JP2013251021A - Optical pickup device and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical pickup device in which an object lens is fastened to a lens holder excellently and a method of manufacturing the same.SOLUTION: An object lens 40 provided in an optical pickup device, includes a lens part 42, and a flange part 44 continued integrally with the periphery of the lens part 42. For a side face of the flange part 44, a projection part 52 projects sidewards from the side face of the flange part 44, and an edge of the projection part 52 is disposed inside an outer peripheral edge part of the flange part 44. Thus, the effect of fitting the projection part 52 to fastening material is obtained.

Description

  The present invention relates to an optical pickup device used for reading and writing of an optical disk and a method for manufacturing the same.

  In an optical pickup device that optically reads or writes signals on an optical disc, an objective lens holder to which an objective lens is attached is supported so as to be displaceable with respect to an actuator frame. In addition, the focus coil is mounted on the lens holder, and the effective area of these drive coils is placed in a predetermined magnetic field formed by a magnetic circuit to drive the objective lens according to the signal supplied to each drive coil. (See Patent Document 1 below).

  With reference to FIG. 7, a configuration in which the objective lens 102 is attached to the lens holder 100 in a general optical pickup device will be described. The objective lens 102 includes a lens portion 104 through which laser light passes and a flange portion 106 provided so as to surround the peripheral portion of the lens portion 104. The objective lens 102 is placed on the lens holder 100 when the lower surface of the flange portion 106 of the objective lens 102 contacts the upper surface of the lens holder 100. Further, the objective lens 102 is fixed to the lens holder 100 by applying the fixing material 108 so as to contact the side surface of the flange portion 106 and the upper surface of the lens holder 100.

JP 2008-226292 A

  However, the above-described fixing structure of the objective lens 102 has a problem that the objective lens 102 cannot be fixed satisfactorily.

  Specifically, since the side surface of the flange portion 106 is a vertical surface, the area where the fixing material 108 contacts the side surface of the flange portion 106 is reduced, and the objective lens 102 is fixed to the lens holder 100 by the fixing material 108. There was also a fear that would become smaller.

  The present invention has been made in view of the above problems. An object of the present invention is to provide an optical pickup device in which an objective lens is well fixed to a lens holder and a method for manufacturing the same.

  An optical pickup device of the present invention includes an objective lens that focuses laser light on an information recording layer of an optical disc, and a lens holder to which the objective lens is fixed, and the objective lens is a lens through which laser light is transmitted. And an end portion of the protruding portion that protrudes laterally from the side surface of the flange portion is disposed inside the outer peripheral end portion of the upper end or the lower end of the flange portion. It is characterized by being.

  The method of manufacturing an optical pickup device of the present invention provides a molding die having a cavity having a shape corresponding to an objective lens including a lens portion through which laser light is transmitted and a flange portion surrounding the lens portion, A step of injecting resin into the cavity of the molding die via a runner, the objective lens made of the resin hardened in the cavity, and the resin made of the resin hardened by the runner are integrally formed from the side surface of the flange portion. Removing the continuous runner part from the molding die, and cutting the runner part to leave a part of the runner part continuous from the side surface of the flange part as a protruding part. In the step of cutting the runner portion, the end portion of the protruding portion is arranged inside the outer peripheral end portion of the upper end or the lower end of the flange portion. , And it performs the cutting.

  According to the present invention, since the protruding portion that protrudes laterally from the flange portion of the objective lens is provided, the fixing material used for fixing the objective lens is fitted to the protruding portion, and the fixing strength by the fixing material is improved. . Furthermore, since the end portion of the protruding portion is arranged on the inner side of the outer peripheral end portion of the flange portion, the protruding portion does not protrude to the outside from the outer peripheral edge portion. It is suppressed that a protrusion part is caught in another member.

It is a figure which shows the optical pick-up apparatus of this invention. It is a figure which shows the objective lens of this invention, (A) is a perspective view, (B) is sectional drawing, (C) (C1) is sectional drawing which shows the other shape of an objective lens, ( D) is a plan view showing another embodiment. It is a figure which shows the objective lens of this invention, (A) is a perspective view, (B) (B1) is sectional drawing, (C) is sectional drawing which shows the other shape of an objective lens. It is a figure which shows the structure by which an objective lens is fixed to a lens holder with the optical pick-up apparatus of this invention, (A) is a perspective view, (B) and (C) are sectional drawings. It is a perspective view which shows the lens holder used for the optical pick-up apparatus of this invention. It is a figure which shows the manufacturing method of the objective lens of this invention, (A) is a top view which shows the metal mold | die used, (B) is sectional drawing of a metal mold | die, (C) is the objective manufactured. It is sectional drawing which shows a lens partially, (D) is a top view which shows the metal mold | die of another form. It is sectional drawing which shows partially the optical pick-up apparatus of background art.

  With reference to FIG. 1, a basic configuration of the optical pickup device of the present embodiment will be described.

  The optical pickup device 10 focuses a laser beam of BD (Blu-ray Disc), DVD (Digital Versatile Disk) or CD (Compact Disk) standard on an information recording layer of an optical disc (information recording medium), and records the information. It has a function of receiving reflected light from the layer and converting it into an electrical signal. Here, the optical pickup device 10 does not necessarily correspond to laser beams of three types of standards, and may correspond to laser beams of one or two standards.

  The specific configuration of the optical pickup device 10 includes a housing 12 and various optical elements built in the housing 12. As optical elements, a laser unit 14, a diffraction grating 16, a half mirror 22, a quarter wavelength plate 24, a collimator lens 26, an objective lens 40, and a photodetector 18 are illustrated. Further, an engaging portion 34 to which the guide shaft is engaged and an insertion portion 36 through which the guide shaft is inserted are provided on the upper and lower ends of the housing 12 in the drawing.

  The objective lens 40 is fixed to the upper surface of the lens holder 32, and this lens holder 32 is held by the objective lens driving device 28 so as to be movable via a wire.

  The laser unit 14 includes a laser diode, and the above-mentioned standard laser light is emitted from the laser diode. Specifically, a laser beam having a blue-violet (blue) wavelength band 395 nm to 420 nm (for example, a wavelength of 405 nm) suitable for BD, a laser beam having a red wavelength band 645 nm to 675 nm (for example, a wavelength of 650 nm) suitable for DVD, or Laser light having an infrared wavelength band of 765 nm to 805 nm (for example, a wavelength of 780 nm) suitable for CD is emitted from the laser diode.

  Laser light emitted from the laser unit 14 is separated into zero-order light, + 1st-order light, and −1st-order light by the diffraction grating 16 and reflected by the half mirror 22, and then the quarter-wave plate 24 and the collimator lens 26. Is reflected by a rising mirror (not shown) and focused on the information recording layer of the optical disc by the objective lens 40. Then, the return laser beam reflected by the information recording layer of the optical disk passes through the rising mirror, the collimator lens 26, the quarter wavelength plate 24, and the half mirror 22, and then detected by the photodetector 18 (PDIC). Is done. A control signal is supplied to the coil of the lens holder 32 based on the signal detected by the photodetector 18. As a result, focus control, tracking control, and radial tilt control are performed.

  With reference to FIG. 2, the objective lens 40 of this form is demonstrated. 2A is a perspective view showing the objective lens 40, FIG. 2B is a cross-sectional view taken along the line BB ′ of FIG. 2A, and FIG. It is sectional drawing which shows another form.

  Here, regarding the side surface of the flange portion, a vertical range and an inclination range will be described. FIG. 7, which is a conventional structure, is a case where the side surfaces are formed vertically, and there are cases where a slight taper angle is provided in consideration of ease of removal from the mold. For example, in Japanese Patent Application Laid-Open No. 2008-119830, etc., in FIG. 7 of the present application, the side surface is inclined inwardly from the upper surface to the back surface of the flange portion, and the angle is about 0 degree to 5 degrees. In other words, the ease of pulling out is considered, and the degree of inclination in this range from the upper surface of the flange portion to the inside and the outside is considered to be a vertical side surface.

  Referring to FIG. 2A, the objective lens 40 includes a central lens portion 42 and a flange portion 44 surrounding the lens portion 42. The lens unit 42 has a function of focusing the laser light emitted from the laser diode onto the information recording layer of the optical disc. The flange portion 44 is a portion that contacts the lens holder when the objective lens 40 is fixed to the lens holder. When the objective lens 40 is viewed from above, it has a substantially circular shape, and the side surface of the flange portion 44 is visible. As will be described later, this is realized by making the side surface of the flange portion 44 an inclined surface or a stepped shape. As the material of the objective lens 40, an olefin resin material is employed.

  Referring to FIGS. 2A and 2B, the upper surface and the lower surface of the lens portion 42 have a curved surface shape for focusing laser light incident from above. A flange portion 44 is provided around the lens portion 42, and when the objective lens 40 is fixed to the lens holder, the lower surface of the entire circumference of the flange portion 44 contacts the lens holder. The flange portion 44 includes a first main surface 45 that is a lower surface on the paper surface, a second main surface 47 that faces the first main surface 45, and an inclined surface 46 that connects the first main surface 45 and the second main surface 47. (Side surface), and extends in a ring shape in plan view.

  The first main surface 45 is a surface that contacts the lens holder of the optical pickup device, is a flat surface perpendicular to the traveling direction of the laser light passing through the objective lens 40, and is a top portion below the lens portion 42. It is located in front (upper surface side). The second main surface 47 is a surface substantially parallel to the first main surface 45, and is disposed above the upper end of the lens portion 42. Accordingly, for example, the upper surface of the lens portion 42 can be protected by the second main surface 47 that is the upper end portion of the flange portion 44 under use conditions or in the middle of the manufacturing process.

  As will be described later with reference to FIG. 6, the objective lens 40 is made by molding plastic with a mold. The resin is not particularly limited, but is transparent to light, for example, the olefin resin. In the objective lens 40, a lens portion 42 and a flange portion 44 are integrally formed by a mold. The lens unit 42 has a first curved surface and a second curved surface that can focus light, and is circular when viewed from above. The flange portion 44 is in the form of a ring having a substantial thickness. The inner diameter is slightly larger than the lens portion 42, and the outer side surface is inclined. It is a shape in which the lens and the lens part 42 are inserted into the cylindrical hollow portion inside the flange, and there is a boundary part connecting the lens part 42 and the flange part 44 between them.

  In this embodiment, the outer peripheral end portion of the second main surface 47 of the flange portion 44 is disposed on the inner side of the outer peripheral end portion of the first main surface 45. And the inclined surface 46 which connects the 1st main surface 45 and the 2nd main surface 47 of the flange part 44 is the inclined surface 46 in which an upper part faces an inner side. Here, the angle θ at which the inclined surface 46 is inclined from the vertical surface is, for example, not less than 15 degrees and not more than 60 degrees. Thereby, the structure to which the objective lens 40 is fixed is strengthened, and there is an effect that the application of the fixing material becomes easy. Details of this effect will be described with reference to FIG.

  Here, the entire circumference of the side surface of the flange portion 44 may be the inclined surface 46, only the side surface to which the fixing material is attached when fixed to the lens holder is the inclined surface 46, and the other side surface is the first main surface 45. It is also possible to use a surface perpendicular to (or an inclined surface slightly inclined inward). As described above, the vertical plane is considered as a vertical plane even if the draft angle is taken into consideration and the angle θ is about 0 to 5 degrees. Furthermore, here, the inclined surface 46 has a cross-sectional shape that is linearly inclined, but the cross-sectional shape of the inclined surface 46 may be a curved shape that bulges outward or inward.

  Referring to FIG. 2C, here, the side surface of the flange portion 44 is a stepped stepped portion 48 so that the outer peripheral end portion of the second main surface 47 is more than the outer peripheral end portion of the first main surface 45. Also placed inside. Thus, by making the side surface of the flange part into a step shape, the objective lens 40 can be easily moved by sandwiching the step part 48 in the manufacturing process of the optical pickup device.

  Here, the stepped portion 48 has a staircase shape having a vertical surface and a horizontal surface, but the side surface of the flange portion 44 may be configured by a stepped portion formed of an inclined surface (non-vertical surface and non-horizontal surface) (see FIG. 2 (C1)). Furthermore, although the stepped portion 48 has a single stepped shape, a stepped shape having two or more steps may be employed.

  Referring to FIG. 2 (D), most of the outer peripheral side of the flange portion 44 is a vertical surface or an inclined surface that is slightly inclined, and two or more are evenly balanced. Here, two arrangements are illustrated, and the side edges of the left and right end portions opposed to each other on the paper surface are partially formed as the inclined surface 46 or the step surface described above.

  With reference to FIG. 3, the objective lens 40 of another form is demonstrated. The basic shape of the objective lens 40 described with reference to this figure is the same as that described with reference to FIG. 2, and is different in that it has a concave region 50 (removed portion) and a protruding portion 52. 3A is a perspective view showing the objective lens 40, FIG. 3B is a cross-sectional view taken along line BB ′ of FIG. 3A, and FIG. It is sectional drawing which shows another shape.

  With reference to FIG. 3 (A) and FIG. 3 (B), the concave region 50 is provided by partially excising the flange portion 44 of the objective lens 40. Here, the side surface of the flange portion 44 is the inclined surface 46 as a whole, and the side surface of the flange portion 44 located in the concave region 50 is also the inclined surface 46A.

  In addition, referring to FIG. 3 (B), a protruding portion 52 that protrudes laterally from an inclined surface 46 </ b> A located in concave region 50 is provided. By providing the protruding portion 52, a fixing material (adhesive) used for fixing the objective lens 40 is stacked on the protruding portion 52, and an effect that the fixing material adheres well to the objective lens 40 is obtained. Here, the protruding portion 52 protrudes leftward from the inclined surface 46A on the paper surface, but the tip end portion of the protruding portion 52 is disposed on the inner side of the outer peripheral portion of the first main surface 45 of the flange portion 44. Yes. Accordingly, the protrusion 52 is prevented from protruding outward from the outer peripheral edge of the inclined surface of the objective lens 40, and the protrusion 52 is caught by an external member and is damaged during use or during manufacturing. Is suppressed. Here, the protrusion 52 is disposed inside the concave region 50. However, as shown in FIG. 3B1, the protrusion 52 is simply disposed on the inclined surface 46 without providing the concave region 50, and the protrusion You may arrange | position the edge part of the part 52 inside the edge part of the 1st main surface 45 of the flange part 44. FIG.

  Referring to FIG. 3C, in the structure in which the stepped portion 48 having a side surface perpendicular to the entire side surface of the flange portion 44 and a horizontal surface is provided, the above-described recessed region 50 is provided. A protruding portion 52 may be provided. Even with such a structure, the above-described effects can be obtained.

  With reference to FIG. 4, the lens holder 32 provided with the objective lens 40 of an above-described structure is demonstrated. 4A is a perspective view showing the lens holder 32 to which the objective lens 40 is fixed, and FIG. 4B is a sectional view taken along line BB ′ of FIG. 4A. C) is a cross-sectional view showing another configuration to which the objective lens 40 is fixed.

  Referring to FIG. 4A, the objective lens 40 is fixed near the center of the upper surface of the lens holder 32, and a protective portion 58 is provided on the upper surface of the lens holder 32 at a position surrounding the periphery of the objective lens 40. ing. In addition, a plurality of binding portions 56 are provided on the side surfaces facing each other in the left-right direction of the lens holder 32, and wires that support the lens holder 32 are connected to these binding portions 56. Further, a coil 54 for driving the lens holder 32 is wound on the side surface on the near side of the lens holder 32 as viewed in the drawing.

  With reference to FIG. 4B, in this embodiment, the objective lens 40 is fixed to the upper surface around the opening of the lens holder 32, whereby the lens portion 42 of the objective lens 40 is attached to the opening of the lens holder 32. Is placed.

  The lower surface (first main surface) of the flange portion 44 of the objective lens 40 contacts the upper surface around the opening of the lens holder 32, and the fixing material 60 adheres to the upper surface of the lens holder 32 and the side surface of the flange portion 44. The objective lens 40 is fixed to the lens holder 32.

  Here, as described above, the outer peripheral side surface of the flange portion 44 of the objective lens 40 is the inclined surface 46. Therefore, compared with the case where the outer peripheral side surface is a vertical surface, the area where the fixing material 60 and the inclined surface 46 are in close contact with each other is large, so that the fixing strength between the objective lens 40 and the lens holder 32 is improved. Further, when the fixing material 60 is supplied to the side surface of the objective lens 40 and the lens holder 32 by the dispenser in the manufacturing process, the side surface of the flange portion 44 is the inclined surface 46, so that the dispenser is applied without contacting the flange portion 44. can do. Furthermore, the contact of the dispenser and the like is prevented in this way, so that it is possible to prevent the fixing material 60 from adhering to the upper surface of the flange portion 44 and causing a defect.

  The protection unit 58 is provided in a frame shape so as to surround the objective lens 40, and the upper end portion of the protection unit 58 is disposed above the upper end portion of the objective lens 40. Therefore, the protection unit 58 avoids contact of the objective lens 40 with other members (for example, the surface of the optical disk) under the usage conditions. Further, as the material of the protection part 58, a resin material that is softer than the material of the lens holder 32 is employed. Here, the protection portion 58 has a substantially rectangular shape, but a circular shape may be employed.

  Referring to FIG. 4C, here, the side surface located at the opening of the lens holder 32 is an inclined gonio surface 62 (inclined surface), and the flange portion of the objective lens 40 is formed on the gonio surface 62. The lower end of the outer periphery of 44 is in contact. In this case, after the objective lens is brought into contact with the gonio surface 62 of the lens holder 32, the relative positional relationship between the objective lens 40 and the lens holder 32 is determined while vibrating the lens holder 32. Here, the first main surface is horizontal. Thereafter, the fixing material 60 is applied and solidified on both the inclined surface 46 of the objective lens and the lens holder 32 to fix the objective lens 40 to the lens holder 32. Even in such a case, since the side surface of the flange portion 44 is the inclined surface 46, the same effect as described above is exhibited. In particular, since the gonio surface and the flange side surface are inclined, the movement area of the dispenser is secured, and a V-shaped groove is formed, so that an anchor effect can also be expected.

  Another form of the lens holder 32 will be described with reference to FIG. Here, a groove 66 extending from the edge of the circular opening 64 to the periphery is provided on the upper surface of the lens holder 32. The groove 66 is for supplying a liquid fixing material to the objective lens in the manufacturing process. The groove 66 is symmetrical with respect to the center of the opening 64 in consideration of the weight balance of the lens holder 32. Is provided. In the method using the groove 66, the objective lens is placed on the upper surface of the lens holder 32 so as to close the opening 64, and then the fixing material is supplied to the objective lens through the groove 66. Thereby, since it is not necessary to make the tip of a dispenser approach an objective lens, contact with a dispenser and an objective lens is prevented.

  With reference to FIG. 6, a method of manufacturing the above-described objective lens by injection molding will be described. 6A is a plan view showing an outline of a mold 70 to be used, FIG. 6B is a sectional view thereof, and FIG. 6C is a sectional view showing a collimating lens to be molded. .

  Referring to FIG. 6A, the mold 70 used in this step includes a plurality of cavities 72 arranged in a matrix (2 rows × X columns: X is an integer), and communicates with the plurality of cavities 72. A runner 74 is provided.

  Each cavity 72 has the same shape as the objective lens 40 shown in FIG. The runner 74 is an elongated path through which the liquid resin material supplied to each cavity passes and communicates with each cavity 72.

  In this step, first, referring to FIG. 6A, a resin material as a material of the objective lens is heated and melted to be in a liquid or semi-solid state, and the resin material is supplied to each cavity 72 via a runner 74. To do. In the figure, the path through which the molten resin material passes is indicated by arrows. After all the cavities 72 are filled with the resin material, the filled resin material is cured, and each objective lens 40 made of the cured resin material is taken out from the mold 70.

  With reference to FIG. 6B, the shape of the inner wall of each cavity 72 has a shape corresponding to the lens portion 42 and the flange portion 44 of the objective lens 40. In addition, the side surface of each cavity 72 has a shape corresponding to the inclined surface 46 and the concave region 50 shown in FIG. Furthermore, the runner 74 is connected to a portion corresponding to the inclined surface facing the concave region 50 of the objective lens 40. In this figure, the contact surface where the upper mold and the lower mold constituting the mold 70 are in contact is indicated by a dotted line. This contact surface may be disposed at the lower end of the inclined surface 46 or may be disposed in the middle of the inclined surface 46.

  FIG. 6C partially shows the objective lens 40 taken out from the mold 70. As shown in this figure, each objective lens 40 is connected by a runner portion 76 made of a resin material filled in the runner 74.

  In order to separate each objective lens 40, it is necessary to cut the runner portion 76 and the objective lens 40. In a normal lens molding method, both are cut and separated at the boundary between the runner portion 76 and the objective lens 40. In this embodiment, the runner portion 76 is cut at an intermediate portion. In the drawing, a portion where the runner portion 76 is cut is indicated by a dotted line, and is located inside the end of the flange portion 44, that is, inside the concave region 50.

  If this cutting location is provided at the boundary between the objective lens 40 and the runner portion 76, an aberration occurs in the objective lens 40 due to the stress caused by the cutting, and the reading accuracy and writing accuracy may be deteriorated. Further, if the cut portion is arranged outside the outer edge end portion of the flange portion 44, the problem of aberration deterioration is alleviated, but the remaining portion of the runner portion 76 protrudes outward as a protruding portion, and it is used under use conditions or in the manufacturing process. Therefore, there is a possibility that the protruding portion collides with another member. Therefore, in this embodiment, the cut portion of the runner portion 76 is set so that the remaining portion of the runner portion 76 is disposed inside the outer peripheral edge portion of the flange portion 44. Thereby, the remaining part of the runner part 76 becomes a part of the objective lens 40 as the protruding part 52 shown in FIG.

  In addition, FIG. 6D may be employed, and a plurality of cavities 72 may be connected through the runner 74 inside the mold 70. Thereby, the runner portions 76 shown in FIG. 6C are formed on both sides of the objective lens 40, and the protruding portions 52 shown in FIG. 3B are formed on both sides. Furthermore, a concave region 50 shown in FIG. 6C may be provided at the opposite end of the objective lens 40, and a runner portion 76 may be formed inside the concave region 50.

  Since the objective lens is formed by a molding method using a mold such as transfer molding or injection, a gate is always present. Although this gate varies depending on the designer, it is somewhere on the plastic lens, and there is a gate residue when it is removed from the mold.

  Since the lens is plastic and has a property of being easily scratched, the lens cannot be rolled and removed like a deburring machine, and is generally removed manually by a human.

  However, in the structure of this embodiment, the burr may be left as it is as long as it does not protrude from the outer end portion between the inclined surfaces. An anchor can be obtained by attaching an adhesive to the protrusion and fixing it.

  On the other hand, in the case where it is taken manually, the work is performed so as not to leave it with as high accuracy as possible, but the present invention may be rough to some extent. After all, these operations may be rougher than before, and there is an advantage that the operation time can be reduced and the operator's fatigue can be reduced and the operation efficiency can be increased.

  As shown in FIG. 4, the objective lens 40 manufactured by the above process is mounted on a predetermined portion of the lens holder 32 and then fixed to the lens holder by applying a fixing material 60. Further, the optical pickup device 10 is manufactured by housing the lens holder 32 including the objective lens 40 in the housing 12 together with the other optical elements shown in FIG.

DESCRIPTION OF SYMBOLS 10 Optical pick-up apparatus 12 Housing 14 Laser unit 16 Diffraction grating 18 Photo detector 22 Half mirror 24 1/4 wavelength plate 26 Collimator lens 28 Objective lens drive device 32 Lens holder 34 Engagement part 36 Insertion part 38 Disc 40 Objective lens 42 Lens Portion 44 Flange portion 45 First main surface 46 Inclined surface 46A Inclined surface 47 Second main surface 48 Stepped portion 50 Concave region 52 Projection portion 54 Coil 56 Tying portion 58 Protection portion 60 Adhering material 62 Gonior surface 64 Opening portion 66 Groove 70 Mold 72 Cavity 74 Runner 76 Runner part

Claims (6)

An objective lens for condensing laser light on the information recording layer of the optical disc, and a lens holder to which the objective lens is fixed,
The objective lens has a lens part through which laser light is transmitted, and a flange part surrounding the lens part,
An optical pickup device, wherein an end portion of a projecting portion projecting laterally from a side surface of the flange portion is disposed inside an outer peripheral end portion of an upper end or a lower end of the flange portion.   A portion of the flange portion is recessed inward to provide a concave region, the protruding portion protrudes laterally from a side surface of the flange of the concave region, and an end portion of the protruding portion faces the concave region. The optical pickup device according to claim 1, wherein the optical pickup device is disposed inside an upper end portion or a lower end portion of the portion.   2. The objective lens according to claim 1, wherein the objective lens is molded by filling a cavity of a molding die with a resin via a runner, and the protrusion is made of a part of the resin cured by the runner. Item 3. The optical pickup device according to Item 2.   4. The optical pickup device according to claim 2, wherein the concave region is formed in a stepped shape.   The flange portion has a first main surface and a second main surface facing the first main surface, and an end of the projecting portion is an outer peripheral end of the first main surface or the second main surface. 5. The optical pickup device according to claim 1, wherein the optical pickup device is disposed on an inner side of the optical pickup device. A molding die having a cavity conforming to the objective lens having a lens portion through which laser light is transmitted and a flange portion surrounding the lens portion is prepared, and a runner is passed through the runner to the cavity of the molding die. Injecting resin
Removing the objective lens made of the resin hardened in the cavity and the runner part integrally made of the resin hardened by the runner from the side surface of the flange part from the molding die;
Cutting the runner part, leaving a part of the runner part continuous from the side of the flange part as a protruding part, and
In the step of cutting the runner portion, the cutting is performed so that an end portion of the protruding portion is disposed inside an outer peripheral end portion of an upper end or a lower end of the flange portion. Manufacturing method.

Images