JP2006209856A - Objective lens drive device, pickup device and optical disk apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a proper light spot by preventing temperature rise of an objective lens thereby securing optical characteristics, and to conduct a stable servo, by preventing the temperature of an objective lens holding member from rising thereby prevent higher-order resonance characteristics from changing. <P>SOLUTION: The objective lens driving device has an objective lens 1, an objective lens holding member 2, which holds the objective lens 1 and printed coil substrates 3 which are mounted on the objective lens holding member 2 and have printed coils formed by spiral conductor patterns in insulated substrates. Projected ribs 10 are formed on the mounting surface of the printed coil substrates 3 in the objective lens holding member 2. The ribs 10 are formed at the locations, which differ from the conductor pattern regions of the printed coils, and a space is provided between the objective lens holding member 2 and the printed coil substrates 3. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention holds an objective lens that irradiates an optical disk with a laser beam and drives it in a focusing direction and a tracking direction, an optical pickup apparatus that reads information from the optical disk, and records information on the optical disk The present invention relates to an optical disc apparatus that performs reproduction.

  In an optical disk device, information is read by irradiating an optical disk with a laser beam and identifying the reflected light. Here, the objective lens driving device mounted on the optical disc apparatus uses the control signal obtained from the reflected light to control the objective lens so as to follow movements such as surface deflection and eccentricity of the media. Driven in the focusing direction and the tracking direction, spots are formed on the recording surface of the medium.

  By the way, in recent years, large-capacity media have spread in the market, and it is desired to perform recording and reproduction at high speed when handling such large-capacity data. Therefore, it is necessary to rotate the media at high speed. However, when a medium with surface wobbling or eccentricity is rotated at high speed, the acceleration becomes very large, and an objective lens driving device capable of generating a large thrust is required to make the objective lens follow the medium with high accuracy. I need it.

  In order to generate a large thrust, it is conceivable to increase the current sensitivity (thrust per current) of the motor or increase the current flowing through the drive coil. The current sensitivity of the motor is determined by the configuration, the magnetic flux density generated by the magnet, the mass of the moving part, the spring constant, etc., and is improved daily. On the other hand, the allowable current that can be passed through the drive coil is limited by the damage of the drive coil itself due to the heat generation of the drive coil itself or the allowable temperature of the objective lens.

  The allowable temperature of the objective lens differs depending on the material. Conventionally, the material of the objective lens is often made of glass. However, plastic materials have been used due to technological advances and low cost demands. The allowable temperature of the plastic objective lens tends to be inferior to that of glass, and it is strongly desired to suppress the temperature rise of the objective lens.

  In addition, a winding coil in which a wire-shaped coil wire is wound in a spiral shape has been the mainstream as a drive coil, but recently, a printed coil in which a spiral conductor pattern is formed in an insulator has been used. Yes. Since the printed coil has a plurality of coils arranged in the substrate, it is easy to assemble, and since the pattern is protected by the substrate, it has better heat resistance than the winding coil.

  Further, as this type of conventional technology, there are those described in Patent Documents 1 and 2.

  As shown in FIG. 13, the technique described in Patent Document 1 forms a plurality of ribs 101 on the coil mounting surface on the side surface of the objective lens holding member 100, and the side surface of the objective lens holding member 100 on which the rib 101 is formed. By attaching the focusing coil 102 and the tracking coil 103, a gap is formed between the objective lens holding member 100 and the coils 102, 103. With this configuration, the coils 102, 103 are generated. It can suppress that the temperature of the objective lens 104 and the objective-lens holding member 100 rises by the heat which performed.

As shown in FIG. 14, the technique described in Patent Document 2 is configured such that a focus coil 203 is wound around an outer peripheral side surface of an objective lens holding member 202 that holds an objective lens 201, and a tracking coil 204 is used as an objective lens holding member. Two tracking coils 202 are fixed to the outer peripheral side surface parallel to the tracking direction of 202. A yoke hole 205 for inserting the inner yoke of the magnetic circuit is provided between the objective lens 201 and the tracking coil 204 in the objective lens holding member 202, and further penetrates between the objective lens 201 and the focus coil 203. A heat dissipation hole 206 is provided. With this configuration, it is possible to prevent the temperature of the objective lens 201 from rising due to the heat generated in the coils 203 and 204.
Japanese Utility Model Publication No. 4-41461 JP-A-9-91725

  However, according to the prior art described in Patent Document 1, the convex portion of the drive coil and the objective lens holding member overlaps depending on the position of the concave and convex shapes, so that heat transfer from the drive coil to the objective lens holding member is sufficiently suppressed. There is a risk of not being able to. In addition, the contact area between the objective lens holding member and the drive coil is reduced, and the temperature at that portion is likely to rise, and the strength at this portion may be reduced.

  Further, according to the prior art described in Patent Document 2, since the drive coil and the objective lens holding member are in contact with each other over a wide area, heat is easily transmitted to the objective lens holding member. Furthermore, since the material of the objective lens holding member is often resin, the rigidity is likely to decrease as the temperature rises. For this reason, the resonance characteristics (high-order resonance characteristics) due to the elastic deformation of the movable part change, and the gain margin may become insufficient, which may cause an adverse servo effect.

  The present invention solves such problems, prevents an increase in the temperature of the objective lens, secures optical characteristics, obtains a good light spot, and prevents an increase in the temperature of the objective lens holding member, thereby providing higher-order resonance characteristics. An object of the present invention is to provide an objective lens driving device, a pickup device, and an optical disc device that prevent the change and realize stable servo.

  In order to achieve the above object, the present invention comprises an objective lens, an objective lens holding member that holds the objective lens, and a drive coil attached to the objective lens holding member, and the drive in the objective lens holding member. In the objective lens driving device having a convex rib on the coil mounting surface, the driving coil is a printed coil formed by forming a spiral conductor pattern in an insulating substrate, and the rib is a conductor pattern region of the printed coil. It is characterized in that it is formed at a different position. With this configuration, heat transfer from the printed coil to the objective lens can be reduced, and a good spot can be maintained. In addition, by reducing heat transfer to the objective lens holding member, it is possible to reduce a decrease in rigidity (stiffness fluctuation) due to a temperature rise of the objective lens holding member, and to maintain good high-order resonance characteristics.

  Further, the present invention comprises an objective lens, an objective lens holding member that holds the objective lens, and a drive coil attached to the objective lens holding member, and is convex on the mounting surface of the drive coil in the objective lens holding member. In the objective lens driving device provided with a shaped rib, the drive coil is a printed coil formed by forming a spiral conductor pattern in an insulating substrate, and the rib is at least a region parallel to the conductor pattern of the printed coil. It is characterized by being formed at different positions. With this configuration, heat transfer from the drive coil to the objective lens can be reduced, and a good spot can be maintained. In addition, by reducing heat transfer to the objective lens holding member, it is possible to reduce a decrease in rigidity (stiffness fluctuation) due to a temperature rise of the objective lens holding member, and to maintain good high-order resonance characteristics.

  In the invention, it is preferable that the rib is formed on an outer edge of a region where the outer shape of the printed coil and the outer shape of the objective lens holding member overlap. With this configuration, it is possible to increase the rigidity of the objective lens holding member and obtain good high-order resonance characteristics.

  In the invention, it is preferable that the rib has a longitudinal direction in a focus direction and a tracking direction, and the ribs intersect at least at one place. With this configuration, it is possible to increase the rigidity with respect to the deformation mode excited by the focusing operation and the tracking operation, and to obtain good high-order resonance characteristics.

  Further, the present invention is characterized in that there is only one rib whose longitudinal direction is the tracking direction of the rib. With this configuration, it is possible to simplify by reducing the sliding direction of the mold, and it is possible to reduce the manufacturing cost.

  Further, in the present invention, when the cross section of the rib is substantially rectangular, the width dimension in the direction parallel to the printed coil surface is W, and the thickness dimension in the direction perpendicular to the printed coil surface is t, W / t> It is characterized by 1. With this configuration, it is possible to maintain higher-order resonance characteristics by increasing the strength of the resonance mode excited by driving in the focusing direction and tracking direction.

  The present invention is characterized in that a heat radiation pattern is arranged in a region different from the rib in the printed coil and in a region other than a conductive pattern and a land pattern serving as an electrode. With this configuration, the heat from the printed coil can be radiated through the heat radiation pattern, and the temperature of the objective lens and the objective lens holding member can be made difficult to rise.

  The present invention is characterized in that the heat radiation pattern is disposed on the opposite side of the objective lens with a center of gravity of a movable portion including the objective lens, the objective lens holding member, and the printed coil interposed therebetween. With such a configuration, a heat dissipation effect can be obtained without increasing the mass of the movable part.

  The present invention comprises an optical pickup device comprising a laser light source that emits irradiation light to an optical disc, a light receiving optical system that receives reflected light from the optical disc, and an objective lens driving device for the optical disc of the invention. It is characterized by. With such a configuration, it is possible to provide an optical pickup capable of maintaining a good spot and obtaining a good signal.

  The present invention is characterized in that an optical disc apparatus includes a rotational drive system for rotationally driving an optical disc, and the optical pickup device of the present invention provided to be movable in a radial direction of the optical disc. With this configuration, it is possible to provide an optical disc apparatus capable of maintaining a good spot and reading and writing data satisfactorily.

  According to the present invention, heat transfer from the printed coil to the objective lens can be reduced, and a good spot can be maintained. In addition, by reducing heat transfer to the objective lens holding member, it is possible to reduce a decrease in rigidity (stiffness fluctuation) due to a temperature rise of the objective lens holding member, and to maintain good high-order resonance characteristics.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a perspective view of an objective lens driving apparatus for explaining the first embodiment of the present invention, wherein 1 is an objective lens, 2 is an objective lens holding member having the objective lens 1 installed at the center upper portion, and 3 is an objective lens holding unit. A printed coil board held by the member 2, 4 wire springs holding the objective lens holding member 2, 5 a fixed member disposed on the base 6 facing the tangential direction of the movable part, and 6 a base , 7 is a driving magnet placed opposite to the printed coil board 3, 8 is a wiring board that is connected to the wire spring 4 and supplies current from the outside, and 9 is attached to both sides of the objective lens holding member 2 in the tracking direction. It is a relay board.

  A printed coil board 3 is attached to both side surfaces in the tangential direction of the objective lens holding member 2 that holds the objective lens 1, and an end portion of the coil provided in the printed coil board 3 is a wiring formed on the relay board 9. It is electrically connected to the pattern. Hereinafter, the objective lens 1, the objective lens holding member 2 holding the printed coil substrate 3 and the relay substrate 9 are referred to as a movable portion, and the driving magnetic circuit of the movable portion including the printed coil substrate 3 and the driving magnet 7 is referred to as a motor portion. To.

  The objective lens holding member 2 that holds the objective lens 1 is elastically supported with respect to the fixing member 7 by a wire spring 4 whose longitudinal direction is the tangential direction. Each wire spring 4 is parallel to the tangential direction, and two wire springs 4 are arranged in parallel in the focusing direction on each side of the movable portion in the tracking direction.

  Furthermore, the relay substrate 9 has one end portion of a conductive wire spring 6 that supports the movable portion so as to be displaceable in the focusing direction, tracking direction, and radial tilt direction. The wiring pattern is electrically connected and the other end is fixed to the wiring board 8 and electrically connected to the printed wiring of the wiring board 8.

  Further, a driving magnet 7 is provided facing the printed coil substrate 3, and the driving magnet 7 is fixed to a yoke formed integrally with the base 6. The fixing member 5 is attached to a part of the base 6 and the wiring board 8 is fixed, so that the movable part is cantilevered by the wire spring 4. A current is supplied from the outside to the coil of the printed coil substrate 3 of the movable part through the wiring substrate 8.

  FIG. 2 is a schematic diagram showing the configuration of the magnetic circuit according to the first embodiment. Reference numeral 10 denotes ribs provided on both side surfaces of the objective lens holding member 2 that face each other in the tangential direction. 3 is installed. The printed coil substrate 3 has a printed coil formed by stacking spiral conductive wire patterns in two layers in an insulating substrate 11, and two focus coils and one track coil are formed as printed coils. Yes.

  The driving magnet 7 is a rectangular parallelepiped type, and as shown in FIG. 2B, a magnetization boundary line a parallel to the focusing direction is provided at the center. In addition, an L-shaped magnetization boundary line b is provided at one corner of the driving magnet 7, and an L-shape is formed at a corner located diagonally to the corner having the magnetization boundary b. A mold magnetization boundary line c is provided. Here, the lines parallel to the tracking direction at the L-shaped magnetization boundary lines b and c exist on the same straight line passing through the center of the drive magnet 7. The two drive magnets 7 are fixed to the base 6 so that the same magnetic poles face each other.

  3A and 3B are explanatory views showing the configuration of the printed coil board. FIG. 3A is a schematic view when the printed coil board is viewed from the focus direction, and FIG. 3B is a view when the printed coil board is viewed from the tangential direction. FIG.

As shown in FIG. 3A, the printed coil substrate 3 has a two-layer structure, and the first layer is a focus coil 3a ₁ , a track coil as a printed coil made of a spiral conductive wire pattern between two insulating substrates 11. 3b ₁ and focus coil 3c ₁ are formed side by side in the tracking direction. Similarly, the second layer is formed by arranging a focus coil 3a ₂ , a track coil 3b ₂ , and a focus coil 3c ₂ in the tracking direction as a print coil having a spiral conductive wire pattern between two insulating substrates 11. It is. In addition, a through hole 11a ₁ , a through hole 11b ₁ , and a through hole 11c ₁ are formed in the insulating substrate 11 on the second layer side in the first layer corresponding to the position of one end of each coil. A through hole 11a ₂ , a through hole 11b ₂ , and a through hole 11c ₂ are formed in the insulating substrate 11 on the first layer side in the two layers corresponding to the position of one end of each coil. The material is filled.

Therefore, when the first layer and the second layer are overlapped, the conductive materials of the through hole 11a ₁ , the through hole 11b ₁ , and the through hole 11c _{1 and} the conductivity of the through hole 11a ₂ , the through hole 11b ₂ , and the through hole 11c ₂ are overlapped. The material is electrically connected, and the focus coil 3a ₁ and the focus coil 3a ₂ are connected in series via the through holes 11a ₁ and 11a ₂ . Similarly, the focus coil 3c ₁ and focus coil 3c ₂ is via a through-hole _11c 1, 11c _2, and the track coil 3b ₁ and the track coil 3b ₂ are connected in series via a through hole _11b 1, 11b ₂ Is done.

Further, as shown in FIG. 3B, since the focus coil 3a ₂ and the focus coil 3c ₂ are connected in series by the conductive pattern in the insulating substrate 11, the focus coil 3a ₁ , the focus coil 3a ₂ , and the focus The coil 3c ₂ and the focus coil 3c ₁ are connected in series in this order.

As shown in FIG. 3C, the first layer insulating substrate 11 is provided with four terminal lands 12a, 12b, 12c, and 12d. The focus coil 3a ₁ , the track coil 3b ₁ , the other end of the focus coil 3c ₁ are respectively connected terminal lands 12a, 12b, to 12c. The other end of the tracking coils 3b ₂ is connected to the terminal lands 12d via the conductive material in the through holes 11d.

  The terminal lands 12a, 12b, 12c, and 12d are electrically connected to the four wires 4, respectively, and are fed to the focus coil 3a, the track coil 3b, and the focus coil 3c through the four wires 4.

  When the movable part is fixed to the fixing member 5 via the wire 4, the printed coil substrate 3 faces the driving magnets 7 and 7. At this time, the central portion of the focus coil 3a faces the tracking direction line at the magnetization boundary line b. Similarly, the center portion of the focus coil 3c faces the tracking direction line at the magnetization boundary line c. Further, the central portion of the track coil 3b faces the magnetization boundary line a.

  A thrust is generated by passing an electric current through the wire spring 4 to the printed coil, and the movable part of the objective lens driving device can be driven in the focusing direction and the tracking direction.

  By the way, since the printed coil is manufactured by etching, the positional accuracy of the coil pattern is high, positioning of the coils is unnecessary, and the forming process of the coil end line, which is troublesome with the conventional winding coil, is not necessary. Assemblability is greatly improved. Moreover, since the conductor part is hold | maintained by the insulated substrate, the printed coil has the merit that permissible current is higher than a winding coil.

  On the other hand, when recording and reproducing a disk with large surface deflection and eccentricity at high speed, the objective lens driving device requires a large thrust to follow this, and a large current flows through the printed coil. This generates heat from the printed coil. Since the printed coil is close to the objective lens, the generated heat is easily transmitted to the objective lens, and the optical performance of the objective lens may be deteriorated.

  Therefore, according to the embodiment, the convex rib 10 is formed on the side surface of the objective lens holding member 2, and an air layer is formed between the objective lens holding member 2 and the printed coil substrate 3 by the rib 10. This makes it difficult to transfer the heat of the printed coil to the objective lens holding member 2.

  FIG. 4 is a distribution diagram showing the temperature distribution (simulation result) of the printed coil during heat generation, and it can be seen that when the current is supplied to the printed coil, the spiral conductive wire pattern portion has the highest temperature. Therefore, when the spiral pattern and the rib 10 formed on the objective lens holding member 2 are formed at the same place, heat is directly transferred to the objective lens holding member 2.

  FIG. 5 is an explanatory view showing an arrangement example of ribs formed on the objective lens holding member. As shown in FIG. 5, the ribs 10 are provided on both sides of the mounting surface of the printed coil substrate 3 in the objective lens holding member 2, between the focus coil 3a and the track coil 3b, and between the track coil 3b and the focus coil 3c. It is formed to avoid the spiral pattern of the printed coil.

  By arranging in this way, heat generated in the printed coil is hardly transmitted to the objective lens holding member 2 and the objective lens 1. Another advantage is that the strength can be maintained because the joining portion does not reach a high temperature.

  The spiral pattern shape of the coils 3a, 3b, 3c in the printed coil substrate 3 varies depending on the motor design. As a result, when the spiral pattern gap is small or there is little margin from the coil pattern outer shape with respect to the printed coil outer shape, it may be impossible to secure a place for arranging the rib 10. When there is such a restriction, the rib 10 may be arranged avoiding only the region parallel to the focusing direction in the spiral pattern as shown in FIG.

  As described above, the first embodiment has been described. However, in the configuration in which the rib is formed in the portion where the drive coil of the objective lens holding member is attached as in the first embodiment described above, the space is formed by the rib. As a result, a problem may occur in higher-order resonance characteristics. The second embodiment described below is made in view of this point.

  FIG. 7 is an explanatory diagram showing a main configuration of the second embodiment of the present invention. In addition, about the member in Embodiment 1 shown in FIGS. 1-6, and the same member or a member of the same function, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

  The second embodiment shown in FIG. 7 is different from the first embodiment in the shape of the rib 10 of the objective lens holding member 2, and the other configurations are the same. That is, the objective lens holding member 2 is provided with a rib parallel to the focusing direction at a position passing through the center of the focus coil 3a, between the focus coil 3a and the track coil 3b, and between the track coil 3b and the focus coil 3c. The ribs parallel to the tracking direction are formed on both sides in the focusing direction of the objective lens holding member 2 so as to connect the end portions of the ribs parallel to the focusing direction. It is formed outside the spiral pattern formation region of 3a, 3b, 3c.

  As described above, according to the second embodiment, since the rib 10 is formed on the outer edge of the region where the outer shape of the objective lens holding member 2 and the outer shape of the printed coil substrate 3 overlap, the objective lens holding member 2 and the printed coil substrate 3 are Since the parts having the largest operating radius are fixed to each other when the deformation is relatively rotated, the resonance frequency in such an eigenmode can be increased. In particular, it is highly effective in the eigenmode in which the objective lens holding member 2 and the printed coil substrate 3 are twisted in the radial tilt direction, and a triaxial drive objective lens drive device that performs a radial tilt operation in addition to the focus drive and tracking drive. Then it becomes important.

  Further, in the second embodiment, the rib 10 formed on the side surface portion of the objective lens holding member 2 to which the printed coil substrate 3 is attached is formed with the focusing direction and the tracking direction as longitudinal directions. With this configuration, deformation when driven in the focusing direction and the tracking direction can be reduced. Further, the higher order resonance is caused by an eigenmode due to elastic deformation of the movable part, and even if the rigidity is small, it does not become a big problem if it is not excited by driving (external force). Even if the objective lens holding member 2 or the printed coil substrate 3 is deformed, the characteristics do not deteriorate unless the spot formed by the objective lens 1 fluctuates. Therefore, by forming a rib whose longitudinal direction is the focusing direction and the tracking direction as in the second embodiment, it is possible to suppress deformation due to an eigenmode that is easily excited by driving (external force) in the focusing direction and the tracking direction.

  FIG. 8 is an explanatory view showing a first modification of the second embodiment, and this first modification is configured by only one rib whose longitudinal direction is the tracking direction. That is, the rib 10 parallel to the focusing direction is formed on the objective lens holding member 2 at a position passing through the central portion of the focus coil 3a and a position passing through the central portion of the focus coil 3c, and further, the coils 3a, 3b, 3c. The rib 10 parallel to the tracking direction is formed so as to connect the centers of the ribs 10 and the rib 10 is formed in an H shape.

  The objective lens holding member 2 is often manufactured by injection molding of a resin, and in order to form the opening of the objective lens 1, the molding die is mostly set to have a focusing direction as a punching direction. Therefore, by setting the number of ribs in the tracking direction to one, the drawing direction can be adjusted only in the focus direction, so that it is possible to manufacture with a mold structure that does not require a slide or the like. As a result, the manufacturing cost can be reduced.

  FIG. 9 is a perspective view showing a second modification of the second embodiment. In the second modification, the objective lens holding member 2 is provided with ribs 10 parallel to the focusing direction, and the track coil 3b. Ribs 10 which are added to positions passing through the central portion and are parallel to the focusing direction on both sides of the tracking direction are formed at both ends of the objective lens holding member 2. Here, the cross-sectional shape of the rib 10 formed on the objective lens holding member 2 is a square shape as shown in FIG. 9, and the dimension perpendicular to the surface of the printed coil substrate 3 is t, and the parallel direction. When the dimension of W is W, the relationship is W / t> 1. With this configuration, deformation in the focusing direction and the tracking direction can be suppressed.

  Needless to say, the rib 10 of the objective lens holding member 2 shown in FIG. 9 may be formed like the rib 10 shown in FIG. 7 or FIG.

  FIG. 10 is an explanatory diagram showing the main configuration of the third embodiment of the present invention. In addition, about the member in Embodiment 1 shown in FIGS. 1-6, or the member in Embodiment 2 shown in FIGS. 7-9, about the same member or a member of the same function, attach | subject the same code | symbol and detailed description Is omitted.

  In the third embodiment, as shown in FIG. 10, a heat radiation pattern 20 is formed on the printed coil substrate 3, and the configuration excluding the heat radiation pattern 20 is the same as in the first and second embodiments. In the third embodiment, a spiral pattern that forms the coils 3a, 3b, and 3c in the printed coil substrate 3 and terminal lands 12a, 12b, 12c, and 12d for supplying current to the spiral pattern from outside are provided. A heat radiation pattern 20 made of a conductor pattern having a predetermined area is formed in the portion.

  Here, it is desirable that the heat radiation pattern 20 is configured not to overlap the rib 10 formed on the side surface of the objective lens holding member 2. That is, when a current is supplied to the printed coil board 3, heat is generated in a portion having a large resistance (proportional to [current I] ^ 2 × [resistance R]). Most heat is generated in the part. Normally, the material of the conductor pattern formed on the printed coil substrate 3 is copper, and since copper has high thermal conductivity, the heat generated in the spiral portion immediately moves to the heat radiation pattern 20 having a predetermined area. . Since the heat radiation pattern 20 is disposed at a position that does not overlap the rib 10 of the objective lens holding member 2 and the surface is in contact with air, heat can be efficiently radiated to the outside.

  Here, since the specific gravity of the conductor pattern (copper) of the printed coil substrate 3 is very large with respect to the specific gravity of the substrate, the provision of the heat radiation pattern 20 increases the mass of the movable part and deteriorates the acceleration sensitivity characteristic. . Here, by disposing the heat radiation pattern 20 on the side opposite to the objective lens 1 with respect to the center of gravity of the movable part, the heat radiation pattern 20 is also used as a mass balancer for the objective lens 1, thereby suppressing an increase in mass of the movable part. Is possible.

(Embodiment of optical pickup device)
FIG. 11 is a schematic configuration diagram for explaining an embodiment of the optical pickup device according to the present invention on which the objective lens driving device according to the embodiment described in FIGS. 1 to 10 is mounted. Collimating lens, 33 is a beam splitter, 34 is a rising mirror, 35 is a condensing lens, 36 is a cylindrical lens, 37 is a light receiving element as a light receiving optical means, 38 is an optical disk, 39 is the objective lens of the above embodiment It is a drive device.

  The diffused light emitted from the light source 31 becomes substantially parallel light by the collimating lens 32. Thereafter, the beam passes through the beam splitter 33 and is bent by the rising mirror 34. The parallel light bent by the rising mirror 34 enters the objective lens 1 of the objective lens driving device 39 to form a light spot S on the optical disk 38. The reflected light of the light spot S from the optical disk 38 is deflected by the beam splitter 33, passes through the condenser lens 35 and the cylindrical lens 36, and then enters the light receiving element 37.

  In this manner, the light spot S reflected on the optical disk 38 is arranged so that it is incident on the light receiving element 37. Based on the signal obtained by the light receiving element 37, a control signal is generated by an objective lens control means (not shown) such as an arithmetic processing unit and is output to the objective lens driving device 39, whereby a focus coil, a track coil And the information recorded on the optical disk 38 can be reproduced by causing the objective lens 1 to follow the optical disk 38.

  Here, the objective lens driving device 39 is an objective lens driving device having the configuration of each embodiment described in FIGS. 1 to 10, and as described above, by using this objective lens driving device 39, Since the temperature rise of the objective lens and the objective lens holding member is small even during high-speed rotation, an optical pickup with good spot quality can be configured even at high temperatures.

(Embodiment of optical disc apparatus)
FIG. 12A is a plan view showing a schematic configuration for explaining an embodiment of an optical disc apparatus equipped with the optical pickup device of FIG. 11 provided with the objective lens driving device of the embodiment explained in FIGS. 12B is a front view of the optical disk apparatus of FIG. 11, and 40 is the optical pickup apparatus described in FIG. 31. The optical pickup apparatus 40 includes a light source 31, a collimating lens 32, a cylindrical lens 36, It comprises a light receiving element 37, an objective lens driving device 39 and the like.

  Further, 41 is a housing of the optical disk apparatus, 42 is a vibration isolating rubber, 43 is a spindle motor which is a rotation driving means of the optical disk 38, 44 is a seek rail, and 45 is a pickup module base. A pickup module base 45 is installed via a vibration isolating rubber 42. The pickup module base 45 is provided with a spindle motor 43 that rotates the optical disk 38. An optical pickup device 40 is mounted on the seek rail 44 attached to the pickup module base 45. The optical pickup device 40 is driven to move in the radial direction of the optical disk 28 on the seek rail 44 by pickup drive means such as a seek motor (not shown).

  Here, the optical pickup device 40 mounted on the optical disk device shown in FIGS. 11 and 12 is the optical pickup device having the above-described configuration, and the temperature rise of the objective lens and the objective lens holding member is small even at high speed rotation. Thus, an optical disc drive having excellent recording / reproducing performance can be configured. In addition, even when the drive current increases during high-speed rotation, the high-order resonance characteristics hardly change and stable servo can be performed.

  The present invention is applicable to a recording / reproducing apparatus using a high-density, large-capacity optical disk as a recording medium.

The perspective view of the objective lens drive device for demonstrating Embodiment 1 of this invention Schematic diagram showing the configuration of the magnetic circuit in the first embodiment Diagram showing the configuration of the printed coil board Distribution diagram showing the temperature distribution (simulation results) of the printed coil board during heat generation Explanatory drawing which shows the example of arrangement | positioning of the rib formed in the objective lens holding member Explanatory drawing which shows the other example of arrangement | positioning of the rib formed in the objective lens holding member. Explanatory drawing which shows the principal part structure in Embodiment 2 of this invention. Explanatory drawing which shows the modification 1 of Embodiment 2. FIG. The perspective view which shows the modification 2 of Embodiment 2. FIG. Explanatory drawing which shows the principal part structure in Embodiment 3 of this invention. 1 to 10 are schematic configuration diagrams for explaining an embodiment of an optical pickup device according to the present invention on which the objective lens driving device according to the embodiment described with reference to FIGS. FIG. 11 is a schematic configuration diagram for explaining an embodiment of an optical disk device on which the optical pickup device of FIG. The perspective view which shows the structure of the objective lens holding member in the conventional objective lens drive device, and its periphery The perspective view which shows the other example of the conventional objective lens drive device

Explanation of symbols

1 the objective lens 2 objective lens holding member 3 printed coil board _3a, 3a 1, 3a ₂ focusing coils _3b, 3b 1, 3b ₂ tracking coils _3c, 3c 1, 3c ₂ focusing coil 4 wire spring 5 fixing member 6 base 7 for driving Magnet 8 Wiring board 9 Relay board 10 Rib 11 Insulating boards 11a, 11b, 11c, 11d Through holes 12a, 12b, 12c, 12d Terminal land 20 Heat radiation pattern 31 Light source 37 Light receiving element 39 Objective lens driving device 40 Optical pickup device 43 Spindle motor

Claims (10)

An objective lens, an objective lens holding member for holding the objective lens, and a drive coil attached to the objective lens holding member, and having a convex rib on a mounting surface of the drive coil in the objective lens holding member In the objective lens driving device,
An objective lens driving device for an optical disk, wherein the driving coil is a printed coil formed by forming a spiral conductor pattern in an insulating substrate, and the rib is formed at a position different from a conductor pattern region of the printed coil. . An objective lens, an objective lens holding member for holding the objective lens, and a drive coil attached to the objective lens holding member, and having a convex rib on a mounting surface of the drive coil in the objective lens holding member In the objective lens driving device,
An optical disc characterized in that the drive coil is a printed coil formed by forming a spiral conductor pattern in an insulating substrate, and the rib is formed at a position different from at least a region parallel to the conductor pattern of the printed coil. Objective lens drive.   3. The objective lens driving device for an optical disk according to claim 1, wherein the rib is formed at an outer edge of a region where an outer shape of the printed coil and an outer shape of the objective lens holding member overlap.   4. The objective lens driving device for an optical disk according to claim 1, wherein the rib has a longitudinal direction in a focus direction and a tracking direction, and the ribs intersect at least at one place.   5. The objective lens driving device for an optical disk according to claim 4, wherein the rib has only one rib whose longitudinal direction is the tracking direction.   W / t> 1, where the rib has a substantially square cross section, the width dimension in the direction parallel to the printed coil surface is W, and the thickness dimension in the direction perpendicular to the printed coil surface is t. 6. The objective lens driving device for an optical disc according to claim 1, wherein the objective lens driving device is an optical disc.   The optical disk according to claim 1, wherein a heat radiation pattern is arranged in a region different from the rib in the printed coil and in a region other than a conductive pattern and a land pattern serving as an electrode. Objective lens drive device.   The heat radiation pattern is arranged on the opposite side of the objective lens with a center of gravity of a movable portion including the objective lens, the objective lens holding member, and the printed coil interposed therebetween. An objective lens driving device for an optical disk as described in the above section.   An optical disk objective lens driving device according to claim 1, comprising: a laser light source that emits irradiation light to the optical disk; a light receiving optical system that receives reflected light from the optical disk; and an optical disk objective lens driving device according to claim 1. A characteristic optical pickup device.   An optical disc apparatus comprising: a rotation drive system for rotating the optical disc; and the optical pickup device according to claim 9 movably provided in a radial direction of the optical disc.

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