U.S. patent application number 10/685520 was filed with the patent office on 2004-04-29 for optical pickup lens, molded optical component, handling method, and mold for optical component.
This patent application is currently assigned to Konica Corporation. Invention is credited to Arai, Norikazu, Atarashi, Yuichi, Hattori, Hiroyuki, Ishida, Kazuo, Kurihara, Etsuzo, Matsumaru, Takashi, Saito, Shinichiro, Saito, Taichiro, Yamamoto, Shogo.
Application Number | 20040081060 10/685520 |
Document ID | / |
Family ID | 26619944 |
Filed Date | 2004-04-29 |
United States Patent
Application |
20040081060 |
Kind Code |
A1 |
Yamamoto, Shogo ; et
al. |
April 29, 2004 |
Optical pickup lens, molded optical component, handling method, and
mold for optical component
Abstract
An objective lens for use in an optical pickup apparatus for
conducting recording and/or reproducing information for an optical
information recording medium, has a lens section shaped in an
approximate circle and including a flange section; and a connecting
section integrally provided to the lens section. The objective lens
satisfies the following conditional formulas:
0.5.ltoreq.A.ltoreq.2.0, 0.3A.ltoreq.B.ltoreq.1.7A where A is a
diameter of the lens section when the lens section is viewed from
an direction of an optical axis, and B is a width of the connecting
section when the connecting section is viewed from the direction of
the optical axis.
Inventors: |
Yamamoto, Shogo; (Tokyo,
JP) ; Hattori, Hiroyuki; (Tokyo, JP) ;
Kurihara, Etsuzo; (Tokyo, JP) ; Saito,
Shinichiro; (Tokyo, JP) ; Matsumaru, Takashi;
(Tokyo, JP) ; Saito, Taichiro; (Tokyo, JP)
; Ishida, Kazuo; (Tokyo, JP) ; Atarashi,
Yuichi; (Tokyo, JP) ; Arai, Norikazu; (Tokyo,
JP) |
Correspondence
Address: |
FINNEGAN, HENDERSON, FARABOW, GARRETT & DUNNER
LLP
1300 I STREET, NW
WASHINGTON
DC
20005
US
|
Assignee: |
Konica Corporation
|
Family ID: |
26619944 |
Appl. No.: |
10/685520 |
Filed: |
October 16, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10685520 |
Oct 16, 2003 |
|
|
|
10206187 |
Jul 29, 2002 |
|
|
|
Current U.S.
Class: |
369/112.23 ;
G9B/7.121 |
Current CPC
Class: |
C03B 2215/49 20130101;
G11B 7/22 20130101; G11B 7/1374 20130101; B29D 11/00432 20130101;
C03B 2215/404 20130101; C03B 11/08 20130101; G02B 3/04 20130101;
B29D 11/00009 20130101; G11B 11/10543 20130101; B29L 2011/0016
20130101; Y02P 40/57 20151101; B29C 45/27 20130101 |
Class at
Publication: |
369/112.23 |
International
Class: |
G11B 007/135 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 3, 2001 |
JP |
2001-236797 |
Sep 14, 2001 |
JP |
2001-279636 |
Claims
What is claimed is:
1. An objective lens for use in an optical pickup apparatus for
conducting recording and/or reproducing information for an optical
information recording medium, comprising: a lens section shaped in
an approximate circle and including a flange section; and a
connecting section integrally provided to the lens section; wherein
the following conditional formulas are satisfied:
0.5.ltoreq.A.ltoreq.2.0 0.3A.ltoreq.B.ltoreq.1.7A where A is a
diameter of the lens section when the lens section is viewed from
an direction of an optical axis, and B is a width of the connecting
section when the connecting section is viewed from the direction of
the optical axis.
2. The objective lens of claim 1, wherein the connecting section is
extended from the lens section in a direction substantially
perpendicular to the optical axis.
3. The objective lens of claim 2, wherein the following conditional
formulas are satisfied: 0.3A.ltoreq.B.ltoreq.0.8A
4. The objective lens of claim 1, further comprising a second
connecting section integrally provided to the lens section, wherein
the connecting section and the second connecting section are
extended from the lens section in respective opposite directions
each substantially perpendicular to the optical axis.
5. The objective lens of claim 4, wherein the size of the
connecting section is different from that of the second connecting
section.
6. The objective lens of claim 5, wherein the thickness of the
connecting section in the direction of the optical axis is
different from that of the second connecting section.
7. The objective lens of claim 4, wherein the length of the
connecting section in the direction perpendicular to the optical
axis is different from that of the second connecting section.
8. The objective lens of claim 5, wherein the width of the
connecting section when the connecting is viewed from the optical
axis is different from that of the second connecting section.
9. The objective lens of claim 1, wherein the connecting is shaped
in a square and the lens section is positioned at the center of the
square.
10. The objective lens of claim 1, wherein the lens section is an
aspheric lens section.
11. The objective lens of claim 1, wherein the lens section is
provided with a diffractive structure.
12. The objective lens of claim 1, wherein the objective lens is
made of a plastic.
13. The objective lens of claim 1, wherein the objective lens is
made of a glass.
14. The objective lens of claim 1, wherein the objective lens is a
molded lens with a resin.
15. The objective lens of claim 14, wherein the resin is filled
through a single gate in a mold so that the molded lens has a
single connecting section.
16. The objective lens of claim 15, wherein the connecting section
is used as a resin flowing passage in a mold.
17. The objective lens of claim 14, wherein the resin is filled
through plural gates in a mold so that the molded lens has plural
connecting sections.
18. The objective lens of claim 14, wherein the resin is filled
through two opposite gates in a mold so that the molded lens has
two opposite connecting sections.
19. The objective lens of claim 14, wherein the molded lens has a
square connecting section and the resin is filled through one end
of the square connecting section.
20. The objective lens of claim 14, wherein the molded lens has a
weld portion at a position other than an optical functional
section.
21. The objective lens of claim 14, wherein the molded lens is
produced by a method of injection molding.
22. The objective lens of claim 14, wherein the molded lens is
produced by a method of compression molding.
23. A molded optical component, comprising: a supporting shaft
section having a first cross-sectional area; a connecting section
integrally provided to the supporting shaft section and extended in
an axial direction of the supporting shaft section, and the
connecting section having a second cross-sectional area smaller
than the first cross sectional area; and an optical functional
section integrally provided to the connecting section.
24. The molded optical component of claim 23, wherein the sum
weight of the supporting shaft section and the connecting section
is greater than the weight of the optical functional section.
25. The molded optical component of claim 23, wherein the sum
weight of the supporting shaft section and the connecting section
is 70% or more of the total weight of the molded optical
component.
26. The molded optical component of claim 23, further comprising:
an information recording section provided on the supporting shaft
section.
27. The molded optical component of claim 23, further comprising:
an information recording section provided on the connecting
section.
28. The molded optical component of claim 23, wherein the sectional
form of the supporting shaft section is shaped in almost a
circle.
29. The molded optical component of claim 23, wherein the sectional
form of the supporting shaft section is shaped in almost a
trapezoid.
30. The molded optical component of claim 23, wherein the sectional
form of the supporting shaft section is shaped in almost a
semicircle.
31. The molded optical component of claim 30, wherein a parallel
flat portion that is almost in parallel with a chord section of the
semicircle is formed on a part of an arc section of the semicircle
of the supporting section.
32. The molded optical component of claim 31, wherein a protruded
portion that is protruded from the parallel flat portion and is
shaped in almost a truncated square pyramid is formed on the
parallel flat portion.
33. The molded optical component of claim 32, wherein the protruded
portion has four side sections comprising a pair of longitudinal
sides which face each other in the longitudinal direction of the
supporting shaft section and a pair of lateral sides which face
each other in the lateral direction, and wherein an angle formed
between the longitudinal side and the parallel flat section is made
to be 45.degree. or less.
34. The molded optical component of claim 30, wherein a normal line
on a chord section of the semicircle almost agrees with an optical
axis on an optical functional surface of the optical functional
section.
35. The molded optical component of claim 23, wherein a protruded
portion is formed on the supporting shaft section.
36. The molded optical component of claim 35, wherein the protruded
portion is shaped in a truncated square pyramid.
37. The molded optical component of claim 35, wherein a corner
section of the protruded portion is chamfered.
38. The molded optical component of claim 23, wherein a concave
portion is provided on the supporting shaft section.
39. The molded optical component of claim 23, wherein a
stress-concentration portion is formed on the connecting
section.
40. The molded optical component of claim 39, wherein the
stress-concentration portion is a V-shaped concave portion shaped
in a direction perpendicular to an optical axis of an optical
functional surface of the optical functional section.
41. The molded optical component of claim 39, wherein the
stress-concentration portion is a V-shaped concave portion shaped
in a direction almost equal to a direction of an optical axis of an
optical functional surface of the optical functional section.
42. The molded optical component of claim 23, wherein an index
section is provided on the connecting section on a basis of a
distance from a center of the optical axis of the optical
functional section.
43. The molded optical component of claim 42, wherein the index
section is formed by cutting a mark in the connecting section.
44. The molded optical component of claim 42, wherein the index
section is formed by protruding a mark from the connecting
section.
45. The molded optical component of claim 42, wherein the index
section is formed to be a straight line extended along the
widthwise direction of the connecting section.
46. The molded optical component of claim 42, wherein the index
section is formed to be a locus of a circle having a prescribed
radius whose center is on the optical axis.
47. A method of handling a molded optical component, comprising
steps of: molding an optical component by a mold which is provided
with a first resin flow path having a first cross sectional area, a
second resin flow path which locates in continuation to the first
resin flow path in a resin flow direction and has a second cross
section area smaller than the first cross sectional area, and an
optical functional section forming section which locates in
continuation to the second resin flow path in a resin flow
direction; taking out the molded optical component from the mold,
wherein the molded optical component comprises a supporting shaft
section corresponding to the first resin flow path, a connecting
section corresponding to the second resin flow path and an optical
functional section corresponding to the optical functional section
forming section; and handling the molded optical component on a
basis of the supporting shaft section.
48. The method of claim 47, further comprising: cutting the
supporting shaft section of the molded optical component.
49. The method of claim 48, wherein the supporting shaft section is
cut out at a predetermined section.
50. The method of claim 49, wherein the supporting shaft section is
cut out so as to have a predetermined length.
51. The method of claim 47, wherein the handling step is a step of
positioning the molded optical component.
52. The method of claim 47, wherein the handling step is a step of
holding the molded optical component.
53. The method of claim 47, wherein the handling step is a step of
mounting the molded optical component.
54. The method of claim 47, wherein the handling step is a step of
cutting the molded optical component.
55. The method of claim 47, wherein the handling step comprises a
stem of assembling the molded optical component with another member
and thereafter a step of cutting the connecting section.
56. The method of claim 55, wherein the another member is a
cartridge for conveyance.
57. The method of claim 55, wherein the another member is an
optical pickup unit.
58. The method of claim 47, wherein the handling step is a step of
recording information on the supporting shaft section.
59. The method of claim 47, wherein the handling step is a step of
recording information on the connecting section.
60. The method of claim 58, wherein the information is a reference
number of a mold.
61. The method of claim 58, wherein the information is a reference
number of a cavity.
62. The method of claim 58, wherein the step of recording
information is conducted by marking.
63. The method of claim 58, wherein the step of recording
information is conducted by printing.
64. The method of claim 58, wherein the step of recording
information is conducted by pasting.
65. The method of claim 47, wherein the first resin flow path is
adapted to provide a protruded portion or a concave portion on the
supporting shaft section, the protruded portion or the concave
portion is used as a guide for positioning.
66. The method of claim 47, wherein the first resin flow path is
adapted to provide a protruded portion or a concave portion on the
supporting shaft section, the protruded portion or the concave
portion is used as a guide for handling.
67. A mold for producing as optical component, comprising: a first
resin flow path having a first cross sectional area; a second resin
flow path which locates in continuation to the first resin flow
path in a resin flow direction and has a second cross section area
smaller than the first cross sectional area; and an optical
functional section forming section which locates in continuation to
the second resin flow path in a resin flow direction; wherein the
molded optical component comprises a supporting shaft section
corresponding to the first resin flow path, a connecting section
corresponding to the second resin flow path and an optical
functional section corresponding to the optical functional section
forming section.
68. The mold of claim 67, wherein the first resin flow path is
shaped to have a portion to form a three-dimensional distinguishing
mark on the supporting shaft section.
69. The mold of claim 67, wherein a flow direction of a resin
through the first resin flow path and the second resin flow path is
almost a straight line.
70. The mold of claim 67, wherein a flow direction of a resin on
the first resin flow path conforms with that on the second resin
flow path and is almost a straight line.
71. The mold of claim 67, wherein a flow direction of a resin on
the first resin flow path is perpendicular to that on the second
resin flow path.
72. The mold of claim 67, wherein the first resin flow path is a
runner.
73. The mold of claim 67, wherein the first resin flow path is a
gate.
74. The mold of claim 67, wherein the first resin flow path is
shaped such that the cross sectional form of the supporting shaft
section becomes almost a circle.
75. The mold of claim 67, wherein the first resin flow path is
shaped such that the cross sectional form of the supporting shaft
section becomes almost a trapezoid.
76. The mold of claim 67, wherein the first resin flow path is
shaped such that the cross sectional form of the supporting shaft
section becomes almost a semicircle.
77. The mold of claim 67, wherein the first resin flow path and the
optical component forming section are shaped such that a normal
line on a chord section of the semicircle almost agrees with an
optical axis on an optical functional surface of the optical
functional section.
78. The mold of claim 67, wherein the first resin flow path is
shaped such that a protruded portion is formed on the supporting
shaft section.
79. The mold of claim 67, wherein the first resin flow path is
shaped such that a concave portion is formed on the supporting
shaft section.
80. The mold of claim 67, wherein the second resin flow path is
shaped such that a stress-concentration portion is formed on the
connecting section.
81. A method of molding an optical component with a mold described
in claim 67.
82. A method of molding an optical component with a mold having
plural gates for a cavity corresponding to the optical component,
comprising: filling resin into the cavity thorough the plural
gates, wherein a timing to start filling the resin is different for
each of the plural gates.
83. An optical pickup apparatus, comprising: the objective lens
described in claim 1.
84. A method of assembling an optical pickup unit, comprising steps
of: mounting the optical functional section of the molded optical
component described in claim 23 on an optical pickup apparatus
while holding the supporting shaft section of the molded optical
component; and cutting the connecting section.
85. The method of claim 84, wherein in the cutting step, the
connecting section is removed from the lens section so that the
lens section becomes a circle-shaped lens section provided with no
portion protruded from the circle-shaped lens section.
86. The method of claim 84, wherein the weight of the supporting
shaft section is greater that that of the optical functional
section.
87. The method of claim 84, wherein the volume of the supporting
shaft section is greater that that of the optical functional
section.
88. A method of assembling a package, comprising steps of: mounting
the optical functional section of the molded optical component
described in claim 23 on a container while holding the supporting
shaft section of the molded optical component; and cutting the
connecting section.
89. The method of claim 88, wherein the weight of the supporting
shaft section is greater that that of the optical functional
section.
90. The method of claim 88, wherein the volume of the supporting
shaft section is greater that that of the optical functional
section.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a pickup lens for an
optical disk which is used for reading information from a storage
medium, or recording, mainly by using a laser beam, and in
particular, to a pickup lens for an extremely small optical
disk.
[0002] There are various formats (specifications) for information
recording media available on the market, and various technologies
are employed and studied for the various formats.
[0003] In recent years, in particular, a broadband has become
popular to create a broadband age, and there are circulating
high-volume contents of images, animations and sounds. It is
therefore necessary, even for general users, to stock high-volume
data.
[0004] With respect to a recording medium for data stocking,
original ones were those wherein audio cassette tapes were used,
and FD (floppy disk) is still used even today. In recent years, Zip
(high-volume floppy disk having the measure of capacity of 100
M-200 M), MO (photo-electro-magnetic disk having the measure of
capacity of 640 M-2.3 G), CD (optical disk having the measure of
capacity of 640-700 M) and DVD (optical disk having the measure of
capacity of 4.7 G) are used, which shows that the measure of
capacity has grown great.
[0005] Among the aforesaid recording media, those utilizing light
have their own optical systems.
[0006] The optical disks mentioned above have started from the
music CD, and therefore, it is always necessary for the DVD which
is becoming a leading recording medium now to consider
interchangeability with CD, and a size of the DVD is large, which
makes it difficult to provide a small-sized equipment, resulting in
a problem. To solve this problem, a small-sized medium in a size of
8 cm and a deformed medium having a size of a business card have
made an appearance, but it is unavoidable that they have less
capacity.
[0007] Further, the DVD has a problem that many standards
concerning information recording are present and interchangeability
between them is insufficient.
[0008] With respect to the photo-electro-magnetic disk, problems of
interchangeability with standards for low volume and problems that
a size of a medium restricts a size of equipment remain unchanged,
although the measure of capacity has been made great.
[0009] For those problems, there has been proposed a standard
concerning a small-sized recording medium which is quite novel.
[0010] However, when a medium is small in size, an optical pickup
lens and a unit are required to be small in size.
[0011] When an optical pickup lens and a unit are made to be small
in size, manufacturing, assembling and adjustment of the lens
itself become extremely difficult.
SUMMARY OF THE INVENTION
[0012] An object of the invention, therefore, is to propose forms
which make manufacturing, assembling and adjustment to be easy for
an optical pickup lens and an optical pickup unit which are
extremely small.
[0013] The above object can be attained by the following structures
and methods in respective Item.
[0014] Item (1-1)
[0015] An objective lens used in an optical pickup device that
conducts recording and/or reproduction of information for an
optical information recording medium,
[0016] wherein there are provided
[0017] a lens section which includes a flange section and is almost
in a circular form, and a connecting section used as a supporting
section for the lens section, the connecting section is provided to
be solid with the lens section, and each of them satisfies the
following relations;
0.5.ltoreq.A.ltoreq.2.0
0.3A.ltoreq.B.ltoreq.1.7A
[0018] where A represents a diameter (mm) of the lens section
viewed in the optical axis direction, and B represents a width (mm)
of the connecting section viewed in the optical axis direction.
[0019] Item (1-2)
[0020] The objective lens according to Item (1-1), wherein a
connecting section is provided to be extended from the lens
section.
[0021] Item (1-3)
[0022] The objective lens according to Item (1-2), wherein the
objective lens is formed by filling resins through a single inlet
in a metal mold.
[0023] Item (1-4)
[0024] The objective lens described in Item (1-2) or in Item (1-3),
wherein the following expression is satisfied.
0.3A.ltoreq.B.ltoreq.0.8A
[0025] Item (1-5)
[0026] The objective lens described in Items (1-2)-(1-4), wherein
the connecting section is cut so that nothing may be protruded
outside a shape which is roughly circular when viewed in the
direction of an optical axis.
[0027] Item (1-6)
[0028] The objective lens according to Item (1-1), wherein two
connecting sections are provided to be extended from the lens
section in the direction to face each other.
[0029] Item (1-7)
[0030] The objective lens according to Item (1-6), wherein the two
connecting sections are different from each other.
[0031] Item (1-8)
[0032] The objective lens according to Item (1-7), wherein the two
connecting sections are different from each other in terms of
thickness in the optical axis direction.
[0033] Item (1-9)
[0034] The objective lens according to Item (1-6)-Item (1-8),
wherein the two connecting sections are different from each other
in terms of thickness in the direction perpendicular to the optical
axis.
[0035] Item (1-10)
[0036] The objective lens according to Item (1-6)-Item (1-9),
wherein the two connecting sections are different from each other
in terms of a length of the width viewed in the direction of the
optical axis.
[0037] Item (1-11)
[0038] The objective lens according to Item (1-1), wherein a lens
section is formed to be arranged at the center of a rectangular
connecting section.
[0039] Item (1-12)
[0040] The objective lens according to Item (1-6)-Item (1-11),
wherein the objective lens is formed by filling resins through a
single or plural inlets in a metal mold.
[0041] Item (1-13)
[0042] The objective lens according to Item (1-6)-Item (1-10) or to
Item (1-12), wherein two connecting sections are provided to be
extended from the lens section in the direction to face each other,
and are formed with resins filled through an edge portion of each
connecting section.
[0043] Item (1-14)
[0044] The objective lens according to Item (1-11) or Item (1-12),
wherein a lens section is formed to be arranged at the center of a
rectangular connecting section, and resins are filled through an
edge portion of the connecting section to be formed.
[0045] Item (1-15)
[0046] The objective lens according to Item (1-12)-Item (1-14),
wherein a weld is located outside an optical functional surface of
the lens section.
[0047] Item (1-16)
[0048] The objective lens according to Item (1-1)-Item (1-15),
wherein the objective lens is an aspherical lens.
[0049] Item (1-17)
[0050] The objective lens according to Item (1-1)-Item (1-16),
wherein the objective lens is a lens obtained through compression
molding.
[0051] Item (1-18)
[0052] The objective lens according to Item (1-1)-Item (1-16),
wherein the objective lens is a lens obtained through injection
molding.
[0053] Item (1-19)
[0054] The objective lens according to Item (1-18), wherein the
connecting section serves also as a resin inflow path for the lens
section.
[0055] Item (1-20)
[0056] The objective lens according to Item (1-18)-Item (1-19),
wherein the objective lens is a plastic lens.
[0057] Item (1-21)
[0058] The objective lens according to Item (1-17), wherein the
objective lens is a glass lens.
[0059] Item (1-22)
[0060] The objective lens according to Item (1-1)-Item (1-21),
wherein a diffractive Item is formed on the optical functional
surface of the objective lens.
[0061] Item (1-23)
[0062] A manufacturing method for an optical element for forming by
filling resins through a plurality of inlets in a metal mold,
wherein the time to start injecting resins is staggered when
filling resins through the plural inlets.
[0063] Inventions relating to a handling method among the present
inventions are attained by the following Items.
[0064] Item (2-1)
[0065] An optical molded component having therein a supporting
shaft section having a first cross-sectional area, a connecting
section that is provided to be continued in the axial direction of
the supporting shaft section and has a cross-sectional area smaller
than the first cross-sectional area and an optical functional
section provided to be continued from the connecting section,
wherein the total weight of the supporting shaft section and the
connecting section is greater than the weight of the optical
functional section.
[0066] Item (2-2)
[0067] An optical molded component having therein a supporting
shaft section having a first cross-sectional area, a connecting
section that is provided to be continued in the axial direction of
the supporting shaft section and has a cross-sectional area smaller
than the first cross-sectional area and an optical functional
section provided to be continued from the connecting section,
wherein the total weight of the supporting shaft section and the
connecting section is not less than 70% of the whole weight.
[0068] Item (2-3)
[0069] An optical molded component having therein a supporting
shaft section having a first cross-sectional area, a connecting
section that is provided to be continued in the axial direction of
the supporting shaft section and has a cross-sectional area smaller
than the first cross-sectional area and an optical functional
section provided to be continued from the connecting section,
wherein an information recording site is provided on the supporting
shaft section.
[0070] Item (2-4)
[0071] An optical molded component having therein a supporting
shaft section having a first cross-sectional area, a connecting
section that is provided to be continued in the axial direction of
the supporting shaft section and has a cross-sectional area smaller
than the first cross-sectional area and an optical functional
section provided to be continued from the connecting section,
wherein an information recording site is provided on the connecting
section.
[0072] Item (2-5)
[0073] The optical molded component described in Item (2-1)-Item
(2-4), wherein a shape of a section of the supporting shaft section
is almost circular.
[0074] Item (2-6)
[0075] The optical molded component described in Item (2-1)-Item
(2-5), wherein a shape of a section of the supporting shaft section
is almost trapezoid.
[0076] Item (2-7)
[0077] The optical molded component described in Item (2-1)-Item
(2-6), wherein a shape of a section of the supporting shaft section
is almost semicircular.
[0078] Item (2-8)
[0079] In the invention described in Item (2-8), it is
characterized that a parallel flat portion that is almost in
parallel with a chord section is formed on a part of an arc section
of the supporting section in the optical molded component described
in Item (2-7).
[0080] Item (2-9)
[0081] In the invention described in Item (2-9), it is
characterized that a protruded portion that is protruded from the
parallel flat portion stated above and is in a shape which is
almost a truncated square pyramid is formed in the optical molded
component described in Item (2-8).
[0082] Item (2-10)
[0083] In the invention described in Item (2-10), it is
characterized that a side section of the protruded portion is
composed of a pair of longitudinal sides which face each other in
the longitudinal direction of the supporting section and a pair of
lateral sides which face each other in the lateral direction, and
an angle formed between the longitudinal side and the parallel flat
section is made to be 45.degree. or less, in the optical molded
component described in Item (2-9).
[0084] Item (2-11)
[0085] The optical molded component described in Item (2-7) to Item
(2-10), wherein a normal line on a chord section of the approximate
semicircle almost agrees with an optical axis on an optical
functional surface of the optical functional section.
[0086] Item (2-12)
[0087] The optical molded component described in Item (2-1)-Item
(2-11), wherein a protruded portion is formed on the supporting
shaft section.
[0088] Item (2-13)
[0089] In the invention described in Item (2-13), it is
characterized that the protruded portion is formed to be almost in
a truncated square pyramid, in the optical molded component
described in Item (2-12).
[0090] Item (2-14)
[0091] In the invention described in Item (2-14), it is
characterized that a corner section of the convex portion is
chamfered, in the optical molded component described in Item
(2-13).
[0092] Item (2-15)
[0093] The optical molded component described in Item (2-1)-Item
(2-14), wherein a concave portion is formed on the supporting shaft
section.
[0094] Item (2-16)
[0095] The optical molded component described in Item (2-1) Item
(2-15), wherein a stress-concentration portion is formed on the
connecting section.
[0096] Item (2-17)
[0097] The optical molded component described in Item (2-16),
wherein the stress-concentration portion is a V-shaped concave
portion which is concave in the direction which is mostly
perpendicular to the optical axis on the optical functional surface
of the optical functional section.
[0098] Item (2-18)
[0099] The optical molded component described in Item (2-16),
wherein the stress-concentration portion is a V-shaped concave
portion which is concave in the direction which is mostly the same
as the optical axis on the optical functional surface of the
optical functional section.
[0100] Item (2-19)
[0101] In the invention described in Item (2-19), it is
characterized that the connecting section has an index portion that
is based on a distance from the center of an optical axis of the
optical functional section, in the optical molded component
described in either one of Items (2-1)-(2-18).
[0102] Item (2-20)
[0103] In the invention described in Item (2-20), it is
characterized that the index portion is formed by cutting into the
connecting section, in the optical molded component described in
Item (2-19).
[0104] Item (2-21)
[0105] In the invention described in Item (2-21), it is
characterized that the index portion is formed to be protruded from
the connecting section, in the optical molded component described
in Item (2-19).
[0106] Item (2-22)
[0107] In the invention described in Item (2-22), it is
characterized that the index portion is formed to be a straight
line extending in the lateral direction of the connecting section,
in the optical molded component described in either one of Items
(2-19)-(2-21).
[0108] Item (2-23)
[0109] In the invention described in Item (2-23), it is
characterized that the index portion is formed to be a locus of a
circle having a prescribed radius whose center is on the optical
axis in the optical molded component described in either one of
Items (2-19)-(2-21).
[0110] Item (2-24)
[0111] When handling the optical molded component described in Item
(2-19 to (2-23), a method of handling an molded optical component
is characterized in that an optical molded component is taken out
of a metal mold for molding an optical molded component that is
provided with a first resin inflow path having a first
cross-sectional area, a second resin inflow path being located
ahead of the first resin inflow path in the direction of resin flow
and having a cross-sectional area smaller than the first
cross-sectional area and an optical functional section molding
section being located further ahead of the second resin inflow path
in the direction of resin flow, and then, the optical molded
component is handled on the basis of a site formed by the first
resin inflow path.
[0112] Item (2-25)
[0113] When handling the optical molded component described in Item
(2-19 to (2-23), a method of handling an molded optical component
is characterized in that an optical molded component is taken out
of a metal mold for molding an optical molded component that is
provided with a first resin inflow path having a first
cross-sectional area, a second resin inflow path being located
ahead of the first resin inflow path in the direction of resin flow
and having a cross-sectional area smaller than the first
cross-sectional area and an optical functional section molding
section being located further ahead of the second resin inflow path
in the direction of resin flow, and then, the optical molded
component is handled on the basis of a site which is formed by the
first resin inflow path and is continued to a site formed by the
second resin inflow path, after the site formed by the first resin
inflow path is cut.
[0114] Item (2-26)
[0115] When handling the optical molded component described in Item
(2-19 to (2-23), a method of handling an molded optical component
is characterized in that an optical molded component is taken out
of a metal mold for molding an optical molded component that is
provided with a first resin inflow path having a first
cross-sectional area, a second resin inflow path being located
ahead of the first resin inflow path in the direction of resin flow
and having a cross-sectional area smaller than the first
cross-sectional area and an optical functional section molding
section being located further ahead of the second resin inflow path
in the direction of resin flow, and then, the optical molded
component is handled on the basis of a site which is formed by the
first resin inflow path and is continued to a site formed by the
second resin inflow path, after the prescribed site formed by the
first resin inflow path is cut.
[0116] Item (2-27)
[0117] The method of handling an optical molded component described
in Item (2-26), wherein the aforementioned prescribed site is a
site formed by the first resin inflow path mentioned above that is
away, by a distance determined in advance, from a boundary between
the site formed by the first resin inflow path and the site formed
by the second resin inflow path.
[0118] Item (2-28)
[0119] The method of handling an optical molded component described
in Item (2-24)-Item (2-27), wherein "handling" means positioning of
the optical molded component.
[0120] Item (2-29)
[0121] The method of handling an optical molded component described
in Item (2-24)-Item (2-28), wherein "handling" means holding of the
optical molded component.
[0122] Item (2-30)
[0123] The method of handling an optical molded component described
in Item (2-24)-Item (2-29), wherein "handling" means mounting of
the optical molded component.
[0124] Item (2-31)
[0125] The method of handling an optical molded component described
in Item (2-24)-Item (2-30), wherein "handling" means cutting of the
optical molded component.
[0126] Item (2-32)
[0127] The method of handling an optical molded component described
in Item (2-24)-Item (2-31), wherein "handling" means cutting of the
site formed by the second resin inflow path after combining the
optical functional section of the optical molded component with
another member.
[0128] Item (2-33)
[0129] The method of handling an optical molded component described
in Item (2-32), wherein another member stated above is a cartridge
for conveyance.
[0130] Item (2-34)
[0131] The method of handling an optical molded component described
in Item (2-32), wherein another member stated above is a pickup
unit.
[0132] Item (2-35)
[0133] The method of handling an optical molded component described
in Item (2-24)-Item (2-34), wherein "handling" means recording
information on the site formed by the first resin inflow path.
[0134] Item (2-36)
[0135] In the invention described in Item (2-36), it is
characterized that the "handling" is to record information on a
portion formed by the second resin inflow path in the optical
molded component, in the method of handling an optical molded
component described in either one of Item (2-24)-(2-34).
[0136] Item (2-37)
[0137] The method of handling an optical molded component described
in Item (2-35) or (2-36), wherein the information means a number of
a metal mold.
[0138] Item (2-38)
[0139] The method of handling an optical molded component described
in Item (2-35)-Item (2-37), wherein the information means a cavity
number.
[0140] Item (2-39)
[0141] The method of handling an optical molded component described
in Item (2-35)-Item (2-38), wherein the recording of information is
conducted by marking.
[0142] Item (2-40)
[0143] The method of handling an optical molded component described
in Item (2-35)-Item (2-39), wherein the recording of information is
conducted by printing.
[0144] Item (2-41)
[0145] The method of handling an optical molded component described
in Item (2-35)-Item (2-40), wherein the recording of information is
conducted by pasting.
[0146] The invention of the handling method relating to the molded
component among the present inventions can be attained by the
following means.
[0147] Item (2-42)
[0148] The method of handling an optical molded component described
in Item (2-12)-Item (2-15), wherein the protruded portion and/or
the concave portion is used as an index for positioning.
[0149] Item (2-43)
[0150] The method of handling an optical molded component described
in Item (2-12)-Item (2-15), wherein the protruded portion and/or
the concave portion is used as a guide in the course of
handling.
[0151] Item (2-44)
[0152] A metal mold for molding an optical molded component
described in any one of Items (2-1) to (2-23), having therein a
first resin inflow path having a first cross-sectional area, a
second resin inflow path being located ahead of the first resin
inflow path in the direction of resin flow and having a
cross-sectional area smaller than the first cross-sectional area
and an optical functional section molding section being located
further ahead of the second resin inflow path in the direction of
resin flow, wherein there is formed an optical molded component
having therein a supporting shaft section formed by the first resin
inflow path, a connecting section formed by the second resin inflow
path and an optical functional section formed by the optical
functional section molding section.
[0153] Item (2-45)
[0154] The metal mold for molding an optical molded component
described in Item (2-44), wherein a part of the first resin inflow
path is formed so that a three-dimensional distinguishing mark may
be formed.
[0155] Item (2-46)
[0156] The metal mold for molding an optical molded component
described in Item (2-44)-Item (2-45), wherein the direction of
resin flow for each of the first resin inflow path and the second
resin inflow path is almost linear.
[0157] Item (2-47)
[0158] The metal mold for molding an optical molded component
described in Item (2-44)-Item (2-46), wherein the direction of
resin flow for the first resin inflow path and that for the second
resin inflow path are in accord with each other, and are mostly
linear.
[0159] Item (2-48)
[0160] The metal mold for molding an optical molded component
described in Item (2-44)-Item (2-47), wherein the direction of
resin flow for the first resin inflow path and that for the second
resin inflow path are in the relationship to cross mostly at right
angles.
[0161] Item (2-49)
[0162] The metal mold for molding an optical molded component
described in Item (2-44)-Item (2-48), wherein the first resin
inflow path is a runner.
[0163] Item (2-50)
[0164] The metal mold for molding an optical molded component
described in Item (2-44)-Item (2-49), wherein the second resin
inflow path is a gate.
[0165] Item (2-51)
[0166] The metal mold for molding an optical molded component
described in Item (2-44)-Item (2-50), wherein the first resin
inflow path is formed so that a shape of a section of the
supporting shaft section may be almost circular.
[0167] Item (2-52)
[0168] The metal mold for molding an optical molded component
described in Item (2-44)-Item (2-50), wherein the first resin
inflow path is formed so that a shape of a section of the
supporting shaft section may be almost trapezoid.
[0169] Item (2-53)
[0170] The metal mold for molding an optical molded component
described in Item (2-44)-Item (2-50), wherein the first resin
inflow path is formed so that a shape of a section of the
supporting shaft section may be almost semicircular.
[0171] Item (2-54)
[0172] The metal mold for molding an optical molded component
described in Item (2-53), wherein the first resin inflow path and
the optical functional section molding section are formed so that a
normal line on a chord section of the approximate semicircle may
almost agree with an optical axis on an optical functional surface
of the optical functional section.
[0173] Item (2-55)
[0174] The metal mold for molding an optical molded component
described in Item (2-44)-Item (2-54), wherein the first resin
inflow path is formed so that a protruded portion may be formed on
the supporting shaft section.
[0175] Item (2-56)
[0176] The metal mold for molding an optical molded component
described in Item (2-44)-Item (2-55), wherein the first resin
inflow path is formed so that a concave portion may be formed on
the supporting shaft section.
[0177] Item (2-57)
[0178] The metal mold for molding an optical molded component
described in Item (2-44)-Item (2-56), wherein the second resin
inflow path is formed so that a stress-concentration portion may be
formed on the connecting section.
[0179] The invention relating to the method of molding employing a
metal mold among the present inventions can be attained by the
following means.
[0180] Item (2-58)
[0181] An optical molded component that is molded by the metal mold
for molding an optical molded component in the aforesaid Items
(2-44)-(2-57), and has a supporting shaft section formed by the
first resin inflow path, a connecting section formed by the second
resin inflow path and the optical functional section formed by the
optical functional section molding section.
[0182] The invention relating to the method of molding employing a
metal mold among the present inventions can be attained by the
following means.
[0183] Item (2-59)
[0184] A method of molding an optical molding component that molds
an optical molded component by the use of the metal mold for
molding an optical molded component in the aforesaid Items
(2-44)-(2-57).
[0185] Item (2-60)
[0186] In the invention described in Item (2-60), it is
characterized that the optical molded component described in either
one of Items (2-1)-(2-23) is provided in the optical pickup
unit.
[0187] The invention relating to a method of assembling an optical
pickup unit among the present inventions can be attained by the
following means.
[0188] Item (2-61)
[0189] An optical pickup unit assembling method for the optical
pickup unit described in Item (2-60) wherein a molded component in
which an optical functional section and a supporting shaft section
that is greater than the optical functional section are formed
integrally through a connecting section is incorporated with an
optical pickup unit through the optical functional section while
holding the supporting shaft section, and then, the connecting
section is cut.
[0190] Item (2-62)
[0191] An optical pickup unit assembling method for the optical
pickup unit described in Item (2-60) wherein a molded component in
which an optical functional section and a supporting shaft section
that is greater than the optical functional section are formed
integrally through a connecting section is incorporated with a
housing container through the optical functional section while
holding the supporting shaft section, and then, the connecting
section is cut.
[0192] Item (2-63)
[0193] The optical pickup unit assembling method described in Item
(2-61)-Item (2-62), wherein the supporting shaft portion is greater
than the optical functional section in terms of volume.
[0194] Item (2-64)
[0195] The optical pickup unit assembling method described in Item
(2-61)-Item (2-63), wherein the supporting shaft portion is greater
than the optical functional section in terms of weight.
BRIEF DESCRIPTION OF THE DRAWINGS
[0196] FIG. 1 is a diagram of an objective lens relating to Example
1 that is viewed in the direction of an optical axis.
[0197] FIG. 2 is a diagram of the objective lens shown in FIG. 1
that is viewed in the direction shown with "a".
[0198] FIG. 3 is a diagram of an objective lens relating to Example
2 that is viewed in the direction of an optical axis.
[0199] FIG. 4 is a diagram of the objective lens shown in FIG. 3
that is viewed in the direction shown with "a".
[0200] FIG. 5 is an example of an objective lens relating to
Example 2.
[0201] FIG. 6 is an example of an objective lens relating to
Example 2.
[0202] FIG. 7 is an example of an objective lens relating to
Example 2.
[0203] FIG. 8 is a diagram of an objective lens relating to Example
3 that is viewed in the direction of an optical axis.
[0204] FIG. 9 is a diagram of the objective lens shown in FIG. 8
that is viewed in the direction shown with "a".
[0205] FIG. 10 shows a schematic view of the metal mold relating to
the invention.
[0206] FIG. 11 is an enlarged drawing of primary portions of the
metal mold relating to the invention.
[0207] FIG. 12 is a perspective view of the molded component
relating to the invention.
[0208] FIGS. 13(a) to 13(g) each is a sectional view of the molded
component relating to the invention.
[0209] FIG. 14 is a perspective view in the state where information
is given to the supporting shaft section of the molded component
relating to the invention.
[0210] FIGS. 15(a) to 15(d) each is a sectional view of an example
wherein a three-dimensional distinguishing mark is provided on the
supporting shaft portion of the molded component relating to the
invention.
[0211] FIGS. 16(a) to 16(g) each is a perspective view of an
example wherein a three-dimensional distinguishing mark is provided
on the supporting shaft portion of the molded component relating to
the invention.
[0212] FIG. 17 is a sectional view of a metal mold wherein a
three-dimensional distinguishing mark is provided on the supporting
shaft portion of the molded component relating to the
invention.
[0213] FIGS. 18(a) to 18(d) each is an enlarged drawing of primary
portions of the example wherein a stress-concentration portion is
provided on the connecting section of the molded component relating
to the invention.
[0214] FIGS. 19(a) and 19(b) each is a perspective view of an
example wherein an information recording site is provided on the
supporting shaft portion of the molded component relating to the
invention.
[0215] FIGS. 20(a) and 20(b) each is a perspective view of an
example of the molded component relating to the invention.
[0216] FIGS. 21(a) and 21(b) each is a perspective view of an
example of the molded component relating to the invention.
[0217] FIG. 22 is a sectional view explaining the separation of an
optical molded component from a mold.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0218] The contents of the invention will be explained in detail as
follows based on the drawings, to which, however, embodiments of
the invention are not limited.
EXAMPLE 1
[0219] FIG. 1 is a diagram showing objective lens 1 in Example 1
viewed in the optical axis direction, and FIG. 2 is a sectional
view showing the same objective lens viewed in the direction shown
by the arrow (X).
[0220] The objective lens 1 is an objective lens made of plastic
obtained by injection-molding resins filled in a metal mold.
[0221] Lens section 10 is composed of lens (optical functional
surface) 11 having an optical function and of a flange section
provided to surround the lens 11, and diameter A of the lens
section 10 is 1.3 mm, while, the width of connecting section 20 is
1.2 mm. In the present example, B is equal to 0.92A, while, the
conditions in Item (1-1) are satisfied, and the shape in Item (1-2)
is kept.
[0222] Therefore, handling and incorporating in a pickup device are
easy in spite of an extremely small lens, because a connecting
section is provided for handling and for supporting the lens
section, which is a merit. That is, the connecting section is used
as a supporting section for the lens section. It is further
possible to give a product name, a lot number and a metal mold
number by conducting some printing and marking or other on the
connecting section.
[0223] It is also possible to structure so that no flange section
may be provided, however, it is preferable to provide a flange when
positioning, handling, an influence on the lens surface and
protection of the lens surface are taken into consideration.
[0224] The plastic lens which is injection-molded as stated above
employs technologies in Item (1-18) and Item (1-19). Therefore, it
is possible to manufacture a large number of lenses in the same
shape stably and at high speed. In particular, the plastic lens has
an advantage that inflow of resins and moldability are excellent
because dimensional conditions stipulated in Item (1-1) are
satisfied.
[0225] Further, a shape of the metal mold is formed so that resins
may flow in from connecting section 20, and technologies in Item
(1-3) and Item (1-18) are employed. Due to this, the shape and
structure of the metal mold are not complicated, and a resin inflow
path can be used as a constitutional component.
[0226] The lens section 10 is arranged so that it may be positioned
when its flange section comes in contact with an unillustrated
component on the part of a pickup device when the lens section 10
is incorporated in the pickup device, and NA is further stipulated
as occasion demands on the optical functional surface of lens
surface 11.
[0227] In the objective lens 1, technologies of Item (1-16) are
employed for improving light-converging power, and the optical
functional surface thereof is formed to be in a shape of an
aspheric surface.
[0228] Further, for the purpose of temperature compensation
(improvement of temperature characteristics), a diffractive
structure is formed on the optical functional surface to be in a
form of ring shaped zones by the use of technologies of Item
(1-22). The diffracting surface may be provided either on the whole
optical functional surface or on the desired locations at need. It
is further possible to provide the diffracting surface not only for
the temperature compensation but also for improvement of optical
characteristics and for optical characteristics to be given,
including correction of various aberrations.
[0229] When no diffracting surface is required in particular,
optical functions may also be attained by a refracting interface
only without providing the diffracting surface.
[0230] Incidentally, though the total length C including a lens
section and a width section is 3 mm, maximum thickness D (axial
thickness in this case) of the lens section is 0.41 mm and
thickness E of the connecting section is 0.2 mm in the foregoing,
these figures may further be selected suitably to be
preferable.
[0231] As a comparison, a lens with a general view shown in FIG. 1
wherein a diameter of a lens section and a width of a connecting
section are made to be different in terms of dimension was prepared
to be studied. With respect to a size of the lens section first,
when the size was smaller than that stipulated in the invention,
insufficient quantity of light was caused, and sufficient optical
efficiency was not attained. In addition, handling properties were
lowered and assembling properties were worsened. Further, inflow of
resins in the metal mold was worsened, and a yield for injection
molding was lowered. When the size was greater than that stipulated
in the invention, on the contrary, the lens was closer to an
objective lens for CD or DVD available presently on the market, and
it was difficult to downsize a recording medium and a pickup
device, although optical characteristics were able to be attained.
When the size of the connecting section was smaller than that
stipulated in the invention, the resin inflow path was narrowed and
resins did not flow in sufficiently, making injection molding
itself to be impossible. When the connecting section was greater
than that stipulated in the invention, on the contrary, a shrinkage
cavity (defectively molded portion to which no resins flowed in)
was caused on the connecting section, which also made it impossible
to conduct excellent injection molding.
[0232] In comparison with lenses stated above, the objective lens
that was made to be within a range stipulated by the invention
proved to be excellent in terms of moldability and handling
property and to be of no problem in optical efficiency after the
objective lens was incorporated in a pickup device.
EXAMPLE 2
[0233] A general view shown in FIG. 3 represents a diagram of
objective lens 2 made of plastic in Example 2 that is viewed in the
direction of the optical axis, and FIG. 4 is a sectional view of
the same objective lens viewed in the direction shown by the arrow
(a), in which the technology of Item (1-4) is employed.
[0234] A point of difference between Example 1 and Example 2 is
that second connecting section 21 is further provided in Example 2,
and other points are the same as those in Example 1. Therefore, the
same symbols are given to the same structure, and explanation
therefore will be omitted.
[0235] Due to the two connecting sections provided, there are
advantages that handling property is improved by holding both
connecting sections and that an area where marking and printing can
be conducted is increased.
[0236] Regarding these two connecting sections, it is either
possible that at least one of 20 and 21 serves also as a resin
inflow path as mentioned in Item (1-3) or Item (1-18), or possible
that each of them serves also as a resin inflow path as mentioned
in Item (1-11) and Item (1-12).
[0237] When both of the connecting sections are resin inflow paths,
it is possible to form at high speed and surely because resins flow
in at high speed, and to prevent occurrence of a shrinkage cavity.
Further, the time required for injection molding can be reduced,
and a cycle time is shortened, improving production efficiency.
[0238] Even when resins are made to flow in from the connecting
section on one side, it is possible to form without any problem,
provided that the dimensional conditions stipulated by the
invention are satisfied.
[0239] Next, there will be explained an embodiment wherein a shape
of connecting section 20 is different from that of connecting
section 21.
[0240] When resins flow in from both of two connecting sections,
resins which are unequal in terms of conditions meet in a metal
mold, and a weld is naturally caused. If this weld interferes an
optical functional surface of the lens section, optical functions
themselves are affected, including a fall of transmittance and
extension of errors in aspherical shapes. Therefore, it is
necessary to devise proper arrangement.
[0241] As a method of solution from the aspect of a shape, it is an
effective technology to make the connecting sections to be
different in terms of size as shown in Item (1-5)-Item (1-10). As a
practical method to make connecting sections to be different in
terms of size, it is possible to employ a method to change a
thickness in the direction of an optical axis, a method to change a
length in the direction perpendicular to an optical axis and a
method to change a length of a width viewed in the direction of an
optical axis, by selecting properly or by combining them. To be
concrete, shapes shown in FIGS. 5, 6 and 7 are conceivable. When a
length of a width of the connecting section is made to be
different, in particular, the length is required to be within the
conditional range shown in Item (1-1).
[0242] By constituting as in the foregoing, meeting of resins is
caused at a portion other than a lens section, because resins
flowed in do not arrive the optical functional surface
simultaneously. Accordingly, a weld is naturally positioned outside
the optical functional surface.
[0243] In the example shown in FIG. 5, thicknesses of the
connecting sections are made respectively to be 0.1 mm and 0.2
mm.
[0244] In the example shown in FIG. 6, lengths of the connecting
sections are made respectively to be 0.65 mm and 1.3 mm.
[0245] In the example shown in FIG. 7, widths of the connecting
sections are made respectively to be 0.8 mm and 1.2 mm.
Incidentally, they correspond respectively to 0.92A and 0.62A, and
they satisfy the condition of Item (1-1).
[0246] Next, as a solution from the aspect of a manufacturing
method, there is a method wherein the time to start injecting
resins is staggered as shown in the technology of Item (1-23).
[0247] With respect to resin injection to a metal mold, it is
difficult to make each resin inflow speed for each resin inflow
port to be different from others, when injection conditions
including a melting temperature of resins are taken into
consideration. Therefore, it is preferable that the time to start
injecting resins is staggered, for controlling the meeting timing
(meeting position) for both resins.
[0248] When the above-mentioned method is employed, it is possible
to control the position of a weld without requiring a substantial
cost increase.
[0249] Further, two connecting sections which are different each
other in terms of a shape make it easy to grasp the direction of a
lens, which is an advantage.
EXAMPLE 3
[0250] A general view shown in FIG. 8 represents a diagram of
objective lens 2 in Example 3 that is viewed in the direction of
the optical axis, and FIG. 9 is a sectional view of the same
objective lens viewed in the direction shown by the arrow (a), in
which the technology of Item (1-14) is employed.
[0251] In the structure of the present example, a lens section is
provided in the form of a floating island at the center of the
connecting section extending in a form of a square as a rectangular
shape. The shape thereof is different from those of Examples 1 and
2, and dimensions of the connecting section are also determined
based on the conditions in Item (1-1). Accordingly, there is no
problem of injection molding. Since connecting sections are
extending in almost all directions from the lens section, handling
is more easy, and an area for data marking and printing is
increased, which is an advantage. Further, when the connecting
section is made to hit, it is easy to position both in x direction
and y direction on the plane that is perpendicular to the optical
axis, which is an advantage.
[0252] In the present example, a lens section is 0.85 mm, and a
length of one side of the rectangular connecting section in the
form of a square is 1.3 mm (1.53A), which satisfy the conditions in
Item (1-1).
[0253] Though no flange is provided on the lens section, it is also
possible to provide the flange.
[0254] Though a plastic lens is used in the same way as in Examples
1 and 2, a glass mold lens made through compression molding may
also be used. In particular, the shape is suitable for compression
molding, because of the shape wherein connecting sections are
extending from the whole circumference of the lens section.
[0255] Further, the connecting section is in a shape of a square in
the example shown in FIG. 8, but it is also possible to chamfer or
to round the corner of the connecting section at need. If the
extent of chamfering is made to be different depending on each
corner, this may be utilized for adjusting the lens direction. Even
when the rectangle is changed, as occasion demands, to a shape of a
rectangle, a shape of a trapezoid, a shape of a parallelogram and a
five-or-more-cornered rectangular shape, these shapes are naturally
within a scope of the invention.
[0256] Incidentally, in the case of an asymmetric shape, an
objective lens can be positioned easily and the direction of the
objective lens can be determined easily.
[0257] When conducting injection molding for this lens, resins are
also made to flow in through a part of the connecting section, and
in this case, two or more inflow ports may be provided without
sticking to one inflow port, as occasion demands, and it is also
possible to change a thickness of the connecting section depending
on its location.
EXAMPLE 4
[0258] An objective lens in Example 4 is exactly the same in terms
of shape as those in FIGS. 1-9, and it is a glass lens obtained by
heating a glass pre-form representing a material and then by
compression-molding, in which technologies in Items (1-17) and
(1-21) are used.
[0259] Since this is a glass lens, it is excellent in optical
characteristics, and it is excellent also in temperature
characteristics compared with a plastic lens.
[0260] Even in this lens manufactured through compression molding,
it is necessary to satisfy the conditions in Item (1-1).
[0261] Namely, it is necessary that the pre-form is subjected to
compression molding so that a lens section may have sufficient
optical functions and a connecting section may be formed. If the
width of the connecting section is out of the range of Item (1-1),
there is caused a problem that no connecting section is formed, or
molding troubles are generated in a lens section in an extreme
occasion.
[0262] Therefore, even when a small-sized lens is made with glass
material through compression molding, if the shape of the lens
satisfies the conditions specified in Item (1-1), excellent molding
can be carried out.
[0263] As stated above, the inventions in Items (1-1) and (1-2)
offer an advantage that handling and incorporating in a pickup
device are easy. An advantage that inflow of resins and moldability
are excellent is also offered. Even in the case of compression
molding, an excellent lens is obtained if this condition is
satisfied.
[0264] In the invention in Item (1-3), the shape and structure of
the metal mold are not complicated, and a resin inflow path can be
used as a constitutional component.
[0265] In the invention of Item (1-4), when the lower limit value
of the relational expression described in Item (1-4) is exceeded
downward, materials do not flow in smoothly and moldability is
worsened. When the upper limit value is exceeded upward, on the
other hand, a width of a connecting section is broadened, resulting
in an increase of the time required for cutting work of the
connecting section and an increase of lens load, which is not
preferable from the viewpoint of a thermal strain.
[0266] In the invention of Item (1-5), each individual lens is cut
to be in a circular shape, and it can be subjected to rotary
adjustment, and can be mounted easily.
[0267] In the invention in Item (1-6), there are advantages that
handling property is improved by holding both connecting sections
and that an area where marking and printing can be conducted is
increased.
[0268] The inventions in Items (1-7)-(1-10), meeting of resins is
caused at a portion other than a lens section, because resins
flowed in do not arrive the optical functional surface
simultaneously. Accordingly, a weld can naturally be positioned
outside the optical functional surface.
[0269] In the invention in Item (1-11), since connecting sections
are extending in almost all directions from the lens section,
handling is more easy, and an area for data marking and printing is
increased, which is an advantage. Further, when the connecting
section is made to hit, it is easy to position both in x direction
and y direction on the plane that is perpendicular to the optical
axis, which is an advantage.
[0270] In the case of filling resins through a plurality of
injecting ports in Item (1-12) and in the case of the inventions in
Items (1-11) and (1-12), it is possible to mold surely and at high
speed, and to restrain occurrence of a shrinkage cavity. In
addition, the time required for injection molding can be shortened,
which makes a cycle time to be shorter, resulting in improvement of
production efficiency.
[0271] Further, two connecting sections which are different each
other in terms of a shape make it easy to grasp the direction of a
lens, which is an advantage.
[0272] In the invention in Item (1-15), a weld is located outside
an optical functional surface, which makes it possible to obtain a
lens having excellent optical characteristics.
[0273] In the invention in Item (1-16), it is possible to obtain a
lens having excellent optical characteristics.
[0274] In the invention in Item (1-17), it is possible to
manufacture a large number of lenses in the same shape stably and
at high speed.
[0275] In the invention in Item (1-18), it is possible to
manufacture a large number of lenses in the same shape stably and
at high speed. Since the dimensional conditions stipulated in Item
(1-1) are satisfied, in particular, inflow of resins and
moldability are excellent, which is an advantage.
[0276] In the invention in Item (1-19), the shape and structure of
the metal mold are not complicated, and a resin inflow path can be
used as a constitutional component.
[0277] In the invention in Item (1-20), it is possible to
manufacture a large number of lenses in the same shape stably and
at high speed. Since the dimensional conditions stipulated in Item
(1-1) are satisfied, in particular, inflow of resins and
moldability are excellent, which is an advantage.
[0278] In the invention in Item (1-21), it is possible to obtain a
lens that is excellent in temperature characteristics and in
transmittance.
[0279] In the invention in Item (1-22), it is possible to give
desired optical power by a diffractive surface.
[0280] In the invention in Item (1-23), it is possible to control
the position of a weld without requiring a substantial cost
increase.
[0281] Next, based on the drawings, there will be explained in
detail the molding process of the invention to which, however, the
invention is not limited.
[0282] The characteristic of the invention is to form integrally a
optical molded component P which is greater in terms of volume and
weight than the lens that is incorporated finally in the optical
pickup unit, in advance, then, to handle the molded component in
the handling process by holding its portion other than the lens as
a reference position, and to cut the portion other than the lens
after incorporating the molded component in the optical pickup unit
or in the containing cartridge.
[0283] The symbol 0 shown in FIG. 10 represents a schematic view of
a part of a metal mold M that is used for molding an optical molded
component P relating to the invention. The metal mold has a resin
inflow path which is mostly H-shaped, and it is the so-called
multi-cavity metal mold (8-cavity, in this case) wherein melted
plastic resin flows in the large diameter path section located at
the center, in the direction perpendicular to the page, and 8
pieces of optical molded components in total are formed in a single
metal mold. As is known commonly, the metal mold is composed of a
fixed side and a movable side, and these sides are closed when
resin flows in, and are parted to open the inside of the metal mold
when the resin is cooled after flowing in and molding is completed,
so that the molded component may be taken out.
[0284] FIG. 11 is a sectional view of a certain molding site
(including the fixed side and movable side) that is viewed in the
direction 1 in the metal mold. The numeral 31 represents a runner
that is the first resin inflow path, 32 represents a gate that is
the second resin inflow path and 33 represents an optical
functional section molding section. A section of the first resin
inflow path is circular and a section of the second resin inflow
path is rectangular.
[0285] As is known commonly, an inner surface of the metal mold,
namely, the molding surface has surface finish conducted by any of
various types of processing methods. The optical functional section
molding section, in particular, can be structured so that not only
an aspheric surface but also diffractive ring-shaped zones,
phase-shifted ring-shaped zones and optical path difference
provided ring-shaped zones may be formed, and in that case, a
cutting tool having an extremely sharp edge is used to machine the
metal mold. As a material for the metal mold, appropriate materials
including plated iron can be selected.
[0286] Though a section of the first resin inflow path (runner) is
circular and has a uniform diameter in the drawing, a diameter and
a shape of this runner section do not always need to be uniform.
With respect to a cross-sectional area and a shape, a diameter, for
example, may either be changed from 6 to 4 discontinuously or be
changed from 6 to 4 continuously to become a tapered shape.
Further, a shape of a section may suffer a change such as a change
from a circle to a rectangle.
[0287] Then, the melted resin flows in the second resin inflow path
32 from the first resin inflow path 31, and further flows in the
optical functional section molding section 33 through the second
resin inflow path 32, and is cooled, thus, molding is completed and
the metal mold is opened.
[0288] In this example of the metal mold, the inflow direction of
the resin is linear for both the first resin inflow path and the
second resin inflow path, and both directions agree with each
other.
[0289] However, the aforementioned structure may be changed to
comply with the total structure of the metal mold and with other
circumstances. For example, it is possible to make the first resin
inflow path to have a prescribed curve. Further, it is possible to
make the resin inflow direction of the first resin inflow path and
that of the second resin inflow path to be linear, and further to
make them to be in the positional relationship to cross at right
angles. Under this condition, a metal mold takes a
three-dimensional shape, resulting in an advantage that the number
of cavities is increased. For example, a shape of the molded
component that is molded by the use of the metal mold mentioned
above is one shown in FIG. 20.
[0290] An optical molded component P formed by metal mold M shown
in FIG. 10 is formed to be in a shape shown in FIG. 10.
[0291] With respect to each section formed by metal mold M in this
case, a diameter of supporting shaft section 41 is 5 mm, a shape of
a section of connecting section 42 is a rectangle whose one side is
0.5-1 mm and a diameter of optical functional section 43 is 1 mm
-1.5 mm.
[0292] Therefore, it is extremely difficult to handle by holding
directly the optical functional section 3 that represents a lens
site. However, it is easy to hold supporting shaft section 41 that
is formed by the first resin inflow path 31 (runner) by handling it
as a reference, and other operations can be conducted
satisfactorily.
[0293] To be concrete, the supporting shaft section 1 is handled as
a reference for various operations, including holding (grasping)
and conveyance in the case of taking out the molded component by
opening the metal mold, holding (grasping), conveyance, positioning
and attaching (or incorporating or assembling) to another member
after taking out, and holding (grasping) for cutting.
[0294] The molded component formed by the metal mold 0 is cut at
the position shown by AA' in FIG. 11.
[0295] Shape P of the optical molded component that has been cut at
the position AA' is shown in FIG. 12.
[0296] In the figure, the numeral 41 represents a supporting shaft
section formed by the first resin inflow path 31 (runner), 42
represents a connecting section (or a cross linkage section) formed
by the second resin inflow path 32 (gate) and 43 represents an
optical functional section formed by the optical functional section
molding section 33.
[0297] As explained earlier, what is incorporated actually in the
equipment such as an optical pickup unit is the optical functional
section 43 which is extremely small as stated above and is
difficult to be handled individually. Therefore, it is conveyed
under the condition of molded component P wherein it is united
solidly with supporting shaft section 41 and connecting section 42,
and it is cut at the position of the connecting section 42
immediately before it is incorporated in the optical pickup unit
finally or after being incorporated, so that the optical functional
section 43 may be mounted on the optical pickup unit. It is further
possible for the connecting section 42 to be cut after the molded
component P has been housed in a cartridge for conveyance.
[0298] Further, when considering a size of supporting shaft section
41--optical functional section 43, it is preferable that the
supporting shaft section 41 and the connecting section 42 are
naturally greater in terms of weight than the optical functional
section 3 in the molded component P, for conducting various types
of handling stated above.
[0299] It is further preferable that the total weight of supporting
shaft section 41 and connecting section 42 is not less than 70% of
the whole weight.
[0300] In other words, an optical molded component mentioned in
Item (2-35) is one like molded component P in the state including a
supporting shaft section, a connecting section and an optical
functional section in FIG. 12, for example, and it is not one
showing the state of molding after the fixed section and the
movable section are parted after completion of the molding in the
metal mold shown in FIG. 10.
[0301] Incidentally, for making the handling of the optical molded
component after the molding to be more easy, it is possible to
improve the shape of the metal mold by which the molded component P
is molded.
[0302] FIG. 13 shows variations of sectional shapes for the first
resin inflow path 31 (runner) shape. FIG. 13(a) shows a circle,
FIG. 13(b) shows a semicircle and FIG. 13(c) shows a trapezoid that
is symmetrical laterally. When an asymmetric shape like FIG. 13(b)
or FIG. 13(c) is used, it is possible to prevent that supporting
shaft section 41 rolls down when it is placed on the stand.
Further, in the case of registering, the shape itself serves as an
index, which is an advantage.
[0303] It is further possible to employ the shapes of FIG. 13(d)
and FIG. 13(e), taking handling property, moldability and stiffness
of the finished molded component into consideration as other
factors.
[0304] FIG. 13(d) shows a shape of a section in which a rectangular
portion (a trapezoid portion that is symmetric laterally) is
provided on a chord of the semicircle. Due to this shape, stiffness
is enhanced, rotation can be prevented and positioning can be
conducted easily.
[0305] FIG. 13(e) shows a shape of a section in which a plurality
of trapezoids each being symmetric laterally are combined. Due to
this shape, stiffness is enhanced, rotation can be prevented and
positioning can be conducted easily.
[0306] Optical molded component P shown in FIG. 13(f) is one
wherein parallel flat portion 41a that is almost in parallel with a
chord section is formed on a part of an arc section of supporting
section 1. Prevention of its rotation is possible, and positioning
thereof is easy. Further, by making this parallel flat portion 41a
to be a fixed side of metal mold M, and by making the chord section
to be a movable side of the metal mold M, the optical molded
component P can be removed easily from the fixed side after molding
by the metal mold M. Due to this, deformation of supporting section
1 caused in the course of removing can be controlled, and excellent
optical molded component P can be obtained.
[0307] Further, it is also possible to provide protruded portion
41b in a shape which is almost truncated square pyramid (so-called
tapered shape) on the parallel flat section 41a, as shown in FIG.
13(g) and FIG. 21(a). This protruded portion 41b has a pair of
longitudinal sides 41c which face each other in the longitudinal
direction of the supporting section 41 and a pair of lateral sides
41d which face each other in the lateral direction. Incidentally,
the corner section of the protruded portion 41b is chamfered to
make the removing from the metal mold M to be excellent.
[0308] This chamfering may either be in a cornered shape or be in a
rounded shape, but the rounded shape is better on the point of
releasability. When the structure shown in FIG. 13(g) is employed,
action and effect in the case of the structure shown in FIG. 13(f)
can naturally be exhibited, and further, positioning by using the
protruded portion 41b is possible. Incidentally, protruded portion
41b may also be formed to be in a shape of a rectangular
parallelepiped without being in a shape of almost truncated square
pyramid, as shown in FIG. 21(b).
[0309] As shown in FIG. 22, when O represents an intersecting point
of a straight line suspended vertically from the side end portion
of connecting section 42 of a pedestal section of the protruded
portion 41b to the parallel flat portion 41a and the parallel flat
portion 41a, when the metal mold M is opened, there is generated
moment whose center is on O on supporting section 41. Namely, it is
preferable that angle .theta. formed between parallel flat portion
41a and longitudinal side 41c is not more than an angle which
creates a tangent line of the circle whose center is at O and whose
radius is (L.sup.2+T.sup.2).sup.1/2, when L represents a length of
a pedestal portion of the protruded portion 41b in the longitudinal
direction and T represents a length of protruded portion of 41b in
the direction of its height. Namely, when the angle .theta. is made
to be 45.degree. or less, the moment generated in the supporting
shaft portion 41 is reduced, and releasability is improved
greatly.
[0310] Incidentally, the smaller the angle .theta. is, the more the
releasability is improved. In addition, the releasability is
further improved if the joint section between the longitudinal side
41b and the parallel flat portion 41a is made to have a radius of
curvature that makes a gentle curve.
[0311] When a semicircular shape like FIG. 13(b) is employed, in
particular, if an arrangement is made so that a normal line on the
chord section of the semicircle may agree with an optical axis on
an optical functional surface of optical functional section 43, it
is possible to conduct positioning easily in the case of mounting
by utilizing the surface corresponding to the chord section, which
results in the handling that is more convenient.
[0312] When considering the relationship between the optical
functional section and an optical axis, shapes of FIGS. 13(a)-13(g)
can also be applied, without being limited to the shape of FIG.
13(b). Namely, in the case of a trapezoidal shape that is symmetric
laterally, a line that is perpendicular to prarallel two sides of
the trapezoid has only to agree with an optical axis of the optical
functional section.
[0313] Further, as another improvement, it is also possible to
provide a three-dimensional distinguishing mark on supporting shaft
section 1 through molding as shown in FIG. 14. In this case, the
first resin inflow path 31 (runner) of the metal mold is processed
in advance so that the distinguishing mark may be formed
thereon.
[0314] Now, as shown in FIGS. 18(c) and 18(d), index portion 42a
may be provided on connecting section 42. In this case, gate 2 of
the metal mold M has only to be machined in advance so that the
index portion 42a may be formed on connecting section 42.
[0315] In the example shown in FIG. 14, there are formed bar code
and letters. A direction, a size and a shape of these
distinguishing mark can be established independently.
[0316] Incidentally, although the bar code and the letters are
formed on the supporting section 41 in FIG. 14, the bar code and
the letters may be formed on the connecting section 42.
[0317] Further, the distinguishing mark like this can also include
a metal mold number and a cavity number in addition to symbols
indicating a product name and a lot. If these distinguishing marks
are included, it is possible to use them when checking and
extracting defective products in the succeeding process.
[0318] Further, as shown in FIGS. 18(c) and 18(d), index portion
42a that is based on a distance from the center of an optical axis
of the optical functional section 43 may be provided on connecting
section 42. FIG. 18(d) shows that the index portion 42a is formed
by cutting into the connecting section 42, while, FIG. 18(c) shows
that the index portion 42a is formed to be protruded from the
connecting section 42. Further, FIG. 18(d) shows that the index
portion 42a is formed to be in a shape of a straight line that
extends in the lateral direction of the connecting section 42. FIG.
18(c) shows that the index portion 42a is formed to be a locus of a
circle having a prescribed radius whose center is on the optical
axis. Due to this, it is possible to cut based on the index portion
42a when cutting the connecting section 42.
[0319] Further, as another improvement, a concave portion or a
convex portion may be provided on the supporting shaft section 41
as shown in FIG. 15 and FIG. 16. Even in this case, the first resin
inflow path 31 (runner) of the metal mold is processed so that
these portions may be formed thereon as shown in FIG. 17.
[0320] These concave portions and convex portions can be used as a
mark for positioning, a stand for placing and as a jig for fixing.
For example, a conveyance guide such as a rail is provided, and
when conveying molded component P in a way that it slides on the
rail, if the concave portion and/or convex portion and the rail are
in the state of loose fitting, the molded component P does not come
off the rail. Even in the case of storing the molded component P in
a housing container such as a cartridge, if the concave or convex
portion is in the state of fitting with a member on the housing
container, a problem of coming off or damage of the molded
component in the container can be solved.
[0321] In this case, the convex portion may be formed to be in a
shape that is almost a truncated square pyramid as shown in FIG.
16(g), or if a corner section of the convex portion is chamfered,
friction with a rail can be reduced. If the chamfering in this case
is in a rounded shape as shown in FIG. 16(g), friction can be
reduced greatly, which is extremely advantageous in practical
use.
[0322] Further, as another improvement, it is possible to provide a
stress concentration portion on connecting section 2 as shown in
FIG. 18, so that the connecting section 2 may be cut easily.
[0323] If there is formed a V-shaped concave portion that is
concave in the direction that is almost perpendicular to an optical
axis on an optical functional surface of optical functional section
43, as shown in FIG. 18(a), it is possible to cut connecting
section 42 only by tilting supporting shaft section 41 in the
direction of the optical axis after incorporating the molded
component P in an equipment such as an optical pickup unit. It is
also possible to provide a V-shaped concave portion that is concave
in the direction which is mostly the same as an optical axis on the
optical functional surface of the optical functional section 43, as
shown in FIG. 18(b).
[0324] Though it is possible to provide the stress concentration
portion of this kind by arranging some device on the metal mold, in
the same way as in the aforementioned case, there is sometimes
caused a problem because a cross-sectional area of the path through
which the resin passes becomes small in the second resin inflow
path 32. It is therefore possible to form a stress concentration
portion of this kind through half-cutting or stamping after
completion of molding.
[0325] Though there has been explained a technology to make
handling after molding to be easy by improving mainly a metal mold,
it is also possible to devise the handling in the state of molded
component P, after molding.
[0326] For example, in the example shown in FIG. 14, a
distinguishing mark is provided on supporting shaft section 41 by
devising a shape of the first resin inflow path 31, in which,
however, a problem that information to be given in the course of
molding is fixed is caused.
[0327] After molding, therefore, some pieces of information can be
given. Recording of information of this kind is also an embodiment
of what is called "handling" in the invention.
[0328] As an example therefore, there is given an occasion wherein
the first resin inflow path 31 is processed to provide an
information recording site as shown in FIG. 19. In this case, it is
preferable that an area representing a rough surface is formed so
that an operation to give information and a position to give
information may be distinguished. Incidentally, by processing the
gate section 31, the information may be provided on the connecting
section 42.
[0329] A method to give information includes, for example,
stamping, printing and pasting of a label. When simplicity and cost
are taken into consideration, in particular, printing of an ink jet
system is preferable. It is also possible to combine stamping,
printing and pasting of a label appropriately for using them.
[0330] Further, as information to be given or to be recorded, it is
possible to include also a metal mold number and a cavity number in
addition to symbols indicating a product name and a lot. If these
distinguishing marks are included, it is possible to use them when
checking and extracting defective products in the succeeding
process.
[0331] In the case of printing and label pasting, classification by
coloring can also increase an amount of information.
[0332] As stated above, in the invention of Item (2-1) and Item
(2-2), it is possible to hold stably because weight of the portion
other than the optical functional section is greater than that of
the optical functional section.
[0333] In the invention of Item (2-3), Item (2-4), Item (2-35)-Item
(2-38), information is recorded on the supporting shaft section
which is larger than the optical functional section, therefore,
various pieces of information can be held as a molded component
even in the case of a small-sized optical functional section. If
the recorded information is a metal mold number, it is possible to
trace the relationship between the molded component and the metal
mold that has molded the molded component. If the recorded
information is a cavity number, it is possible to trace about the
molded component, retroacting to the moment of molding
operations.
[0334] In the invention of Item (2-5) and Item (2-51), a resin
circulation path can be manufactured easily, because a supporting
shaft section is formed so that a shape of its section may be
circular.
[0335] In the invention of Item (2-6) and Item (2-52), there can be
formed a molded component that is stable when it is placed, because
a section of the supporting shaft section is formed to be almost
trapezoidal.
[0336] In the invention of Item (2-7) to (2-10) and Item (2-53),
there can be formed a molded component that is stable when it is
placed, because a section of the supporting shaft section is formed
to be almost semicircular.
[0337] In the invention of Item (2-11) and Item (2-54), a metal
mold can be designed easily, and positioning is easy.
[0338] In the invention of Item (2-12) to (2-14) and Item (2-55),
holding and conveyance of a molded component are easy because the
convex portion is formed on the supporting shaft section.
[0339] In the invention of Item (2-15) and Item (2-56), holding and
conveyance of a molded component are easy because the concave
portion is formed on the supporting shaft section.
[0340] In the invention of Item (2-16) and Item (2-57), cutting is
easy because the stress-concentration portion is formed.
[0341] In the invention of Item (2-17), it is possible to conduct
cutting easily by tilting the supporting shaft section from the
optical axis.
[0342] In the invention of Item (2-18), it is possible to conduct
cutting easily by tilting the supporting shaft section from the
optical functional section without moving it in the optical
axis.
[0343] In the invention of Item (2-19) to Item (2-23), information
is recorded on the connecting section, therefore, various pieces of
information can be held as an optical molded component even in the
case of a small-sized optical functional section. If the recorded
information is a metal mold number, it is possible to trace the
relationship between the molded component and the metal mold that
has molded the molded component. If the recorded information is a
cavity number, it is possible to trace about the molded component,
retroacting to the moment of molding operations.
[0344] In the inventions of Item (2-24)-Item (2-26), even a lens
which is extremely small in size can be conveyed and positioned in
the process easily, and it can further be incorporated easily in a
pickup unit, when the lens is handled with a reference represented
by a supporting shaft section provided solidly with the lens, which
is an advantage.
[0345] In the invention of Item (2-27), a prescribed position
serves as reference and it does not have an influence on the
optical functional section, thereby, operations can be
equalized.
[0346] In the invention of Item (2-28), positioning is conducted by
using the supporting shaft section which is larger than the optical
functional section, thereby, positioning can be conducted
accurately.
[0347] In the invention of Item (2-29), the supporting shaft
section which is larger than the optical functional section is held
(gripped), thereby, holding is easy.
[0348] In the invention of Item (2-30), assembling is conducted by
using the supporting shaft section which is larger than the optical
functional section, thereby, mounting and assembling can be
conducted surely.
[0349] In the invention of Item (2-31), cutting is conducted with
reference of the supporting shaft section which is larger than the
optical functional section, thereby, holding and gripping are sure,
and erroneous cutting is prevented.
[0350] In the invention of Item (2-32) to Item (2-34), assembling
is conducted by using the supporting shaft section which is larger
than the optical functional section, and cutting is conducted with
reference of the supporting shaft section which is larger than the
optical functional section, thereby, the extremely small lens can
be incorporated in the device easily.
[0351] In the invention of Item (2-39), recording of information is
conducted through the method of stamping, and therefore,
information can be given freely as occasion demands after molding,
and information is not separated from the molded component because
information is recorded integrally.
[0352] In the invention of Item (2-40), recording of information is
conducted through the method of printing, and therefore,
information can be given freely as occasion demands after molding,
and information is not separated from the molded component because
information is recorded integrally. If information is given through
an ink jet system, in particular, an amount of information can be
increased by classification by coloring.
[0353] In the invention of Item (2-41), recording of information is
conducted through the method of label pasting, and therefore,
information can be given freely as occasion demands after molding,
and an amount of information can be increased by classification by
coloring.
[0354] In the invention of Item (2-42), the positioning for the
optical molded component can be done easily, therefore, it is very
advantageous for the actual use of it.
[0355] In the invention of Item (2-43), the optical molded
component can be surly guided in a production line in a factory,
therefore, it is very advantageous for the actual use of it.
[0356] In the invention of Items (2-44), (2-58) and (2-59), a
supporting shaft section, a connecting section and a molded
component having an optical functional section can be formed
easily.
[0357] In the invention of Item (2-45), handling after molding is
easy because a three-dimensional distinguishing mark is formed
simultaneously in the course of molding.
[0358] In the invention of Item (2-46), a resin flow is excellent
because the direction of resin inflow is linear.
[0359] In the invention of Item (2-47), a resin flow is excellent
because the direction of resin inflow is linear continuously.
[0360] In the invention of Item (2-48), a metal mold can be
structured in three dimensions, because a resin inflow path is
provided to cross at right angles.
[0361] In the invention of Item (2-49) and Item (2-50), it can be
applied to a mold having a runner or a gate, therefore, it is very
advantageous for the actual use of it.
[0362] In the invention of Item (2-60) and Item (2-64), assembling
the optical molded component onto a unit can be done easily,
therefore, the manufacturing cost, of course, can be reduced.
Further, the accuracy in the assembling each component onto the
entire unit can be enhanced.
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