U.S. patent application number 10/522714 was filed with the patent office on 2005-06-16 for hydrating case for moisture-containing lens and hydrating method using it.
Invention is credited to Nakagawa, Makoto.
Application Number | 20050126940 10/522714 |
Document ID | / |
Family ID | 31943815 |
Filed Date | 2005-06-16 |
United States Patent
Application |
20050126940 |
Kind Code |
A1 |
Nakagawa, Makoto |
June 16, 2005 |
Hydrating case for moisture-containing lens and hydrating method
using it
Abstract
The invention relates to a case for hydrating a
moisture-containing contact lens in a dry condition, a hydrating
device, and a hydrating method. A case (2) comprises a plurality of
grooves (8) provided in the inside face (6) of a recess (4). A lens
is placed in the case, a proper amount of a hydrating liquid is
poured along the inside wall face of the recess (4) in the case in
a first step. Then in a second step, a hydrating liquid is poured
into the recess from above the case to allow the contact lens (3)
to absorb water and swell. Accordingly, a wide extent of a lens
front surface can come into contact evenly with the hydrating
liquid in the first step, and the entire lens can be hydrated in
the second step, whereby an efficient hydration is possible with
lens curling and bubble entrapping prevented.
Inventors: |
Nakagawa, Makoto; (Aichi,
JP) |
Correspondence
Address: |
OLIFF & BERRIDGE, PLC
P.O. BOX 19928
ALEXANDRIA
VA
22320
US
|
Family ID: |
31943815 |
Appl. No.: |
10/522714 |
Filed: |
January 28, 2005 |
PCT Filed: |
August 12, 2003 |
PCT NO: |
PCT/JP03/10262 |
Current U.S.
Class: |
206/316.1 |
Current CPC
Class: |
A45C 11/005 20130101;
B29D 11/00067 20130101 |
Class at
Publication: |
206/316.1 |
International
Class: |
B65D 085/38 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 12, 2002 |
JP |
2002234742 |
Claims
1. A hydrating case having a containment recess for containing
therein a moisture-containing contact lens and used for bringing
the moisture-containing contact lens in a dry state into contact
with a hydrating liquid within the containment recess in order to
absorb water and swell, the hydrating case being characterized in
that an area of a concave inside face of the containment recess on
which the moisture-containing contact lens rests is formed as a
concave bowed face having a curvature generally equivalent to that
of a front surface of the moisture-containing contact lens, and a
depression that opens out onto the concave bowed face is formed in
order to create a gap between the moisture-containing contact lens
and the containment recess so that when the hydrating liquid flows
down along the concave inside face, the hydrating liquid enters the
gap.
2. A hydrating case according to claim 1, wherein the depression is
formed in such a way that, when the moisture-containing contact
lens is placed on the concave bowed face of the containment recess,
the gap formed between the moisture-containing contact lens and the
containment recess has a opening that opens to an outer peripheral
side of the moisture-containing contact lens, and extends
continuously diametrically inward from the opening.
3. A hydrating case according to claim 1, wherein the depression is
formed by at least one groove.
4. A hydrating case according to claim 3, wherein the at least one
grooves is of a pattern extending generally in the circumferential
direction of the concave bowed face.
5. A hydrating case according to claim 3, wherein the at least one
grooves has a pattern extending in the generally diametrical
direction of the concave bowed face.
6. A hydrating case according to claim 1, wherein a groove depth
dimension is 0.05 mm or more where a groove width dimension is 1 mm
or less, whereas the depth dimension is less than 0.05 mm where the
groove width dimension is 3 mm or more.
7. A hydrating case according to claim 1, wherein a ratio of an
area: Ab occupied by the depression to a total area: Aa of the
concave bowed face on which the moisture-containing contact lens
rests, is such that 0.2.ltoreq.Ab/Aa.ltoreq.0.8.
8. A hydrating case according to claim 1, wherein a center support
portion having no grooves is formed in a center portion of the
concave bowed face so that a center portion of the
moisture-containing contact lens is superimposed over an entire
face of the center support portion.
9. A hydrating case according to claim 1, wherein a center
depression is formed in a center portion of the containment recess
so that a lens center is supported floating above the containment
recess by the center depression.
10. A hydrating case according to claim 1, wherein both the concave
bowed face and a bottom face of the depression have smooth,
generally mirrored surfaces.
11. A hydrating case according to claim 1, wherein a mating portion
is formed in a rim of a mouth of the containment recess, and a
cover is detachably attached by being mated with the mating
portion.
12. A hydrating case according to claim 11, wherein the cover has a
tube through-hole formed therein, and a supply tube for supplying
the hydrating liquid to the containment recess is inserted through
the tube through-hole so that with the containment recess covered
by the cover the hydrating liquid is supplied to the containment
recess through the supply tube.
13. A hydrating case according to claim 11, wherein the mouth of
the containment recess is provided with a liquid tight closure by
the cover so as to constitute a distribution case in which the
moisture-containing contact lens is sealed within the containment
recess in a state of being immersed in a distribution storage
liquid.
14. A hydrating device employing a hydrating case having a
containment recess for containing therein a moisture-containing
contact lens and used for bringing the moisture-containing contact
lens in a dry state into contact with a hydrating liquid within the
containment recess in order to absorb water and swell, the
hydrating case being characterized in that an area of a concave
inside face of the containment recess on which the
moisture-containing contact lens rests is formed as a concave bowed
face having a curvature generally equivalent to that of a front
surface of the moisture-containing contact lens, and a depression
that opens out onto the concave bowed face is formed in order to
create a gap between the moisture-containing contact lens and the
containment recess so that when the hydrating liquid flows down
along the concave inside face, the hydrating liquid enters the gap,
for use to allow the moisture-containing contact lens in the dry
state within the containment recess of the hydrating case to absorb
water and swell, the hydrating device being characterized by
comprising: a flow tube set bordering a mouth of the containment
recess in the hydrating case; and a first injection port and a
second injection port formed in the flow tube for supplying the
hydrating liquid to the containment recess, the first injection
port opening towards the concave inside face on a mouth side from
the concave bowed face in the containment recess of the hydrating
case, and the second injection port opening towards a back surface
of the moisture-containing contact lens resting on the concave
bowed face of the lens, wherein a supply of the hydrating liquid
through the first injection port and a supply of the hydrating
liquid through the second injection port are independently
controllable.
15. A hydrating device employing a hydrating case having a
containment recess for containing therein a moisture-containing
contact lens and used for bringing the moisture-containing contact
lens in a dry state into contact with a hydrating liquid within the
containment recess in order to absorb water and swell, the
hydrating case being characterized in that an area of a concave
inside face of the containment recess on which the
moisture-containing contact lens rests is formed as a concave bowed
face having a curvature generally equivalent to that of a front
surface of the moisture-containing contact lens, and a depression
that opens out onto the concave bowed face is formed in order to
create a gap between the moisture-containing contact lens and the
containment recess so that when the hydrating liquid flows down
along the concave inside face, the hydrating liquid enters the gap,
for use to allow the moisture-containing contact lens in the dry
state within the containment recess of the hydrating case to absorb
water and swell, the hydrating device being characterized by
comprising: a flow tube set bordering the mouth of the containment
recess in the hydrating case; and an injection port formed in the
flow tube for supplying the hydrating liquid to the containment
recess, the flow tube being inclined with respect to the hydrating
case whereby an opening direction of the injection port is variable
with respect to the containment recess, and being selectively
positionable at either a first opening location at which the
injection port opens towards the concave inside face on a mouth
side from the concave bowed face in the containment recess of the
hydrating case, and a second opening location at which the
injection port opens towards a back surface of the
moisture-containing contact lens resting on the concave bowed face
of the lens.
16. A hydrating device according to claim 14, wherein a drain port
opening into the containment recess is formed in the flow tube, the
hydrating liquid supplied to the containment recess being sucked
out through the drain port in order to drain the liquid from the
containment recess.
17. A moisture-containing contact lens hydrating method employing a
hydrating case having a containment recess for containing therein a
moisture-containing contact lens and used for bringing the
moisture-containing contact lens in a dry state into contact with a
hydrating liquid within the containment recess in order to absorb
water and swell, the hydrating case being characterized in that an
area of a concave inside face of the containment recess on which
the moisture-containing contact lens rests is formed as a concave
bowed face having a curvature generally equivalent to that of a
front surface of the moisture-containing contact lens, and a
depression that opens out onto the concave bowed face is formed in
order to create a gap between the moisture-containing contact lens
and the containment recess so that when the hydrating liquid flows
down along the concave inside face, the hydrating liquid enters the
gap, for use to allow the moisture-containing contact lens in the
dry state within the containment recess of the hydrating case to
absorb water and swell, the hydrating method being characterized by
comprising: a first injection step wherein the moisture-containing
contact lens in the dry state is placed in the containment recess
of the hydrating case, and with the front surface of the
moisture-containing contact lens resting supported on the concave
bowed face, the hydrating liquid is supplied along the concave
inside face on the mouth side from the concave bowed face in the
containment recess, whereby the hydrating liquid is made to enter
the gap formed between the moisture-containing contact lens and the
containment recess by means of the depression; and a second
injection step wherein after the first injection step, the
hydrating liquid is supplied towards the back surface of the
moisture-containing contact lens contained within the containment
recess, whereby the moisture-containing contact lens is immersed in
the hydrating liquid within the containment recess.
18. A moisture-containing contact lens hydrating method according
to claim 17, wherein a hydrating liquid feed during the first
injection step is 2 mL or less.
19. A moisture-containing contact lens hydrating method according
to claim 17, wherein after the second injection step, a flow step
in which more hydrating liquid is supplied continuously to the
containment recess while draining the excess hydrating liquid from
the containment recess at the same time is performed.
20. A moisture-containing contact lens hydrating method according
to claim 19, wherein in the flow step, the flow rate produced
through the containment recess by means of supplying and draining
the hydrating liquid is varied in stepwise fashion.
Description
TECHNICAL FIELD
[0001] The present invention relates to a hydrating case for a
moisture-containing contact lens and to a hydrating method using
the same, and more particular relates to a hydrating case for
eluting unreacted monomer from a moisture-containing contact lens
in a dry condition, and bringing the moisture-containing contact
lens to an equilibrium swelled condition that is as uniform as
possible, and to a hydrating method therefor.
BACKGROUND ART
[0002] Typically, a moisture-containing contact lens is brought to
finished product form by first fabricating a lens of the desired
shape by various methods, and then subjecting it to a hydrating
process and washing process in order to eliminate impurities such
as unreacted monomer and the like. Treatment receptacles for
carrying out. such hydrating/washing processes are disclosed in
JP-A-7-113990 and JP-A-4-227643, for example.
[0003] Specifically, the lens treatment receptacles taught in the
publications cited hereinabove are formed so as to have a male
chamber and a female chamber of an arrangement that can be
assembled together in the vertical direction. With the male and
female chambers assembled together, there is formed between the
opposing faces a space capable of accommodating a lens. The male
chamber is provided with a single filling port (disclosed as a
washing conduit in the aforementioned publication) that, when
assembled with the female chamber, allows the space accommodating
the lens to be supplied with water for carrying out the lens
hydrating/washing process. This port passes through the center
portions of the opposing faces of the male chamber and female
chamber in the vertical direction. A plurality of drain ports for
draining the treatment water from the space are formed at equal
intervals in the circumferential direction in the side wall
extending vertically from the circumferential edge of the opposing
face of the male chamber. With this treatment receptacle, the male
and female chambers are assembled together, and in the space formed
therebetween is accommodated a lens that has just been fabricated
to predetermined lens shape. In this condition, the treatment water
is supplied continuously to the space through the filling port of
the male chamber in order to fill the space with the treatment
water, so that the lens within the space is immersed in the
treatment water and is induced to swell, to bring about hydration
of the lens. The excess treatment water supplied to the space
drains out from the plurality of drain ports, with the treatment
water flowing through from the filling port to the plurality of
drain ports so that the treatment water is induced to flow radially
outward over the lens inside face and outside face from the center
portions thereof, to effect washing of the lens.
[0004] With a treatment receptacle of this structure, it is
necessary after completing the lens hydration process to transfer
the lens to a case for commercial distribution. While a
moisture-containing contact lens easy to handle mechanically prior
to being hydrated with water, once hydrated it becomes soft,
becoming susceptible to being damaged by even slight action during
handling, and becoming difficult to handle mechanically.
Accordingly, it is important to minimize handling of a
moisture-containing contact lens to the greatest extent possible
once the lens has been processed and formed. In particular, it is
desirable to avoid handling that would involve direct contact with
the lens in the hydrated state.
[0005] In order to address such problems, there is disclosed, for
example, in JP-A-2002-221696 a technique wherein a commercial
distribution case is used as the case for the hydrating process,
and a moisture-containing contact lens in the dry state is housed
within a housing recess provided in the hydrating process case.
This case is brought into contact with hydrating process solution
to hydrate and swell the lens, and is then washed in water flowing
through. The hydrating process case is then sealed and used as the
distribution case.
[0006] In a distribution case of conventional design such as that
taught in JP-A-2002-221696, the inside face of the lens housing
portion is typically made a smooth spherical concave face having
curvature approximating that of the front surface of the contact
lens, in order to avoid deformation of the contact lens during
storage. However, moisture-containing contact lenses, due to their
pliability, tend to become attracted onto such spherical concave
faces, creating the problem of lens deformation, and difficulty in
extracting the lens when removing it.
[0007] Further, it has been found by the inventors that when the
hydrating method taught in JP-A-2002-221696 is followed, curling
can occur during swelling of the moisture-containing contact lens
in the dry state, and bubbles can become entrapped in curled
portions, so that the moisture-containing contact lens floats in
the treatment space in the case. Once air has been entrapped by a
moisture-containing contact lens, it is subsequently very difficult
to remove it from the moisture-containing contact lens, and if the
moisture-containing contact lens floats, this poses the risk of
impairing uniform water absorption and swelling, as well as of poor
efficiency in elution of unreacted monomer.
DISCLOSURE OF THE INVENTION
[0008] With the foregoing in view, it is an object of the present
invention to provide a hydrating case of novel structure affording
reduced curling and other non-uniform deformation of a
moisture-containing contact lens during hydration of the
moisture-containing contact lens, as well as enabling the hydrating
process to be carried out in a consistent manner; and a novel
hydrating method employing this hydrating case.
[0009] It is yet another object of the invention to provide
hydrating case of novel structure affording reduced entrapment of
bubbles during the moisture-containing contact lens hydrating
process, whereby the moisture-containing contact lens can be
induced to evenly absorb water and swell, and whereby unreacted
monomer can be eluted efficiently; and a novel hydrating method
employing this hydrating case.
[0010] To address such problems, as disclosed hereinbelow, the
invention provides (I) a hydrating case for a moisture-containing
contact lens, (II) a moisture-containing contact lens hydrating
device employing the hydrating case, and (III) a
moisture-containing contact lens hydrating method employing the
hydrating case.
[0011] (First Mode of the Invention Relating to a Hydrating
Case)
[0012] The invention in a first mode thereof relating to a
hydrating case is a hydrating case having a containment recess for
containing therein a moisture-containing contact lens and used for
bringing the moisture-containing contact lens in a dry state into
contact with a hydrating liquid within the containment recess in
order to absorb water and swell, said hydrating case being
characterized in that an area of a concave inside face of the
containment recess on which the moisture-containing contact lens
rests is formed as a concave bowed face having a curvature
generally equivalent to that of a front surface of the
moisture-containing contact lens, and a depression that opens out
onto the concave bowed face is formed in order to create a gap
between the moisture-containing contact lens and the containment
recess so that when the hydrating liquid flows down along the
concave inside face, the hydrating liquid enters the gap.
[0013] In the hydrating case of structure according to this mode,
since a depression is formed on the concave inside face forming the
containment recess in which the moisture-containing contact lens is
placed and contained, the area of contact between the
moisture-containing contact lens and the concave inside face
(concave bowed face) is minimized, and a gap can be formed between
the moisture-containing contact lens and the containment recess. By
means of hydrating liquid entering this gap, the entire front
surface of the moisture-containing contact lens is readily
contacted by the hydrating liquid, making it possible to improve
the efficiency of elution of unreacted monomer and the like.
[0014] Additionally, in the hydrating case according to this mode,
since a small gap is formed between the moisture-containing contact
lens and the containment recess, capillary action of the hydrating
liquid is exhibited by the gap by means of hydrating liquid flowing
down along the concave inside face, making it possible for the
hydrating liquid to advantageously enter between the
moisture-containing contact lens and the containment recess. By
means of causing the hydrating liquid to actively come into contact
with the moisture-containing contact lens over a wide area of its
front surface, it is possible to advantageously avoid curling and
other types of irregular deformation during swelling of the
moisture-containing contact lens, as well as improving efficiency
of removal of unreacted monomer remaining inside the
moisture-containing contact lens.
[0015] Further, in the hydrating case pertaining to this mode,
since the concave bowed face per se has curvature generally
equivalent to that of the front surface of the moisture-containing
contact lens, in areas where depressions are not formed, the front
surface of the moisture-containing contact lens is supported over a
sufficiently large area by the concave bowed face. Therefore, for
example, the moisture-containing contact lens can consistently hold
its shape during the moisture-containing contact lens
hydration/swelling process, and the moisture-containing contact
lens can consistently hold its shape in the event of being stored
for an extended period.
[0016] Additionally, by means of the depression formed therein,
contact of the concave bowed face with the entire front surface of
the moisture-containing contact lens can be avoided, whereby
physical adhesion between the moisture-containing contact lens and
the concave bowed face can be prevented, and free movement of the
moisture-containing contact lens during hydration and during
storage can be ensured. This arrangement improves the efficiency of
water absorption/swelling and avoids lens deformation and the like,
while making it easy for the moisture-containing contact lens to be
removed from the hydrating case.
[0017] The number, shape and locations of depressions in this mode
can be selected freely insofar as no deformation or other adverse
effects are produced by supporting force on the moisture-containing
contact lens positioned contained therein, and an adequate area of
contact of hydrating liquid with the front surface of the
moisture-containing contact lens can be assured, and insofar as
such depressions are formable with a linear shape, spiral shape,
serpentine shape, a shape having a geometrical pattern, or a shape
combining portions of these shapes, for example. The depressions
may be utilized to impart text, patterns, markings or the like to
the container case, or to impart some design element to appeal to
the taste of the user. Since the hydrating case is typically
produced by injection molding of synthetic resin, employing of
various shapes for the depressions can be accomplished readily by
means of imparting the corresponding shape to the forming mold.
[0018] (Second Mode of the Invention Relating to a Hydrating
Case)
[0019] The invention in a second mode thereof relating to a
hydrating case is a hydrating case according to the first mode,
wherein the depression is formed in such a way that, when the
moisture-containing contact lens is placed on the concave bowed
face of the containment recess, the gap formed between the
moisture-containing contact lens and the containment recess has a
opening that opens to an outer peripheral side of the
moisture-containing contact lens, and extends continuously
diametrically inward from the opening.
[0020] In this mode, it is possible to advantageously induce the
hydrating liquid flowing down the concave inside face to enter into
the gap formed between the moisture-containing contact lens and the
containment recess. With this arrangement, the hydrating liquid can
be made to quickly enter the gap, so that the moisture-containing
contact lens hydrating process may be carried out with a higher
level of efficiency.
[0021] (Third Mode of the Invention Relating to a Hydrating
Case)
[0022] The invention in a third mode thereof relating to a
hydrating case is a hydrating case according to the first or second
mode, wherein the depression is formed by at least one groove.
[0023] In this mode, by establishing an appropriate pattern for the
groove(s) which form the gap between the moisture-containing
contact lens and the containment recess, it is possible to control
the flow of hydrating liquid entering into the gap. Thus, it
becomes possible, for example, to make the hydrating liquid contact
more uniformly over a large area of the moisture-containing contact
lens, or in the initial stage of contact with the hydrating liquid,
to bring about hydration and swelling starting from a specific area
of the moisture-containing contact lens. Also, by forming the
depression with a groove form, the gap can exhibit a higher level
of capillary action on the hydrating liquid, making it possible to
accelerate entry of the hydrating liquid.
[0024] (Fourth Mode of the Invention Relating to a Hydrating
Case)
[0025] The invention in a fourth mode thereof relating to a
hydrating case is a hydrating case according to the third mode,
wherein at least one of the grooves is of a pattern extending
generally in the circumferential direction of the concave bowed
face.
[0026] In this mode, it is possible to guide the hydrating liquid
generally uniformly and rapidly along the front surface of the
moisture-containing contact lens and in particular in the
circumferential direction thereof, so that when subjecting the
moisture-containing contact lens to the hydrating process, it is
possible to more advantageously hold down irregular deformation in
the circumferential direction thereof. The groove(s) extending in
the circumferential direction according to this mode is
advantageously formed, for example, as a plurality of concentric
annular grooves, or as one or an appropriate number of spiral
grooves. The grooves extending in the circumferential direction may
be given generally identical cross sectional shape and dimensions
over the entire extension thereof, in order to avoid a situation
where the hydrating liquid enters and flows easily only into a
certain groove or grooves. Alternatively, by locating a plurality
of grooves at generally equal intervals in diametrical cross
section, or by gradually differentiating the spacing between the
plurality of grooves or giving the plurality of grooves mutually
different shapes, it is possible to adjust diffusion of the
hydrating liquid.
[0027] (Fifth Mode of the Invention Relating to a Hydrating
Case)
[0028] The invention in a fifth mode thereof relating to a
hydrating case is a hydrating case according to the third or fourth
mode, wherein at least one of the grooves has a pattern extending
in the generally diametrical direction of the concave bowed
face.
[0029] In this mode, it is possible to guide the hydrating liquid
generally uniformly and rapidly along the front surface of the
moisture-containing contact lens and in particular in the
diametrical direction thereof, so that when subjecting the
moisture-containing contact lens to the hydrating process, it is
possible to more advantageously hold down irregular deformation in
the diametrical direction thereof. It is also possible to give a
groove or grooves extending in the diametrical direction a shape
that constricts gradually moving diametrically inward. Grooves
extending in the diametrical direction need not be straight, but
may instead be curved like the distal ends of the blades of a fan.
Additionally, grooves extending in the diametrical direction
pertaining to this mode may be combined with grooves extending in
the circumferential direction pertaining to the fourth mode
described previously. The two types of grooves are formed in a
mutually intersecting pattern, whereby it is possible to guide the
hydrating liquid more advantageously over a large area, in both the
circumferential direction and diametrical direction at the front
surface of the moisture-containing contact lens.
[0030] (Sixth Mode of the Invention Relating to a Hydrating
Case)
[0031] The invention in a sixth mode thereof relating to a
hydrating case is a hydrating case according to any of the third to
fifth modes, wherein a groove depth dimension is 0.05 mm or more
where a groove width dimension is 1 mm or less, whereas the depth
dimension is less than 0.05 mm where the groove width dimension is
3 mm or more.
[0032] (Seventh Mode of the Invention Relating to a Hydrating
Case)
[0033] The invention in a seventh mode thereof relating to a
hydrating case is a hydrating case according to any of the first to
sixth modes, wherein a ratio of an area: Ab occupied by the
depression to a total area: Aa of the concave bowed face on which
the moisture-containing contact lens rests, is such that
0.2.ltoreq.Ab/Aa.ltoreq.0.8.
[0034] According to the sixth mode and the seventh mode, good entry
of hydrating liquid into the gap formed between the
moisture-containing contact lens and the containment recess by the
depression (including grooves) can be achieved, while holding down
deformation of the moisture-containing contact lens caused by
formation of the depression, so that the objective hydrating
process can be carried out more rapidly and with a high degree of
accuracy.
[0035] That is, while groove width dimension and depth dimension in
the third mode etc. of the invention herein are not particularly
limited, where groove width is large, it is preferable to make the
groove shallow as well so that the moisture-containing contact lens
does not enter the groove and become deformed. On the other hand,
where groove width is narrow, since there is no risk of the
moisture-containing contact lens entering the groove, it is
preferable to make the groove deep in consideration of flow rate
and ease of flow of the hydrating liquid, i.e. circulation of the
hydrating liquid. In this sense, where groove width is 3 mm or more
it is preferable for the groove to be shallower than 0.05 mm, and
where groove width is narrow, i.e. 1 mm or less, it is preferable
for the groove to be 0.05 mm or more in depth.
[0036] Additionally, while the area ratio (Ab/Aa) of the concave
bowed face of the depression (including the grooves of the third
mode etc.) to the concave bowed face in the first mode etc. of the
invention is not particularly limited, in preferred practice it
will be on the order of 20-80%, more preferably 50%. Namely, if the
area ratio of the depression to the concave bowed face is too
large, the support area provided by the concave bowed face
supporting the moisture-containing contact lens through contact
with the moisture-containing contact lens will become too small,
and may end up promoting deformation of the moisture-containing
contact lens, whereas if the area ratio of the depression to the
concave bowed face is too small, the efficiency of contact of
hydrating liquid with the front surface of the moisture-containing
contact lens may be diminished.
[0037] (Eighth Mode of the Invention Relating to a Hydrating
Case)
[0038] The invention in an eighth mode thereof relating to a
hydrating case is a hydrating case according to any of the first to
seventh modes, wherein a center support portion having no grooves
is formed in a center portion of the concave bowed face so that a
center portion of the moisture-containing contact lens is
superimposed over an entire face of the center support portion.
[0039] (Ninth Mode of the Invention Relating to a Hydrating
Case)
[0040] The invention in a ninth mode thereof relating to a
hydrating case is a hydrating case according to any of the first to
seventh modes wherein a center depression is formed in a center
portion of the containment recess so that a lens center is
supported floating above the containment recess by the center
depression.
[0041] According to the eighth and ninth modes described
hereinabove, the center portion of a moisture-containing contact
lens of which accuracy in dimensions and shape are especially
required to impart intended optical characteristics can be
supported at the front surface thereof in a generally uniform
manner by a center support portion (eighth mode) or float entirely
above the case at the front surface thereof by means of a center
depression (ninth mode). With this arrangement, localized stress in
the center portion of the lens and warping resulting therefrom can
be effectively prevented, so that the intended optical
characteristics can be achieved more advantageously.
[0042] (Tenth Mode of the Invention Relating to a Hydrating
Case)
[0043] The invention in a tenth mode thereof relating to a
hydrating case is a hydrating case according to any of the first to
ninth modes wherein both the concave bowed face and a bottom face
of the depression have smooth, generally mirrored surfaces.
[0044] In this mode, by manufacturing the hydrating case from
transparent synthetic resin, it becomes possible to see the
moisture-containing contact lens inside the containment recess,
from outside the bottom of the hydrating case. This arrangement
makes it possible, for example, to check if the moisture-containing
contact lens is present in the sealed hydrating case without having
to unseal the case, or to inspect the lens for damage or the like.
During lens inspection, it is typical to employ a method of
acquiring an image of the lens inside the hydrating case,
distribution case, or other container case, and inspect the surface
condition. As compared to the case where the concave bowed face of
the container case is a semi-sphere having constant curvature,
where grooves or other depressions are provided, contrast is
intensified at the boundaries of the depressions, thus aiding in
the discovery of any flaws in the lens.
[0045] (Eleventh Mode of the Invention Relating to a Hydrating
Case)
[0046] The invention in an eleventh mode thereof relating to a
hydrating case is a hydrating case according to any of the first to
tenth modes wherein a mating portion is formed in a rim of a mouth
of the containment recess, and a cover is detachably attached by
being mated with the mating portion.
[0047] In this mode, the containment recess that houses the
moisture-containing contact lens may be readily covered by means of
a cover, whereby by employing the twelfth or thirteenth mode
hereinbelow, for example, it becomes possible to easily and
advantageously prevent infiltration of foreign matter or bacteria
into the containment recess during the moisture-containing contact
lens hydrating process or during distribution.
[0048] (Twelfth Mode of the Invention Relating to a Hydrating
Case)
[0049] The invention in a twelfth mode thereof relating to a
hydrating case is a hydrating case according to the eleventh mode
wherein the cover has a tube through-hole formed therein, and a
supply tube for supplying the hydrating liquid to the containment
recess is inserted through the tube through-hole so that with the
containment recess covered by the cover the hydrating liquid is
supplied to the containment recess through the supply tube.
[0050] In the hydrating case of structure according to this mode in
particular, while making it possible to supply hydrating liquid to
the containment recess during the hydrating process, it is possible
as well to advantageous maintain the containment recess in a
covered state. That is, it is possible in the hydrating process to
carry out the hydrating process by pouring in and draining the
hydrating liquid without covering the containment recess of the
treatment case. However, in order to extract unreacted monomer from
the moisture-containing contact lens, it is typical practice to
repeat a procedure of letting the moisture-containing contact lens
stand soaking in the hydrating liquid for several minutes or more,
to allow time for unreacted monomer to elute from inside the
moisture-containing contact lens, and then pouring in fresh
hydrating liquid to effect liquid exchange within the containment
recess. Therefore, if a cover is not used, during the repeated
hydrating liquid filling/draining procedure, there is a risk that
hydrating liquid will overflow to the outside, or that during the
standing period the hydrating liquid filling the containment recess
will become contaminated by foreign matter.
[0051] In the hydrating case of structure according to this mode,
it is possible to cover the containment recess with a cover during
the hydrating process, and to insert a guide tube (i.e. a supply
tube for supplying hydrating liquid, or an additional drain tube
for draining) through the tube through-hole provided in the cover,
whereby hydrating liquid can be poured in through the guide tube,
as well as draining out the hydrating liquid, making it possible to
flow hydrating liquid through the containment recess interior,
while maintaining the hydrating liquid in constant contact with the
moisture-containing contact lens. This arrangement makes it
possible to more efficiently and easily carry out the hydration
process of the moisture-containing contact lens (including
elimination of extracted unreacted monomer) while inside the
containment recess. Since the containment recess is covered by the
cover, contamination by foreign matter during the hydrating process
interval can be prevented, and it is also possible to prevent
hydrating liquid from overflowing to outside the hydrating case
when the hydrating liquid is poured in, while at the same time
completely filling the containment recess interior with hydrating
liquid, so that contact of the hydrating liquid with the
moisture-containing contact lens can be carried out more
advantageously and consistently.
[0052] In this mode, as mentioned previously, during the standing
period in which the moisture-containing contact lens is allowed to
stand soaking in the hydrating liquid for a predetermined time
period in order to allow time for unreacted monomer to elute from
inside the moisture-containing contact lens, the tube may be
withdrawn from the tube through-hole in the cover. At this time,
since the mouth of the containment recess is constricted by the
cover so that the area of the opening to the outside is small,
contamination by foreign matter of hydrating liquid accumulated in
the containment recess can be avoided.
[0053] In preferred practice, the portion of the guide tube
situated inside the containment recess, i.e. the guide tube distal
end (nozzle) for injecting the hydrating liquid will have a unitary
tube structure, while comprising all injection ports and drain
ports for supplying/draining all of the hydrating liquid. This
arrangement makes it possible to form a single through-hole in the
cover, whereby the guide tube arrangement is simpler than a
structure incorporating a number of tubes, and contamination by
foreign matter of the lens containment space interior through the
through-hole in the cover can be effectively reduced.
[0054] In this mode, preferably a guide tube having an injection
port for pouring in hydrating liquid and a drain port for draining
the hydrating liquid is inserted through at least one through-hole
provided in the cover, and the guide tube is affixed so as to hold
the cover on the hydrating case. In this mode, since the guide tube
is affixed so as to hold the cover on the hydrating case, it
becomes possible to readily separate the guide tube and the cover
after the hydrating liquid injection and draining process. By
adopting such an mode, it is also possible to quickly carry out
hydrating liquid injection and draining processes continuously in
succession on hydrating cases of other subsequent lenses (with
cover attached), whereby it is possible to incorporate it as a step
in an automated mass production system. As a result, reductions in
production costs can be advantageously achieved.
[0055] Further, in a mode of this kind, by holding down the guide
tube for guiding the hydrating liquid into the containment recess
from above a through-hole provided in the cover, the interior of
the contact lens containment recess composed of the hydrating case,
the cover, and the guide tube is provided with a hermetic
structure. That is, a structure in which the containment recess
formed between the opposing faces of the treatment case recess and
the cover, and communicating with the outside through a
through-hole in the cover, is rendered hermetic by means of
inserting the guide tube through the through-hole, whereby during
injection of hydrating liquid the containment recess interior can
be filled with the hydrating liquid, without the hydrating liquid
spilling out from the hydrating case. Accordingly, in preferred
practice the hydrating case and the cover may each be fabricated of
resin, whereby the force holding the guide tube and the repulsive
force of the resin of the cover based thereon can be utilized to
increase the hermetic seal of the containment space. The mode by
which the guide tube is held down from above the through-hole
provided in the cover includes a mode in which a guide tube of
outer peripheral shape the same as or slightly larger than the
through-hole is employed, the guide tube being forced into the
through-hole so that the guide tube inserts through the
through-hole with the outer peripheral surface thereof coming into
substantially intimate contact with the inside rim of the
through-hole around the entire circumference thereof.
[0056] (Thirteenth Mode of the Invention Relating to a Hydrating
Case)
[0057] The invention in a thirteenth mode thereof relating to a
hydrating case is a hydrating case according to the eleventh or
twelfth mode wherein the mouth of the containment recess is
provided with a liquid tight closure by the cover so as to
constitute a distribution case in which the moisture-containing
contact lens is sealed within the containment recess in a state of
being immersed in a distribution storage liquid.
[0058] In this mode in particular, the hydrating case for carrying
out the hydrating process can be used as the distribution case,
whereby without any direct contact, the hydrated contact lens can
be shipped out and put into distribution channels, thereby avoiding
problems such as damage or defects due to contact with the contact
lens in the hydrated state. Additionally, in the hydrating case
used in this mode, since the support face on which the front face
of the moisture-containing contact lens rests has a concave bowed
face with curvature equivalent to that of the front face of the
moisture-containing contact lens, even if the lens is stored
contained therein for an extended period of time, the problem of
deformation of the moisture-containing contact lens can be avoided
as much as possible. Additionally, since the concave bowed face has
an appropriate depression formed thereon, there is no adhesion of
the moisture-containing contact lens to the inside surface of the
containment recess during storage or during shipping, as can occur
with a curved surface simply having smooth curvature.
[0059] In the event that the hydrating case is used also as the
distribution case, once injection and draining of the hydrating
liquid have been repeated to sufficiently extract unreacted monomer
from the lens, then finally filled with distribution storing
liquid. In the case of a hydrating case of structure in accordance
with the aforementioned twelfth mode for example, with the .guide
tube withdrawn from the cover and the cover attached or with the
cover removed, the area surrounding the containment recess that
contains the moisture-containing contact lens for which the
hydrating process has been completed is covered with a sealing
sheet (for example, a laminate of polypropylene or other suitable
plastic film with aluminum foil; or a single pliable sheet composed
of silicon oxide forming a barrier material having a plastic
layer), and by means of subjecting the sealing sheet in the flat
portions thereof extending around the containment recess to heat
sealing or the like, forming a hermetic environment for the
moisture-containing contact lens contained therein, whereby there
can be produced as the completed product a blister case of the kind
commonly offered for sale.
[0060] Where for example a hydrating case of structure in
accordance with the aforementioned eleventh or twelfth mode has
been sealed with the cover in place, by bonding the sealing sheet
and the cover at least in part by means of heat, it becomes
possible to remove the cover adhering to the sheet, at the same
time that the sheet is peeled off, thereby simplifying the
procedure to remove the lens, and allowing the case to be handled
just like a conventional one sealed with a sheet only. Where the
cover is thusly sealed together with the sealing sheet, whereas
with blister cases of conventional type unintentional impact
applied to the sealing sheet during the distribution process etc.
could result in a hole in the sealing sheet or in the container
losing its sterile condition, where the cover is thusly sealed
together with the sealing sheet in this way, the reinforcing effect
provided to the sealing sheet by the cover can advantageously
prevent damage to the sealing sheet.
[0061] Further, in the event that a hydrating case of structure in
accordance with the aforementioned twelfth mode doubles as the
distribution case, in order to prevent the treatment case interior
from becoming contaminated by foreign matter when the containment
space with the exception of the guide tube is open, it is
preferable for the through-holes formed in the cover to be few in
number, and for the diameter thereof to be small as well.
[0062] (First Mode of the Invention Relating to a Hydrating
Device)
[0063] The invention in a first mode thereof relating to a
hydrating device is a hydrating device employing the hydrating case
defined in any one of the first to thirteenth modes of the
invention relating to a hydrating case, for use to allow the
moisture-containing contact lens in the dry state within the
containment recess of the hydrating case to absorb water and swell,
the hydrating device being characterized by comprising: a flow tube
set bordering a mouth of the containment recess in the hydrating
case; and a first injection port and a second injection port formed
in the flow tube for supplying the hydrating liquid to the
containment recess, the first injection port opening towards the
concave inside face on a mouth side from the concave bowed face in
the containment recess of the hydrating case, and the second
injection port opening towards a back surface of the
moisture-containing contact lens resting on the concave bowed face
of the lens, wherein a supply of the hydrating liquid through the
first injection port and a supply of the hydrating liquid through
the second injection port are independently controllable.
[0064] (Second Mode of the Invention Relating to a Hydrating
Device)
[0065] The invention in a first mode thereof relating to a
hydrating device is a hydrating device employing the hydrating case
defined in any one of the first to thirteenth modes of the
invention relating to a hydrating case, for use to allow the
moisture-containing contact lens in the dry state within the
containment recess of the hydrating case to absorb water and swell,
the hydrating device being characterized by comprising: a flow tube
set bordering the mouth of the containment recess in the hydrating
case; and an injection port formed in the flow tube for supplying
the hydrating liquid to the containment recess, the flow tube being
inclined with respect to the hydrating case whereby an opening
direction of the injection port is variable with respect to the
containment recess, and being selectively positionable at either a
first opening location at which the injection port opens towards
the concave inside face on a mouth side from the concave bowed face
in the containment recess of the hydrating case, and a second
opening location at which the injection port opens towards a back
surface of the moisture-containing contact lens resting on the
concave bowed face of the lens.
[0066] In the hydrating device of structure according to the first
or second mode of the invention, the flow of hydrating liquid
emitted from the first injection port (first mode) or at the first
opening location (second mode) is directed onto the concave inside
face on the mouth side from the concave bowed face in the
containment recess of the hydrating case so as to flow down the
concave inside face, whereby it is guided into the gap between the
containment recess and the moisture-containing contact lens being
stored in the hydrating case. By means of the depression which
forms the gap, the hydrating liquid advantageously enters over a
sufficiently large area of the front surface of the
moisture-containing contact lens, whereby the moisture-containing
contact lens can be subjected to the hydrating process from the
front surface thereof, and over a large area.
[0067] After the hydrating liquid has been emitted from the first
injection port or the first opening location, the hydrating liquid
emitted from the second injection port (first mode) or at the
second opening location (second mode) is supplied to the hydrating
case while being directed towards the upward-opening back surface
of the moisture-containing contact lens housed in the hydrating
case. With this arrangement, the moisture-containing contact lens
can be restrained from floating up, while keeping the
moisture-containing contact lens immersed within the containment
recess of the hydrating case.
[0068] (Third Mode of the Invention Relating to a Hydrating
Device)
[0069] The invention in a first mode thereof relating to a
hydrating device is a hydrating device of structure according to
the first or second mode, wherein a drain port opening into the
containment recess is formed in the flow tube, the hydrating liquid
supplied to the containment recess being sucked out through the
drain port in order to drain the liquid from the containment
recess.
[0070] In the hydrating device of structure according to this mode,
by draining the hydrating liquid through the drain port while
supplying the hydrating liquid into the containment recess of the
hydrating case through the injection port, liquid can be
continuously circulate through the containment recess, whereby it
is possible to more effectively carry out the hydrating process
(including the process of extraction unreacted monomer and the
like) of the moisture-containing contact lens contained placed
within the containment recess.
[0071] As noted, in this mode, by carrying out injection of the
hydrating liquid and draining of the hydrating liquid
simultaneously, it is possible to create flow of hydrating liquid
within the containment recess, i.e. agitation with the containment
recess by means of the injected hydrating liquid, and carry out
exchange of the hydrating liquid, while draining the processed
hydrating liquid from the drain port; alternatively it would also
be possible, after draining out from the drain port the hydrating
liquid placed in the containment recess from the beginning, to then
fill the containment recess with fresh hydrating liquid.
[0072] (First Mode of the Invention Relating to a Hydrating
Method)
[0073] The invention in a first mode thereof relating to a
hydrating method is a hydrating method employing a hydrating case
defined in any one of the first to thirteenth modes of the
invention relating to a hydrating case, for use to allow the
moisture-containing contact lens in the dry state, the
moisture-containing contact lens hydrating method being
characterized by comprising: (a) a first injection step wherein the
moisture-containing contact lens in the dry state is placed in the
containment recess of the hydrating case, and with the front
surface of the moisture-containing contact lens resting supported
on the concave bowed face, the hydrating liquid is supplied along
the concave inside face on the mouth side from the concave bowed
face in the containment recess, whereby the hydrating liquid is
made to enter the gap formed between the moisture-containing
contact lens and the containment recess by means of the depression;
and (b) a second injection step wherein after the first injection
step, the hydrating liquid is supplied towards the back surface of
the moisture-containing contact lens contained within the
containment recess, whereby the moisture-containing contact lens is
immersed in the hydrating liquid within the containment recess.
[0074] According to the hydrating method of this mode, in the first
injection step, the hydrating liquid is brought into contact with
the front surface of the moisture-containing contact lens in the
dry state, whereby the moisture-containing contact lens is hydrated
and swelled from the front face. Since a depression has been formed
in the concave bowed face which supports the front face of the
moisture-containing contact lens, the hydrating liquid is
advantageously and rapidly guided into contact with a large area of
the lens front face by means of the gap formed by the depression.
Thus, curling and other such non-uniform deformation of the
moisture-containing contact lens due to hydration and swelling of
the moisture-containing contact lens, as well associated
entrainment of air bubbles, can be prevented, and the
hydration/swelling process may be carried out in a consistent
manner.
[0075] Additionally, since at the front surface of the
moisture-containing contact lens there is formed a widening gap by
the depression on the concave bowed face supporting it, the contact
area of the moisture-containing contact lens and the hydrating
liquid supplied in the first injection process can be made
sufficiently large at the lens front surface, and the extraction
efficiency of unreacted monomer and the like may be improved.
[0076] Further, once the moisture-containing contact lens has been
hydrated and swelled from the front surface, by means of the second
injection step, the moisture-containing contact lens immersed in
the hydrating liquid which is poured into the containment recess
from the back surface of the moisture-containing contact lens,
whereby hydration and swelling of the entire moisture-containing
contact lens can proceed while maintaining consistent shape of the
moisture-containing contact lens, in a condition free of entrapped
bubbles.
[0077] That is, when a moisture-containing contact lens in the dry
state prior to being hydrated comes into contact with hydrating
liquid, it will rapidly absorb liquid, and thus if the containment
space containing the moisture-containing contact lens in the dry
state suddenly begins to be filled with hydrating liquid, the
contact lens may curl, and as the contact lens curls bubbles may
become entrapped at the curled portions, so that the contact lens
floats up within the containment space, posing the risk that
uniform absorption and swelling by the contact lens will be
hampered and that unreacted monomer will not be extracted
efficiently. Additionally, it is typically difficult to separate
air from a contact lens once entrapped. Thus, according to this
mode, in the first injection step, the space between the concave
bowed face and the front face of the dry moisture-containing
contact lens is first primed with hydrating liquid; then in the
second injection step, the containment space is filled with
additional hydrating liquid from the back surface side of the
moisture-containing contact lens, whereby the contact lens is held
fixedly along the concave bowed face in the first injection step,
while in the second step it is possible to avoid entrapment of
bubbles and floating of the contact lens while filling the recess
with the hydrating liquid.
[0078] (Second Mode of the Invention Relating to a Hydrating
Method)
[0079] The invention in a second mode thereof relating to a
hydrating method is a hydrating method according to the first mode,
wherein a hydrating liquid feed during the first injection step is
2 mL or less.
[0080] According to this mode, it is possible to avoid a situation
in which injection of an excessive amount of hydrating liquid in
the first injection step results in the hydrating liquid rising up
onto the back surface of the moisture-containing contact lens, so
that the shape stabilizing action afforded by a hydration/swelling
process taking place from the front surface of the
moisture-containing contact lens can be more effectively realized.
That is, the amount of hydrating liquid introduced in the first
hydrating step need simply be sufficient to lubricate the lens
front surface and the treatment case concave bowed face and
surrounding area, whereas introduction of a large amount creates
the possibility of curling of the contact lens and entrapment of
air bubbles. Thus, a small amount, preferably 2 mL or less and more
preferably 1 mL or less, or depending on lens size and the shape of
the depression in the concave bowed face, even 0.5 mL or less, will
suffice. Once the first hydrating step has been completed, in the
second hydrating step which is carried out after a brief interval,
the hydrating liquid is added in an amount sufficient to maintain
the moisture-containing contact lens completely immersed in the
containment recess, preferably an amount sufficient to fill up the
containment recess.
[0081] (Third Mode of the Invention Relating to a Hydrating
Method)
[0082] The invention in a third mode thereof relating to a
hydrating method is a hydrating method according to the first or
second mode, wherein after the second injection step, a flow step
in which more hydrating liquid is supplied continuously to the
containment recess while draining the excess hydrating liquid from
the containment recess at the same time is performed.
[0083] According to this mode, it is possible to more efficiently
eliminate unreacted monomer that is extracted from the surfaces of
the moisture-containing contact lens by means of the first and
second steps. When implementing the method of this mode, the
hydrating case pertaining to the aforementioned twelfth mode of the
invention relating to a hydrating case is advantageously employed,
and the hydrating device pertaining to any of the first to third
modes relating to a hydrating device is advantageously
employed.
[0084] (Fourth Mode of the Invention Relating to a Hydrating
Method)
[0085] The invention in a fourth mode thereof relating to a
hydrating method is a hydrating method according to the third mode,
wherein in the flow step, the flow rate produced through the
containment recess by means of supplying and draining the hydrating
liquid is varied in stepwise fashion.
[0086] According to this mode, it is possible to more effectively
bring about extraction of unreacted monomer from the
moisture-containing contact lens and elimination of dust etc.
adhering to contact lens surfaces, by taking into consideration
temporal change in the level of extraction of unreacted
monomer.
[0087] Where a hydrating process is carried out according the
method of the invention pertaining to any of the first to fourth
modes described hereinabove, in the event that using the hydrating
case pertaining to the aforementioned thirteenth mode relating to a
hydrating case, the hydrating case is to be used as the
distribution case, the lens case will typically be manufactured by
injection molding. By lacing the finished moisture-containing
contact lens in the dry state just after molding, into the
containment recess and covering it with a cover or the like as
described previously, it is possible to largely eliminate
contamination by dust or the like infiltrating into the containment
recess. Still more favorably, better effect in improving product
quality can be achieved by carrying out the hydration process
steps, including the procedure for placing the moisture-containing
contact lens in the containment recess, entirely within a clean
area.
BRIEF DESCRIPTION OF THE DRAWINGS
[0088] FIG. 1 is a perspective view of the hydrating case as a
first embodiment of the invention.
[0089] FIG. 2 is a plan view of the hydrating case shown in FIG.
1.
[0090] FIG. 3 is a sectional view taken along line III-III in FIG.
2.
[0091] FIG. 4 is a sectional view of the treatment case employed in
the hydrating method of the invention.
[0092] FIG. 5 is an illustration of implementation of the hydrating
method of the invention.
[0093] FIG. 6 is a perspective view showing another embodiment of
the hydrating case of the invention.
[0094] FIG. 7 is a perspective view showing another embodiment of
the hydrating case of the invention.
[0095] FIG. 8 is a perspective view showing another embodiment of
the hydrating case of the invention.
[0096] FIG. 9 is a perspective view showing another embodiment of
the hydrating case of the invention.
[0097] FIG. 10 is a perspective view showing another embodiment of
the hydrating case of the invention.
[0098] FIG. 11 is a perspective view showing another embodiment of
the hydrating method of the invention.
BEST MODE FOR CARRYING OUT THE INVENTION
[0099] In order to illustrate the invention more concretely, the
embodiments of the invention are described in detail hereinbelow,
making reference to the accompanying drawings.
[0100] A treatment case 2 for a moisture-containing contact lens is
shown in FIG. 1 to FIG. 3 by way of a first embodiment of the
invention. This case 2 has a recess 4 as a containment recess for
containing the moisture-containing contact lens (3). In the
description hereinbelow, as a general rule, the vertical direction
in FIG. 3 shall be deemed the vertical direction.
[0101] More specifically, the case 2 structure has a rectangular
top panel 5, and four leg portions extending integrally in the
thickness direction of the top panel 5, i.e. downward, from the
four corners of the top panel 5. In this embodiment, the top panel
5 has a square shape overall. In the generally central portion of
the top panel 5 is formed a recess 4 that opens in the other the
thickness direction of the top panel 5, i.e. upward. This recess 4
has a circular mouth, giving it an overall shape resembling half of
a hollow sphere. A circumferential groove 7 is formed around the
entire circumference of the rim of the mouth of the recess 4, as a
mating portion.
[0102] In this embodiment, the recess 4 formed in the case 2 has a
mouth whose diameter dimension is of a size such that the
moisture-containing contact lens (3) can be readily placed in and
removed through the mouth, specifically, a size greater than the
diameter of the contact lens (3), but less than twice the diameter
of the contact lens (3). The depth dimension of the recess 4 is a
depth dimension such that the contact lens (3) immersed in the
hydrating liquid can be accommodated together with the hydrating
liquid used to carry out the hydration and washing processes of the
contact lens (3), specifically, smaller than the diameter of the
contact lens (3), but greater than the radius of the contact lens
(3).
[0103] The concave inside face of the recess 4, in an area on the
bottom side of the recess 4, has a concave bowed face 6 of
curvature generally equivalent to that of the contact lens (3), in
particular the front surface of the moisture-containing contact
lens (3). With this arrangement, the concave bowed face 6 has
curvature greater than the outside face curvature of the contact
lens (3) in the dry state, so that the contact lens (3) in the
hydrated state will not be subjected to excessive outside force. In
particular, in this embodiment, curvature differs between the
portion on the bottom side and the portion on the mouth side,
thereby forming a shoulder at the boundary of the bottom side
portion and the mouth side portion, i.e., the portion having the
concave bowed face 6 formed thereon, and the portion not.
[0104] In this way, a plurality of grooves 8 are formed as
depressions in the recess 4. This plurality of grooves 8 extend
linearly from the rim of the recess 4 to the center of the recess
4, i.e. to the center portion on the bottom of the recess 4, and
are formed at equidistant intervals about the circumference of the
recess 4. That is, the plurality of grooves 8 are formed radially
from the center of the bottom of the recess 4 to the rim of the
recess 4, at spacing that is equidistant in the circumferential
direction. Accordingly, in this embodiment, the plurality of
grooves 8 are formed so as to open onto the concave bowed face 6,
so that no grooves are formed on the mouth rim side of the recess
4. Also, in this embodiment, the groove 8 bottom faces and the
concave inside face have the same curvature with each other. Also,
the grooves 8 are formed extending in the diametrical direction
with mutually identical cross sections, and in this embodiment the
width dimension thereof constricts gradually going from the mouth
rim side to the center portion of the bottom, with the depth
dimension decreasing as well. In this embodiment, the center
portion of the bottom of the recess 4, i.e. the center portion of
the concave bowed face 6, has no grooves formed thereon. This
center portion of the concave bowed face 6 devoid of grooves
constitutes a central support portion 9. By forming a plurality of
grooves 8 on the concave bowed face 6, with the front face, i.e.
the convex side, of the contact lens (3) resting on the concave
bowed face 6, a gap is formed between the contact lens (3) and the
recess 4, whereby the contact area between the concave bowed face 6
and the contact lens (3) may be adjusted. With the contact lens (3)
positioned with its front face side resting on the concave bowed
face 6, the gap formed between the contact lens (3) and the recess
4 opens to the outside peripheral side of the contact lens (3),
with the hydrating liquid entering through this opening.
[0105] The groove 8 surfaces, i.e. the groove 8 bottom faces, do
not come into direct contact with the contact lens (3), and for
this reason can be irregular surfaces. However, in consideration of
the fact that the contact lens (3) will be inspected while placed
in the case 2, flat surfaces or mirror-finish surfaces are
preferred. On the other hand, since in locations other than where
the grooves 8 are formed the concave bowed face 6 comes into direct
contact with the contact lens (3), a smooth surface is preferred in
order to avoid damaging the contact lens (3). In particular, in
this embodiment, the concave bowed face 6, in portions thereof
where the plurality of grooves 8 are not formed, is formed overall
as a convex surface having curvature approximating the curvature of
the entire face of the contact lens (3).
[0106] In order to be inexpensive and easy to handle, the case 2 of
this structure can be formed of thermoplastic plastic selected
appropriately, for example, from polyethylene, polypropylene,
ethylene vinyl acetate, propylene copolymer, polystyrene, nylon or
the like, and molded by means of an injection molding or
thermocompression molding process.
[0107] The hydrating method using this treatment case 2 will now be
described. This hydrating method is carried out using a treatment
container 1 like that shown in FIG. 4, the treatment container 1
being compose of the treatment case 2, and a cover 10 for attaching
to the treatment case 2. This cover 10 is formed of synthetic resin
material, and overall has a shape slightly larger than the mouth of
the recess 4 that is provided in the case 2. In this embodiment in
particular, the cover 10 has a disk shape overall. The cover 10 in
the center portion thereof has formed a single through hole 21
serving as a tube insertion hole, and at the outside peripheral
edge has a ridge 11 extending continuously all the way around the
circumference in the circumferential direction.
[0108] This cover 10 is attached to the case 2 in such a way as to
cover the mouth of the recess in the case 2. With the cover 10
attached to the case 2 in this way, the ridge 11 of the cover 10
mates with the circumferential groove 7. By so doing, there is
formed between the opposing faces of the cover 10 and the recess 4
a containment space 12 for containing the contact lens 3 positioned
therein, the containment space 12 being connected to the outside
space exclusively through the through hole 21 provided in the cover
10. Attachment of the cover 20 to the case 2 is carried out with
the contact lens 3 contained within the recess 4.
[0109] Next, as shown in FIG. 5, a guide tube 20 serving as a
supply tube (flow tube) is attached to the cover 10 making up the
treatment container 1. This guide tube 20 has a structure
comprising two injection-end passages 32, 33 and a single drain-end
passage 34. The distal end of the guide tube 20 forms an injection
nozzle having two injection ports 22, 23 for injecting into the
containment space 12 the hydrating liquid flowing through the
injection-end passages 32, 33, and a drain port 24 for draining
through the drain-end passage 34 the hydrating liquid that has been
injected into the containment space 12. In this embodiment, the
injection port 22 opens out at the distal end portion of the guide
tube 20, i.e. the cylindrical outside peripheral surface of the
injection nozzle, whereas the injection port 23 opens at the
projecting distal end face of the injection nozzle. In this
embodiment, the drain port 24 opens out onto the cylindrical
outside peripheral surface of the injection nozzle. Further, in
this embodiment, the injection nozzle is smaller in diameter than
the main body portion of the guide tube 20, thereby forming an
annular shoulder face at the boundary of the injection nozzle and
the main body portion. As will be apparent from the previous
description, in this embodiment, the injection port 22 constitutes
the first injection port, and the injection port 23 constitutes the
second injection port.
[0110] While not shown clearly in the drawings, the guide tube 20
is also connected to an injection pump for injecting the hydrating
liquid into the containment space 12 through the injection-end
passages 32, 33; an injection-end tank for storing the hydrating
liquid which will be injected into the containment space 12; and a
drain-end tank for storing the hydrating liquid which has been
drained out through the drain-end passage 34. If necessary, there
may also be provided a suction pump for draining out through the
drain-end passage 34 the hydrating liquid injected into the
containment space 12. The injection pump and the suction pump are
controlled by means of a control unit. As will be apparent from the
above, in this embodiment, the hydrating device arrangement
includes the guide tube 20, the tanks and pumps connected to the
guide tube 20, and the control unit for controlling the pumps.
[0111] The guide tube 20 is attached to the cover 10 by inserting
the injection nozzle of the guide tube 20 through the through-hole
21. During this process, by causing the guide tube 20 to be
detained on the cover 10, specifically, by pushing the guide tube
20 so that the annular shoulder face formed at the boundary of the
injection nozzle and the main body portion becomes detained outside
(above in the drawing) the outside face of the cover 10 surrounding
the through-hole 21, the guide tube 20 and the cover 10 are placed
in intimate contact. Thus, the through-hole 21 is sealed off in
fluid-tight fashion, and the ridge 11 of the cover 10 mates with
the circumferential groove 7 of the case 2 ensuring that the
containment space 12 is fluid tight, whereby the containment space
12 becomes a space hermetically sealed off from the outside. In
this case, the pressure at which the guide tube 20 is detained on
the cover 10 can be a level of pressure sufficient to prevent the
hydrating liquid from leaking out from the containment space 12
when the hydrating liquid is injected into the containment space
12. During this time, it is preferable that the air already present
within the containment space 12 be removed quickly. Specifically,
by way of example, an air bleed hole could be provided to the
injection nozzle, or an air bleed gap of a size such that hydrating
liquid leakage is negligible could be formed between the cover 10
and the guide tube 20, for example.
[0112] Next, a first hydration process step is carried out by way
of a first injection step for injecting an aqueous treatment liquid
from the injection port 22 through one of the injection-end
passages 32 of the guide tube 20. This aqueous treatment liquid may
be selected appropriately from, for example, deionized water,
aqueous solution containing surfactant, physiological saline, or
other liquid used conventionally for moisture-containing contact
lens hydrating processes and cleaning processes. In the first
hydration process step, the hydrating liquid is injecting in from
the injection port 22 towards the side wall of the recess 4 in the
case 2, i.e. towards the side wall in proximity to the edge of the
mouth of the recess, whereupon the injected hydrating liquid flows
down along the concave inside face to the bottom end of the recess
4, i.e. the area where the contact lens 3 is located. From the area
surrounding the contact lens 3, the hydrating liquid then primes
the gap between the contact lens 3 and the wall surface at the
bottom end of the recess 4, to bring about preliminary hydration of
the contact lens 3. With this arrangement, the contact lens 3 is
appropriately attracted on the curved face of the recess 4, and
hydrated.
[0113] Subsequently, after a predetermined time interval (for
example, several seconds to several tens of seconds), a second
hydration process step is carried out by way of a second injection
step for injecting the hydrating liquid from the injection port 23
through the other injection-end passage 33 of the guide tube 20.
The hydrating liquid injected in this second hydration process step
is the same as that injected in the first hydration process step.
The hydrating liquid is injected from the injection port 23 towards
the back surface of the contact lens 3, and once the containment
space 12 has become filled with the hydrating liquid, the contact
lens 3 is immersed therein for an appropriate period of time, to
extract unreacted monomer remaining in the contact lens 3. Next, a
circulation step in which fresh hydrating liquid is injected into
the containment space 12 through the two injection-end passages 32,
33, while draining out the hydrating liquid overflow from the drain
port 24 through the drain-end passage 34 to drain it from the
containment space 12 is carried out.
[0114] Here, switching between the injection-end passages 32, 33
when injecting the hydrating liquid in the manner described above
can be accomplished, for example, in a case in which an injection
tank and pump are connected to each injection-end passage, turning
the power supply to each pump on and off. Alternatively in a case
in which the injection-end passage are furnished with a shared
injection tank and pump, disposing a changeover valve for switching
between the injection-end passages 32, 33 on the line connecting
the pump to the injection-end passages 32, 33, and operating this
changeover valve. By means of employing such an arrangement, the
supply of hydrating liquid through the injection port 22 and the
supply of hydrating liquid through the injection port 23 are
controllable independently.
[0115] In the hydrating process described above, the flow rate of
hydrating liquid within the containment space 12 is preferably on
the order of several cc/sec to several tens of cc/sec. The
temperature of the hydrating liquid is preferably on the order of
20-80.degree. C. Further, the exchange interval of the hydrating
liquid is preferably from several minutes to several tens of
minutes. The injection of warm water effectively eliminates
unreacted monomer from within the contact lens 3.
[0116] By carrying out hydrating liquid flow rate or injection in a
multi-stepwise manner, efficiency of the cleaning and hydration
process of the contact lens 3 can be improved. For example, when
transitioning from a dry state to a hydrated state during initial
injection, since the contact lens 3 becomes swelled and larger in
size, its shape tend to become unstable. If the flow rate at this
time is too high there is a risk of deformation of the contact lens
3 obtained subsequently. Therefore, the initial flow rate should be
kept fairly low, with the second and subsequent fill-ups of
hydrating liquid conversely taking place at faster flow rates so
that the internal solution, i.e. the hydrating liquid within the
containment space 12, is agitated and the efficiency of exchange is
increased. At the point in time that the hydration state is thought
to reach equilibrium, fresh hydrating liquid is brought into
contact with the contact lens 3 at a higher flow rate, in order to
promote elution of unreacted monomer and the like extracted from
the contact lens 3. The interval for hydrating liquid exchange is
carried out at relatively brief intervals initially due to the
large amount of unreacted monomer that is extracted, with the
exchange interval gradually increasing thereafter, to improve the
efficiency of utilization of the hydrating liquid.
[0117] Further, there is no need for the guide tube 20 to be
connected continuously to the containment space 12 until the
contact lens 3 processing is completed; rather, the guide tube 20
may be used efficiently by connecting the guide tube to another
treatment container during the time interval that the contact lens
3 is simply being immersed.
[0118] When the hydration process is complete, in the final
circulation process, a contact lens 3 storage solution is injected
into the containment space 12, and the guide tube 20 is withdrawn.
Then, with the cover 10 still in place or removed, the top panel 5
of the case is covered with a sealing sheet, and then heat sealed
to make the recess 4 into a hermetic space.
[0119] In this way, in the present embodiment the contact lens 3
case 2 serves as both the treatment case and the distribution case,
and thus there is no direct mechanical contact with the contact
lens 3 in the hydrated state, so that damage or other defects of
the lens 3 can be effectively prevented. The treatment case 2
sealed in this way may optionally be subjected to a sterilization
process, to appropriate packaging, imprinting and the like, and
then sent to the distribution process.
[0120] In order to impart good adhesion by means of heat sealing or
adhesive, the sealing sheet which is sealed after processing of the
contact lens 3 is finished will preferably consist of material
composed of a laminate of polyethylene, polypropylene or other
material similar to the material of the treatment case, having a
layer of aluminum foil on the surface; or another material composed
of silicon oxide forming a barrier material having a plastic
layer.
[0121] In the hydrating method according to this embodiment, the
hydrating process is carried out using a treatment case 2 that has
a plurality of grooves 8 formed on the concave bowed face 6, and
thus it is possible to adjust the surface of the recess 4, in
particular the contact area between the concave bowed face 6 and
the contact lens 3, whereby the hydrating liquid can be induced to
spread over the entire lens while permitting freer movement of the
contact lens 3. Thus, the contact lens 3 in the dry state is able
to absorb liquid over its entirety, thereby promoting uniform
swelling and avoiding deformation of lens shape, which tends to
become irregular if there is sudden absorption during the initial
phase of the hydration process.
[0122] Also, in this embodiment, since grooves are disposed
uniformly/evenly over substantially the entire surface of the
concave bowed face in the recess 4, deformation of the contact lens
3 during lens hydration and storage may be effectively
prevented.
[0123] Further, in this embodiment, the concave bowed face 6 in the
recess 4, considered apart from those portions where the grooves 8
are located, forms overall a concave face having curvature similar
to the overall curvature of the contact lens 3, so that when
employed as the distribution case, the contact lens 3 is not
subjected to excessive stress during storage for an extended
period, so that deformation of the contact lens 3 can be
advantageously prevented.
[0124] Also, in this embodiment, since the depth of the recess 4
can be adjusted appropriately, the contact lens 3 will not rotate
during transport.
[0125] Further, in this embodiment, since a plurality of grooves 8
are formed on the concave bowed face 6, it is possible to prevent
physical adhesion of the contact lens 3 to the concave bowed face,
to assure free movement of the contact lens 3 during hydration,
storage, and transport, and to avoid deformation of the contact
lens 3.
[0126] Also, in this embodiment, by carrying out initial filling in
two stages, as compared to the case of filling the contact lens 3
with hydrating liquid from above from the outset, it is possible to
carry out filling without bubbles adhering to the contact lens 3
and without curling of the contact lens 3.
[0127] While certain specific arrangements of invention have been
shown hereinabove, these are merely exemplary, the invention being
in no way limited to the disclosure hereinabove.
[0128] For example, whereas in the preceding embodiment the
plurality of grooves 8 are formed radially, they could instead have
shapes such as those depicted in FIG. 6 to FIG. 9. The grooves 8
shown in FIG. 6 are formed in spiral shape. The grooves 8 shown in
FIG. 7 are formed in serpentine shape, with the grooves 8 extending
in the generally circumferential direction. The grooves 8 shown in
FIG. 8 are formed as multiple annular grooves. That is, the grooves
8 shown in FIG. 8 are each formed extending in the circumferential
direction. Those shown in FIG. 9 have formed portions of the
straight grooves 8 shown in FIG. 1. These groove configurations are
merely exemplary; provided that the hydrating process can be
carried out with efficiency, various configurations which combine
these or are formed from portions thereof are possible as well.
These grooves may also form part of a pattern.
[0129] In the embodiment hereinabove, the contact lens 3, when
placed inside the recess 4, is disposed with center portion of the
front surface in contact with the portion of the concave bowed face
6 devoid of grooves 8, i.e. the center support portion 9. However,
it could instead not contact the recess 4, as shown in FIG. 10.
[0130] Specifically, whereas in the embodiment hereinabove, each
groove 8 has decreasing depth dimension going towards the bottom of
the recess 4, with no grooves 8 being formed in the center portion
of the bottom of the recess 4 and the center portion of the contact
lens 3 front surface contacting the bottom of the recess 4, in the
embodiment shown in FIG. 10, the grooves 8 have unchanging depth
dimension going towards the bottom of the recess 4, being formed as
if the side wall portions of the grooves 8 are cut off. The contact
lens 3 comes into contact exclusively with the upper faces of the
groove 8 side wall portions, whereby with the contact lens 3 placed
within the recess 4, the center portion of the contact lens 3 front
surface does not contact the recess 4. As will be apparent from the
above, in the embodiment depicted in FIG. 10, a central depression
13 is formed in the center portion of the bottom of the recess 4.
To aid in understanding, components and regions similar in
structure to those in the first embodiment are assigned the same
symbols as in the first embodiment.
[0131] In the embodiment hereinabove, there was described a
treatment method employed in the case where the cover 10 has a
single through-hole 21. However, where treatment is carried using
for example, both the guide tube having injection ports 22, 23 and
passages 32, 33 communicating therewith, and the guide tube having
the drain port 24 and the passage 34 communicating therewith, a
cover with two through-holes would be acceptable; or even where
only a single through-hole is provided, the process could be
carried out by alternately coupling the guide tubes to the
cover.
[0132] Further, the concave bowed face 6 having curvature generally
equivalent to that of the front face of the moisture-containing
contact lens will preferably support the center portion of the
contact lens 3 front face abutting it over a sufficiently large
area, whereby deformation of the moisture-containing contact lens
can be prevented more advantageously. The outside peripheral edge
portion of the moisture-containing contact lens, on the other hand,
may float up to some extent from the concave bowed face 6. By means
of this, entry of the hydrating liquid from the gap onto the front
face of the moisture-containing contact lens is promoted. An
embodiment wherein the outside peripheral edge portion of the
moisture-containing contact lens floats slightly above the concave
bowed face 6 of the moisture-containing contact lens in this manner
also falls within the scope of generally equivalent curvature, and
represents one mode of embodiment of the invention.
[0133] In FIG. 11 is shown another example wherein a single
injection tube is used in the first injection step which is the
first stage, as the injection port in order to spray the hydrating
liquid towards the concave inside face constituting the concave
surface side wall, and in the second injection step which is the
second stage, to introduce hydrating liquid directed in the
direction of the lens. In this example, the single injection tube
40 projects from the guide tube 20 serving as the flow tube. In
order to change the spray direction of the hydrating liquid from
the single injection tube 40, the angle at which the injection tube
40 is inserted into the through-hole 21 of the cover 10 is varied
between a first stage (shown in FIG. 11(a)) and a second stage
(shown in FIG. 11(b)). The projecting distal end portion of the
injection tube 40 is curved appropriately so that in the first
injection step, the angle at which the injection tube 40 inserts
into the through-hole 21 of the cover 10, i.e. the angle of slope
of the guide tube 20 with respect to the perpendicular to the upper
face of the cover 10, is not excessive, and so that in the second
injection step, the hydrating liquid can be introduced in the
direction of the lens. As will be apparent from the preceding
description, the location of the opening of the injection tube 40
in the first stage is the first opening location, whereas the
location of the opening of the injection tube 40 in the second
stage is the second opening location. An advantage of this method
is that since a single injection tube suffices, the number of pumps
connected thereto can be reduced, as can the number of conduit
pipes connecting to the injection tube, thereby providing
reductions in terms of equipment and costs, and greater simplicity
in spatial arrangement.
[0134] In FIG. 5 and FIG. 11 are shown examples where the cover is
provided with one or two through-holes; however, it would be
possible to provide three or more through-holes, and for the
locations of the through-holes to be eccentric from the center.
Further, the shape and size of the recess 4 and the top panel 5 may
be modified appropriately.
[0135] As set forth hereinabove, in the moisture-containing contact
lens case according to the invention and the hydrating method
employing it, as well as in the hydrating device of structure
according to the invention, curling of the contact lens and
entrapment of air bubbles may be avoided, while making it possible
to advantageously carry out hydration of the contact lens.
* * * * *