WO2011122106A1 - Moule, machine à mouler par injection et procédé de fabrication d'un élément optique d'objectif - Google Patents

Moule, machine à mouler par injection et procédé de fabrication d'un élément optique d'objectif Download PDF

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Publication number
WO2011122106A1
WO2011122106A1 PCT/JP2011/052486 JP2011052486W WO2011122106A1 WO 2011122106 A1 WO2011122106 A1 WO 2011122106A1 JP 2011052486 W JP2011052486 W JP 2011052486W WO 2011122106 A1 WO2011122106 A1 WO 2011122106A1
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WO
WIPO (PCT)
Prior art keywords
optical
optical element
core
template
objective
Prior art date
Application number
PCT/JP2011/052486
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English (en)
Japanese (ja)
Inventor
清水　勉
鈴木　洋介
Original Assignee
コニカミノルタオプト株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Publication date
Application filed by コニカミノルタオプト株式会社 filed Critical コニカミノルタオプト株式会社
Priority to JP2012508126A priority Critical patent/JP5765333B2/ja
Priority to CN2011800171495A priority patent/CN102834240A/zh
Publication of WO2011122106A1 publication Critical patent/WO2011122106A1/fr

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17—Component parts, details or accessories; Auxiliary operations
    • B29C45/26—Moulds
    • B29C45/37—Mould cavity walls, i.e. the inner surface forming the mould cavity, e.g. linings
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
    • B29D11/00—Producing optical elements, e.g. lenses or prisms
    • B29D11/00009—Production of simple or compound lenses
    • B29D11/0048—Moulds for lenses
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
    • G11B7/1372—Lenses
    • G11B7/1374—Objective lenses
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G11B7/22—Apparatus or processes for the manufacture of optical heads, e.g. assembly
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17—Component parts, details or accessories; Auxiliary operations
    • B29C45/26—Moulds
    • B29C45/2673—Moulds with exchangeable mould parts, e.g. cassette moulds
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
    • B29L2011/00—Optical elements, e.g. lenses, prisms

Definitions

  • the present invention relates to a molding die, an injection molding machine, and a method for manufacturing an objective optical element.
  • the core forms a core (first molding surface) of the molded product. 2 core) and a core (first core) that forms other than the main molding surface disposed on the outer periphery of the second core.
  • the core provided with this divided structure is mounted in the template, but in this case, not only between the first core and the template, but also the first core and the second core. Clearance is also generated between the cores.
  • the shift is a displacement in a direction perpendicular to the ideal optical axis of the mold, and the tilt is a tilt with respect to the ideal optical axis.
  • Such a tilt or shift causes misalignment of the two optical functional surfaces constituting the lens. This misalignment becomes a cause of coma aberration that causes deterioration of optical characteristics.
  • a high-recording capacity disc such as a Blu-ray disc (BD) using a blue-violet laser near 400 nm and an objective lens having an NA value of about 0.85, and an optical pickup using the disc.
  • the device has also been put into practical use.
  • An objective lens used for recording or reproducing on a high recording capacity disk using such a blue-violet laser is required to have a higher NA value than an objective lens corresponding to a CD or DVD.
  • the amount of occurrence of coma due to misalignment increases as the NA value increases, and in addition, the allowable range of coma in the objective lens for BD is narrower than that in the objective lens for CD and DVD. Therefore, it is necessary to reduce the occurrence of coma aberration due to lens misalignment, particularly when forming an objective lens for BD.
  • Patent Document 1 when a split structure is provided in the core, the number of parts increases. Therefore, it takes time to assemble the core and adjust the molding die, resulting in a problem that workability deteriorates.
  • An object of the present invention is to provide a molding die, an injection molding machine, and a method for manufacturing an objective optical element that reduce the occurrence of coma aberration due to lens misalignment and have good workability.
  • the molding die according to claim 1 is a molding die for injection molding for manufacturing an objective optical element for an optical pickup device having an NA value of 0.70 or more and 0.95 or less.
  • a first template, a first core, a second template, and a second core wherein the first template has a first core support hole for mounting the first core; Has a second core support hole for mounting the second core, and the second template is disposed so as to overlap the vertical direction of the gravitational direction with respect to the first template.
  • One core has a first optical transfer surface for forming a first optical surface of the objective optical element, and the objective optical element is opened when the first template and the second template are opened.
  • the second core has a second optical transfer surface for forming a second optical surface of the objective optical element, the first template and the second
  • the objective optical element is not held when the plate is opened, and the absolute value of the radius of curvature of the first optical transfer surface is smaller than the absolute value of the radius of curvature of the second optical transfer surface.
  • the first template has a first core support hole for mounting the first core
  • the second template has a second core support hole for mounting the second core.
  • the second template is arranged so as to overlap the vertical direction of the gravity direction with respect to the first template. Accordingly, the first mold plate and the second mold plate are uniformly subjected to gravity, and the parallelism between the first mold plate and the second mold plate can be obtained. Therefore, it is possible to obtain parallelism between the first core and the second core mounted on each template, to reduce misalignment, and to reduce occurrence of coma aberration. Become.
  • the core mounted on the stencil above the gravitational direction is urged downward according to gravity.
  • the operator looks into the underside of the template and carefully supports the core with one hand to avoid damage from dropping, while using the other hand to fix the core to the template or other member. It is necessary to tighten the bolt. Therefore, when the core has a configuration that requires assembly such as a split structure, there is a possibility that the workability of mounting the core on the template further deteriorates. Further, when a transfer surface such as an objective optical element is formed on the core, the transfer surface may be contaminated by an operator's inadvertent touch, which requires additional work such as cleaning. Regarding such a problem, when a split structure is provided in the core, it is necessary to assemble the core, and there is a high possibility that the transfer surface may be touched during the assembly, resulting in further deterioration in workability. It is done.
  • the core is directly mounted on the template without providing a split structure, the two templates are stacked vertically in the direction of gravity. Even in the case of disposing, the workability can be improved.
  • compression molding is one of the methods for molding a lens.
  • a metered material is put between two mold plates heated to a predetermined temperature, and when the material becomes fluid, molding is performed by closing and pressurizing the two mold plates.
  • the two mold plates are tightened while crushing the material, so that there is a problem that misalignment is likely to occur.
  • molding is performed by injection molding, and the resin as the material is charged in a state where the two template plates are clamped, that is, in a state where the cores of the core are aligned in advance.
  • thermoplastic resin when molded by injection molding, the production efficiency can be improved compared to the case of compression molding, and mass production is possible.
  • misalignment can be reduced, and the occurrence of coma aberration can be reduced.
  • even when molding a BD objective lens that is prone to misalignment due to a large NA value and has a narrow tolerance for coma compared to an objective lens for CD or DVD It becomes possible to mold an objective lens having characteristics.
  • the second mold plate is disposed so as to overlap the first mold plate in the vertical direction of the gravity direction. It may be arranged on the upper side in the direction, or the second template may be arranged on the lower side in the direction of gravity with respect to the first template. Moreover, it is preferable that the template is attached to members such as a mounting plate and a receiving plate that are arranged either above or below the gravity direction of the template. Furthermore, it is preferable that the template has at least two core support holes for mounting the core.
  • the molding die according to claim 2 is characterized in that, in the molding die according to claim 1, the second template is arranged on the upper side in the direction of gravity with respect to the first template. To do.
  • the second template is disposed on the upper side in the direction of gravity with respect to the first template, that is, the first optical transfer surface having the smaller absolute value of the radius of curvature. Is arranged on the lower side in the direction of gravity.
  • the first optical transfer surface has a fine step shape such as a diffractive structure
  • the molten resin is caused by its own weight during molding. Since it enters into the fine step shape forming the diffractive structure, it becomes possible to eliminate air accumulation and improve transferability.
  • the molding die according to claim 3 is the molding die according to claim 1 or 2, wherein at least a part of the first optical transfer surface has an optical path difference providing structure including a plurality of steps. It is characterized by.
  • At least a part of the first optical transfer surface has an optical path difference providing structure consisting of a plurality of steps, that is, at least a part of the optical surface of the objective optical element to be molded has an optical path difference providing structure consisting of a plurality of steps.
  • the present invention since it is possible to reduce the misalignment of the optical surface of the lens, even if the optical surface has an optical path difference providing structure, an objective optical element that can obtain good optical characteristics is molded. It becomes possible to do.
  • the optical path difference providing structure is a general term for structures that give an optical path difference to an incident light beam.
  • the optical path difference providing structure also includes a phase difference providing structure for providing a phase difference.
  • the phase difference providing structure includes a diffractive structure.
  • the optical path difference providing structure of the present invention is preferably a diffractive structure.
  • the optical path difference providing structure has a step, preferably a plurality of steps. This step adds an optical path difference and / or phase difference to the incident light flux.
  • the molding die according to claim 4 is the molding die according to any one of claims 1 to 3, wherein the objective optical element is a first light beam having a wavelength ⁇ 1 (375 nm ⁇ ⁇ 1 ⁇ 435 nm). Is condensed on the information recording surface of the first optical disk having the protective layer having the thickness t1, and the second optical disk having the protective layer having the thickness t2 (t1 ⁇ t2) is irradiated with the second light beam having the wavelength ⁇ 2 ( ⁇ 1 ⁇ 2).
  • An objective optical element for an optical pickup device that records and / or reproduces information by condensing on the information recording surface, and the objective optical element is provided in a central region including the optical axis and in the periphery thereof.
  • the first luminous flux that has passed through the central area is condensed so that information can be recorded and / or reproduced on the information recording surface of the first optical disk, and passes through the central area.
  • the second luminous flux is The first light flux that has been focused on the information recording surface of the second optical disc so that information can be recorded and / or reproduced and passed through the peripheral area is recorded and / or recorded on the information recording surface of the first optical disc.
  • the second light flux that has been condensed so that it can be reproduced and has passed through the peripheral region is not condensed so that information can be recorded and / or reproduced on the information recording surface of the second optical disc. .
  • an incompatible dedicated objective that records and / or reproduces information on only one type of optical disc.
  • the misalignment of the optical surface of the lens can be reduced.
  • an objective optical element that records and / or reproduces information can be molded with good optical characteristics.
  • the molding die according to claim 5 is the molding die according to any one of claims 1 to 3, wherein the objective optical element is a first light beam having a wavelength ⁇ 1 (375 nm ⁇ ⁇ 1 ⁇ 435 nm). Is condensed on the information recording surface of the first optical disk having the protective layer having the thickness t1, and the second optical disk having the protective layer having the thickness t2 (t1 ⁇ t2) is irradiated with the second light beam having the wavelength ⁇ 2 ( ⁇ 1 ⁇ 2). Information is collected on the information recording surface, and the third light beam having the wavelength ⁇ 3 ( ⁇ 2 ⁇ 3) is condensed on the information recording surface of the third optical disc having the protective layer having the thickness t3 (t2 ⁇ t3).
  • the objective optical element is a first light beam having a wavelength ⁇ 1 (375 nm ⁇ ⁇ 1 ⁇ 435 nm). Is condensed on the information recording surface of the first optical disk having the protective layer having the thickness t1, and the second optical disk having the
  • An objective optical element for an optical pickup that performs recording and / or reproduction of the optical pickup, and the objective optical element includes a central region including an optical axis, a peripheral region provided around the central region, and the central region and the peripheral region. And at least an intermediate region provided therebetween
  • the first light flux that has passed through the central area is condensed so that information can be recorded and / or reproduced on the information recording surface of the first optical disc
  • the second light flux that has passed through the central area is (2)
  • the third light flux that has been focused on the information recording surface of the optical disc so that information can be recorded and / or reproduced, and has passed through the central area, is recorded and / or information on the information recording surface of the third optical disc.
  • the first light flux that has been condensed so that it can be reproduced and passed through the intermediate area is condensed so that information can be recorded and / or reproduced on the information recording surface of the first optical disc, and then passed through the intermediate area.
  • the second luminous flux is focused on the information recording surface of the second optical disc so that information can be recorded and / or reproduced
  • the third luminous flux that has passed through the intermediate region is the information recording surface of the third optical disc.
  • the first light flux that has not been condensed so as to be able to be recorded and / or reproduced and has passed through the peripheral area is condensed on the information recording surface of the first optical disc
  • the second light flux that has passed through the peripheral area is
  • the third light flux that has not been condensed on the information recording surface of the second optical disc and has passed through the peripheral area is not condensed on the information recording surface of the third optical disc.
  • the objective optical element that records and / or reproduces information on at least three types of optical disks the objective optical element that records and / or reproduces information only on one or two kinds of optical disks.
  • an objective optical element that records and / or reproduces information can be molded with good optical characteristics.
  • the molding die according to claim 6 is the molding die according to claim 4 or 5, wherein the focal length of the first optical flux of the objective optical element is f1 (mm), and When the center thickness is d (mm), 0.7 ⁇ d / f1 ⁇ 2.0 is satisfied.
  • the molding die according to claim 7 is the molding die according to any one of claims 1 to 3, which is an objective optical element for an optical pickup device, and has a wavelength ⁇ 1 (375 nm ⁇ ⁇ 1 ⁇ An optical pickup device that records and / or reproduces information only with respect to the first optical disc by condensing the first light beam of 435 nm) on the information recording surface of the first optical disc having the protective layer with thickness t1. It is an objective optical element for use.
  • an objective optical element corresponding to an optical disk with a short wavelength and a high NA for example, an objective optical element for BD
  • the present invention since it is possible to reduce the misalignment of the optical surface of the lens, even such an objective optical element corresponding to an optical disk with a short wavelength and a high NA can be molded with good optical characteristics. It becomes.
  • the molding die according to claim 8 is the molding die according to claim 7, wherein the focal length of the first optical flux of the objective optical element is f1 (mm), and the center thickness of the objective optical element is When d (mm), 0.9 ⁇ d / f1 ⁇ 2.0 is satisfied.
  • the first optical disc has a protective substrate having a thickness t1 and an information recording surface
  • the second optical disc has a protective substrate having a thickness 2 (t1 ⁇ t2) and an information recording surface.
  • the third optical disc has a protective substrate having a thickness t3 (t2 ⁇ t3) and an information recording surface.
  • the first optical disc is preferably a BD (Blu-ray Disc)
  • the second optical disc is preferably a DVD
  • the third optical disc is preferably a CD, but is not limited thereto.
  • the first optical disc, the second optical disc, or the third optical disc may be a multi-layer optical disc having a plurality of information recording surfaces.
  • the thickness of the protective substrate includes the case of 0, and when the protective film having a thickness of several to several tens of ⁇ m is applied to the optical disk, the thickness thereof is also included.
  • DVD is a general term for DVD series optical discs in which information is recorded / reproduced by an objective optical element having an NA of about 0.60 to 0.67, and a protective substrate has a thickness of about 0.6 mm.
  • ROM, DVD-Video, DVD-Audio, DVD-RAM, DVD-R, DVD-RW, DVD + R, DVD + RW and the like are included.
  • a CD is a CD series optical disc in which information is recorded / reproduced by an objective optical element having an NA of about 0.45 to 0.53 and the thickness of the protective substrate is about 1.2 mm. It is a generic term and includes CD-ROM, CD-Audio, CD-Video, CD-R, CD-RW and the like.
  • the recording density the recording density of BD is the highest, followed by the order of DVD and CD.
  • the thickness of the protective substrate referred to here is the thickness of the protective substrate provided on the surface of the optical disk. That is, the thickness of the protective substrate from the optical disc surface to the information recording surface closest to the surface.
  • the first light source, the second light source, and the third light source are preferably laser light sources.
  • the laser light source a semiconductor laser, a silicon laser, or the like can be preferably used.
  • the wavelength ⁇ 3 ( ⁇ 3> ⁇ 2) preferably satisfies the following conditional expressions (4) and (5).
  • the first wavelength ⁇ 1 of the first light source is preferably 375 nm or more and 435 nm or less, more preferably 390 nm.
  • the second wavelength ⁇ 2 of the second light source is preferably 570 nm or more and 680 nm or less, more preferably 630 nm or more and 680 nm or less, and the third wavelength ⁇ 3 of the third light source is preferably 750 nm.
  • the thickness is 850 nm or less, more preferably 760 nm or more and 820 nm or less.
  • the injection molding machine according to claim 9 has the molding die according to any one of claims 1 to 8.
  • lens misalignment can be reduced, occurrence of coma aberration can be reduced, and an injection molding machine with excellent workability can be provided.
  • an objective optical element for an optical pickup device having an NA value of 0.70 or more and 0.95 or less is manufactured using a molding die.
  • a first template, a first core, a second template, and a second core wherein the first template has a first core support hole for mounting the first core, and the second template
  • the template has a second core support hole for mounting the second core, and the second template is arranged so as to overlap in the vertical direction of the gravitational direction with respect to the first template.
  • the first core has a first optical transfer surface for forming a first optical surface of the objective optical element
  • the second core is a first optical surface for forming a second optical surface of the objective optical element.
  • the absolute value of the radius of curvature of the first optical transfer surface is the absolute value of the radius of curvature of the second optical transfer surface.
  • the objective optical element includes a step of holding the objective optical element by the first core, and a step of releasing the objective optical element from the first core holding the objective optical element in a mold open state.
  • this manufacturing method it is possible to reduce the misalignment of the lens and to reduce the occurrence of coma. For this reason, even when forming an objective lens used in an optical pickup apparatus in which the occurrence of coma aberration due to lens misalignment is a particular problem, it is possible to mold an objective lens that provides good optical characteristics. Furthermore, even when molding a BD objective lens that is prone to misalignment due to a large NA value and has a narrow tolerance range for coma compared with a CD or DVD objective lens, good optical performance can be obtained. It becomes possible to mold an objective lens having characteristics.
  • the present invention it is possible to reduce the misalignment of the lens and to reduce the occurrence of coma. For this reason, even when forming an objective lens used in an optical pickup apparatus in which the occurrence of coma aberration due to lens misalignment is a particular problem, it is possible to mold an objective lens that provides good optical characteristics. In particular, even when molding a BD objective lens that is prone to misalignment due to a large NA value and has a narrow tolerance for coma compared to an objective lens for CD or DVD It becomes possible to mold an objective lens having characteristics. Furthermore, according to the present invention, it is possible to improve workability during molding and improve production efficiency.
  • FIG. 1 is a schematic cross-sectional view showing an example of a molding die according to the present embodiment. This figure shows a molding die for a resin lens.
  • the molding die according to this embodiment is a molding die for injection molding for manufacturing an objective optical element for an optical pickup device having an NA value of 0.70 or more and 0.95 or less. As shown in FIG. 1, the molding die has a first template 5, a first core 7, a second template 6, and a second core 8.
  • the first template 5 has a first core support hole 18 for mounting the first core 7, and the second template 6 has a second core support hole 19 for mounting the second core 8. is doing. As shown in FIG. 1, the first core support holes 18 and the second core support holes 19 are arranged in the same straight line. Further, the second template 6 is disposed so as to overlap the first template 5 in the vertical direction of the gravity direction. In the present embodiment, the second template 6 is arranged on the upper side in the gravity direction with respect to the first template 5.
  • the molding die has a first receiving plate 3 and a second receiving plate 4.
  • a first receiving plate 3 is attached to the first mounting plate 1, and a first template 5 is attached to the first receiving plate 3.
  • a second receiving plate 4 is attached to the second mounting plate 2, and a second template 6 is attached to the second receiving plate 4.
  • the 1st template 5 and the 2nd template 6 can be opened and closed by the parting line PL.
  • the first core 7 has a first optical transfer surface 9 for forming the first optical surface of the objective optical element, and the second core 8 is a second optical surface for forming the second optical surface of the objective optical element.
  • An optical transfer surface 10 is provided.
  • the first optical transfer surface 9 and the second optical transfer surface 10 form an optical functional surface of the objective optical element.
  • the first core 7 has a first flange forming surface 11 for forming the flange portion of the objective optical element, and the second core is a second flange forming surface for forming the flange portion of the objective optical element. 12.
  • the absolute value of the radius of curvature of the first optical transfer surface 9 is smaller than the absolute value of the radius of curvature of the second optical transfer surface 10.
  • the first optical transfer surface 9 has an optical path difference providing structure (not shown) composed of a plurality of steps.
  • the optical path difference providing structure provided on the first optical transfer surface 9 is a diffractive structure including a plurality of steps.
  • the first optical transfer surface 9 can also be constituted by a refractive surface that does not have an optical path difference providing structure.
  • a cavity 13 is a molding space in which an objective optical element is formed.
  • the cavity 13 includes a first optical transfer surface 9 and a first flange forming surface 11 provided on the first core 7, and a second optical transfer surface 10 and a second flange forming surface 12 provided on the second core 8. And a molding space formed by the first core support hole 18 of the first template 5.
  • the first flange forming surface 11 and the second flange forming surface 12 are surfaces for forming a flange portion of the objective optical element.
  • the flow path 14 communicates with a mold temperature controller (not shown), a heat medium supplied from the mold temperature controller is circulated through the flow path 14, and the temperature of the first mold plate 5 and the second mold plate 6. Is adjusted.
  • a water temperature controller using water as a heat medium is used as the mold temperature controller.
  • An oil temperature controller that uses oil as the heat medium can also be used.
  • the water temperature controller is more preferable than the oil temperature controller because it can shorten the time required for temperature increase and decrease.
  • the resin melted by the injection device (not shown) is injected and filled into the cavity 13 through the sprue 15, the runner 16, and the gate 17, and is cooled and solidified.
  • the flange of the objective optical element and the gate are integrally formed, and the gate portion is cut in a later gate cutting step.
  • the first template 5 and the second template 6 are opened.
  • the objective optical element as a molded product is held by the first core 7 and is not held by the second core 8.
  • the objective optical element as a molded product is released from the first core 7 holding the objective optical element.
  • the objective optical element which is a molded product is held by the first core 7, that is, the objective optical element which is the molded product is arranged on the lower side in the gravity direction. Remains on 5. For this reason, even if the objective optical element is released from the first core, the objective optical element remains on the first mold plate, so that the objective optical element falls during the release and damages the lens surface. There is no danger of it.
  • the first core 7 is slidable in the first core support hole 18, and the objective optical element is projected and separated by sliding the first core 7 toward the second template 6 side. I'm typing.
  • the first optical transfer surface 9 formed on the first core 7 has an optical path difference providing structure composed of a plurality of steps, the first core 7 is slid toward the second template 6 side.
  • the optical path difference providing structure between the first optical transfer surface 9 of the first core 7 and the objective optical element is possible to manufacture an objective optical element having an optical path difference providing structure that can obtain desired optical characteristics with higher accuracy.
  • an ejector mechanism such as an ejector pin is provided on the first core 7 or the first template 5, and the flange part of the objective optical element is The mold may be released by protruding the first optical surface of the objective optical element.
  • the flange portion of the objective optical element is protruded, it is more preferable because there is no fear of deforming the optical path difference providing structure formed on the objective optical element by the protrusion.
  • An objective optical element for an optical pickup device that has at least a central region including an optical axis and a peripheral region provided around the optical region, and a first light flux that has passed through the central region is an information recording surface of the first optical disc
  • the second light flux that passes through the central region is condensed so that information can be recorded and / or reproduced on the information recording surface of the second optical disc.
  • Surrounding area The first luminous flux that has passed is condensed on the information recording surface of the first optical disc so that information can be recorded and / or reproduced, and the second luminous flux that has passed through the peripheral area is recorded on the information recording surface of the second optical disc.
  • An optical path difference providing structure is formed in at least one of the central region and the peripheral region.
  • the focal length of the objective optical element in the first light flux is f1 (mm), and the center thickness of the objective optical element is d (mm).
  • d / f1 1.1, and 0.7 ⁇ d / f1 ⁇ 2.0 is satisfied.
  • the second template is disposed on the upper side in the gravity direction with respect to the first template, that is, the first optical transfer surface having the smaller absolute value of the radius of curvature is located on the lower side in the gravity direction. It is the composition arranged in. Therefore, even when an objective optical element having a d / f1 value of 0.7 ⁇ d / f1 ⁇ 2.0 is manufactured, air accumulation can be eliminated and transferability can be improved.
  • the first light flux that is an element and has at least a central region including the optical axis, a peripheral region provided around the central region, and an intermediate region provided between the central region and the peripheral region.
  • 1st optical display So that information can be recorded and / or reproduced on the information recording surface, and the second light flux that has passed through the central region can be recorded and / or reproduced on the information recording surface of the second optical disc.
  • the third light flux that has been condensed and passed through the central region is condensed so that information can be recorded and / or reproduced on the information recording surface of the third optical disc, and the first light flux that has passed through the intermediate region is reflected on the first optical disc.
  • the second light flux that has been condensed so that information can be recorded and / or reproduced on the information recording surface and has passed through the intermediate area is collected so that information can be recorded and / or reproduced on the information recording surface of the second optical disc.
  • the third light beam that has passed through the intermediate area is not condensed so that information can be recorded and / or reproduced on the information recording surface of the third optical disk, and the first light beam that has passed through the peripheral area is not collected on the first optical disk. Focused on the information recording surface,
  • the second light flux that has passed through the side area is not condensed on the information recording surface of the second optical disk, and the third light flux that has passed through the peripheral area is not condensed on the information recording surface of the third optical disk. It may be an optical element.
  • the present invention can provide a molding die, an injection molding machine, and an objective optical element manufacturing method that can reduce the occurrence of coma due to lens misalignment and can easily adjust the molding die. Therefore, it is possible to provide an objective optical element for an optical pickup device that can obtain good optical characteristics with high molding accuracy.
  • SYMBOLS 1 1st mounting plate 2 2nd mounting plate 3 1st receiving plate 4 2nd receiving plate 5 1st type plate 6 2nd type plate 7 1st core 8 2nd core 9 1st optical transfer surface 10 2nd optical transfer surface DESCRIPTION OF SYMBOLS 11 1st flange formation surface 12 2nd flange formation surface 13 Cavity 14 Flow path 15 Sprue 16 Runner 17 Gate 18 1st core support hole 19 2nd core support hole

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  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Health & Medical Sciences (AREA)
  • Ophthalmology & Optometry (AREA)
  • Optical Head (AREA)
  • Moulds For Moulding Plastics Or The Like (AREA)

Abstract

L'invention porte sur un moule, sur une machine à mouler par injection et sur un procédé de fabrication d'un élément optique d'objectif qui réduisent l'aberration de coma due à un déplacement de l'axe de la lentille et assurent une haute capacité de travail et un haut rendement de production. L'invention porte spécialement sur un moule d'injection destiné à la fabrication d'un élément optique d'objectif pour un dispositif de capture optique ayant une valeur ouverture numérique NA de 0,70-0,95, ledit moule comprenant une première plaque de moule, un premier noyau, une deuxième plaque de moule et un deuxième noyau, la première plaque de moule présentant un premier trou de support de noyau et la deuxième plaque de moule présentant un deuxième trou de support de noyau, la deuxième plaque de moule étant empilée sur le dessus de la première plaque de moule dans la direction de la force de gravité, le premier noyau possédant une première surface de transfert optique destinée à former une première surface optique de l'élément optique d'objectif et tenant l'élément optique d'objectif lorsque le moule est ouvert, le deuxième noyau possédant une deuxième surface de transfert optique destinée à former une deuxième surface optique de l'élément optique d'objectif et ne tenant pas l'élément optique d'objectif lorsque le moule est ouvert, et la valeur absolue du rayon de courbure de la première surface de transfert optique étant plus petite que la valeur absolue du rayon de courbure de la deuxième surface de transfert optique.
PCT/JP2011/052486 2010-03-31 2011-02-07 Moule, machine à mouler par injection et procédé de fabrication d'un élément optique d'objectif WO2011122106A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP2012508126A JP5765333B2 (ja) 2010-03-31 2011-02-07 成形金型、射出成形機及び対物光学素子の製造方法
CN2011800171495A CN102834240A (zh) 2010-03-31 2011-02-07 成型模具、注射成型机以及物镜光学元件的制造方法

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2010080831 2010-03-31
JP2010-080831 2010-03-31

Publications (1)

Publication Number Publication Date
WO2011122106A1 true WO2011122106A1 (fr) 2011-10-06

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PCT/JP2011/052486 WO2011122106A1 (fr) 2010-03-31 2011-02-07 Moule, machine à mouler par injection et procédé de fabrication d'un élément optique d'objectif

Country Status (3)

Country Link
JP (1) JP5765333B2 (fr)
CN (1) CN102834240A (fr)
WO (1) WO2011122106A1 (fr)

Citations (2)

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Publication number Priority date Publication date Assignee Title
JP2008234724A (ja) * 2007-03-19 2008-10-02 Konica Minolta Opto Inc 複合対物レンズ成形金型、複合対物レンズ、及び光ピックアップ装置
JP2009181645A (ja) * 2008-01-31 2009-08-13 Konica Minolta Opto Inc 対物光学素子及び光ピックアップ装置

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JPH0768614A (ja) * 1993-09-03 1995-03-14 Olympus Optical Co Ltd 光学素子の射出成形金型および射出成形方法
JP3477249B2 (ja) * 1994-08-12 2003-12-10 ファナック株式会社 竪・竪形の射出成形機
JP2006343387A (ja) * 2005-06-07 2006-12-21 Konica Minolta Opto Inc 光学素子及びその製造方法
KR101377787B1 (ko) * 2006-08-30 2014-03-25 코니카 미놀타 어드밴스드 레이어즈 인코포레이티드 광학 소자 성형 장치
CN101529300B (zh) * 2006-11-01 2011-01-19 柯尼卡美能达精密光学株式会社 光学元件、树脂成型用模具及光学元件制造方法
JP2008230125A (ja) * 2007-03-22 2008-10-02 Konica Minolta Opto Inc 射出成形装置及び成形方法
WO2009122862A1 (fr) * 2008-03-31 2009-10-08 コニカミノルタオプト株式会社 Procédé de fabrication d'élément optique, matrice de moulage d'élément optique et élément optique

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008234724A (ja) * 2007-03-19 2008-10-02 Konica Minolta Opto Inc 複合対物レンズ成形金型、複合対物レンズ、及び光ピックアップ装置
JP2009181645A (ja) * 2008-01-31 2009-08-13 Konica Minolta Opto Inc 対物光学素子及び光ピックアップ装置

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