JP6546515B2 - Optical pickup and optical disc apparatus - Google Patents

Description

  The present invention relates to an optical disc apparatus which records information on an optical disc using a laser beam or reproduces information from an optical disc, and an optical pickup thereof.

  The optical pickup is a main part of an optical disc apparatus which records or reproduces data by making a focus position of an objective lens follow a target data track on a rotating optical disc. In the optical pickup, (1) an optical element group which condenses the light emitted from the semiconductor laser onto the disc and guides the return light from the optical disc to the light detector, and (2) the focal position of the objective lens An actuator for moving in the focusing direction and in the tracking direction is mounted. These mounting components are bonded to the housing using an adhesive.

  The emitted light emitted from the semiconductor laser is split into three beams by passing through a diffraction grating, and then enters a beam splitter prism (hereinafter referred to as "prism"). The outgoing light entering the prism is bent at a right angle, passes through the collimating lens, becomes a parallel light flux, and enters the rising mirror. The outgoing light incident on the rising mirror is again bent at a right angle, and then enters the objective lens to be condensed on the optical disc. The return light diffracted and reflected by the data track on the optical disk travels the same optical path as the forward path, and is converted into a convergent light beam by the collimator lens. The return light converted into the convergent light beam passes through the prism and the cylindrical lens and enters the light receiving surface on the light detector. The return light incident on the light receiving surface is converted into an electrical signal according to light and dark, and the electrical signal is used to generate a reproduction signal or an error signal.

  Optical pickups are required to have reliability over the wide range of operating environment from low temperature to high temperature so as not to impair each quality at the time of recording and reproduction. However, when the environmental temperature changes, the optical element is likely to be displaced or tilted due to thermal expansion or contraction of the adhesive in addition to the mounted components and the housing. In particular, the inclination of the prism or the raising mirror causes the light incident on the objective lens to be inclined, which causes the position of the light condensing point on the optical disc to be shifted. The "displacement" between the focus point on the optical disc and the focal point of the objective lens is recognized as "displacement" with respect to the data track of the focal point of the objective lens, causing the focal point of the objective lens to meander with respect to the track. The meandering of the focal point of the objective lens may affect the stability and accuracy of the focal point positioning control system of the objective lens and may deteriorate the recording / reproducing performance.

  Patent Document 1 describes an example of an optical element bonding structure that solves such a problem. The prism unit described in the document includes (1) three or more circular seating surfaces in contact with the lower surface of the prism, and (2) one bonding portion for bonding the lower surface of the prism with an adhesive. Are placed on the pedestal so as to be mirror-symmetrical to the reflecting surface of the prism. Thereby, the difference in the degree of thermal expansion or contraction between the prism and the base when the environmental temperature changes is absorbed by the sliding at the interface between the prism and the seat surface, and the relative inclination between the prism and the base is suppressed. And optical performance deterioration is prevented.

JP, 2009-134209, A

  Generally, materials of parts mounted on the optical pickup are various, and the degree of expansion and contraction when the environmental temperature changes depending on the parts is different. Therefore, free thermal expansion or contraction of the housing is prevented by the mounted components, and as a result, the housing warps or twists. Although the relative inclination between the prism and the housing can be suppressed in the above-mentioned prior art, there is a possibility that the prism may be inclined following the warping or twisting of the housing.

  Therefore, even if the housing is warped or twisted due to the change of the environmental temperature, the present inventor autonomously suppresses the inclination of the rotation direction of the prism and enables the stable recording or reproducing operation. And realize an optical disc apparatus.

  In order to solve the above problems, the present invention adopts, for example, the configuration described in the claims. Although this specification includes a plurality of means for solving the above-mentioned problems, to mention one example, “a pedestal protruding from the surface of the housing, a flat surface disposed at the center of the upper surface of the pedestal, and the pedestal A plurality of inclined surfaces disposed on the upper surface outer edge, each of which is inclined in the same rotational direction, an adhesive covering the flat surface and the upper surface of the inclined surface, and bonded to the pedestal via the adhesive And an optical element.

  As another example, “a pedestal protruding from the surface of the housing, a flat surface disposed at the center of the upper surface of the pedestal, and a plurality of elongated recesses disposed at the upper surface outer edge of the pedestal (but An adhesive which covers the flat surface and the upper surface of the elongated recess, and an optical element bonded to the pedestal via the adhesive, except those arranged in mirror symmetry with respect to the pedestal; It is an optical pickup to have.

  According to the present invention, even when the housing is warped or twisted due to a change in environmental temperature, the inclination in the rotational direction of the prism due to the warping or twisting can be canceled out, and the stability by the optical pickup can be canceled. Recording / reproducing operation can be realized. Problems, configurations, and effects other than those described above will be apparent from the description of the embodiments below.

BRIEF DESCRIPTION OF THE DRAWINGS The disassembled perspective view which shows schematic structure of an optical disk apparatus (Example 1). BRIEF DESCRIPTION OF THE DRAWINGS The perspective view which shows schematic structure of an optical pick-up (Example 1). The perspective view explaining the adhesion | attachment junction part of a prism (Example 1). The perspective view which expands and shows the upper surface shape of a base (Example 1). The side view which shows the adhesion | attachment junction part of a prism (Example 1). A diagram for explaining the relationship between thermal deformation of a prism, a pedestal, and an adhesive filled between them under a high temperature environment and a circumferential thermal stress acting on the bonding interface of the prism (Example 1) ). FIG. 5 is a perspective view showing thermal deformation of the optical pickup in a high temperature environment with an enlarged amount of deformation (Example 1). The upper figure which expands the deformation amount and shows the thermal deformation in the high temperature environment of the adhesive bonding part of a prism (Example 1). FIG. 14 is an upper view showing the thermal deformation of the adhesive bonding portion of the prism under a high temperature environment, in which the amount of deformation is enlarged, in the optical pickup in which the prior art is applied to the prism bonding structure. The perspective view which expands and shows the upper surface shape of a base (Example 2). A plan view showing a relationship between thermal deformation of a prism, a pedestal, and an adhesive filled between them under a high temperature environment and a circumferential thermal stress acting on a bonding interface of the prism (Example 2) ). The perspective view which expands and shows the upper surface shape of a base (Example 3). A plan view showing the relationship between the thermal deformation of the prism, the pedestal, and the adhesive filled between them under a high temperature environment and the circumferential thermal stress acting on the bonding interface of the prism (Example 3) ). The perspective view explaining the shape of an inappropriate pedestal.

  Hereinafter, embodiments of the present invention will be described based on the drawings. In addition, the aspect of implementation of this invention is not limited to the form example mentioned later, In the range of the technical thought, various deformation | transformation are possible.

(1) Example 1
FIG. 1 shows a disassembled structure of the optical disc apparatus 1. The optical disc apparatus 1 mainly carries a main body 2 as a frame constituting the apparatus body, a top cover 3 covering the upper surface of the main body 2, a bottom cover 4 and an optical disc into or out of the apparatus. And the disk tray 5 of FIG. The main body 2 has a lock mechanism (not shown) for holding the disk tray 5, a loading mechanism (not shown) for carrying the disk tray 5 along the guide rail 6, and drive control and signal processing of each electronic component A circuit board 7 is mounted.

  In the case of FIG. 1, a mechanical chassis 8 is attached to the disk tray 5. A front cover 9 is attached to the front of the mechanical chassis 8. The mechanical chassis 8 includes a spindle motor 10 for holding and rotating an optical disc, and an optical pickup 11 for focusing light from a laser or the like with a lens and irradiating the light onto the disc to record or reproduce information on the disc. It is mounted. The detailed configuration of the optical pickup 11 will be described later. In FIG. 1, the radial direction of the optical disk (not shown), the tangential direction of the disk circumference, and the optical axis direction of an objective lens (not described) (not shown) are respectively represented by x-axis, y-axis and z-axis. The same is true for the other drawings.

  The detailed configuration of the optical pickup 11 is shown in FIG. FIG. 2 shows the configuration of an optical pickup 11 to which a prism junction structure is applied. Of course, the structure of the optical pickup 11 may be another structure. As described above, various mounting components are joined to the housing 20 of the optical pickup 11 via an adhesive. For example, in the housing 20, an optical element group that condenses the emitted light emitted from the semiconductor laser 21 onto the optical disc and guides the return light from the optical disc to the photodetector 28, and the objective lens 26 in the x direction and z An actuator for moving in the direction is mounted.

  Here, the optical element group includes (1) a prism 23 for bending an optical path of emitted light, (2) a rising mirror (not shown), (3) a collimating lens 24 for condensing emitted light on an optical disc, (4) The lens 26, (5) a diffraction grating 22 that generates an error signal used for positioning control of the focal point of the objective lens 26, (6) a cylindrical lens 27 and the like are included. In the actuator, (1) permanent magnet 31 for forming a magnetic field, (2) yoke 32, (3) movable lens holder 33 for holding objective lens 26, and (4) fixation for elastically supporting lens holder 33 And the like. Each of these mounted components is joined via an adhesive 30 to a housing 20 formed by injection molding or die casting.

  FIG. 3 is an enlarged view of the adhesive joint between the prism 23 and the housing 20. As shown in FIG. That is, the figure which expanded the upper surface shape of the base 201 is shown. As shown in FIG. 3, the prism 23 is bonded to the upper surface of the pedestal 201 protruding from the surface of the housing 20 via an adhesive 30. FIG. 4 shows an enlarged perspective view of the pedestal 201, and FIG. 5 shows a side view of the pedestal 201 (as viewed from the y direction).

  It returns to the explanation of FIG. As shown in FIG. 4, the base 201 of the present embodiment is a cylinder having a flat surface 2014 at the center of the upper surface, and is inclined at an upper surface outer edge by an angle α1 along the circumferential direction (counterclockwise in FIG. 4). Four inclined surfaces 2011 are formed with respect to the z-axis (normal line passing the center of the pedestal 201). In the case of the present embodiment, the four inclined surfaces 2011 have the same shape, and are formed on the pedestal 201 so as to be symmetrical with respect to the normal passing through the center of the pedestal 201 a plurality of times.

  The adhesive 30 is applied so as to cover the upper surfaces of the four inclined surfaces 2011 and the flat surface 2014, and fills the space formed between the prism 23 and the pedestal 201, as shown in FIG. Since the inclined surface 2011 is inclined in the counterclockwise direction, the thickness of the outer peripheral portion of the filled adhesive 30 gradually increases along the inclination direction of the inclined surface 2011, and the end (the next inclined surface 2011 Beginning: thins sharply at 2013. The adhesive 30 repeats this change counterclockwise. Note that the inclination direction of the inclined surface 2011 and the size of the angle α are set to directions and angles that can cancel out the direction and amount of deviation of the rotation direction of the prism 23 assumed due to a change in environmental temperature.

  Hereinafter, the effect obtained by using the pedestal 201 having the above-described shape will be described in comparison with the prior art. 6 shows the thermal deformation of the prism 23, the pedestal 201, and the adhesive 30 filled between them under a high temperature environment, and the circumferential thermal stress acting on the bonding interface of the prism 23. It is a top view which shows F1. The amount of thermal expansion of the adhesive 30 is larger than that of the housing 20 and the prism 23, so the adhesive 30 tends to expand when the environmental temperature rises. On the other hand, the housing 20 and the prism 23 try to suppress the expansion of the adhesive 30 from both sides in the z direction.

  The thick portion of the adhesive 30 is less likely to be restrained by the housing 20, and therefore tends to expand in both the thickness direction and the outer peripheral direction than the periphery, and the prism 23 suppresses the expansion. As a result, the thermal stress F1 in the circumferential direction acts on the boundary portion (that is, the end portion 2013) of the inclined surfaces 2011 in which the thickness of the adhesive 30 changes discontinuously among the bonding interface of the prism 23. The circumferential thermal stress F1 generates a clockwise moment with respect to the z axis. As a result, the prism 23 tilts clockwise with respect to the pedestal 201 of the housing 20 by the wedge 1.

  FIG. 7 is a perspective view showing the thermal deformation of the optical pickup 11 in a high temperature environment in the present embodiment with the amount of deformation enlarged. FIG. 8 is an enlarged top view of the adhesive joint of the prism 23 of FIG. FIG. 9 is an upper view showing the thermal deformation under the high temperature environment of the bonded joint of the prism 23 in the case where the prior art is used for the joint structure of the prism 23, with the amount of deformation enlarged. The broken lines in FIGS. 8 and 9 both represent the outer shapes of the housing 20 and the prism 23 under a normal temperature environment.

  The material constituting the mounting part of the optical pickup 11 is (1) steel plate of yoke 32, (2) optical glass such as prism 23 or rising mirror, (3) fixing portion 34, (4) lens holder 33, (5) There are various types of plastics used for various lenses, and the amount of expansion when the environmental temperature rises differs depending on the material. Therefore, the casing 20 is twisted around the y-axis due to the thermal expansion of the fixing portion 34 or the thermal expansion of the casing 20 is hindered by the semiconductor laser 21 to be deformed.

  At this time, as shown in FIG. 7 and FIG. 8, the prism junction of the housing 20 is warped by θ in the counterclockwise direction with respect to the z-axis. On the other hand, due to the thermal stress F1 described above, the prism 23 is inclined with respect to the pedestal 201 clockwise by only the wedge 1 under a high temperature environment. Due to this inclination ψ1, the inclination of the prism 23 following the warp θ of the housing 20 is reduced to (θ−ψ1).

  On the other hand, when the prior art is applied to the junction structure of the prisms 23 (FIG. 9), while relative inclination between the prisms 23 and the housing 20 does not occur, the prisms 23 follow the warpage θ of the housing 20 and θ The z-axis is tilted about the same rotation angle by about the same θ0. As described above, by using the pedestal 201 having the upper surface structure described in the present embodiment, the displacement of the prism 23 in a high temperature environment can be extremely reduced as compared with the prior art.

  In the present embodiment, although four inclined surfaces 2011 inclined (falling) at an angle α1 counterclockwise with respect to the z axis are disposed on the upper surface of the pedestal 201, they are inclined (falling) at an angle α1 clockwise Four oriented inclined surfaces 2011 can be arranged on the upper surface of the pedestal 201. In this case, a counterclockwise thermal stress F1 can be generated in a high temperature environment, and the prism 23 can be inclined counterclockwise with respect to the z-axis. Therefore, the direction of the warp generated in the portion of the pedestal 201 of the housing 20 with the rise of the environmental temperature is grasped in advance, and the direction of the inclined surface 2011 installed on the pedestal 201 according to the direction of the warp By appropriately selecting α1), the size of the inclination of the prism 23 that follows the warpage of the housing 20 can be reduced compared to the prior art.

  Further, although four inclined surfaces 2011 are disposed on the upper surface of the pedestal 201 in the present embodiment, the number of the inclined surfaces 2011 is not limited to four, and the same effect can be obtained if there are a plurality. Thus, the optical pickup 11 capable of stable recording / reproducing operation can be provided.

  More desirably, the plurality of inclined surfaces 2011 may be arranged so as to be symmetric with respect to the z axis (normals passing through the center of the pedestal 201) a plurality of times. In other words, the pedestal 201 may be formed to have a shape that is symmetrical with respect to a normal (z axis) passing through the center thereof. In this case, the thermal stress F1 acting on the bonding interface of the prism 23 with the change of the environmental temperature also has a plurality of symmetry about the z axis, and the prism 23 is inclined about the x axis and the y axis. The generation of a moment is suppressed, and the prism 23 can be prevented from tilting about the x axis and the y axis. Therefore, the optical pickup 11 capable of more stable recording / reproducing operation can be provided.

(2) Example 2
The structure of the pedestal 202 according to the second embodiment will be described with reference to FIG. 10 and FIG. FIG. 10 is an enlarged view of the upper surface shape of the pedestal 202 to which the prism 23 is adhesively bonded. The pedestal 202 is a quadrangular prism having a flat surface 2024 at the center of the upper surface, but as in the case of the first embodiment, the inclined surface 2021 of the angle α2 is z-axis (the center of the pedestal 202 passes Four are arranged counterclockwise with respect to the normal).

  Therefore, also in the present embodiment, the thickness of the outer peripheral portion of the adhesive 30 filled between the prism 23 and the pedestal 202 gradually increases along the inclination direction of the inclined surface 2021, and the end of the inclined surface 2021 At the beginning of the next inclined surface 2011, the steep thinning change 2023 is repeated counterclockwise. Further, by making the upper surface of the pedestal 202 square, the bonding area can be expanded to the outer shape of the prism 23, and the bonding reliability of the prism 23 can be increased accordingly.

  11 shows thermal deformation in the high temperature environment in each of the prism 23, the pedestal 202, and the adhesive 30 filled between them, and circumferential thermal stress acting on the bonding interface of the prism 23. It is a top view which shows F2. Also in the case of the present embodiment, for the same reason as the first embodiment, among the bonding interface of the prism 23, particularly the boundary portion between the inclined surfaces 2021 where the thickness of the adhesive 30 changes discontinuously (that is, the end 2023) The thermal stress F2 in the circumferential direction acts on the The moment due to the circumferential thermal stress F2 causes the prism 23 to tilt clockwise by に 対 し て 2 with respect to the z-axis. Even when the pedestal 202 mounted on the housing 20 by the mounting component is warped counterclockwise with respect to the z axis when the environmental temperature rises due to the inclination ψ 2, the prism 23 following the warpage of the housing 20 Can be reduced to (θ−ψ2).

  In the present embodiment, four inclined surfaces 2021 inclined (falling) at an angle α2 counterclockwise with respect to the z axis are disposed on the upper surface of the pedestal 202, but the number of inclined surfaces 2021 is also the same in this embodiment Similar effects can be obtained if there are a plurality. As described above, it is possible to provide an optical pickup capable of performing a stable recording / reproducing operation even in the second embodiment in which the adhesion reliability is enhanced.

  More preferably, the shape of the pedestal 202 is a square prism, and the plurality of inclined surfaces 2021 may be arranged in multiple symmetry with respect to the z-axis (normal line passing the center of the pedestal 202). In other words, the pedestal 202 may be formed to have a shape that is symmetrical with respect to a normal (z axis) passing through the center thereof. In this case, the thermal stress F2 acting on the bonding interface of the prism 23 with the change of the environmental temperature also has a plurality of symmetry about the z axis, and the prism 23 is inclined about the x axis and the y axis. The generation of a moment is suppressed, and the prism 23 can be prevented from tilting about the x axis and the y axis. Therefore, an optical pickup capable of more stable recording / reproducing operation can be provided.

(3) Example 3
The structure of the pedestal 203 according to the third embodiment will be described with reference to FIGS. 12 and 13. FIG. 12 is an enlarged view of the upper surface shape of the pedestal 203 to which the prism 23 is adhesively bonded. The pedestal 203 of the third embodiment is a square pole having a flat surface 2034 at the center, as in the second embodiment. However, on each side of the pedestal 203, one elongated recess 2032 having a circumferential length L3 and a width W3 is disposed. The recesses 2032 each have a certain height from the bottom surface of the pedestal 203 and do not have an inclined surface as in the first and second embodiments. Along the outer periphery of the pedestal 203, four recesses 2032 are arranged so that the long side of the length L3 and the short side of the width W3 appear alternately. For this reason, the shape of the flat surface 2034 is a concave polygon.

  Also in the present embodiment, the thickness of the outer peripheral portion of the adhesive 30 filled between the prism 23 and the pedestal 203 repeats the change in the circumferential direction in which the thickness increases for each arrangement position of the recess 2032. By making the shape disposed at the outer edge of the pedestal 203 a simple concave shape as shown in FIG. 12, the manufacture of a mold for molding the housing 20 is facilitated.

  FIG. 13 shows thermal deformation of the prism 23, the pedestal 203, and the adhesive 30 filled between them under a high temperature environment, and two kinds of thermal stress in the circumferential direction acting on the bonding interface of the prism 23 It is a top view which shows thermal stress F3 and f3). Also in the case of this embodiment, for the same reason as in the previous embodiment, the inner wall portion (the boundary with the flat surface 2034) of the recess 2032 where the thickness of the adhesive 30 changes discontinuously among the bonding interface of the prism 23 (2) two types of thermal stress F3 and f3 acting in the circumferential direction act on the wall surface located in

  As described above, the recess 2032 has a rectangular shape (an elongated shape in which one side is longer than the other side) (ie, L3> W3). Therefore, the circumferential thermal stress F3 generated in the inner wall portion having the length L3 is larger than the circumferential thermal stress f3 generated in the inner wall portion having the width W3. In the present embodiment, all the four thermal stresses F3 are aligned clockwise (the thermal stress f3 is aligned counterclockwise).

  Therefore, the combined stress of these thermal stresses F3 and f3 generates a moment for tilting the prism 23 clockwise with respect to the z-axis. Even when the pedestal 203 of the housing 20 is warped by θ the counter clockwise with respect to the z-axis due to the environmental temperature rising due to the inclination ψ 3 of the prism 23 due to this moment, the prism following the warp of the housing 20 The slope of 23 can be reduced to (θ−ψ3). Therefore, even in the case of using the pedestal 203 having a simple structure as in the third embodiment, it is possible to provide an optical pickup capable of stable recording / reproducing operation.

  More preferably, the shape of the pedestal 203 is a square prism, and the recess 2032 may be symmetrically arranged a plurality of times with respect to the z-axis (normal line passing the center of the pedestal 203). In this case, the thermal stress acting on the bonding interface of the prism 23 along with the change of the environmental temperature also has multiple symmetry around the z-axis. As a result, generation of a moment to tilt the prism 23 around the x axis and y axis is suppressed, and the prism 23 can be prevented from tilting around the x axis and y axis. Therefore, an optical pickup capable of more stable recording / reproducing operation can be provided.

(4) Inappropriate example Finally, an example that is inappropriate as the shape of the pedestal will be described. FIG. 14 shows an example of an inappropriate pedestal 204 structure. The pedestal 204 is a cylinder whose main body shape is cylindrical, and has a configuration in which four recesses 2042 are disposed on the upper surface thereof. However, the pedestal 204 is mirror-symmetrical. For this reason, the thermal stress in the circumferential direction acting on the bonding interface of the prism 23 is also mirror-symmetrical, and a moment for tilting the prism 23 around the z axis as in the above-described embodiments does not occur. I can not play an effect. The same is true even if the shape of the pedestal is a square prism.

(5) Other Embodiments The present invention is not limited to the above-described embodiments, but includes various modifications. For example, although the structure of the part used for adhesive bonding of the prism 23 was exclusively described in the above-mentioned embodiment, the above-mentioned structure may be used for bonding with a mirror or other optical element. The optical device having the adhesive bonding structure described above can be applied not only to the optical pickup described above, but also to other optical devices such as a projection type image display device.

  In addition, in order to realize the present invention, it is not necessary to have all the configurations described above. Also, part of one embodiment can be replaced with the configuration of another embodiment. Also, the configuration of another embodiment can be added to the configuration of one embodiment. In addition, with respect to a part of the configuration of each embodiment, a part of the configuration of another embodiment can be added, deleted or replaced.

1 ... optical disc device,
2 ... main body,
3 ... top cover,
4 ... bottom cover,
5 ... Disc tray 6 ... Guide rail,
7 ... circuit board,
8 ... mechanical chassis,
9 ... front cover,
10 ... spindle motor,
11: Optical pickup,
20 ... housing,
21: Semiconductor laser,
22 ... a diffraction grating,
23 ... prism,
24 ... collimate lens,
26 ... objective lens,
27 ... cylindrical lens,
28 ... photodetector,
30 ... adhesive,
31 ... permanent magnet,
32 ... Yoke,
33: Lens holder,
34 ... fixed part,
201, 202, 203, 204 ... pedestal,
2011, 2021 ... inclined surface,
2013, 2023 ... termination,
2014, 2024, 2034, 2044 ... flat surface,
2032, 2042 ... dents,
α1, α2 ... angle of inclination,
L3 ... dent length,
W3: Width of dent,
θ: Warpage about the z-axis of the base of the housing under high temperature environment,
θ0: Inclination of the prism around the z axis following the warpage of the base portion of the housing in a high temperature environment,
ψ1, ψ2, ψ3 ... inclination about the z axis with respect to the base of the prism under high temperature environment,
F1, F2, F3, f3 ... circumferential thermal stress acting on the bonding interface of the prism in a high temperature environment
x ... radial direction of the disc,
y: Tangent direction of the disk circumference,
z ... optical axis direction of the objective lens.

Claims (18)

A pedestal projecting from the surface of the housing;
A flat surface disposed at the center of the upper surface of the pedestal;
A plurality of inclined surfaces disposed on the upper surface outer edge of the pedestal, each of which is inclined in the same rotational direction;
An adhesive covering the upper surface of the flat surface and the inclined surface;
An optical element bonded to the pedestal via the adhesive;
With an optical pickup. In the optical pickup according to claim 1,
An optical pickup characterized in that the thickness of the adhesive at the upper surface outer edge of the pedestal changes a plurality of times along the outer periphery of the pedestal. In the optical pickup according to claim 1,
An optical pickup characterized in that the plurality of inclined surfaces are symmetric with respect to a normal passing through the center of the pedestal. In the optical pickup according to claim 2,
An optical pickup characterized in that the plurality of inclined surfaces are symmetric with respect to a normal passing through the center of the pedestal. In the optical pickup according to claim 1,
An optical pickup characterized in that the pedestal is a cylinder or a square prism. A pedestal projecting from the surface of the housing;
A flat surface disposed at the center of the upper surface of the pedestal;
A plurality of elongated recesses disposed on the upper surface outer edge of the pedestal (except those disposed in mirror symmetry to the pedestal);
An adhesive covering the top surface of the flat surface and the elongated recess;
An optical element bonded to the pedestal via the adhesive;
With an optical pickup. In the optical pickup according to claim 6,
An optical pickup characterized in that the thickness of the adhesive at the upper surface outer edge of the pedestal changes a plurality of times along the outer periphery of the pedestal. In the optical pickup according to claim 6,
An optical pickup characterized in that the plurality of inclined surfaces are symmetric with respect to a normal passing through the center of the pedestal. In the optical pickup according to claim 7,
An optical pickup characterized in that the plurality of inclined surfaces are symmetric with respect to a normal passing through the center of the pedestal. In the optical pickup according to claim 6,
An optical pickup characterized in that the pedestal is a cylinder or a square prism. The device body,
A spindle motor that rotates an optical disc,
An optical pickup for recording information on the optical disc or reproducing information from the optical disc;
The optical pickup is
A pedestal projecting from the surface of the housing;
A flat surface disposed at the center of the upper surface of the pedestal;
A plurality of inclined surfaces disposed on the upper surface outer edge of the pedestal, each of which is inclined in the same rotational direction;
An adhesive covering the upper surface of the flat surface and the inclined surface;
An optical element bonded to the pedestal via the adhesive. In the optical disk device according to claim 11,
The thickness of the adhesive on the upper surface outer edge of the pedestal varies a plurality of times along the outer periphery of the pedestal. In the optical disk device according to claim 11,
The optical disk apparatus according to claim 1, wherein the plurality of inclined surfaces are symmetrical with respect to a normal passing through a center of the pedestal. In the optical disk device according to claim 11,
The optical disc apparatus, wherein the pedestal is a cylinder or a square prism. The device body,
A spindle motor that rotates an optical disc,
An optical pickup for recording information on the optical disc or reproducing information from the optical disc;
The optical pickup is
A pedestal projecting from the surface of the housing;
A flat surface disposed at the center of the upper surface of the pedestal;
A plurality of elongated recesses disposed on the upper surface outer edge of the pedestal (except those disposed in mirror symmetry to the pedestal);
An adhesive covering the top surface of the flat surface and the elongated recess;
An optical element bonded to the pedestal via the adhesive. In the optical disk device according to claim 15,
The thickness of the adhesive on the upper surface outer edge of the pedestal varies a plurality of times along the outer periphery of the pedestal. In the optical disk device according to claim 15,
The optical disk apparatus according to claim 1, wherein the plurality of inclined surfaces are symmetrical with respect to a normal passing through a center of the pedestal. In the optical disk device according to claim 15,
The optical disc apparatus, wherein the pedestal is a cylinder or a square prism.

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