U.S. patent application number 13/130013 was filed with the patent office on 2011-09-15 for fiber optic plate and method for producing the same.
This patent application is currently assigned to HAMAMATSU PHOTONICS K.K.. Invention is credited to Takeo Sugawara.
Application Number | 20110222827 13/130013 |
Document ID | / |
Family ID | 42198092 |
Filed Date | 2011-09-15 |
United States Patent
Application |
20110222827 |
Kind Code |
A1 |
Sugawara; Takeo |
September 15, 2011 |
FIBER OPTIC PLATE AND METHOD FOR PRODUCING THE SAME
Abstract
In an FOP 1, a glass body 8 is configured by including
antimicrobial glass portions 10 made of antimicrobial glass
containing Ag.sub.2O. Here, the glass containing silver does not
have chemical durability, so that it has properties to easily emit
Ag ions due to moisture. Ag ions have an excellent antimicrobial
effect. Therefore, by configuring the glass body 8 to include the
antimicrobial glass portions 10 containing Ag.sub.2O, the glass
body 8 can obtain a sterilization effect due to the action of Ag
ions. Therefore, the FOP 1 can be provided with antimicrobial
activities.
Inventors: |
Sugawara; Takeo; (Shizuoka,
JP) |
Assignee: |
HAMAMATSU PHOTONICS K.K.
SHIZUOKA
JP
|
Family ID: |
42198092 |
Appl. No.: |
13/130013 |
Filed: |
September 25, 2009 |
PCT Filed: |
September 25, 2009 |
PCT NO: |
PCT/JP2009/066653 |
371 Date: |
May 18, 2011 |
Current U.S.
Class: |
385/120 ;
65/501 |
Current CPC
Class: |
C03C 13/046 20130101;
G02B 6/08 20130101; C03C 3/102 20130101; C03C 4/08 20130101; C03C
3/064 20130101; C03C 3/093 20130101 |
Class at
Publication: |
385/120 ;
65/501 |
International
Class: |
G02B 6/08 20060101
G02B006/08; C03C 13/04 20060101 C03C013/04; C03C 4/00 20060101
C03C004/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 19, 2008 |
JP |
2008-295615 |
Claims
1. A fiber optic plate configured by bundling a plurality of
optical fibers, comprising: a plurality of cores that propagate
light; claddings for covering the cores; and a glass body which is
disposed among the cores and has light absorbability for absorbing
stray light that leaked from the cores and entered the claddings
and antimicrobial activities obtained by containing silver
oxide.
2. The fiber optic plate according to claim 1, wherein the glass
body includes a glass portion made of a glass material having the
absorbability and the antimicrobial activities.
3. The fiber optic plate according to claim 1, wherein the glass
body includes a first glass portion made of a glass material with
the absorbability and a second glass portion made of a glass
material with the antimicrobial activities.
4. The fiber optic plate according to claim 3, wherein the second
glass portion is covered by a third glass portion that does not
contain silver oxide.
5. A method for producing a fiber optic plate configured by
bundling a plurality of optical fibers, wherein a plurality of
cores that propagate light; claddings for covering the cores; and a
glass body which is disposed among the cores and has light
absorbability for absorbing stray light that leaked from the cores
and entered the claddings and antimicrobial activities obtained by
containing silver oxide, are integrated.
Description
TECHNICAL FIELD
[0001] The present invention relates to a fiber optic plate and a
method for producing the same.
BACKGROUND ART
[0002] A fiber optic plate is an optical device configured by
bundling optical fibers of several microns, and is used as an
optical waveguide of optical equipment such as an image
intensifier, a face plate of a CRT, and a CCD coupling, etc.
[0003] As one detailed technique used in the fiber optic plate,
there is fingerprint detection (direct image taking) in a
fingerprint identification device. In fingerprint detection using a
fiber optic plate, it is necessary that a finger of a person to be
identified must be made to touch the fiber optic plate, so that in
a case where fingerprints of many people to be identified are
detected, people who have a resistance to touching the fiber optic
plate are not negligible. Therefore, a measure for eliminating such
a resistance has been demanded.
[0004] In recent years, from the point of view of sanitation and
users' rising concerns about cleanliness, home electric appliances,
groceries, and textile products, etc., have been required to have
antimicrobial activities, and antimicrobial glass with
antimicrobial activities may be contained in resins and fibers
forming these products (for example, refer to Patent Documents 1 to
3).
CITATION LIST
Patent Literature
[0005] Patent Document 1: Japanese Published Unexamined Patent
Application No. 2000-203876 [0006] Patent Document 2: Japanese
Published Unexamined Patent Application No. 2001-247333 [0007]
Patent Document 3: International Publication WO 05/087675
SUMMARY OF INVENTION
Technical Problem
[0008] Thus, antimicrobial activities of home electric appliances,
groceries, and textile products, etc., are realized and realization
of antimicrobial activities of a fiber optic plate has also been
demanded, and a best mode for this has been demanded.
[0009] Therefore, the present invention has been made in view of
these circumstances, and an object thereof is to provide a fiber
optic plate with antimicrobial activities.
Solution to Problem
[0010] In order to achieve the above-described object, a fiber
optic plate according to the present invention is configured by
bundling a plurality of optical fibers, and includes a plurality of
cores that propagates light, claddings for covering the cores, and
a glass body which is disposed among the cores and has light
absorbability for absorbing stray light that leaked from the cores
and entered the claddings and antimicrobial activities obtained by
containing silver oxide.
[0011] In this fiber optic plate, the glass body has antimicrobial
activities obtained by containing silver oxide. Here, the glass
containing silver oxide does not have chemical durability, so that
it has properties of easily emitting Ag ions due to moisture. Ag
ions have an excellent antimicrobial effect. Due to silver oxide
contained in the glass body, the glass body can obtain a
sterilization effect according to the action of Ag ions. Therefore,
the fiber optic plate can be provided with antimicrobial
activities. It is difficult to provide the cores and claddings with
antimicrobial activities in terms of transmittance and production.
However, by providing the glass body with antimicrobial activities,
antimicrobial activities of the fiber optic plate can be realized
while eliminating the above-described problem.
[0012] The fiber optic plate according to the present invention
preferably includes a glass portion made of a glass material having
absorbability and antimicrobial activities. With this
configuration, the glass portion has antimicrobial activities, so
that the fiber optic plate can be reliably provided with
antimicrobial activities.
[0013] In the fiber optic plate according to the present invention,
the glass body preferably includes a first glass portion made of a
glass material with absorbability and a second glass portion made
of a glass material with antimicrobial activities. With this
configuration, the second glass portion has antimicrobial
activities, so that the fiber optic plate can be reliably provided
with antimicrobial activities.
[0014] In the fiber optic plate according to the present invention,
the second glass portion is preferably covered by a third glass
portion that does not contain silver oxide. Ag ions become metallic
Ag when they coexist with Fe ions in glass. This metallic Ag may
deteriorate the sterilization effect of the antimicrobial glass
surface. Therefore, by covering the second glass portion that has
antimicrobial activities due to containing silver oxide by a third
glass portion that does not contain silver oxide, coexistence with
Fe ions of the first glass portion can be avoided, so that the
antimicrobial effect can be prevented from being deteriorated. As a
result, the fiber optic plate can be more reliably provided with
antimicrobial activities.
[0015] A method for producing a fiber optic plate according to the
present invention is for producing a fiber optic plate configured
by bundling a plurality of optical fibers, and by the method, a
plurality of cores that propagate light, claddings that cover the
cores, and a glass body which is disposed among the cores and has
light absorbability for absorbing stray light that leaked from the
cores and entered the claddings and antimicrobial activities
obtained by containing silver oxide, are integrated.
[0016] According to this method for producing a fiber optic plate,
the above-described fiber optic plate according to the present
invention can be preferably produced.
Advantageous Effects of Invention
[0017] According to the present invention, a fiber optic plate can
be provided with antimicrobial activities.
BRIEF DESCRIPTION OF DRAWINGS
[0018] FIG. 1 is a perspective view of a fiber optic plate
according to a first embodiment of the present invention.
[0019] FIG. 2 is a perspective view of an internal structure of the
fiber optic plate in an enlarged manner.
[0020] FIG. 3 is a sectional view of a part of FIG. 2 in an
enlarged manner.
[0021] FIG. 4 is a sectional view showing a part of FIG. 3 in a
further enlarged manner.
[0022] FIG. 5 is a sectional view showing details of an
antimicrobial glass portion.
[0023] FIG. 6 is a diagram showing sizes of constituent materials
of the fiber optic plate.
[0024] FIG. 7 is a diagram showing examples of compositions and
characteristics of constituent materials of the fiber optic
plate.
[0025] FIG. 8 is a diagram showing compositions and characteristics
of antimicrobial glasses used for manufacturing the fiber optic
plate.
[0026] FIG. 9 are diagrams showing antimicrobial effect judgment
results of the fiber optic plate.
[0027] FIG. 10 is a diagram showing relative transmittances of a
conventional fiber optic plate and a fiber optic plate of the
embodiment.
[0028] FIG. 11 is an enlarged sectional view of a part of a fiber
optic plate according to a second embodiment of the present
invention.
[0029] FIG. 12 is a view showing an internal structure of a fiber
optic plate manufactured according to an ISA method in an enlarged
manner.
DESCRIPTION OF EMBODIMENTS
[0030] Hereinafter, preferred embodiments of the present invention
will be described in detail with reference to the drawings. In the
drawings, portions identical or equivalent to each other are
provided with the same reference numeral, and overlapping
description will be omitted.
First Embodiment
[0031] FIG. 1 is a perspective view of a fiber optic plate
according to a first embodiment of the present invention. The fiber
optic plate (hereinafter, referred to as FOP) 1 shown in FIG. 1 is
a columnar optical device configured by bundling a plurality of
optical fibers 7, and has an incidence plane 2 and an exit plane 3.
The FOP 1 has a function of transmitting light and image 4 that
entered from the incidence plane 2 to the exit plane 3, and is used
as an optical waveguide of optical equipment, for example, an image
intensifier, a face plate of a CRT, a CCD coupling, and a
fingerprint detection device, etc.
[0032] FIG. 2 is a perspective view showing an internal structure
of the FOP in an enlarged manner. FIG. 3 is a sectional view of a
part of FIG. 2 in an enlarged manner, and FIG. 4 is a sectional
view of a part of FIG. 3 in a further enlarged manner. As shown in
FIG. 2 to FIG. 4, the FOP 1 includes a plurality of cores 5 that
transmit light, a plurality of claddings 6 that cover the outer
peripheral portions of the cores 5, and a glass body 8 disposed
among the fibers 7. The glass body 8 has absorbability for
absorbing light (stray light) leaking from the fibers 7 and
antimicrobial activities obtained by containing silver oxide. The
core 5 and the cladding 6 constitute the fiber 7. The FOP 1 shown
in FIG. 2 to FIG. 4 is adopted mainly in a product whose numerical
aperture (NA) of the FOP 1 is not more than 1.
[0033] The cores 5 are fibriform members, and are aligned in a
direction crossing the axial direction. The cores 5 are made of
core glass, and have a function of transmitting light that entered
from one end to the other end.
[0034] The plurality of claddings 6 are provided corresponding to
the plurality of cores 5, and are made of clad glass with a
refractive index lower than that of the core glass. The refractive
index of the cladding 6 is lower than the refractive index of the
core 5, so that light that entered the inside of the core 5 is
totally reflected by the interface between the core 5 and the
cladding 6. Therefore, the core 5 can propagate light from one end
to the other end.
[0035] The glass body 8 is interposed among the plurality of fibers
7. The glass body 8 is disposed to cover the outer peripheral
portions of the fibers 7. The glass body 8 consists of absorbing
glass portions (first glass portion) 9 and antimicrobial glass
portions (second glass portions) 10.
[0036] The absorbing glass portion 9 has a rod-like shape (single
fiber) as shown in FIG. 4, and a plurality of absorbing glass
portions are disposed to surround the outer peripheral portion of
the cladding 6. The absorbing glass portions 9 are made of
absorbing glass having absorbability for absorbing stray light.
[0037] The antimicrobial glass portion 10 has, as shown in FIG. 4,
a rod-like shape (single fiber), and a plurality (four in FIG. 4)
of antimicrobial glass portions are disposed on the outer
peripheral portion of the cladding 6 and among the absorbing glass
portions 9. The antimicrobial glass portions 10 are made of
antimicrobial glass with antimicrobial activities. FIG. 5 is a
sectional view showing details of the antimicrobial glass portion
10. As shown in FIG. 5, the outer peripheral portion of the
antimicrobial glass portion 10 is covered by a covering glass
portion (third glass portion) 11 made of clad glass that does not
contain silver oxide. The covering glass portion 11 has the same
composition as that of the claddings 6 described later. The
antimicrobial glass portions 10 occupy approximately 6% of the
entire end face (refer to FIG. 3) of the FOP 1.
[0038] Next, the sizes of the above-described cores 5, the
claddings 6, the absorbing glass portions 9, and the antimicrobial
glass portions 10 will be described with reference to FIG. 6. As
shown in FIG. 6, the cores 5 have a diameter of 30 mm, and the
claddings 6 have a diameter of 40 mm and a thickness of 4 mm. Both
of the absorbing glass portions 9 and the antimicrobial glass
portions 10 have a diameter of 4 mm.
[0039] Subsequently, constituent materials of the FOP 1 will be
described in detail with reference to FIG. 7. FIG. 7 is a diagram
showing examples of compositions and characteristics of the cores
5, the claddings 6, the absorbing glass portions 9, and the
antimicrobial glass portions 10. In FIG. 7, the contents of
compositions are shown in percentages by weight. As shown in FIG.
7, the core glass forming the cores 5 and the clad glass forming
the claddings 6 are composed mainly of SiO.sub.2 as a glass network
forming oxide (NWF: Network former). The core glass and the clad
glass do not become glass singly, and are composed by containing a
glass network modifying oxide (NWM: Network modifier) that provides
glass with appropriate properties by fusion with the NWF, and an
intermediate oxide that has properties intermediate between the NWF
and the NWM.
[0040] The absorbing glass forming the absorbing glass portions 9
is composed mainly of SiO.sub.2. The absorbing glass contains
Fe.sub.3O.sub.4. This Fe.sub.3O.sub.4 has a wide absorbing band,
and by containing Fe.sub.3O.sub.4 in the absorbing glass portions
9, absorption characteristics excellent from a visible light region
to a near-infrared region can be obtained. The absorbing glass
portions 9 also contain other materials such as PbO.
[0041] The antimicrobial glass forming the antimicrobial glass
portions 10 contains B.sub.2O.sub.3, SiO.sub.2, Al.sub.2O.sub.3,
Na.sub.2O, BaO, CaO, and Ag.sub.2O as raw materials. B.sub.2O.sub.3
acts as an NWF forming the framework of glass, and also contributes
to uniform emission of silver ions (Ag ions). B.sub.2O.sub.3 is
contained in a proportion of 20 to 30% of the entirety of the
antimicrobial glass portions 10. SiO.sub.2 acts as an NWF, and also
contributes to prevention of yellowing due to Ag.sub.2O.
Al.sub.2O.sub.3 emits aluminum ions, and contributes to
stabilization of silver ions by coupling to silver ions. Na.sub.2O
acts as an NWM, and has an activity of improving the transparency
of the antimicrobial glass portion 10 and an activity of promoting
fusion and elution of glass. BaO and CaO have an activity of
assisting fusion of glass.
[0042] Ag.sub.2O (silver oxide) is an essential component of the
antimicrobial glass portion 10, which is eluted in glass and
becomes silver ions having antimicrobial activities, and gives the
antimicrobial glass portion 10 the antimicrobial activities. The
content of Ag.sub.2O is approximately 0.5 mass %.
[0043] Next, an example of a method for producing an FOP 1 using
the above-described constituent materials will be described. A
method for manufacturing the FOP 1 (refer to FIG. 2) having the
above-described configuration will be referred to as an EMA (Extra
Mural Absorption) method.
[0044] First, a composite body formed of core glass fanning the
core 5, clad glass forming the cladding 6, and the absorbing glass
portion 9 and the antimicrobial glass portion 10 is put into a
heating device and stretched with a roller, and accordingly, a
single fiber is obtained.
[0045] Next, by using the manufactured single fiber, a multi-fiber
is manufactured. The multi-fiber is obtained by heating and welding
a plurality of single fibers by aligning the plurality of single
fibers, and putting the single fibers in a heating device and
stretching with a roller.
[0046] Subsequently, by aligning multi-fibers in an octagonal mold
of a hot pressing machine and pressing them at a high temperature,
the plurality of multi-fibers are heated and welded, and
accordingly, an octagonal ingot is obtained. Then, the ingot is
sliced perpendicularly to the axial direction and polished, and
accordingly, an FOP 1 is obtained.
[0047] As described above, in the FOP 1 according to the present
embodiment, a glass body 8 is configured by including the
antimicrobial glass portions 10 made of antimicrobial glass
containing Ag.sub.2O. Here, the glass containing silver does not
have chemical durability, so that it has properties to easily emit
Ag ions due to moisture. Ag ions have an excellent antimicrobial
effect. Therefore, the glass body 8 is configured by including the
antimicrobial glass portions 10 containing Ag.sub.2O, and
accordingly, the glass body 8 can be provided with a sterilization
effect due to the action of Ag ions. Therefore, the FOP 1 can be
provided with antimicrobial activities.
[0048] It is difficult to make the cores 5 and the claddings 6 of
antimicrobial glass in terms of transmittance and production.
However, by making the antimicrobial glass portions 10 constituting
the glass body 8 of antimicrobial glass, antimicrobial activities
of the FOP 1 can be realized while the above-described problem is
solved.
[0049] The antimicrobial glass portion 10 is covered by a covering
glass portion 11 that does not contain silver oxide. Ag ions become
metallic Ag due to coexistence with Fe ions in glass. This metallic
Ag may deteriorate the sterilization effect of the antimicrobial
glass surface. Therefore, by covering the antimicrobial glass
portion 10 provided with antimicrobial activities obtained by
containing Ag.sub.2O by the covering glass portion 11 that does not
contain Ag.sub.2O, coexistence with Fe ions of the absorbing glass
portion 9 can be avoided, so that the sterilization effect can be
prevented from being deteriorated. As a result, the FOP 1 can be
more reliably provided with antimicrobial activities.
Embodiment 1
[0050] Hereinafter, the present invention will be described in
greater detail based on embodiments and conventional examples,
however, the following embodiments are not intended to limit the
present invention at all.
[0051] The inventors of the present invention manufactured a FOP
having the above-described configuration. FIG. 8 shows compositions
and properties of antimicrobial glasses used for manufacturing the
FOP. The antimicrobial effect of this FOP was evaluated according
to the following steps. An antimicrobial test for the FOP was
conducted according to a test method conforming to JIS Z 2801 2000.
Specifically, the surfaces of a conventional unprocessed specimen
not containing Ag.sub.2O and a specimen of the embodiment were
inoculated with test microbes, and the counts of viable microbes
after culture for 24 hours were measured. JIS regulates that in the
case where a logarithmic value difference (antimicrobial activity
value) between the count of viable microbes of the conventional
unprocessed specimen and the count of viable microbes of the
specimen of the embodiment is not less than 2.0, the antimicrobial
effect is effective. As test strains, Staphylococcus aureus and
coliform bacillus were used. The number of inoculated microbes of
Staphylococcus aureus was 1.8.times.10.sup.5, and the number of
inoculated microbes of coliform bacillus was
2.9.times.10.sup.5.
[0052] The results obtained through the above-described test are
shown in FIG. 9(a) and FIG. 9(b). The results shown in FIG. 9(a)
and FIG. 9(b) show the results of an FOP including the
antimicrobial glass of No. 11 of FIG. 8. As shown in FIG. 9(a) and
FIG. 9(b), it was confirmed that the FOP of the embodiment had the
antimicrobial effect.
[0053] FIG. 10 shows relative transmittances of the conventional
FOP and the FOP of the embodiment. In both of the conventional
example and the embodiment, the FOP has a fiber size of 15 .mu.m
and a thickness of 1.75 mm. The relative transmittances shown in
FIG. 10 are relative transmittances for 850 nm diffusion light. As
shown in FIG. 10, the relative transmittance of the FOP of the
embodiment is substantially equal to that of the conventional FOP,
so that it was confirmed that optical characteristics were
substantially the same as those of the conventional product.
Concerning the image quality, a substantially similar result was
obtained.
Second Embodiment
[0054] FIG. 11 is an enlarged sectional view of a part of a fiber
optic plate according to a second embodiment of the present
invention. As shown in FIG. 11, the FOP 20 is configured in much
the same way as the FOP 1 of the first embodiment, and is different
from the first embodiment in that the glass body 21 is formed of
absorbing glass portions (glass portions) 22.
[0055] Specifically, in the first embodiment, the outer peripheral
portion of the cladding 6 is covered by a glass body 8 consisting
of absorbing glass portions 9 and antimicrobial glass portions 10,
however, in the second embodiment, the cladding 6 is covered by a
glass body 21 consisting of the absorbing glass portions 22. The
absorbing glass portions 22 are made of a glass material with
absorbability and antimicrobial activities. This glass material is
made of the absorbing glass and antimicrobial glass containing
Ag.sub.2O shown in the first embodiment. The materials to be used
for the core 5 and the cladding 6 are the same as in the first
embodiment. The FOP 1 is manufactured according to the same
production method as that for the FOP 1 of the first
embodiment.
[0056] As described above, in the FOP 20 according to the second
embodiment, as in the first embodiment, the absorbing glass
portions 22 contain Ag.sub.2O, so that the glass body 21 can obtain
a sterilization effect according to the action of Ag ions.
Therefore, the FOP 20 can be provided with antimicrobial
activities.
[0057] The present invention is not limited to the above-described
embodiments.
[0058] For example, the glass body 8 of the first embodiment is not
limited to the above-described configuration. The glass body 8 may
be formed of an absorber with absorbability and antimicrobial
activities and antimicrobial glass portions. The glass body 8 may
be formed of an absorber and antimicrobial glass portions with
absorbability and antimicrobial activities.
[0059] The above-described FOPs 1 and 20 are manufactured according
to the EMA method, however, they may be manufactured according to a
method called an ISA (Interstitial Absorption) method.
Specifically, FIG. 12 shows an FOP manufactured according to the
ISA method. As shown in this figure, in the FOP 30 manufactured
according to the ISA method, the cladding 31 is formed integrally
and covers the outer peripheral portions of the plurality of cores
5. Further, the cladding 31 covers the outer peripheral portions of
the absorbing glass portions 32. The absorbing glass portions 32
are made of the same material as in the second embodiment.
[0060] The absorbing glass portions 9, 22, and 32 may not be
rod-shaped, but may be tubular. The claddings 6 covering the
antimicrobial glass portions 10 may not be necessarily
provided.
INDUSTRIAL APPLICABILITY
[0061] According to the present invention, a fiber optic plate can
be provided with antimicrobial activities.
REFERENCE SIGNS LIST
[0062] 1, 20, 30: Fiber optic plate (FOP), 5: Core, 6, 31:
Cladding, 8, 21: Glass body, 9: Absorbing glass portion (first
glass portion), 10: Antimicrobial glass portion (second glass
portion), 11: Covering glass portion (third glass portion), 22, 32:
Absorber (glass portion)
* * * * *