, an insulating material is produced using a technique such as coating, electrodeposition, and vapor deposition. As an insulating material, an insulating material such as an epoxy resin, silicon dioxide, or the like can be used. An inorganic insulating material is used. Further, the surface of the suspensions 18a to 18f having conductivity may be subjected to a treatment such as an oxidation treatment to provide an insulating film. Further, the suspension 18a to 18f may be inserted into a tube-shaped insulating material as an insulating film to form an insulating film, or a metal wire passed through a resin wire by insert molding or the like may be used as the suspension 18a to 18f. It is also good.

  29 and 30, the suspensions 18a to 18f are not provided with an insulating film, the suspension holder 17 and the bobbin suspension receiving portions 96 and 97 are made of a non-conductive material, and the lens holder 16 is made of the above-described one. It is also possible to construct with a composite material. According to this configuration, since the member to which the suspensions 18a to 18f themselves are attached has an insulating property, the suspension itself does not need to be insulated. The bobbin suspension receivers 96 and 97 and the lens holder 16 are integrally formed by two-color molding, or the bobbin suspension receivers 96 and 97 and the lens holder 16 are joined by a resin adhesive. In this embodiment, the highly rigid lens holder 16 can be used without subjecting the suspensions 18a to 18f to an insulation treatment or the like.

  Next, the configuration of the lens holder 16 and the objective lens 10 of the optical pickup device in the present embodiment will be described in more detail with reference to FIGS. The members shown in FIGS. 31 to 35 are slightly different from the members shown in FIGS. 6, 7, and 25 to 28, but the members having the same reference numerals have substantially the same functions. have.

  FIG. 31 shows the temperature distribution on the lens holder 16 when a current is passed through the focus coils 33 and 34, tracking coils 35 and 36, and sub-tracking coils 37 and 38. An objective lens 10 for a long wavelength laser and an objective lens 13 for a short wavelength laser are mounted on the lens holder 16. The objective lenses 10 and 13, the focus coils 33 and 34, the tracking coils 35 and 36, and the sub-tracking coils 37 and 38 shown in FIG. The heat generated by passing an electric current through the coil moves to the lens holder 16 and further moves to the objective lenses 10 and 13. The objective lenses 10 and 13 are deformed by the application of heat. This deformation is generally expansion, but may be contracted depending on the material. In general, a resin is deformed more greatly than heat when heated. Further, as can be seen from FIG. 31, the temperature distribution of the lens holder 16 is biased, and for the objective lens 10, the set side of the focus coil 33 and the sub-tracking coil 37 is heated more than the tracking coil 35 side. In other words, the set side of the focus coil 34 and the sub-tracking coil 38 is heated more than the tracking coil 36 side. Due to the deviation of the inflowing heat, the lens is also deformed, and aberration is generated in the light passing through the objective lenses 10 and 13.

  In FIG. 32, 110a, 110b, and 110c are objective lens support surfaces, and 111a, 111b, 111c, 113a, 113b, and 113c are adhesive portions. As described with reference to FIG. 7, the short-wavelength laser objective lens 13 is dropped into the through-hole 16b of the lens holder 16 from the P1 direction shown in FIG. 7, and is fixed with a photocurable adhesive or the like. Further, the objective lens 10 for the long wavelength laser is also dropped into the through hole 16a of the lens holder 16 from the P1 direction shown in FIG. 7, and is fixed with a photocurable adhesive or the like. Of the objective lenses 10 and 13 attached to the lens holder 16 in this way, the objective lens 10 is made of glass or resin, but here, one made of resin is used. This makes it possible to use a technique such as mold molding, so that it is easy to provide a hologram in the objective lens 10 and it is possible to adjust the spherical aberration of light of a plurality of types of wavelengths. The objective lens 13 is made of glass or made of a resin (preferably, a short wavelength light resin). Here, a glass made of glass is used. Thereby, the objective lens 13 is not easily deteriorated even with respect to light having a short wavelength, and good optical characteristics can be maintained. In the present embodiment, the objective lenses 10 and 13 are used. However, it is also possible to configure the lens with other condensing members such as a hologram.

  As described with reference to FIG. 6, the focus coils 33 and 34 are wound in a substantially ring shape, and are provided at diagonal positions of the lens holder 16, respectively. Since the focus coils 33 and 34 are provided on both sides of the lens holder 16 as described above, the optical pickup device can be made compact even if two lenses, the objective lens 10 and the objective lens 13, are mounted on the lens holder 16. It becomes possible to do. Similarly to the focus coils 33 and 34, the tracking coils 35 and 36 are wound in a substantially ring shape, and are provided at diagonal positions different from the focus coils 33 and 34, respectively. Sub-tracking coils 37 and 38 are provided between the focus coils 33 and 34 and the lens holder 16, respectively. By providing the sub-tracking coils 37 and 38, an unnecessary inclination of the lens holder 16 generated during tracking can be suppressed.

  The relationship between the objective lenses 10 and 13 and the lens holder 16 will be described in more detail with reference to FIG. The objective lens 13 is dropped into the through hole 16b formed in a substantially circular shape from the front of the paper to the back, and is fixed to the lens holder 16 with a photo-curable adhesive or the like injected into the bonding portions 113a, 113b, and 113c. The On the other hand, the objective lens 10 is dropped into a substantially circular through-hole 16a from the front to the back of the paper and is supported by the objective lens support surfaces 110a, 110b, and 110c, and is adjusted and bonded. The lens holder 16 is fixed with a photo-curing adhesive or the like injected into the portions 111a, 111b, and 111c. This configuration makes it possible to obtain optimal optical characteristics. Here, as the adhesive, a photocurable adhesive such as an ultraviolet curable adhesive that cures when irradiated with ultraviolet rays is used, but an instantaneous adhesive or other adhesives can also be used. Further, it is conceivable to use an adhesive having a low thermal conductivity, more preferably an adhesive having a heat insulating property that does not conduct heat.

  FIG. 33 shows a state where the objective lens 13 is dropped into the through hole 16b and the objective lens 10 is dropped into the through hole 16a. As described with reference to FIG. 7, the outer peripheral portions of the objective lenses 10 and 13 come into contact with the peripheral portions of the through holes 16 a and 16 b of the lens holder 16. The outer peripheral part of the objective lens 10 is in contact with the peripheral part of the through hole 16b of the lens holder 16 over almost the entire periphery. The contact of the objective lens 10 made of resin with the lens holder 16 will be described in more detail.

  34 is a cross-sectional view taken along line AA in FIG. 33, and FIG. 35 is a cross-sectional view taken along line BB in FIG.

  Reference numeral 10 a denotes an objective lens outer peripheral portion that becomes an edge of the objective lens 10, and the objective lens 10 is in contact with the lens holder 16 at a part of the objective lens outer peripheral portion 10 a and is bonded to the lens holder 16. In this way, the lens holder 16 and the objective lens 10 are fixed. Reference numeral 10b denotes an objective lens lower surface on which light emitted from the long wavelength optical unit 3 enters the objective lens 10, and 10c denotes an objective lens upper surface from which light incident on the objective lens 10 from the objective lens lower surface 10b is emitted. The light passing through the objective lens 10 and emitted from the objective lens upper surface 10c is condensed on the optical disc 2 facing the objective lens upper surface 10c. A hologram is provided on the lower surface 10b of the objective lens, and a light beam having a wavelength of about 660 nm (red: for example, DVD) which is emitted from the long wavelength optical unit 3 and passes through the relay lens 6 and the collimator lens 8 to become parallel light. ) And a light beam of approximately 780 nm (infrared: for example, for CD), the spherical aberration is adjusted by passing through this hologram.

  Reference numeral 110 denotes an objective lens support surface provided on the lens holder 16. 34 is a cross-sectional view taken along the line AA of FIG. 33, the objective lens support surface 110 is precisely the objective lens support surface 110c, but the objective lens support surfaces 110a, 110b, and 110c are substantially the same. Therefore, the objective lens support surfaces 110a, 110b, and 110c are collectively referred to as the objective lens support surface 110 for the sake of simplicity. The objective lens support surface 110 has an inclined surface from the lens holder upper surface 16c of the lens holder 16 toward the through hole 16a. More precisely, the inclined surface is a substantially spherical surface having a concave shape with respect to the lens holder upper surface 16c. When the objective lens 10 is placed on the objective lens support surface 110, the principal point of the objective lens 10 and the center of the substantially spherical surface of the objective lens support surface 110 preferably coincide with each other. The principal point of the objective lens 10 and the center of the substantially spherical surface of the objective lens support surface 110 may be slightly deviated, but a certain degree of deviation is allowed. By providing a substantially spherical surface on the objective lens support surface 110, the objective lens 10 is provided, and the direction of the optical axis of the objective lens 10 can be adjusted.

  Reference numeral 111 denotes an adhesive portion provided on the lens holder 16. 35 is a cross-sectional view taken along the line B-B of FIG. 33, the bonding portion 111 is precisely the bonding portion 111b, but the bonding portions 111a, 111b, and 111c have substantially the same configuration and function. Therefore, for the sake of simplicity, the bonding portions 111a, 111b, and 111c are collectively referred to as the bonding portion 111 here. The adhesion portion 111 is a stepped portion that is lowered to the through hole 16 a side from the lens holder upper surface 16 c of the lens holder 16. The adhesion part 111 is configured so that the objective lens 10 does not hit when the objective lens 10 is slid on the objective lens support surface 110 and adjustment is performed.

  The arrangement of the objective lens support surface 110 and the bonding portion 111 will be described. As shown in FIG. 32, when the peripheral edge of the through hole 16a is viewed from the central axis of the through hole 16a, the angles that the objective lens support surfaces 110a, 110b, 110c occupy in the peripheral edge of the through hole 16a are all about 15 degrees. The angle occupied by the bonding portions 111a, 111b, and 111c in the peripheral portion of the through hole 16a is about 25 degrees. Since the contact portion between the lens holder 16 and the objective lens 10, which is the objective lens support surface 110 and the bonding portion 111, is configured to be small, the heat flow path from the lens holder 16 to the objective lens 10 is reduced, and the objective lens 10 An increase in temperature can be suppressed, and the deformation of the objective lens 10 can be reduced.

  The adhesive portion 111a is disposed at a position that avoids the vicinity of the set of the focus coil 33 and the sub-tracking coil 37 and does not approach the tracking coil 35 too much. In other words, the bonding portion 111 a is disposed at a position closer to the tracking coil 35 than the set of the focus coil 33 and the sub-tracking coil 37. With such a configuration, when the lens holder 16 is driven by passing a current through the focus coils 33 and 34, the tracking coils 35 and 36, and the sub-tracking coils 37 and 38, the focus coil 33 and the sub-tracking coil that are likely to rise in temperature. Between the pair of 37 and the tracking coil 35 whose temperature rise is smaller than that, the bonding portion 111a can be disposed at a low temperature position. The adhesion portions 111b and 111c are arranged at a position where the temperature of the adhesion portion 111a on the lens holder 16 is substantially equal. Here, the temperature difference between the bonding portions 111a, 111b, and 111c is preferably within 1 to 2 degrees. Since the sizes of the bonding portions 111a, 111b, and 111c are substantially equal, the adhesive injected into each bonding portion 111 comes into contact with the objective lens 10 with approximately the same area. As a result, the amount of heat flowing into the objective lens 10 from the bonding portions 111a, 111b, and 111c provided at substantially the same temperature is also substantially constant, and the deformation of the objective lens 10 is less likely to be biased and passes through the objective lens 10. The generation of astigmatism in the light to be transmitted can be suppressed. Furthermore, the bonding portions 111a, 111b, and 111c are arranged at substantially equal angles around the central axis of the through hole 16a so as to be close to the intervals of 120 degrees. Preferably, the bonding portions 111 are arranged at equal intervals (equal angles) every 120 degrees, but are arranged so that the intervals are as close as possible around the through holes 16a at positions where the temperatures during driving are substantially equal. As a result, even if the adhesive injected into the bonding portion 111 is contracted when solidified, the force with which the objective lens 10 is pulled from the lens holder 16 cancels each other, and the positioned objective lens 10 is less likely to be displaced.

  In the present embodiment, the number of bonding portions 111 is three, but the number of bonding portions 111 is not limited to this. When the number of the bonding parts 111 is two, the arrangement of the bonding parts 111 is 180 degrees around the central axis of the through hole 16a, and when the number of the bonding parts 111 is four, Even when the number of the adhesive portions 111 is changed such that the arrangement is 90 degrees apart around the central axis of the through hole 16a, the arrangement of the adhesive portions 111 is preferably equiangular around the central axis of the through hole 16a. However, if the number of the bonding portions 111 is reduced, the force for fixing the objective lens 10 to the lens holder 16 is weakened or the bonding portions 111 need to be widened to prevent it. If the number of bonding portions 111 is increased too much, each bonding portion 111 can be made small, but a large number of positions on the lens holder 16 where the temperatures are almost equal are required, and the number of locations where the adhesive should be injected increases, resulting in an increase in the number of assembly steps. It will increase. It is preferable that the bonding portion 111 is composed of about three.

  Further, in the present embodiment, the adhesive portions 111a, 111b, and 111c are configured to have substantially the same area and are disposed at positions near the temperature on the lens holder 16. The amount of heat flowing from each bonding portion 111 can be made constant by changing the area of the bonding portion 111, for example, the bonding portion 111 is small and the bonding portion 111 provided at a low temperature is made large. It can be implemented similarly.

  The objective lens support surfaces 110a and 110b are adjacent to the bonding portions 111a and 111b, respectively, and are provided at positions closer to the set of the focus coil 33 and the sub-tracking coil 37 than the bonding portions 111a and 111b. The objective lens support surface 110c is adjacent to the bonding portion 111c and is provided at a position closer to the tracking coil 35 than the bonding portion 111c. As described above, by providing the objective lens support surface 110 adjacent to the bonding portion 111, the lens holder 16 is disposed at a low temperature, and heat conduction to the objective lens 10 can be suppressed. . Further, by providing the objective lens support surface 110 adjacent to the bonding portion 111, the objective lens support surface 110 can also be arranged at a substantially equiangular interval around the central axis of the through hole 16a. The objective lens 10 can be stably supported by the lens support surface 110.

  Further, in the present embodiment, the objective lens support surface 110 that is a member that supports the objective lens 10 is composed of three objective lens support surfaces 110a, 110b, and 110c. With this configuration, the lens holder 16 comes into contact with the objective lens outer peripheral portion 10a at three points, and the surface on which the objective lens 10 is supported can be uniquely determined. In the present embodiment, the number of points is three, but the number of points that support the objective lens 10 is not limited to this.

  In the present embodiment, the objective lens support surface 110 and the adhesive portion 111 are provided on the lens holder 16 as different surfaces. With this configuration, it is possible to prevent the adhesive from adhering to the objective lens support surface 110 for tilt adjustment, and it is possible to adjust the objective lens 10 with high accuracy. Further, by providing the bonding portion 111 separately from the objective lens support surface 110 and bonding the objective lens 10 and the lens holder 16, the objective lens 10 and the lens holder 16 can be firmly fixed.

  The objective lens support surfaces 110a and 110b are closer to the set of the focus coil 33 and the sub-tracking coil 37 than the adhesive portions 111a and 111b, respectively, and the objective lens support surface 110c is closer to the tracking coil 35 than the adhesive portion 111c. However, the objective lens 10 and the lens holder 16 are only in contact with each other on the objective lens support surface 110, and the adhesive portion 111 that easily conducts heat can be disposed at a position away from the high temperature portion. Thus, the temperature increase of 10 can be suppressed.

  Also in this embodiment, as described with reference to FIGS. 25 to 30, it is preferable that all or at least a part of the lens holder 16 is made of a material (composite material) in which fibers are dispersed in a resin. As the resin, liquid crystal polymer, epoxy resin, polyimide resin, polyamide resin, acrylic resin, etc. are suitably used, and as the fiber, metal fiber such as carbon fiber, carbon black, copper, nickel, aluminum, stainless steel, etc. In addition, these composite fibers are preferably used. As described above, when the lens holder 16 is made of the composite material, the lens holder 16 may have conductivity, but the rigidity of the lens holder 16 is increased and the resonance frequency is increased. It is possible to perform at least one of recording / reproduction in In the present embodiment, the lens holder 16 is made of a material in which carbon fibers are dispersed in a liquid crystal polymer. According to this configuration, the thermal conductivity of the lens holder 16 may be increased. When the thermal conductivity increases, the temperature of the lens holder 16 tends to be uniform, and the position of the bonding portion 111 can be selected from a wide range. When the thermal conductivity increases, the position of the bonding portion 111 can be selected from a wide range. , At an interval of approximately 120 degrees).

  Next, the light receiving portion 1b of the short wavelength optical unit 1 will be described in more detail with reference to FIGS. The members shown in FIGS. 36 to 49 may be slightly different from the members shown in FIGS. 9 and 10, but the members having the same reference numerals have substantially the same functions.

  FIG. 36 is a perspective view of the photodetecting element 114 constituting the light receiving unit 1b as viewed from the surface of the integrated circuit (IC).

  In FIG. 36, reference numeral 114 denotes a light detecting element which is a light receiving element constituted by a bare chip IC for converting reflected light from the information recording surface of the optical disc into an electric signal. In this light detecting element 114, 114a is a light detecting element 114. , A light detection unit that detects light incident on the light detection element 114, 114b is an electrical circuit unit, 114c is an electrical signal input / output electrode pad, and 114d is provided on the electrical signal input / output electrode pad 114c. These bumps are made of gold, solder or the like for realizing electrical connection. When electrical connection between the electrical signal input / output electrode pad 114c and the electrode pad portion 116 on the flexible printed circuit board 49 to be described later can be reliably performed using the photodetecting element fixing adhesive resin layer 115 to be described later. The bump 114d can be omitted. In this photodetection element 114, the surface having the photodetection portion 114a and the electric signal input / output electrode pad 114c is referred to as a photodetection surface.

  FIG. 37 is a perspective view in which component parts are expanded and displayed in order to explain the configuration and assembly method of the flexible printed circuit board unit 121.

  In FIG. 37, 49 is a flexible printed circuit board which is a flexible electric wiring board, 114 is the photodetecting element described in FIG. 36 (the electrode surface is not seen in the shade), and 115 is protection of interelectrode connection. The photosensitive resin fixing adhesive resin layer 116, which is an anisotropic conductive film (ACF) for fixing the flexible printed circuit board 49 and the light detecting element 114, is flexible at the same interval as the electric signal input / output electrode pads 114c. Electrode pad portions 118 arranged in two rows on the printed circuit board 49, 118 protects the electrode pad 114c for input / output of the electric signal of the photodetecting element 114, and a transparent glass substrate through which reflected light from the disk passes, 117 is a flexible print An adhesive 119 for bonding the substrate 49 and the transparent glass substrate 118 is attached to the end of the flexible printed circuit board 49. The formed electrode pattern, 120 is a decoupling capacitor between power supply grounds for improving the electrical characteristics of the light detecting element 114, and 49a is provided at substantially the center of the electrode pad portion 116 arranged in two rows, and is reflected light from the optical disk. Is a through-hole. Here, the flexible printed circuit board 49 is a single-sided board in which wiring and electrode pads are formed only on one side in order to realize manufacturability and low cost, but a double-sided board in which wirings and electrode pads are formed on both sides is used. It is also possible. Here, the surface on which the wiring and the electrode pad are formed in the light detection element 114 is referred to as an electrode surface.

  In FIG. 37, a substantially rectangular through hole 49a is provided. However, the through hole 49a of the flexible printed circuit board 49 is at least for electric signal input / output when the flexible printed circuit board 49 and the light detection element 114 are joined. A portion of the electrode pad 114c can be seen from the through hole 49a, and the reflected light from the information recording surface of the optical disk that has passed through the transparent glass substrate 118 may reach the light detection unit 114a of the light detection element 114. FIG. May be a substantially polygonal shape such as a substantially diamond shape, a substantially triangular shape or a substantially star shape, or a substantially elliptical or substantially circular through-hole 49a shown in FIG. In addition, if the reflected light from the information recording surface of the optical disk that has passed through the transparent glass substrate 118 reaches the light detection portion 114a of the light detection element 114, a plurality of through holes 49a may be provided as shown in FIG. It can be implemented similarly.

  As described above, the flexible printed circuit board 49 is provided with the through hole 49a, in other words, the flexible printed circuit board 49 surrounds the through hole 49a through which the reflected light from the optical disk passes. Also in the flexible printed circuit board 49, the distance between the rows of the electrode pad portions 116 arranged in two rows is difficult to change, and the electric signal input / output electrode pads 114c of the photodetecting element 114 and the electrode pad portions 116 of the flexible printed circuit board 49 are arranged. Can be securely connected.

  In FIG. 37, a substantially rectangular through hole 115a is provided in the substantially central portion of the photodetecting element fixing adhesive resin layer 115, but at least the electric signal input / output electrode pad 114c of the photodetecting element 114 and the flexible If the photodetection element fixing adhesive resin layer 115 is provided between the electrode pads 116 of the printed circuit board 49, two small photodetection element fixing adhesive resin layers as shown in FIG. It is also possible to configure with 115. In this configuration, it is not necessary to provide the through hole 115a in the photodetecting element fixing adhesive resin layer 115, and the amount of use of the photodetecting element fixing adhesive resin layer 115 can be reduced.

  The flexible printed board 49 is preferably used as the wiring board, but other wiring boards such as a glass epoxy board and a ceramic board can also be used. However, by using the flexible printed board 49, the lightweight and thin board can be used. An optical pickup device can be configured.

  As shown in FIG. 37, the photodetection element 114 and the flexible printed circuit board 49 pressurize the photodetection element 114 on which the bump 114d is formed with the photodetection element fixing adhesive resin layer 115 sandwiched between the electrode pads 116. And it fixes by what is called flip chip mounting fixed by heating. Here, an anisotropic conductive film (ACF) is preferably used as the photodetecting element fixing adhesive resin layer 115, but the present invention is not limited to this.

  Further, a transparent glass substrate 118 is fixed to the back surface of the flexible printed circuit board 49 on which the light detection element 114 is mounted by pressing and heating with an adhesive 117 interposed therebetween, and electric signal input / output formed on the flexible printed circuit board 49 in two rows. A through hole 49a that allows light reflected from the disk to pass therethrough is provided in the approximate center of the electrode pad 114c, so that the reflected light from the disk incident from the transparent glass substrate 118 side can reach the light detection unit 114a in the light detection element 114. It comprised so that it might become. With this configuration, it is possible to hermetically seal the light detection unit 114a in the light detection element 114, protect the connection between the light detection element 114 and the electrodes, and fix the parts.

  In the above description, the flexible printed circuit board 49 is provided with the through hole 49a. However, the reflected light from the information recording surface of the optical disk that has passed through the transparent glass substrate 118 reaches the light detection unit 114a of the light detection element 114. If it is the structure to perform, it can also be comprised by the notch part 49b shown in FIG. The notched portion 49 b can be provided by notching by pressing or the like after the flexible printed circuit board 49 is formed, or can be provided when forming the outer shape of the flexible printed circuit board 49.

  Similarly, if the reflected light from the information recording surface of the optical disk that has passed through the transparent glass substrate 118 reaches the light detection unit 114a of the light detection element 114, the transparent glass member is combined with the flexible printed circuit board 49. It is also possible to provide and configure the window 49c. In FIG. 43, the window portion 49c having a shape in which a transparent glass member is combined with the portion of the through hole 49a described with reference to FIG. 37 is configured. The shape may be a combination of transparent glass members, or other shapes. Since the window 49c does not deteriorate due to the transmission of the short wavelength laser, the reflected light from the information recording surface of the optical disk can be efficiently guided to the light detection unit 114a of the light detection element 114. Moreover, when providing the window part 49c in the flexible printed circuit board 49, it is possible to omit the transparent glass board | substrate 118 and to comprise the light-receiving part 1b of the short wavelength optical unit 1.

  FIG. 44 is a perspective view of the flexible printed circuit board unit 121 configured and assembled as described above.

  As described above, the photodetecting element 114 composed of the bare chip IC is directly mounted on the flexible printed circuit board 49 by using the flip chip mounting to constitute the photodetecting element unit 123, so that the package sealed with the glass lid can be obtained. There is no need to create a photoelectric conversion integrated device, and the light receiving unit 1b corresponding to a short wavelength laser can be configured at low cost. Further, by mounting the photodetecting element 114 composed of a bare chip IC on the flexible printed circuit board 49 as it is, the optical pickup device can be configured in a small size.

  FIG. 45 is a perspective view showing a state where the flexible printed circuit board unit 121 shown in FIG. 44 is bent. A decoupling capacitor 120 between power grounds is soldered and folded on the surface of the flexible printed circuit board 49 so as to be opposed to the back surface of the surface having the light detection portion 114a of the light detection element 114.

  FIG. 46 is a perspective view of the photodetecting element unit 123, and 122 is a flexible printed circuit board unit housing component that houses and holds the flexible printed circuit board unit 121. The flexible printed circuit board unit 121 in the folded state shown in FIG. 45 is fixed to the flexible printed circuit board unit housing component 122 using a photocurable adhesive. Here, as the adhesive, a photocurable adhesive such as an ultraviolet curable adhesive that cures when irradiated with ultraviolet rays is used, but an instantaneous adhesive or other adhesives can also be used. The flexible printed circuit board unit housing component 122 is made of a material such as metal or resin, but is preferably made of metal.

  FIG. 47 is a diagram showing the short wavelength optical unit 1 using the light detecting element unit 123 as the light receiving unit 1b, and 1c is a monitor for the amount of light emitted from the light source unit 1a (not shown) of the short wavelength optical unit 1. The light detecting element unit 123 and the light receiving unit 1c are fixed to the short wavelength optical unit 1 after fine adjustment of the relative position with respect to the short wavelength optical unit 1 as a reference. As shown in FIG. 48, it is incorporated into the base 15 of the optical pickup device. In particular, the light detection element unit 123 grips the flexible printed circuit board unit housing component 122 using a jig or the like to make fine adjustments to the short wavelength optical unit 1, and uses a photo-curing adhesive or the like for the short wavelength optical unit 1. It is fixed to the mounting portion 43. Here, as the adhesive, a photocurable adhesive such as an ultraviolet curable adhesive that cures when irradiated with ultraviolet rays is used, but an instantaneous adhesive or other adhesives can also be used.

  Since the light detection element unit 123 is configured to house and hold the flexible printed circuit board unit 121 using the flexible printed circuit board unit housing component 122 that is more robust than the flexible printed circuit board unit 121, The relative position can be finely adjusted smoothly.

  Here, paying attention to the recorded information reproducing function of the optical pickup device, the operation will be briefly described with reference to FIG.

  In the optical pickup device as shown in FIG. 48, laser light (outgoing light) for reproducing recorded information emitted from the short wavelength optical unit 1 is transmitted by the objective lens 13 via a plurality of optical elements (not shown). The optical disc is designed and manufactured so as to focus on the information recording surface of an optical disc (not shown).

  The light reflected on the information recording surface of the optical disc (return light) follows the same optical path as that of the forward light inside the short-wavelength optical unit 1 immediately before the beam splitter (not shown), and then the light detection element is operated by the beam splitter. It is folded in the direction of the unit 123.

  Next, another configuration of the light detection element unit 123 which is the light receiving unit 1b will be described with reference to FIG.

  49 does not include the flexible printed circuit board unit storage component 122 that stores the flexible printed circuit board unit 121, and the mounting portion 43 is interposed between the flexible printed circuit board 49 and the transparent glass substrate 118. Except that a light receiving attachment portion 48 that is an attachment member for fixing the flexible printed circuit board 49 and the light detecting element 114 fixed to the flexible printed circuit board 49 to the short wavelength optical unit 1 is provided. The configuration is the same as that of the photodetecting element unit 123 described with reference to FIGS. Here, the mounting portion 43 is preferably made of a metal material such as zinc die cast. An anisotropic conductive film (an anisotropic conductive film) is interposed between the photodetection element 114 formed of a bare chip IC in which the photodetection portion 114a for detecting the laser beam is directed toward the flexible print substrate 49 having the through hole 49a and the flexible print substrate 49. The photodetecting element fixing adhesive resin layer 115 composed of ACF) is sandwiched between the photodetecting element 114 and the flexible printed circuit board 49 by applying pressure and heating to bond the photodetecting element 114 and the flexible printed circuit board 49. On the side opposite to the side on which light is fixed, a light receiving mounting portion 48 made of a metal plate and provided with a through hole 45 at a substantially central portion is disposed, and an adhesive 117 that is an organic adhesive such as a thermosetting adhesive is used. The flexible printed circuit board 49 is bonded. A transparent glass substrate 118 is disposed on the opposite side of the light receiving mounting portion 48 bonded to the flexible printed circuit board 49 to the side of the flexible printed circuit board 49 so as to close the through hole 45 of the light receiving mounting portion 48, and a photo-curable adhesive. Bond with an adhesive 126 such as. With this configuration, the photodetecting element unit 123 configured as described above is finely adjusted in position with respect to the short wavelength optical unit 1, and the mounting portion 43 of the short wavelength optical unit 1 is made with a light curing adhesive or the like. And fixed.

  In addition, it is preferable to comprise the light-receiving attachment part 48 with metal materials, such as a zinc die-cast. By configuring the light receiving attachment portion 48 with a metal material such as zinc die cast, the position of the light detection portion 114a of the light detection element unit 123 with respect to the short wavelength optical unit 1 can be finely adjusted with certainty. The configured mounting portion 43 can be easily fixed by the adhesive 127 or the like. When a photocurable adhesive such as an ultraviolet curable adhesive that cures when irradiated with ultraviolet rays is used as the adhesive 127 used here, adhesion between the mounting portion 43 and the photodetecting element unit 123 that have been precisely positioned is adjusted. It can be easily performed.

  As described above with reference to FIGS. 36 to 49, since there is no resin in the path from the optical disk to the light detection element of the reflected light, an optical disk using a short wavelength laser that will be mainstream in the future. Also in the apparatus, it is possible to suppress the deterioration of the light receiving unit 1b due to the passage of the laser and perform highly efficient light detection.

  As described above, in the light receiving unit 1b, the electrode of the photodetecting element 114 configured by the bare chip IC is directly connected to the electrode pad unit 116 on the flexible printed circuit board 49, so that the optical pickup device of the photodetecting element unit is provided. The dimension in the thickness direction can be reduced, and the optical disk device can be downsized.

  In the above description, in the light receiving unit 1 b of the short wavelength optical unit 1, the flexible printed circuit board 49 is provided between the light detection element 114 and the transparent glass substrate 118, and light is received through the through hole 45 of the flexible printed circuit board 49. Although the configuration in which the portion 1b and the transparent glass substrate 118 face each other has been described, the light receiving portion 1c of the short wavelength optical unit 1 is configured in the same manner, thereby suppressing the deterioration of the light receiving portion 1b due to the passage of the short wavelength laser. It is possible to perform light detection well. Further, the light receiving unit 3b and the light receiving unit 3c of the long wavelength optical unit 3 can be similarly configured.

  Hereinafter, the light receiving portion 3b of the long wavelength optical unit 3 will be described with reference to FIG. In addition, the thing of the code | symbol same as the code | symbol shown in FIGS. 36-49 demonstrated about the light-receiving part 1b of the short wavelength optical unit 1 has a substantially the same function, In FIG. Corresponding member.

  In FIG. 50, 49d is a transparent substrate portion made of a transparent resin in the flexible printed circuit board 49. Reflected light from the information recording surface of the optical disc passes through the transparent glass substrate 118, then passes through the transparent substrate portion 49d, and reaches the light detection portion 114a of the light detection element 114. The transparent substrate portion 49d may be formed by forming the through hole 49a and the cutout portion 49b described above with a transparent resin, or may have other shapes. By providing the transparent printed circuit board 49d on the flexible printed circuit board 49, the reflected light from the information recording surface of the optical disk can be efficiently reflected by the light of the light detecting element 114 without providing the through hole 49a and the notch 49b described above. It can guide to the detection part 114a. Further, when the transparent printed circuit board 49 is provided with the transparent substrate 49d, it may be considered that the light receiving unit 3b of the long wavelength optical unit 3 is configured by omitting the transparent glass substrate 118. Further, the transparent printed circuit board 49d, which is a light transmitting part of the flexible printed circuit board 49, can be formed of an opaque member or a member other than resin as long as it transmits light efficiently. is there.

  In FIG. 50, the flexible printed circuit board 49 is provided with the transparent substrate portion 49d. However, if the flexible printed circuit board 49 itself is made of a transparent resin, the transparent printed circuit board portion 49d may be provided without providing the transparent substrate portion 49d. is there.

  As described above, the light receiving unit 3c can be configured similarly to the light receiving unit 3b of the long wavelength optical unit 3.

  In addition, the light transmitting portions such as the transparent glass substrate 118 and the window portion 49c made of transparent glass described so far can be made of an opaque member as long as it transmits light efficiently. It can be similarly implemented by using members.

  As described above with reference to FIGS. 36 to 50, the transparent glass substrate 118 is fixed to the back surface of the flexible printed circuit board 49 on which the light detection element 114 is mounted by pressing and heating with the adhesive 117 interposed therebetween. A light transmission part is provided at the approximate center of the electrode pad part 116 on the flexible printed circuit board 49 formed in a row, and the reflected light from the optical disk incident from the transparent glass substrate 118 side reaches the light detection part 114a in the light detection element 114. By configuring the photodetecting element unit 123 to be configured, it is possible to configure the light receiving portion at a low cost and to reduce the dimension in the thickness direction of the optical pickup device.

  Next, the configuration of the magnets 39 to 42 of the optical pickup device will be described in more detail with reference to FIGS. The members shown in FIGS. 51 to 53 may be slightly different in shape from the members shown in FIGS. 6 and 7, but the members having the same reference numerals have substantially the same functions.

  First, the suspension 18 will be described with reference to FIG. FIG. 51 (b) is a diagram schematically showing the AA cross section of FIG. 51 (a) showing the optical pickup device in the present embodiment, and the suspensions 18d, 18e, 18f are also shown in FIG. 51 for explanation. Yes. FIG. 51B shows the optical disc 2 and the lens holder when no current is passed through the focus coils 33 and 34, the tracking coils 35 and 36, and the sub-tracking coils 37 and 38, that is, when the lens holder 16 is not driven. 16, the positional relationship among the suspension holder 17, the suspensions 18d, 18e, and 18f, the focus coils 33 and 34, the sub-tracking coils 37 and 38, and the magnets 39 and 42 are shown.

  In FIG. 51 (b), the suspension 18d is described by adding a reference numeral, but the suspensions 18e and 18f are also provided between the lens holder 16 and the suspension holder 17 so as to be substantially parallel to the suspension 18d. The same effect is obtained. The same applies to the suspensions 18a, 18b and 18c which are located on the opposite side of the suspensions 18d, 18e and 18f with respect to the lens holder 16 and which are not shown in the drawing. Therefore, hereinafter, the suspensions 18a, 18b, 18c, 18d, 18e, and 18f are collectively referred to as the suspension 18.

  In FIG. 51, reference numeral 1816 denotes a connecting portion where the suspension 18 and the lens holder 16 are connected, and reference numeral 1817 denotes a connecting portion where the suspension 18 and the suspension holder 17 are connected. The suspension 18 is elastically deformed on the suspension holder 17 side with respect to the coupling portion 1816 and on the lens holder 16 side with respect to the coupling portion 1817, that is, between the coupling portion 1816 and the coupling portion 1817, and the lens holder 16 is moved in the height direction shown in FIG. And move in the width direction.

  Further, as shown in FIG. 51 (b), the joint 1816 between the suspension 18 and the lens holder 16 is closer to the objective lenses 10 and 13 than the joint 1817 between the suspension 18 and the suspension holder 17. Here, the objective lens 10 and 13 side indicating the condensing member side in the optical pickup device of the present invention is emitted from the short wavelength optical unit 1 or the long wavelength optical unit 3 and passes through the beam splitter 7 or the collimator lens 8 or the like. This is a direction in which a short wavelength laser or a long wavelength laser is emitted from the objective lens 13 or the objective lens 10 toward the optical disc 2. Next, the relationship with the optical disc 2 will be described.

  d1816 and d1817 indicate the distances between the surface on which information is recorded on the optical disc 2 mounted on the spindle motor 25 and the coupling portions 1816 and 1817, respectively. As shown in FIG. 51B, the relationship between d1816 and d1817 when the lens holder 16 is not driven is d1816 <d1817. That is, the suspension 18 is supported obliquely by the suspension holder 17 in a direction approaching the optical disc 2 and elastically supports the lens holder 16. In other words, the connecting portion 1817 of the suspension 18 with the suspension holder 17 is configured to have a longer distance from the optical disc 2 than the connecting portion 1816 of the suspension 18 with the lens holder 16.

  With this configuration, since the suspension holder 17 supports the suspension 18 at a position away from the optical disc 2, the suspension holder 17 itself can be configured low in the optical pickup device, and the optical disc device can be downsized.

  Next, the magnets 39 to 42 will be described with reference to FIG. FIG. 52B is a diagram schematically showing the AA cross section of FIG.

  In FIG. 52, magnets 39 and 42 are focus magnets for driving the lens holder 16 in the height direction shown in FIG. 52, and magnets 40 and 41 are tracking magnets for driving the lens holder 16 in the width direction shown in FIG. It is. The magnets 39 to 42 are magnetized and arranged as described with reference to FIGS. 6 to 8, and the magnet 42, which is a focus magnet, is located between the lens holder 16 and the suspension holder 17 as in FIGS. 6 and 7. The magnet 39 that is a focus magnet is disposed on the opposite side of the magnet 42 with respect to the lens holder 16, and the magnet 41 that is a tracking magnet is disposed between the lens holder 16 and the suspension holder 17. The magnet 40 that is a tracking magnet is disposed on the opposite side of the magnet 41 with respect to the lens holder 16. Further, the magnet 39 and the magnet 42 are arranged at diagonal positions of the lens holder 16, and the magnet 40 and the magnet 41 are arranged at other diagonal positions of the lens holder 16. Further, the end of each of the magnets 39 to 42 opposite to the end of the optical disk 2 in the height direction, that is, the lower end of each of the magnets 39 to 42 is on the same plane, and each of the magnets 39 to 42 is The long side is arranged in a direction substantially perpendicular to the surface on which information is recorded on the optical disk 2 mounted on the spindle motor 25.

  In FIG. 6, the magnets 40 and 41 are each composed of one magnet. However, as shown in FIG. 52A, the magnets 40 and 41 may be composed of two magnets. Can be implemented. The magnet 40 is arranged such that, of the two magnets, the N pole of one magnet and the S pole of the other magnet are exposed to face the tracking coil 35, and the suspensions 18a, 18b, A magnetic pole appears on the surface facing the tracking coil 35 in the order of N pole and S pole from the center plane (cross section AA in FIG. 6) of 18c and suspensions 18d, 18e, and 18f toward suspensions 18a, 18b, and 18c. The magnet 41 is arranged so that the N pole of one magnet and the S pole of the other magnet are exposed facing the tracking coil 36 and the width of the magnet 41 is about the width direction. The center planes of the suspensions 18a, 18b, 18c and the suspensions 18d, 18e, 18f ( A-A cross-section) from the suspension 18d of 6, 18e, can be placed N pole, S magnet poles on a surface facing the tracking coil 36 in the order is exposed poles towards 18f.

  With such a configuration, the magnetic pole arrangement described with reference to FIG. 6 can be obtained. Further, when the magnetic poles are configured with one magnet as described with reference to FIG. The portion where the magnets 40 and 41 are not magnetized, which occurs at the portion where the lens is switched, can be reduced, and the operation sensitivity in the width direction of the lens holder 16 can be increased.

  The magnets 39 and 42 that are focus magnets for driving the lens holder 16 in the height direction will be described in more detail with reference to FIG.

  As shown in FIG. 52B, the magnet 39 disposed on the opposite side of the lens holder 16 protrudes toward the objective lenses 10 and 13 rather than the magnet 42 disposed between the lens holder 16 and the suspension holder 17. Configured. Hereinafter, description will be made using the relationship with the optical disc 2.

  In FIG. 52B, l39 and l42 indicate the lengths of the magnets 39 and 42 in the height direction, that is, the lengths of the long sides of the magnets 39 and 42, respectively, and d39 and d42 respectively indicate the spindle motor 25. The distances from the surface on which information is recorded on the optical disk 2 mounted to the magnet 39 to the magnet 42 are shown.

  The relationship between the lengths of the magnet 39 and the magnet 42 is l39> l42, and the magnet 42 is shorter than the magnet 39. The dimensions d39, d42, l39, and l42 related to the magnets 39 and 42 have a relationship of d39 + l39≈d42 + l42, and the distance from the optical disk 2 to the lower end of the magnet 39 and the distance from the optical disk 2 to the lower end of the magnet 42 Are approximately equal. In other words, the distance from the surface on which the information on the optical disk 2 mounted on the spindle motor 25 is recorded to the end of the magnet 39 opposite to the end of the optical disk 2 in the height direction, and the mounting on the spindle motor 25. The distance from the recorded surface of the optical disc 2 to the end of the magnet 42 opposite to the end of the optical disc 2 is substantially equal. Thus, the relationship between the distance d39 between the optical disk 2 and the magnet 39 and the distance d42 between the optical disk 2 and the magnet 42 is d39 <d42, that is, the end of the magnet 42 on the optical disk 2 side in the height direction is The distance from the optical disk 2 is longer than the end of the magnet 39 on the optical disk 2 side.

  Further, regarding the distance from the extending surface of the optical disk mounting surface, which is the surface on which the optical disk 2 is mounted, of the spindle motor 25, the distance from the end of the magnet 42 in the height direction to the optical disk 2 side is the optical disk 2 of the magnet 39. It becomes a structure longer than the distance to the edge part of a side.

  Further, with respect to the distance from the housing on the objective lens 10, 13 side of the optical disk apparatus, the distance to the end on the optical disk 2 side in the height direction of the magnet 42 is the distance to the end on the optical disk 2 side of the magnet 39. Longer configuration.

  The distance between each of the magnets 40 and 41 that are tracking magnets for driving the lens holder 16 in the width direction and the optical disk 2 is substantially equal to d39, and the end of the magnets 40 and 41 on the optical disk 2 side in the height direction is The distance from the end of the magnet 39 on the optical disc 2 side is substantially the same. The lengths of the magnets 40 and 41 in the height direction, that is, the lengths of the long sides of the magnets 40 and 41 are equal to those of the magnet 39, and the length is l39. Further, the distance from the optical disk 2 to the lower ends of the magnets 40 and 41 is approximately equal to the distance from the optical disk 2 to the lower end of the magnet 39, and the distance is approximately d39 + 139. That is, the distance from the surface on which information is recorded on the optical disc 2 mounted on the spindle motor 25 to the end on the opposite side of the end on the optical disc 2 side in the height direction in each of the magnets 39 to 42 is substantially equal. In other words, the lower end surfaces of the magnets 39 to 42 configured by connecting the end portions of the magnets 39 to 42 opposite to the end portions on the optical disc 2 side in the height direction, and the surface on which information on the optical disc 2 is recorded. Are configured substantially parallel to each other.

  As shown in FIG. 52B, the magnet 39 and the magnet 42 are magnetized and arranged as described with reference to FIGS. 6 and 7, and 39n and 42n are respectively the magnets 39 and 42, respectively. This is a neutral zone that is generated at the part where the direction of the magnetic pole is switched and is not magnetized. The neutral zone 39n is positioned approximately half of the long side direction of the magnet 39, and the length from the lower end of the magnet 42 to the neutral zone 42n is substantially equal to the length from the lower end of the magnet 39 to the neutral zone 39n. To. That is, the lower end surfaces of the magnets 39 to 42 and the surface formed by connecting the neutral zone 39n and the neutral zone 42n are substantially parallel, and when the lens holder 16 is not driven, the focus coils 33 and 34 and the sub-tracking coils 37 and 38 are driven. The approximate center position in the height direction coincides with the position in the height direction of the surface formed by connecting the neutral zone 39n and the neutral zone 42n. In other words, the S pole portion of the magnet 39 facing the focus coil 33 and the sub tracking coil 37, the N pole portion of the magnet 39 facing the focus coil 33 and the sub tracking coil 37, the focus coil 34 and the sub tracking coil. The area of the south pole of the magnet 42 facing the magnet 38 is substantially the same, but the area of the north pole of the magnet 42 facing the focus coil 34 and the sub-tracking coil 38 has a smaller area. ing. With this configuration, it is possible to suppress the tilt of the lens holder 16 that occurs when the lens holder 16 is driven.

  53 schematically illustrates the behavior of the lens holder 16, and shows the behavior of the lens holder 16 when a current is passed through the focus coils 33 and 34 to drive the lens holder 16 up and down in the height direction. ing. In FIG. 53, the suspensions 18a, 18b, 18c, 18d, 18e, and 18f described so far are collectively shown as the suspension 18. When the lens holder 16 is not driven, the suspension 18 is substantially linear as shown in FIG. 51 (b) when viewed in the width direction shown in FIG. 51 and the like, and the lens holder 16 and the suspension holder are respectively connected at the coupling portions 1816 and 1817. 17, when the lens holder 16 is driven, the suspension 18 is actually curved and the lens holder 16 moves in the height direction. In FIG. 53, the lens holder 16 is schematically driven. The shape of the suspension 18 at that time is also shown in a substantially linear shape.

  When the lens holder 16 is moved up and down by the same amount in the height direction from the non-driving position shown by the solid line in FIG. 53, the suspension 18 is slanted with respect to the surface on which the information on the optical disk 2 is recorded. There is a large difference in the amount of movement in the rotation direction (tangential direction) of the optical disc 2 shown.

When a current is passed through the focus coils 33 and 34 and the lens holder 16 is moved away from the optical disk 2, the distance between the focus coil 33 and the magnet 39 is not much different from the distance between the focus coil 34 and the magnet 42.
For this reason, there is no significant difference between the electromagnetic force generated on the focus coil 34 side and the electromagnetic force generated on the focus coil 33 side.

  On the other hand, when a current is passed through the focus coils 33 and 34 and the lens holder 16 is moved in a direction approaching the optical disc 2, the difference between the distance between the focus coil 33 and the magnet 39 and the distance between the focus coil 34 and the magnet 42 is as follows. growing. As the lens holder 16 moves closer to the optical disc 2, the distance between the focus coil 33 and the magnet 39 increases and the electromagnetic force generated on the focus coil 33 side decreases, but the magnet 42 moves in the height direction from the magnet 39. Since the lens holder 16 is moved closer to the optical disk 2, the magnetic force lines of the magnet 42 passing through the focus coil 34 are reduced, so that the electromagnetic force generated on the focus coil 34 side is also reduced. Thereby, even when the lens holder 16 is moved in the direction approaching the optical disc 2, there is no significant difference between the electromagnetic force generated on the focus coil 34 side and the electromagnetic force generated on the focus coil 33 side. It can be kept small.

  Next, the rising mirror 9 of the optical pickup device will be described with reference to FIGS. The members shown in FIGS. 54 to 59 may be slightly different in shape from the members shown in FIGS. 1 and 5, but the members having the same reference numerals have almost the same functions. Although not shown, the optical pickup apparatus shown in FIGS. 54 to 59 is also provided with the quarter wavelength member 9a shown in FIGS.

  The raising mirror 9 can also be configured as described below with reference to FIG.

  54 shows the mirror 9 raised from the Z direction in the direction of the light beam of the laser beam emitted from the short wavelength optical unit 1 or the long wavelength optical unit 3 and passed through the beam splitter 7 or the collimator lens 8 shown in FIG. 54 is a diagram, and A shown in FIG. 54 is the luminous flux of the laser light that has reached the rising mirror 9.

  In FIG. 54, the rising mirror 9 is provided with a reflecting plate 9d that is a switching means including a wavelength selection film 9b and a reflecting portion 9c, and an actuator 9e that moves the reflecting plate 9d. The wavelength selection film 9b and the reflection portion 9c are provided on the surface of the reflection plate 9d on the beam splitter 7 side, and are composed of a dielectric multilayer film, metal, or the like.

  The wavelength selection film 9b provided on the reflection plate 9d has a function of transmitting light of a predetermined wavelength almost regardless of the polarization state and reflecting light of other wavelengths almost regardless of the polarization state. In the present embodiment, the short wavelength light (light having a wavelength of about 405 nm) emitted from the short wavelength optical unit 1 is transmitted, and the red light (light having a wavelength of about 660 nm) emitted from the long wavelength optical unit 3 is transmitted. And infrared light (light having a wavelength of about 780 nm) is reflected. That is, it has the same configuration and function as the wavelength selection film 9b described in FIG.

  The reflecting portion 9c provided on the reflecting plate 9d has a function of reflecting the reached laser light almost regardless of the wavelength or the polarization state. When the wavelength selection film 9b and the reflection portion 9c are provided on the reflection plate 9d, the reflection portion 9c may reflect light having a predetermined wavelength regardless of the polarization state. In this embodiment, the reflection portion 9c 9c should just be the structure which reflects the short wavelength light (light with a wavelength of about 405 nm) radiate | emitted from the short wavelength optical unit 1 at least.

  The actuator 9e is provided with a gear 9f and a motor (not shown), and the motor rotates the gear 9f. A small DC motor was used as this motor. On the other hand, a rack gear 9g is provided on one side of the reflecting plate 9d and meshes with the gear 9f. The reflector 9d and the housing 9h are configured to be slidable.

  In the optical pickup device including the reflection plate 9d configured as described above, when the optical disc 2 is mounted on the spindle motor 25 described with reference to FIGS. 2 to 4, the control member (not shown) determines the type of the optical disc 2. The control signal is applied to the actuator 9e. The actuator 9e drives the motor by this control signal to rotate the gear 9f, and puts the reflecting plate 9d in and out of the housing 9h of the actuator 9e. Here, the actuator 9e has been described as moving the reflecting plate 9d using a motor. However, if the actuator 9e is driven by a control signal, the reflecting plate 9d is moved using a solenoid, a linear motor, a hydraulic piston, or the like. You may comprise so that it may move.

  FIG. 54 (a) is a diagram showing a state in which the reflection plate 9d is moved by the actuator 9e and the wavelength selection film 9b is present on the optical path, and FIG. 54 (b) is a view in which the reflection plate 9d is moved by the actuator 9e. It is a figure which shows the state in which the reflection part 9c exists on an optical path.

  Hereinafter, the movement of the reflecting plate 9d according to the type of the optical disk 2 mounted on the spindle motor 25 will be described.

  The optical disk 2 mounted on the spindle motor 25 is an optical disk 2 that records / reproduces information by using short wavelength light (light having a wavelength of about 405 nm) with a distance of 0.1 mm between the surface of the optical disk 2 and the recording layer. In some cases, the raising mirror 9 is in a state in which the wavelength selection film 9b of the reflection plate 9d exists on the optical path by driving the actuator 9e.

  Further, the optical disc 2 mounted on the spindle motor 25 has an optical disc 2 having a distance of 0.6 mm between the surface of the optical disc 2 and the recording layer and recording / reproducing information with red light (light having a wavelength of about 660 nm). In this case, the rising mirror 9 is in a state in which the wavelength selection film 9b of the reflecting plate 9d exists on the optical path by driving the actuator 9e.

  The optical disk 2 mounted on the spindle motor 25 is an optical disk on which information is recorded / reproduced by infrared light (light having a wavelength of about 780 nm) with a distance of 1.2 mm between the surface of the optical disk 2 and the recording layer. Also in the case of 2, the rising mirror 9 is in a state where the wavelength selection film 9b of the reflecting plate 9d exists on the optical path by driving the actuator 9e.

  On the other hand, the optical disc 2 mounted on the spindle motor 25 has an optical disc 2 having a distance between the surface of the optical disc 2 and a recording layer of 0.6 mm, and records / reproduces information using short wavelength light (light having a wavelength of about 405 nm). In the case of 2, the rising mirror 9 is in a state where the reflecting portion 9c of the reflecting plate 9d exists on the optical path by driving the actuator 9e. Note that the optical disc 2 mounted on the spindle motor 25 has an optical disc 2 on which the distance between the surface of the optical disc 2 and the recording layer is 0.6 mm, and information is recorded / reproduced by red light (light having a wavelength of about 660 nm). Even when the distance between the surface of the optical disc 2 and the recording layer is 1.2 mm and the information is recorded / reproduced by infrared light (light having a wavelength of about 780 nm), the optical disc 2 is also reflected by driving the actuator 9e. The reflecting portion 9c of the plate 9d may be in a state where it exists on the optical path.

  FIG. 55 is a schematic diagram showing an optical path of laser light in the optical pickup device using the rising mirror 9 of FIG. 54. FIG. 55 (a) shows a state where the wavelength selection film 9b exists on the optical path, and FIG. b) shows a state in which the reflecting portion 9c exists on the optical path. In addition to the configuration described with reference to FIG. 1, the optical component 11 provided between the rising mirror 9 and the objective lens 10 has a short distance of 0.6 mm from the surface of the optical disc 2 to the recording layer. An aperture filter that realizes a required numerical aperture for the optical disc 2 that records / reproduces information using wavelength light (light having a wavelength of about 405 nm) and reacts to short wavelength light (light having a wavelength of about 405 nm). And an auxiliary hologram that has wavelength selectivity and performs spherical aberration correction, color correction, and the like. The aperture filter and the auxiliary hologram can be configured integrally with the optical component 11 or can be configured separately.

  Hereinafter, the optical path of the optical pickup device depending on the type of the optical disc 2 mounted on the spindle motor 25 will be described.

  The optical disk 2 mounted on the spindle motor 25 is an optical disk 2 that records / reproduces information by using short wavelength light (light having a wavelength of about 405 nm) with a distance of 0.1 mm between the surface of the optical disk 2 and the recording layer. In some cases, the rising mirror 9 is in a state where the wavelength selection film 9b of the reflecting plate 9d exists on the optical path as shown in FIG. 55 (a), and is emitted from the short wavelength optical unit 1 and the beam splitter 7 and the collimator lens 8. The short wavelength light (light having a wavelength of about 405 nm) that has passed through the light passes through the wavelength selection film 9b of the rising mirror 9, is reflected by the rising mirror 12, passes through the objective lens 13, and passes from the surface of the optical disc 2. Is condensed on the recording layer at a position of 0.1 mm.

  Further, the optical disc 2 mounted on the spindle motor 25 has an optical disc 2 having a distance of 0.6 mm between the surface of the optical disc 2 and the recording layer and recording / reproducing information with red light (light having a wavelength of about 660 nm). In this case, the rising mirror 9 is in a state where the wavelength selection film 9b of the reflecting plate 9d exists on the optical path as shown in FIG. 55 (a), and is emitted from the long wavelength optical unit 3 and is emitted from the beam splitter 7 and the collimator. The red light that has passed through the lens 8 (light having a wavelength of about 660 nm) is reflected by the wavelength selection film 9b of the rising mirror 9, passes through the optical component 11 and the objective lens 10, and has a distance from the surface of the optical disc 2. The light is focused on the recording layer at a position of 0.6 mm.

  The optical disk 2 mounted on the spindle motor 25 is an optical disk on which information is recorded / reproduced by infrared light (light having a wavelength of about 780 nm) with a distance of 1.2 mm between the surface of the optical disk 2 and the recording layer. 2, the rising mirror 9 is in a state where the wavelength selection film 9b of the reflecting plate 9d exists on the optical path as shown in FIG. 55 (a), and is emitted from the long wavelength optical unit 3 and the beam splitter 7 and the like. Infrared light (light having a wavelength of about 780 nm) that has passed through the collimator lens 8 is reflected by the wavelength selection film 9 b of the rising mirror 9, passes through the optical component 11 and the objective lens 10, and travels from the surface of the optical disc 2. The light is focused on the recording layer at a distance of 1.2 mm.

  On the other hand, the optical disc 2 mounted on the spindle motor 25 has an optical disc 2 having a distance between the surface of the optical disc 2 and a recording layer of 0.6 mm, and records / reproduces information using short wavelength light (light having a wavelength of about 405 nm). 2, the rising mirror 9 is in a state in which the reflecting portion 9 c of the reflecting plate 9 d exists on the optical path as shown in FIG. 55B, and is emitted from the short wavelength optical unit 1 to be used as the beam splitter 7 or the collimator lens. The short wavelength light (light having a wavelength of about 405 nm) that has passed through 8 is reflected by the wavelength selection film 9 b of the rising mirror 9, passes through the optical component 11 and the objective lens 10, and has a distance from the surface of the optical disc 2. The light is focused on the recording layer at a position of 0.6 mm.

  Note that the reflector 9d of the rising mirror 9 described in FIG. 54 can be configured in the same manner as described next with reference to FIGS. Parts that are not particularly described have the same configuration as that described with reference to FIGS.

  The portion of the wavelength selection film 9b shown in FIG. 54 is the base material portion 9i where the base material of the reflection plate 9d is not provided without providing the wavelength selection film 9b, and the surface of the reflection plate 9d on the beam splitter 7 side is the reflection portion 9c. And a portion provided with the reflecting portion 9c described with reference to FIG.

  The base material portion 9i provided on the reflecting plate 9d has a function of transmitting the laser beam that has reached almost regardless of the wavelength or the polarization state. In addition, when providing the base material part 9i and the reflection part 9c in the reflecting plate 9d, the base material part 9i may permeate | transmit the light of a predetermined wavelength irrespective of a polarization state, Here, the base material part 9i May be configured to reflect at least short wavelength light (light having a wavelength of about 405 nm) emitted from the short wavelength optical unit 1.

  The reflecting portion 9c provided on the reflecting plate 9d has a function of reflecting the reached laser light almost regardless of the wavelength or the polarization state. Here, at least short wavelength light (light having a wavelength of about 405 nm) emitted from the short wavelength optical unit 1, red light (light having a wavelength of about 660 nm) and infrared light (substantially about 405 nm) emitted from the long wavelength optical unit 3. 780 nm wavelength light) is reflected.

  Below, the movement according to the optical disk 2 with which the reflecting plate 9d provided with the base material part 9i and the reflection part 9c is mounted | worn with the spindle motor 25 is demonstrated.

  The optical disk 2 mounted on the spindle motor 25 is an optical disk 2 that records / reproduces information by using short wavelength light (light having a wavelength of about 405 nm) with a distance of 0.1 mm between the surface of the optical disk 2 and the recording layer. In some cases, the raising mirror 9 is in a state in which the base portion 9i of the reflecting plate 9d is present on the optical path by driving the actuator 9e.

  On the other hand, the optical disc 2 mounted on the spindle motor 25 has a distance of 0.6 mm between the surface of the optical disc 2 and the recording layer, and records / reproduces information by red light (light having a wavelength of about 660 nm). In this case, the raising mirror 9 is in a state where the reflecting portion 9c of the reflecting plate 9d exists on the optical path by driving the actuator 9e.

  The optical disk 2 mounted on the spindle motor 25 is an optical disk on which information is recorded / reproduced by infrared light (light having a wavelength of about 780 nm) with a distance of 1.2 mm between the surface of the optical disk 2 and the recording layer. Also in the case of 2, the rising mirror 9 is in a state where the reflecting portion 9c of the reflecting plate 9d exists on the optical path by driving the actuator 9e.

  The optical disk 2 mounted on the spindle motor 25 has an optical disk 2 with a distance between the surface of the optical disk 2 and a recording layer of 0.6 mm, and records / reproduces information using short wavelength light (light having a wavelength of about 405 nm). Also in the case of 2, the rising mirror 9 is in a state where the reflecting portion 9c of the reflecting plate 9d exists on the optical path by driving the actuator 9e.

  FIG. 56 is a schematic diagram showing an optical path of laser light in an optical pickup device using a rising mirror 9 provided with a base material portion 9i and a reflection portion 9c, and FIG. 56 (a) shows the base material portion on the optical path. FIG. 56 (b) shows a state where the reflection portion 9c exists on the optical path.

  As shown in FIG. 56, the optical path of the laser beam is the same as that using the reflecting plate 9d described with reference to FIGS. 54 and 55 even when the reflecting plate 9d provided with the base material portion 9i and the reflecting portion 9c is used. become.

  The raising mirror 9 can also be configured as described below with reference to FIG.

  FIG. 57 is similar to FIG. 54, and shows a mirror raised from the Z direction in the direction of the light beam of the laser beam emitted from the short wavelength optical unit 1 or the long wavelength optical unit 3 and passed through the beam splitter 7 or the collimator lens 8 shown in FIG. 9 is a view of the laser beam 9, and A shown in FIG.

  In FIG. 57, the rising mirror 9 has an electric control film 9j, which is a switching means whose optical characteristics are changed by a control signal, on the surface on the beam splitter 7 side, and a signal applying unit 9k that applies the control signal to the electric control film 9j. And are provided.

  The electric control film 9j takes the state of the wavelength selection film 9b described with reference to FIG. 54 and the state of the reflection portion 9c, and these two states are switched by the control signal. By switching the state of the electric control film 9j in accordance with the movement of the reflecting plate 9d described with reference to FIGS. 54 and 55 depending on the type of the optical disk 2 mounted on the spindle motor 25, as shown in FIG. The optical path of the laser light can be switched in the same manner as in FIG.

  The electric control film 9j takes the state of the base material portion 9i and the state of the reflection portion 9c described with reference to FIG. 54, and the two states are switched by a control signal, and is attached to the spindle motor 25. As shown in FIG. 59, the optical path of the laser beam is switched in the same manner as shown in FIG. 56 by switching according to the movement of the reflecting plate 9d described with reference to FIGS. Is possible.

  As described above, according to the optical pickup device described with reference to FIGS. 54 to 59, the optical path of the laser light can be switched depending on the type of the optical disk 2. Recording / reproduction can be performed on the optical disc 2, and in particular, short-wavelength light (light having a wavelength of about 405 nm) is used, and the distance between the surface and the recording layer is different from 0.1 mm and 0.6 mm. It is possible to record / reproduce information for both.

  The optical pickup device and the optical disk device according to the present invention have an effect of realizing miniaturization, and can be applied to portable electronic devices such as notebook personal computers and electronic devices such as stationary personal computers.

1 is a schematic diagram showing an optical pickup device according to an embodiment of the present invention. 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shows a part of optical pick-up apparatus in one embodiment of this invention The figure which shows a part of optical pick-up apparatus in one embodiment of this invention The figure which shows the light radiate | emitted from the light source of the optical pick-up apparatus in one embodiment of this invention The figure which shows the light radiate | emitted from the light source of the optical pick-up apparatus in one embodiment of this invention The figure which shows a part of optical pick-up apparatus in one embodiment of this invention The figure which shows a part of optical pick-up apparatus in one embodiment of this invention The figure which shows a part of optical pick-up apparatus in one embodiment of this invention The figure which shows a part of optical pick-up apparatus in one embodiment of this invention The figure which shows a part of optical pick-up apparatus in one embodiment of this invention The figure which shows a part of optical pick-up apparatus in one 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invention The figure which shows a part of optical pick-up apparatus in one embodiment of this invention The figure which shows a part of optical pick-up apparatus in one embodiment of this invention The figure which shows a part of optical pick-up apparatus in one embodiment of this invention The figure which shows a part of optical pick-up apparatus in one embodiment of this invention The figure which shows a part of optical pick-up apparatus in one embodiment of this invention The figure which shows a part of optical pick-up apparatus in one embodiment of this invention The figure which shows a part of optical pick-up apparatus in one embodiment of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Short wavelength optical unit 3 Long wavelength optical unit 7 Beam splitter 8a Support member 8c Lead screw 8d Gear group 8e Drive member 9,12 Rising mirror 10,13 Objective lens 21,22 Shaft 23 Screw shaft

Claims (6)

A light source that emits light having a first wavelength and light having a wavelength longer than the first wavelength;
Condensing means for condensing light from the light source;
An optical pickup device, comprising: a switching unit that is provided between the light source and the condensing unit and switches between reflection and transmission of the light having the first wavelength regardless of a polarization state. The first light collecting means to which the light reflected by the switching means reaches and the second light collecting means to which the light transmitted through the switching means reaches as the light collecting means. 2. The optical pickup device according to 1. 3. The optical pickup device according to claim 2, wherein the numerical aperture of the first light collecting means is different from the numerical aperture of the second light collecting means. 3. The optical pickup device according to claim 2, wherein the numerical aperture of the first light collecting means is smaller than the numerical aperture of the second light collecting means. The first light unit that emits light of the first wavelength and the second optical unit that emits light of a wavelength longer than the first wavelength are used as the light source. 2. The optical pickup device according to 1. An optical pickup device according to any one of claims 1 to 5,
A base for movably holding the optical pickup device;
An optical disk apparatus comprising: a rotation driving means provided on the base for rotating the medium.

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