U.S. patent application number 11/301904 was filed with the patent office on 2006-05-04 for method of fabricating a holder and optical element device.
Invention is credited to Shigeru Hatakeyama, Kazuhiro Konno, Takehiko Tomisawa.
Application Number | 20060092531 11/301904 |
Document ID | / |
Family ID | 34308380 |
Filed Date | 2006-05-04 |
United States Patent
Application |
20060092531 |
Kind Code |
A1 |
Hatakeyama; Shigeru ; et
al. |
May 4, 2006 |
Method of fabricating a holder and optical element device
Abstract
A holder and optical element device includes a holder having a
substantially cylindrical interior shape and an optical element
fitted in the holder along an inner surface of the holder. The
holder may have a step on the inner surface thereof. This step has
a surface that is inclined downward and inward from the interior
surface of the holder. The optical element may have a convex
optical surface section on a surface thereof and a flat surface
section around the optical surface section, the flat surface
section being disposed on the downward-inclined surface. The
optical element is disposed on the inner surface of the holder in
such a manner that the step is in contact with the peripheral
surface, of the optical element.
Inventors: |
Hatakeyama; Shigeru;
(Miyagi-ken, JP) ; Tomisawa; Takehiko;
(Miyagi-ken, JP) ; Konno; Kazuhiro; (Miyagi-ken,
JP) |
Correspondence
Address: |
BRINKS HOFER GILSON & LIONE
P.O. BOX 10395
CHICAGO
IL
60610
US
|
Family ID: |
34308380 |
Appl. No.: |
11/301904 |
Filed: |
December 13, 2005 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10925496 |
Aug 24, 2004 |
|
|
|
11301904 |
Dec 13, 2005 |
|
|
|
Current U.S.
Class: |
359/811 |
Current CPC
Class: |
G02B 7/02 20130101; G02B
3/04 20130101; G02B 6/4206 20130101 |
Class at
Publication: |
359/811 |
International
Class: |
G02B 7/02 20060101
G02B007/02 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 25, 2003 |
JP |
2000-267294 |
Aug 25, 2003 |
JP |
2003-299861 |
Claims
1.-15. (canceled)
16. A method for fabricating a holder and optical element device
comprising: placing an optical element material inside a holder
having a substantially cylindrical interior surface shape; and
pressing the optical element material by a molding surface of a
die, the optical element contacting an inner surface of the holder,
wherein a surface of the optical element material has a central
portion and a peripheral portion, the central portion being pressed
by a concave optical-surface-molding section in the molding
surface, and the peripheral portion of the optical element material
being pressed by a planar flat-surface-molding section.
17. The method for fabricating a holder and optical element device
according to claim 16, wherein a step is provided on the interior
cylindrical surface of the holder, the step including a surface
that is inclined downward and inward from the interior cylindrical
surface, and when the optical element material is pressed by the
die, the inclined surface of the step and the flat-surface-molding
section of the die face each other.
18. The method for fabricating a holder and optical element device
according to claim 17, wherein the planar flat-surface molding
section is inclined downward and outward.
Description
[0001] This application claims the benefit of priority to Japanese
Patent Application No.: 2003-299861, filed on Aug. 25, 2003, which
is incorporated herein by reference.
BACKGROUND
[0002] The present application may relate to a holder and optical
element device in which an optical element is integrated with a
holder and a method for fabricating the same, and more
particularly, to a holder and optical element device molded by
pressing an optical element material disposed inside the
holder.
BACKGROUND
[0003] Optical elements such as lenses for pick-up heads of CD
players or lenses for collecting signal light in optical
communications need to be mounted with high accuracy. Therefore, to
achieve such high mounting accuracy, generally a holder and optical
element device is mounted by adjusting the position thereof with a
holder, as described in U.S. Pat. No. 6,567,224. This type of
optical element device is formed by softening an optical element
material disposed inside a cylindrical holder by heat, and
press-molding the softened optical element material with a die. The
optical element is in contact with the inner surface of the holder
and thus integrated therewith.
[0004] Generally, an optical surface section having an optical
function is disposed on a surface of the optical element and a flat
surface section is disposed around the optical surface section.
When the convex optical surface section is formed, an optical
element material is pressed by a die having a concave
optical-surface-molding section, which corresponds to the convex
optical surface section, and a flat-surface-molding section, which
corresponds to the flat surface section. The flat-surface-molding
section presses the optical element material towards the center of
the optical element. However, the optical-surface-molding section
cannot be filled with a sufficient amount of the optical element
material, resulting in a defect in the molded optical surface
section.
SUMMARY
[0005] The present application describes a holder and optical
element device having a precisely-formed convex optical surface
section and a method for fabricating the same.
[0006] According to an aspect of the present application, a holder
and optical element device includes a holder having a substantially
cylindrical shape and having an inner surface and a step on the
inner surface, the step having surface that may be inclined
downward and inward from the inner surface and an optical element
having a peripheral surface and fitted in the holder along the
inner surface of the holder, the optical element having a top
surface provided with a convex optical surface section and a flat
surface section around the optical surface section, the flat
surface section being disposed above the downward-inclined surface.
In this holder and optical element device, the optical element is
fitted in the holder such that the step is in contact with the
peripheral surface of the optical element. Therefore, when
press-molding the optical element with a die, part of the pressed
optical element material is easily led toward the center and thus
the optical-surface-molding section is filled with a sufficient
amount of the optical element material. The flat surface section of
the optical element may be inclined downward and outward with
respect to the central axis thereof. The material of the optical
element may be glass or resin or other transparent material with
moldable properties.
[0007] In another aspect, a method for fabricating a holder and
optical element device includes the steps of placing an optical
element material inside a holder having a substantially cylindrical
shape and pressing the optical element material by a molding
surface of a die to form an optical element having a convex optical
surface section, the optical element being in contact with an inner
surface of the holder. In this method for fabricating a holder and
optical element device, the midsection of the optical element
material is pressed by a concave optical-surface-molding section in
the molding surface, and a peripheral portion around the midsection
of the optical element material is pressed inward and downward by a
planar flat-surface-molding section that is inclined downward and
outward. Therefore, part of the optical element material pressed by
the flat-surface-molding section is easily led toward the center
and thus the optical-surface-molding section is filled with a
sufficient amount of the optical element material. According to
another aspect of the method for fabricating a holder and optical
element device, a step is provided on the inner surface of the
holder, the step may include a surface that may inclined downward
and inward from the inner surface, and when the optical element
material is pressed by the die, the downward-inclined surface of
the step and the flat-surface-molding section of the die face each
other.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a cross-sectional view of a holder and optical
element device according to an embodiment;
[0009] FIG. 2 is an enlarged cross-sectional view of the optical
element shown in FIG. 1 and the peripheral portion thereof;
[0010] FIG. 3 is an enlarged cross-sectional view of the optical
element and the peripheral portion thereof prior to press-molding;
and
[0011] FIG. 4 is an enlarged cross-sectional view of the optical
element and the peripheral portion thereof during
press-molding.
[0012] FIG. 5 is a cross-sectional view of the holder interfaced
with a CAN-type optical element.
DETAILED DESCRIPTION
[0013] Exemplary embodiments of the invention may be better
understood with reference to the drawings, but these embodiments
are not intended to be of a limiting nature. Rather, the invention
is to cover all modifications, equivalents, and alternatives
falling within the spirit and scope of the invention which is set
forth by the claims.
[0014] Like numbered elements in the same or different drawings
perform equivalent functions
[0015] The same elements or parts throughout the figures of the
drawings are designated by the same reference characters. FIG. 1 is
a cross-sectional view of a holder and optical element device
according to an embodiment of the present invention. FIG. 2 is an
enlarged cross-sectional view of the holder and optical element
device shown in FIG. 1 and the peripheral portion thereof. FIG. 3
is an enlarged cross-sectional view of the holder and optical
element device and the peripheral portion thereof prior to
press-molding. FIG. 4 is an enlarged cross-sectional view of the
holder and optical element device and the peripheral portion
thereof during press-molding. FIG. 5 is a cross-sectional view of
the holder and optical element device and a relationship to a
CAN-type optical device.
[0016] A holder and optical element device 1 may be attached to an
optical device ("second optical device") such as a laser diode 41
or photodiode 42 of a CAN type 40, or other package type. The
holder and optical element device 1 includes an optical element 10
and a holder 20, as shown in FIG. 1. The optical element 10
refracts light emitted from a first optical device (not shown) and
converges light towards a second optical device 40 (FIG. 5). The
holder 20 supports the optical element 10 and determines the
position of the optical element 10 with respect to second optical
device 40. In the following description, "below" or "lower" denotes
the direction from the second optical device to the optical element
and "above" or "upper" denotes the direction from the optical
element to a first optical device. It should be appreciated that
the first and second optical devices may be either sources,
detectors, or modifiers of light energy, depending on the use of
the holder and optical element.
[0017] Referring to FIG. 2, the optical element 10 is fixed in the
holder 20 such that a peripheral surface 13 of the optical element
10 is in contact with an inner surface 21 of the holder 20. The
optical element 10 has an upper surface 11 and a lower surface 12,
which are externally exposed, and a convex optical surface section
11a and a convex optical surface section 12a are disposed on the
upper surface 11 and the lower surface 12, respectively. The
optical surface section 11a and the optical surface section 12a may
be aspheric and refract light emitted from the first optical device
and converge light toward the second optical device. A flat surface
section 11b is disposed around the optical surface section 11a and
is inclined downward and outward. A flat surface section 12b is
disposed around the optical surface section 12a.
[0018] As shown in FIGS. 1 and 2, the optical element 10 is
disposed in the holder 20 with a substantially cylindrical shape so
as to be in contact with the inner surface 21 of the holder 20. A
step 22 is disposed on the inner surface 21 of the holder 20 and is
provided with a surface 22a that is inclined downward and inward.
This downward-inclined surface 22a guides an optical element
material 10a toward the center when press-molding the optical
element 10. A flat holding section 23 protrudes inwardly from the
bottom end of the inner surface 21 and forms an opening slightly
larger than the optical surface section 12a of the lower surface
12. The holding section 23 has a holding surface 23a, and the
optical element material 10a is placed on the holding surface 23a
in press-molding the optical element 10.
[0019] The holder 20 is provided with an attachment section 24,
whose shape may be independent of the exterior shape of the holder
and serve to adapt the holder and the inner surface 25 of the
attachment section to mate with the dimensional characteristics of
the second optical device (FIG. 5). The attachment section 24 may
extend substantially perpendicularly in the downward direction from
the top edge of the holder 20 and has an inner surface shape 25
that may correspond to that of the side surface or a portion
thereof, of the second optical device 40. The inner surface 25 of
the attachment section 24 may mate with a surface of the optical
device, and the bottom surface of the holder 20 may abut the
surface of the optical device. Therefore, the holder 20 may be
attached to the second optical device and the optical element 10 is
may be aligned to the second optical device. The holder 20 may be
affixed to the second optical element.
[0020] The optical element 10 is disposed in the holder 20 so as to
be in contact with the inner surface 21 of the holder 20. More
specifically, the upper surface 11 of the optical element 10 is
slightly higher than the step 22, whereas the lower surface 12 of
the optical element 10 is slightly lower than the holding surface
23a. The peripheral surface 13 of the optical element 10 is in
contact with the step 22 and the holding surface 23a, as shown in
FIG. 2. The flat surface section 11b of the optical element 10 is
disposed above the downward-inclined surface 22a of the step 22. In
other words, the flat surface section 11b and the downward-inclined
surface 22a have slopes in the vertical direction.
[0021] In another aspect, a method for fabricating the holder and
optical element device 1 is described. The optical element material
10a for forming the optical element 10 and the holder 20 for
accommodating the optical element material 10a are prepared. The
optical element material 10a may be comprised of optical glass or
resin and have a cylindrical column shape. The cylindrical optical
element material 10a has a radius that is large enough for the
optical element material 10a to be placed on the holding section 23
of the holder 20. The optical element material 10a has a volume
sufficient to form the optical element 10. The holder 20 is formed
by cutting or casting, for example, aluminum or stainless
steel.
[0022] As shown in FIG. 3, the optical element material 10a is
placed on the holding surface 23a of the holder 20 and may then be
heated, thereby softening the optical element material 10a.
Subsequently, as shown in FIG. 4, the softened optical element
material 10a is press-molded with a die 30 consisting of an upper
die 31 and a lower die 33. The bottom surface of the upper die 31
is a molding surface 32 and the top surface of the lower die 33 is
a molding surface 34. The molding surface 32 includes an
optical-surface-molding section 32a corresponding to the optical
surface section 11a and a flat-surface-molding section 32b
corresponding to the flat surface section 11b. The molding surface
34 includes an optical-surface-molding section 34a corresponding to
the optical surface section 12a and a flat-surface-molding section
34b corresponding to the flat surface section 12b. The
optical-surface-molding section 32a and the optical-surface-molding
section 34a press the midsection of the optical element material
10a, thereby forming the optical surface section 11a and the
optical surface section 12a. The flat-surface-molding section 32b
and the flat-surface-molding section 34b press the peripheral
portions of the optical element material 10a, thereby forming the
flat surface section 11b and the flat surface section 12b. The
flat-surface-molding section 32b in the upper die 31 is inclined
downward and outward. Therefore, in the press-molding with the
upper die 31, part of the optical element material 10a may be
pressed inward and downward by the flat-surface-molding section 32b
and thus led toward the center. Accordingly, the
optical-surface-molding section 32a and the optical-surface-molding
section 34a are filled with a sufficient amount of the optical
element material 10a. In an aspect, only the flat-surface-molding
section 32b in the upper die 31 may be inclined. Alternatively, the
flat-surface-molding section 34b in the lower die 33 may also be
inclined.
[0023] The step 22 with the downward-inclined surface 22a is
disposed on the inner surface 21 of the holder 20. When the optical
element material 10a is press-molded, the flat surface-molding
section 32b of the upper die 31 and the downward-inclined surface
22a face each other. Therefore, part of the optical element
material 10a pressed by the flat-surface-molding section 32b may be
readily led toward the center by the downward-inclined surface 22a.
Thus, the optical-surface-molding section 32a and the
optical-surface-molding section 34a, which form the convex optical
surface sections 11a and 12a, respectively, are sufficiently filled
with the optical element material 10a.
[0024] The holder and optical element device may attached to an
optical device of a CAN type. However, the holder and optical
element device of the present invention is not limited to the ones
described above and the shape of the holder and optical element
device may be modified depending on the shape of the optical device
to which the holder and optical element device is attached. For
example, in place of the attachment section with a cylindrical
column shape, a support member may support the holder. Furthermore,
as shown in FIG. 6, the attachment section 24 may directly cover
the laser diode 41 and the photodiode 42. Furthermore, in the above
embodiments, the optical element has the convex optical surface
sections on both surfaces thereof but may have a single convex
optical surface section on either surface.
[0025] Although only a few exemplary embodiments of this invention
have been described in detail above, those skilled in the art will
readily appreciate that many modifications are possible in the
exemplary embodiments without materially departing from the novel
teachings and advantages of the invention. Accordingly, all such
modifications are intended to be included within the scope of this
invention as defined in the following claims.
* * * * *