JP2007200487A - Optical pickup device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical pickup device in which handleability during assembly is improved. <P>SOLUTION: Since a cover member CV has notches CVa, CVb exposing a first semiconductor laser LD1 and a laser 2 laser 1 package 2L1P, peripheral parts can be approached to the first semiconductor laser D1 and the 2laser1 package 2L1P as much as possible, and thereby, compact constitution can be obtained. Also, since the cover member CV has a pair of holding parts CVd, CVe projected to both sides of the 2laser 1 package 2L1P, during assembly, before a terminal T of the 2laser 1package 2L1P is abutted, this is abutted to a sub-rail SR, thereby, direct abutting of the terminal T and the sub-rail SR is suppressed, and handleability during assembly can be improved. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical pickup device, and more particularly to an optical pickup device that is thin and capable of appropriately recording and / or reproducing information on an optical information recording medium.

  In recent years, research and development of a high-density optical disk system capable of recording / reproducing information using a blue-violet semiconductor laser having a wavelength of about 400 nm is rapidly progressing. As an example, an optical disc for recording / reproducing information with specifications of NA 0.85 and light source wavelength 405 nm, so-called Blu-ray Disc (BD), is the same size as DVD (NA 0.6, light source wavelength 650 nm, storage capacity 4, 7 GB). On an optical disk with a diameter of 12 cm, information of 20 to 30 GB can be recorded on one surface, and an optical disk that records and reproduces information with specifications of NA 0.65 and light source wavelength 405 nm, so-called HD DVD In addition, it is possible to record information of 15 to 20 GB per side on an optical disk having a diameter of 12 cm. Hereinafter, in this specification, such an optical disc is referred to as a “high density DVD”.

By the way, it cannot be said that the value as a product of the optical pickup device is sufficient only by being able to appropriately record / reproduce information on such a high-density DVD. In light of the fact that DVDs and CDs that record a wide variety of information are currently being sold, it is not only possible to record / reproduce information appropriately for high-density DVDs. For example, conventional DVDs owned by users Alternatively, it is possible to record / reproduce information appropriately for a CD as well, which leads to an increase in the value of a product as a compatible type optical pickup device. From such a background, the optical system used for the compatible type optical pickup device has, of course, a low-cost and simple configuration, and in addition to high-density DVDs, conventional DVDs, and CDs, It is desired to obtain a good spot in order to properly record / reproduce information. In addition, an optical pickup device capable of recording and / or reproducing information in a manner compatible with DVD and CD has been put into practical use, but further downsizing, thinning, and cost reduction with respect to the current configuration. Etc. are desired. In particular, in the case of a notebook personal computer or the like, there is an actual situation that an optical pickup device to be mounted on the personal computer is desired to be thin in order to increase the competitiveness of the product. Here, Patent Document 1 discloses an optical pickup device having a thin configuration.
JP 2005-108300 A

  However, in the case of the optical pickup device of Patent Document 1, a holder that also serves as a cover is attached to the laser diode that is the light source, and the laser diode terminal protrudes from the holder. If the protruding terminal is brought into contact with another component, the laser diode may be damaged. In particular, in the optical pickup device, the distance between the main rail and the sub rail that supports the carrier so as to be movable is determined to some extent, and if this is made thinner, one of the laser diodes is arranged near the main rail or the sub rail. In many cases, when the carrier is assembled between the main rail and the sub rail, the laser diode terminal may be bent by mistakenly contacting the rail.

  The present invention has been made in view of such problems, and an object of the present invention is to provide an optical pickup device with improved handleability during assembly.

The optical pickup device according to claim 1 is configured to record information and / or record information by causing a light beam from a light source to enter an objective lens via an optical system and condensing the objective lens onto an information recording surface of an optical information recording medium. Or in an optical pickup device that performs reproduction,
A carrier that moves along a main rail and a sub rail, and that has the light source mounted in the vicinity of at least one of the main rail and the sub rail;
A cover member covering a part of the upper part or the lower part of the carrier,
The cover member includes a notch that exposes the light source, and a protective portion that is disposed between the light source and the at least one.

  According to the optical pickup device of the present invention, the cover member includes the cutout exposing the light source, and the protection portion disposed between the light source and the at least one. For example, the terminals of the light source can be protected by avoiding direct contact of one rail or the like, and by providing the notch, the light source is exposed, so that the surrounding components can be as far as possible to the light source. By bringing them closer, a compact configuration can be provided. In the present specification, “the protective portion is disposed between the light source and the at least one” only means that the protective portion exists on a straight line connecting the light source and the at least one rail. In other words, when the light source and the at least one rail approach each other, the protection portion is in contact with the at least one rail before the light source contacts the at least one rail. .

  According to a second aspect of the present invention, in the invention of the first aspect, the cover member is a plate member, and the protection portion is a portion that protrudes and bends on both sides of the terminal of the light source. Therefore, the cover member can be easily formed at a low cost. In addition, since it is not necessary to provide a separate protection member, the light source can be protected without increasing the number of parts and the number of mounting steps.

According to a third aspect of the present invention, there is provided an optical pickup device configured to record information and / or record light by causing a light beam from a light source to enter an objective lens through an optical system and condensing the objective lens onto an information recording surface of an optical information recording medium. Or in an optical pickup device that performs reproduction,
A carrier moving along the main rail and the sub rail;
A holder attached to the carrier for holding the light source in the vicinity of at least one of the main rail and the sub rail;
The holder includes a protective portion disposed between the light source and the at least one, and the holder and the protective portion are integrated.

  According to the optical pickup device of the present invention, since the holder includes a protection portion disposed between the light source and the at least one, and the holder and the protection portion are integrated, the protection For example, the terminal of the light source can be protected by avoiding that the at least one rail or the like is in direct contact with the portion. In addition, since it is not necessary to provide a separate protection member, the light source can be protected without increasing the number of parts and the number of mounting steps.

The optical pickup device according to claim 4 is configured to record information and / or record light by causing a light beam from a light source to enter an objective lens through an optical system and condensing the objective lens on an information recording surface of an optical information recording medium. Or in an optical pickup device that performs reproduction,
A carrier moving along a main rail and a sub rail is provided, and the carrier mounts the light source in the vicinity of at least one of the main rail and the sub rail, and is disposed between the light source and the at least one. A protective part is provided, and the carrier and the protective part are integrated.

  According to the optical pickup device of the present invention, the carrier that moves along the main rail and the sub rail is provided, and the carrier mounts the light source in the vicinity of at least one of the main rail and the sub rail, Since the protective portion is disposed between the at least one and the carrier and the protective portion are integrated, the protective portion prevents the at least one rail or the like from coming into direct contact. Thus, for example, a terminal of the light source can be protected. In addition, since it is not necessary to provide a separate protection member, the light source can be protected without increasing the number of parts and the number of mounting steps.

  ADVANTAGE OF THE INVENTION According to this invention, the optical pick-up apparatus which improved the handleability at the time of an assembly | attachment can be provided.

  Hereinafter, the present invention will be described in more detail with reference to the drawings. 1 and 2 are perspective views of the optical pickup device according to the present embodiment. FIG. 1 shows a state where the cover member is removed, and FIG. 2 shows a state where the cover member is attached. In FIG. 1, in an optical pickup device PU capable of appropriately recording / reproducing information with respect to BD or HD DVD, DVD and CD, which are optical information recording media having different thicknesses of protective layers, a carrier CY includes a main rail MR. Is engaged with the sub rail SR parallel to the main rail MR via the engaging portion CYb, and the main rail MR and the sub rail SR are engaged by an actuator (not shown). It is supported so that it can move along. The optical pickup device PU includes a first semiconductor laser LD1 mounted on a carrier CY and capable of emitting a light beam having a wavelength λ1, a second semiconductor laser capable of emitting a light beam having a wavelength λ2, and a third semiconductor capable of emitting a light beam having a wavelength λ3. 2 laser 1 package 2L1P mounted with laser, coupling lens CL, dichroic prism DP, polarization beam splitter PBS, λ / 4 wavelength plate QWP, monitor lens ML, monitor detector MD, lens (first Objective lens that is drivably held by an actuator ACT, an expander lens EXP including a first optical element L1 and a lens (second optical element or movable optical element) L2, a rising mirror M that is a reflective optical element OBJ, servo lens SL supported by cylindrical adjustment member AM, and prism P If, and an optical detector PD.

  The first laser holder LH1 fitted and held with the first semiconductor laser LD1 serving as the light source is screwed to the side surface of the carrier CY, and the second laser holder fitted and held with the two laser 1 package 2L1P serving as the light source. LH2 is screwed to the end surface of the carrier CY on the sub rail SR side. Therefore, the three terminals T protruding from the two lasers 1 package 2L1P are opposed to the outer peripheral surface of the subrail SR.

  Since the laser beam has an elliptical intensity distribution, a beam shaping element that makes it a perfect circle may be used. However, the focal length on the incident side of the expander lens EXP is increased, and the emission point of the laser light source is increased. By separating from the expander lens EXP, by using a portion close to the center of the light beam with little change in the light intensity distribution, even if the beam shaping element is omitted, a good converging spot characteristic can be obtained. However, in the present embodiment, the distance between the main rail MR and the sub rail SR and the distance between the main rail MR and the optical axis of the objective lens OBJ are substantially determined, so the position of the 2 laser 1 package 2L1P is determined by the sub rail SR. It will be restricted. For this reason, even though the first semiconductor laser LD1 can be ideally disposed at a position away from the expander lens EXP, the two lasers 1 package 2L1P may not be disposed at the same focal length. In such a case, the combined focal length on the 2 laser 1 package 2L1P side is adjusted by inserting a coupling lens in the optical path so that the 2 laser 1 package 2L1P can be arranged without interfering with the subrail SR. However, the position of the 2 laser 1 package 2L1P should be kept away from the expander lens EXP so that the combined focal length is as long as possible, so the 2 laser 1 package 2L1P is arranged as close as possible to the subrail SR. It will be.

  As shown in FIG. 2, the cover member CV is formed of a thin metal plate, and is screwed or bonded to the upper part (and / or part of the lower part) of the carrier CY, so that the objective lens It covers the optical system except for and the driving device DR, and has a dustproof function and a function to shield such as electric noise. The outer edge of the cover member CV was cut out at the top of the first semiconductor laser LD1, the cut out CVa cut out at the top of the 2 laser 1 package 2L1P, and the top of the photodetector PD. Notch CVc. Further, a part of the cover member CV protruding from the outer edge is bent, and a pair of holding portions CVd and CVe protruding outward from the terminal T on both sides of the two laser 1 package 2L1P in the direction along the sub rail SR. , And a protective part CVf for protecting the monitor detector MD.

  According to the present embodiment, the cover member CV has the cutouts CVa and CVb exposing the first semiconductor laser LD1 and the laser 2 laser 1 package 2L1P. Therefore, the first semiconductor laser LD1 and the 2 laser 1 are used as much as possible. Since the package 2L1P can be approached, a compact configuration can be provided. Further, since the cover member CV has a pair of holding portions CVd and CVe protruding on both sides of the two-laser one package 2L1P, before the terminal T of the two-laser one package 2L1P contacts, , The direct contact between the terminal T and the sub rail SR is suppressed, and the handleability during assembly can be improved. Note that it is not always necessary to provide two protection portions. Here, the engagement portion CVb of the carrier CY that engages with the sub rail SR is disposed adjacent to the 2 laser 1 package 2L1P. It is sufficient if only the part CVe is provided.

  In FIG. 1, a lens L2, which is a movable optical element, is moved in the optical axis direction with respect to the lens L1 fixed to the carrier CY by a driving device (also referred to as driving means) DR. FIG. 3 is a schematic configuration diagram of the driving device DR, but the amount of distortion of the piezoelectric element is exaggerated from the actual one. In FIG. 3, a piezoelectric element PZ which is an electromechanical conversion element has one end (left end) fixed to a carrier CY (FIG. 1) via a fixing portion FX, and the other end (right end) has a drive shaft (drive). DS (also called a member) is attached. The drive shaft DS is inserted into an opening EHa provided in a holder (also referred to as a movable member) EH that holds the lens L2, and is in contact with a certain amount of frictional force.

  The piezoelectric element PZ is formed by stacking piezoelectric ceramics formed of PZT (zircon / lead titanate) or the like. Piezoelectric ceramics have a property in which the center of gravity of the positive charge and the center of gravity of the negative charge in the crystal lattice do not coincide with each other, are themselves polarized, and extend when a voltage is applied in the polarization direction. However, since the distortion of the piezoelectric ceramics in this direction is very small and it is difficult to drive the driven member by the amount of distortion, a plurality of piezoelectric ceramics PE are stacked between the electrodes as shown in FIG. A multilayer piezoelectric element PZ having a structure in which C is connected in parallel is provided as a practical one. In the present embodiment, this multilayer piezoelectric element PZ is used as a drive source.

  Next, a driving method of the lens L2 by the driving device DR will be described. In general, the multilayer piezoelectric element PZ has a small amount of displacement when a voltage is applied, but has a large generated force and sharp response. Therefore, as shown in FIG. 5A, when a pulse voltage having a substantially sawtooth waveform with a slow rise and a sharp fall is applied, the piezoelectric element PZ extends slowly at the rise of the pulse and more rapidly at the fall. It becomes a stretchable pattern that shrinks. Therefore, when the piezoelectric element PZ is slowly extended from the state shown in FIG. 3A, the holder EH coupled by the frictional force is moved along with the movement of the drive shaft DS, so that the lens L2 held by the holder EH is also light It moves in the axial direction (see FIG. 3B). However, when the piezoelectric element PZ contracts rapidly, the inertia of the holder EH causes the relative movement of the two to exceed the frictional force between the drive shaft DS and the holder EH. Therefore, even if the drive shaft DS moves, the holder EH Will remain in place (see FIG. 3 (c)). Thus, the holder EH can be moved by the distance Δ by applying one pulse to the piezoelectric element PZ and driving it for one stroke. Therefore, when the piezoelectric element PZ is driven by n strokes, the lens L1 can be moved in the optical axis direction by a distance n × Δ. As is clear from the above, as shown in FIG. 5 (b), if a pulse with a sudden rise in voltage and a slow fall is applied, the piezoelectric element PZ has an opposite expansion / contraction pattern. The holder EH and the lens L2 can be moved in the opposite directions. Thus, the driving device DR can drive the lens L2 to an arbitrary position by repeatedly expanding and contracting the piezoelectric element PZ at different speeds in the extending direction and the contracting direction.

  FIG. 6 is a perspective view of the actuator ACT according to the present embodiment. A plate-like base 1 that also serves as a yoke is fixed to a carrier CY (FIG. 1) of the optical pickup device PU. A housing 2 is fixed on the base 1. A base substrate 3 is attached to the front side of the housing 2 in FIG. One end of a total of six wires 4, three on each side, is fixed to the base substrate 3, and the wires 4 on each side are aligned in parallel in the vertical direction and extend along the base 1. Exist. The other end of the wire 4 is soldered to the side surface of the holder 5 via a holder substrate 14. The wire 4 has a function of movably supporting the holder 5 with respect to the base 1 and a function of supplying power to a coil to be described later from the base substrate 3 to which a wiring (not shown) is connected. The casing 2 is filled with a gel (not shown) having a damping effect for the wire 4.

  The resin holder 5 has a substantially pentagonal plate shape, and the objective lens 6 is mounted in a circular opening (not shown) on the back side in FIG. This objective lens 6 is used for condensing a laser beam on an information recording surface of an optical disk in an optical pickup device. Further, the holder 5 has two rectangular openings 5a and 5b on the front side in FIG. 6, and further has a balancer 5c adjacent to the rectangular openings 5a and 5b. Note that the holder 5 is connected between the objective lens 6 side and the opposite side with pillar portions 5d and 5e arranged on both sides of the rectangular opening 5a, and pillars arranged on both sides of the rectangular opening 5b. It can be said that it is connected with the parts 5e and 5f. With such a configuration, the rigidity of the holder 5 can be ensured to be high even if the rectangular openings 5a and 5b have a relatively large cross-sectional area. In addition, when the central axis of the central column portion 5e intersects the optical axis of the objective lens 6 (including its extension line), a good balance of the holder 5 can be obtained.

  In the rectangular opening 5a, a pair of magnets 9A and 10A backed by the yokes 7A and 8A are disposed so as to face each other so that the direction of the magnetic field between the magnets follows the arrow D1. The first coil group G1 (inner coil 12A and outer coil 13A) is arranged so as to wind around the magnet 9A and the yoke 7A. Between the first coil group G1 and the magnet 10A, a tracking coil 11A wound so that the first coil group G1 and the winding axis are orthogonal to each other is disposed.

  On the other hand, in the rectangular opening 5b, a pair of magnets 9B and 10B backed by the yokes 7B and 8B are arranged so as to face each other so that the direction of the magnetic field between the magnets follows the arrow D1. The second coil group G2 (inner coil 12B and outer coil 13B) is arranged so as to wind around the magnet 9B and the yoke 7B. Between the second coil group G2 and the magnet 10B, a tracking coil 11B wound so that the second coil group G2 and the winding axis are orthogonal to each other is disposed. The first coil group G1 is attached to the rectangular opening 5a via a holding body 15A that holds both sides thereof, and the second coil group G2 is attached to the rectangular opening 5b via a holding body 15B that holds both sides thereof. It has been.

  In FIG. 1, the piezoelectric element PZ of the driving device DR includes the optical axis of the objective lens OBJ, and the actuator ACT is separated when the optical pickup device PU is divided by a plane perpendicular to the axis of the incident light beam to the rising mirror M. Arranged on the side. In addition, the piezoelectric element PZ is located on the side opposite to the rotation axis X of the optical disk when the optical pickup device PU is divided by a plane including the optical axis of the objective lens OBJ and the axis of the light beam incident on the rising mirror M. Has been placed. The thickness of the optical pickup device PU (referring to the thickness in the direction along the rotation axis X) is 10 mm or less.

  When recording and / or reproducing information on a first optical disk (not shown) (for example, BD or HD DVD), in the optical pickup apparatus PU of FIG. The light beam emitted from the light source) is reflected by the dichroic prism DP, passes through the polarization beam splitter PBS, passes through the λ / 4 wave plate QWP, passes through the lens L1 of the expander lens EXP, and is driven by the driving device DR. The light passes through the lens L2 moved to the first position, is converted into a substantially parallel light beam, and is incident on the rising mirror M. A part of the light beam reflected by the polarization beam splitter PBS passes through the monitor lens ML, enters the monitor detector MD, and is used for monitoring the laser power.

  The light beam incident on the rising mirror M is reflected there, is incident on the objective lens OBJ, and is collected from here on the information recording surface of the first optical disk (the thickness of the protective layer is 0.1 mm or 0.6 mm). The

  The reflected light beam modulated by the information pits on the information recording surface again passes through the objective lens OBJ, is reflected by the rising mirror M, then passes through the lenses L2 and L1 of the expander lens EXP, and the λ / 4 wavelength plate QWP. , Is reflected by the polarization beam splitter PBS, passes through the servo lens SL and the adjustment member AM, is reflected in the prism PS, and is collected on the light receiving surface of the photodetector PD. Using the output signal of the photodetector PD, a read signal for information recorded on the first optical disk is obtained.

  In addition, focus detection and track detection are performed by detecting a change in the amount of light due to a change in the shape and position of the spot on the photodetector PD. Based on this detection, the actuator ACT performs an objective lens focusing actuator, tracking actuator, and tilt adjustment operation.

  A specific operation of the actuator ACT will be described. In FIG. 6, when power is supplied through the wire 4, current flows through the outer coils 13 </ b> A and 13 </ b> B in the same direction (here, clockwise) and the direction of the magnetic field is the direction of the arrow D <b> 1. According to Fleming's left-hand rule, an upward magnetic force is generated in the outer coil 13A, and an upward magnetic force is generated in the outer coil 13B. Accordingly, the holder 5 to which the first coil group G1 and the second coil group G2 are fixed moves upward in the drawing, thereby realizing the focusing operation by moving the objective lens 6 in the optical axis direction. Can do. If the direction of the current is reversed, the holder 5 moves downward.

  On the other hand, when a current is passed through the inner coil 12A in the clockwise direction and a current is passed through the inner coil 12B in the counterclockwise direction, the inner coil 12A is Is generated, and the inner coil 12B has a downward magnetic force in the figure. Therefore, a moment acts on the holder 5 around its central axis. Tilt adjustment of the objective lens 6 can be performed by tilting the holder 5 using such moment. It is also possible to adopt a magnetic circuit configuration in which the direction of the magnetic field between the magnets is the direction of the arrow D2, the direction of current flow through the inner coils 12A and 12B is the same clockwise, and the direction of current flow through the outer coils 13A and 13B is different. good.

  Furthermore, by passing an electric current through the tracking coils 11A and 11B, the holder 5 can be moved together with the objective lens 6 in a direction perpendicular to the optical axis, thereby performing a tracking operation.

  Further, by finely adjusting the position of the lens L2 by the driving device DR according to the variation in the thickness of the protective layer of the first optical disc or during the movement of the information when recording and / or reproducing information on the multilayer disc, It is possible to correct the spherical aberration of the focused spot on the information recording surface, and it is possible to perform better information recording and / or reproduction.

  When recording and / or reproducing information on a second optical disc (not shown) such as a DVD, the optical pickup apparatus PU shown in FIG. 1 uses a semiconductor laser (second light source) having a light source wavelength of 600 to 700 nm. The emitted light beam is emitted from the 2 laser 1 package 2L1P, and the divergence angle is changed by passing through the coupling lens CL, and passes through the dichroic prism DP and the polarization beam splitter PBS, so that the λ / 4 wavelength plate QWP. , Passes through the lens L1 of the expander lens EXP, passes through the lens L2 moved to the second position by the driving device DR, is converted into a substantially parallel light beam, and enters the rising mirror M. A part of the light beam reflected by the polarization beam splitter PBS passes through the monitor lens ML, enters the monitor detector MD, and is used for monitoring the laser power.

  The light beam incident on the rising mirror M is reflected there, is incident on the objective lens OBJ, and is collected from here on the information recording surface (thickness of the protective layer 0.6 mm) of the second optical disk.

  The reflected light beam modulated by the information pits on the information recording surface again passes through the objective lens OBJ, is reflected by the rising mirror M, then passes through the lenses L2 and L1 of the expander lens EXP, and the λ / 4 wavelength plate QWP. , Is reflected by the polarization beam splitter PBS, passes through the servo lens SL and the adjustment member AM, is reflected in the prism PS, and is collected on the light receiving surface of the photodetector PD. Using the output signal of the photodetector PD, a read signal for information recorded on the second optical disk is obtained.

  In addition, focus detection and track detection are performed by detecting a change in the amount of light due to a change in the shape and position of the spot on the photodetector PD. Based on this detection, the actuator ACT performs an objective lens focusing actuator, tracking actuator, and tilt adjustment operation.

  Further, by finely adjusting the position of the lens L2 by the driving device DR in accordance with the variation in the thickness of the protective layer of the second optical disk or when moving between layers during recording and / or reproduction of information on the multilayer disk, It is possible to correct the spherical aberration of the focused spot on the information recording surface, and it is possible to perform better information recording and / or reproduction.

  When recording and / or reproducing information on a third optical disc (not shown) such as a CD, the optical pickup apparatus PU shown in FIG. 1 uses a semiconductor laser (third light source) having a light source wavelength of 700 to 800 nm. The emitted light beam is emitted from the 2 laser 1 package 2L1P, and the divergence angle is changed by passing through the coupling lens CL, and passes through the dichroic prism DP and the polarization beam splitter PBS, so that the λ / 4 wavelength plate QWP. , Passes through the lens L1 of the expander lens EXP, passes through the lens L2 moved to the third position by the driving device DR, is converted into a finite divergent light beam, and enters the rising mirror M. A part of the light beam reflected by the polarization beam splitter PBS passes through the monitor lens ML, enters the monitor detector MD, and is used for monitoring the laser power.

  The light beam incident on the rising mirror M is reflected there, is incident on the objective lens OBJ, and is collected from here on the information recording surface (the thickness of the protective layer is 1.2 mm) of the third optical disk.

  The reflected light beam modulated by the information pits on the information recording surface again passes through the objective lens OBJ, is reflected by the rising mirror M, then passes through the lenses L2 and L1 of the expander lens EXP, and the λ / 4 wavelength plate QWP. , Is reflected by the polarization beam splitter PBS, passes through the servo lens SL and the adjustment member AM, is reflected in the prism PS, and is collected on the light receiving surface of the photodetector PD. Using the output signal of the photodetector PD, a read signal for information recorded on the third optical disk is obtained.

  In addition, focus detection and track detection are performed by detecting a change in the amount of light due to a change in the shape and position of the spot on the photodetector PD. Based on this detection, the actuator ACT performs an objective lens focusing actuator, tracking actuator, and tilt adjustment operation.

  According to the present embodiment, the piezoelectric element PZ of the driving device DR includes the optical axis of the objective lens OBJ and when the optical pickup device PU is divided by a plane perpendicular to the axis of the incident light beam to the rising mirror M. In addition, since it is arranged on the actuator ACT side, the optical element between the objective lens OBJ and the laser light source LD1 or 2L1P can be separated from the piezoelectric element PZ, and even when the gap between the members is reduced, The influence of heat can be prevented. In addition, the piezoelectric element PZ is located on the side opposite to the rotation axis X of the optical disk when the optical pickup device PU is divided by a plane including the optical axis of the objective lens OBJ and the axis of the light beam incident on the rising mirror M. Since it is arranged, interference with the spindle motor SM that rotates the optical disk can be avoided, and the accessible range of the optical pickup device in the center direction of the rotation axis of the optical disk can be expanded.

  FIG. 7 is a diagram illustrating a modification of the driving device DR. In the driving device DR of FIG. 7, a lens L1 is fixed to one end of the driving shaft DS via a carrier CY. On the other hand, a piezoelectric element PZ, which is an electromechanical conversion element, is fixed to the other end of the drive shaft DS. The piezoelectric element PZ is attached only to the drive shaft DS which is a drive unit. A leaf spring SPG is attached to the L-shaped holder EH to which the lens L2 is attached, and urges the outer periphery of the drive shaft DS toward the holder EH. Also in the present embodiment, the holder EH can be moved in the axial direction by an arbitrary amount by applying a pulsed voltage as shown in FIG. 5 to the piezoelectric element PZ. Such driving devices are disclosed in detail in Japanese Patent Application Laid-Open No. 2002-95274, Japanese Patent Application Laid-Open No. 2002-3000789, Japanese Patent Application Laid-Open No. 2002-300790, Japanese Patent Application Laid-Open No. 2003-33053, and the like.

  FIG. 8 is a perspective view of the optical pickup device according to the second embodiment. In the present embodiment, instead of providing a protective part on the cover member CV, a protective part is provided on the second laser holder LH2. More specifically, in FIG. 8, the second laser holder LH2 is attached to the carrier CY and protrudes from the terminal T of the mounted two laser 1 package 2L1P to the sub rail SR side at the end surface on the sub rail SR side. Wall-shaped protection parts LH2a and LH2b.

  According to the present embodiment, the second laser holder LH2 has the pair of holding portions LH2a and LH2b protruding on both sides of the two laser 1 package 2L1P, so that the terminal T of the two laser 1 package 2L1P is abutted when assembled. Since this contacts with the subrail SR before contacting, direct contact between the terminal T and the subrail SR is suppressed, and handling at the time of assembly can be improved. Note that it is not always necessary to provide two protection portions. Here, the engagement portion CVb of the carrier CY that engages with the sub rail SR is disposed adjacent to the 2 laser 1 package 2L1P. It is sufficient if only the portion LH2b is provided. Further, since the protection portions LH2a and LH2b are integrated with the laser holder LH2, the light source can be protected without increasing the number of parts and the number of mounting steps.

  FIG. 9 is a perspective view of an optical pickup device according to the third embodiment. In the present embodiment, instead of providing a protective part on the cover member CV, a protective part is provided on the carrier CY. More specifically, in FIG. 9, the carrier CY has a wall-shaped protection part CYc protruding from the terminal T of the two laser 1 package 2L1P toward the subrail SR in the vicinity of the second laser holder LH2. .

  According to the present embodiment, the carrier CY has the holding portion CYc protruding in the vicinity of the 2 laser 1 package 2L1P. Therefore, before the terminal T of the 2 laser 1 package 2L1P comes into contact with the carrier CY, , The direct contact between the terminal T and the sub rail SR is suppressed, and the handleability during assembly can be improved. Further, since the protection unit CYc is integrated with the carrier CY, the light source can be protected without increasing the number of components and the number of mounting steps.

  The present invention has been described above with reference to the embodiments. However, the present invention should not be construed as being limited to the above-described embodiments, and can be modified or improved as appropriate.

1 is a perspective view of an optical pickup device according to a first embodiment. 1 is a perspective view of an optical pickup device according to a first embodiment. It is a schematic block diagram of the drive device DR of this Embodiment. FIG. 3 is a perspective view showing a multilayer piezoelectric actuator PZ having a structure in which a plurality of piezoelectric ceramics PE are stacked and electrodes C are connected in parallel therebetween. It is a figure which shows the waveform of the voltage pulse applied to the piezoelectric actuator PZ. It is a perspective view of actuator ACT concerning this embodiment. It is a schematic block diagram of the drive device DR concerning a modification. It is a perspective view of the optical pick-up apparatus concerning 2nd Embodiment. It is a perspective view of the optical pick-up apparatus concerning 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base 2 Case 2L1P 2 Laser 1 Package 3 Base substrate 4 Wire 5 Holder 5a Rectangular opening 5b Rectangular opening 5c Balancer 5d Column 5e Column 5f Column 6 Objective lens 7A Yoke 7B Yoke 8A Yoke 8B Yoke 9A Magnet 9A Magnet 9B Magnet 10B Magnet 11A Tracking coil 11B Tracking coil 12A Inner coil 12B Inner coil 13A Outer coil 13B Outer coil 14 Holder substrate 15A Holding body 15B Holding body ACT Actuator AM Adjustment member C Electrode CL Coupling lens CY Carrier CYa, CYb Engagement part CYc Protective part CV Cover member CVa, CVb, CVc Notch CVd, CVe, CVf Protective part D1, D2 Direction of magnetic field DP Dichroic prism DR Drive device DS Drive shaft EH Hol EHa aperture EXP expander lens FX fixing part G1 first coil group G2 second coil group HD1 first holder HD2 second holder L1 lens L2 movable lens LD1 semiconductor laser LH1 first laser holder LH2 second laser holder LH2a, LH2b protection Part SM Spindle motor SR Sub rail SPG Leaf spring M Mirror MD Monitor detector ML Monitor lens MR Main rail OBJ Objective lens PBS Polarizing beam splitter PD Photodetector PE Piezoelectric ceramics PS Prism PU Optical pickup device PZ Piezoelectric element QWP λ / 4 wave plate SL Servo lens X rotation axis

Claims (4)

In an optical pickup device that records and / or reproduces information by causing a light beam from a light source to enter an objective lens via an optical system and condensing the objective lens onto an information recording surface of an optical information recording medium.
A carrier that moves along a main rail and a sub rail, and that has the light source mounted in the vicinity of at least one of the main rail and the sub rail;
A cover member covering a part of the upper part or the lower part of the carrier,
The optical pickup apparatus, wherein the cover member includes a notch that exposes the light source, and a protective part that is disposed between the light source and the at least one.   2. The optical pickup device according to claim 1, wherein the cover member is a plate member, and the protection portion is a portion that protrudes and bends on both sides of the terminal of the light source. In an optical pickup device that records and / or reproduces information by causing a light beam from a light source to enter an objective lens via an optical system and condensing the objective lens onto an information recording surface of an optical information recording medium.
A carrier moving along the main rail and the sub rail;
A holder attached to the carrier for holding the light source in the vicinity of at least one of the main rail and the sub rail;
The optical pickup device, wherein the holder includes a protection unit disposed between the light source and the at least one, and the holder and the protection unit are integrated. In an optical pickup device that records and / or reproduces information by causing a light beam from a light source to enter an objective lens via an optical system and condensing the objective lens onto an information recording surface of an optical information recording medium.
A carrier moving along a main rail and a sub rail is provided, and the carrier mounts the light source in the vicinity of at least one of the main rail and the sub rail, and is disposed between the light source and the at least one. An optical pickup device comprising a protection part, wherein the carrier and the protection part are integrated.

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