MXPA00009171A - Improvements in variable focus optical devices - Google Patents

Abstract

Variable focus optical devices, in particular lenses, can include a cavity at least partially defined by a flexible membrane (2), which may be retained between engaging portions of a frame member (8) and a ring member (12), such that a peripheral region of the membrane is caused to change direction more than twice. The engaging portions of the ring and frame may be high-friction surfaces. In addition, methods of filling a cavity of a lens with transparent fluid, methods of adjusting the pressure of fluid in the cavity, and methods of sealing such a cavity are described, as well the use of such lenses in adjustable spectacles.

Description

IMPROVEMENTS IN VARIABLE FOCUS OPTICAL DEVICES DESCRIPTION OF THE INVENTION The present invention relates to improvements in the field of variable focus optical devices, in particular to variable focus lenses, for example of the type in which the optical power of the lens is variable by varying the volume and / or the pressure of a transparent fluid inside a transparent envelope. Variable approach lenses are known and have been described for example in British Patent GB-2183059, GB-2184562 and International Publication W096 / 38744. However, to date, despite the many examples of variable approach lenses described in the prior art, none has achieved wide commercial acceptance as an alternative to fixed focus glass or plastic or ground glass lenses. It is believed that the failure of known variable-focus lenses to gain commercial acceptance is due to a number of factors. For example, many known lenses of this type suffer REF: 123407 fluid leakage from the wrapper, in use. In addition, many known lenses of this type suffer from poor optical quality due to the mounting arrangement of the flexible membrane and / or the material chosen for the membrane. An additional contributor to the poor optical quality of the known lenses has been the fluid selected to fill the envelope, which has had a homogeneity of refractive index or less than optimal transparency. An additional reason for the non-acceptance of the known lenses, has been its complex and voluminous configuration that has led to a poor aesthetic effect, for example when the known lenses have been mounted on glasses, and has also increased the cost of such glasses to a level that is not competitive with traditional fixed focus lenses. The present invention seeks to provide a variable focusing lens and a method for the development of a variable focus lens, the modalities of which overcome at least some of the known variable focus lens problems, by means of which a lens can be achieved. more commercially attractive product. It is also sought to provide glasses or glasses that incorporate variable focus lenses. According to an invention described herein, a variable focusing lens is provided comprising a transparent envelope, at least partially defined by a flexible transparent membrane and containing a transparent fluid, a frame member that couples a face of the membrane flexible and a ring member engaging an opposite face of the flexible membrane, the ring member and the frame member are urged towards each other by retaining means, wherein the respective surfaces of the frame member and the ring member which are coupled to the flexible membrane are substantially complementary and shaped to cause a peripheral region of the flexible membrane to change direction more than once. It has been found by the applicant that, in order to obtain a high optical quality of the membrane, the membrane must be kept under tension at all times. Furthermore, it has been found by the applicant that the membrane, when under tension, and particularly when formed of preferred materials such as Mylar, tends to form its own seal against the frame member or the ring member. The profiles of the coupling surfaces of the frame member and the ring member allow the flexible membrane to be retained under tension on the frame member simply by the action of the coupling surfaces. In this way the construction of the variable focusing lens is considerably simplified compared to such known lenses. The profiles of the coupling surfaces can be staggered or comprise one or more projections and one or more complementary recesses. The portions of the mating surfaces substantially perpendicular to the plane of the undrawn membrane will tend to frictionally engage the membrane as the ring member is pushed towards the frame member by the retaining means. Such frictional engagement will tend to stretch the membrane over the frame member, ensuring that the membrane is under tension.

In a particularly advantageous arrangement, the surfaces comprise at least one oblique surface which increases in radial extent towards the frame member. In this way, as the ring member is pushed towards the frame member by the retaining means, the friction between the oblique surface of the ring member and the flexible membrane tends to push the periphery of the membrane radially outward, thereby which increases the tension in the membrane, for example the stretching of the membrane. The ring member and the frame member may be of a material or materials that is or is sufficiently rigid to positively inter-engage with one another, and to ensure that the ring member and the frame member can keep the flexible membrane under tension . The material of the ring member and the frame member is preferably also of light weight to facilitate incorporation into glasses of the lenses described herein. In this way, the ring member and the frame member can be made, for example, of a high-impact plastic material, or of aluminum or titanium.

It is generally advantageous to maximize the friction between the coupling surfaces and the membrane, not only to maximize the stretching effect described above, but also to ensure that the membrane is held securely by the ring member and the frame in the lens assembled Preferably and therefore, at least one of the surfaces is a high friction surface. It is believed that this in itself is novel and thus according to an invention described herein, a variable focusing lens comprising a transparent envelope at least partially defined by a transparent, flexible membrane and containing a fluid is provided. transparent, a frame member engaging one face of the flexible membrane and a ring member engaging an opposite face of the flexible membrane, the ring member and the frame member are pushed towards each other by the retaining means, wherein the respective surfaces of the frame member and the ring member engaging the flexible membrane are substantially complementary and at least one of the surfaces is a high friction surface.

For example, one or more of the frame member and the ring member can be made of a material having a high coefficient of friction on its surface. Alternatively, at least one of the coupling surfaces may have been roughened or expanded to increase its surface friction. In a preferred arrangement, however, at least one of the coupling surfaces is provided with a coating of high friction material. A particularly preferred material for this coating is rubber or a synthetic elastomer, since the applicant has found that it fits perfectly with the preferred materials for the membrane, such as Mylar. A further advantage of providing at least one of the coupling surfaces with a rubber or synthetic elastomer coating is that rubber or elastomer tends to form a high integrity fluid seal at the interface between the coupling surface and the membrane . Thus, according to an invention defined herein, a variable focusing lens is provided comprising a transparent envelope at least partially defined by a transparent membrane, flexible and containing a transparent fluid, a frame member that is coupled to one face of the flexible membrane, and a ring member engaging an opposite face of the flexible membrane, the ring member and the frame member are pushed towards each other by the retaining means, wherein at least one of the coupling surfaces is provided with a rubber or synthetic elastomer coating. The applicant has found that the coating needs only to be thin, in order to achieve an advantageous effect. For example, the coating may have a thickness of less than 100 μm, or less than 50 μm, or less than 20 μm or even less than 10 μm. Preferably, the coating is provided on the coupling surface which engages the face of the membrane which also forms an inner surface of the envelope, so that the sealing interface aids in the containment of the fluid. This surface will be provided in general on the frame member. Of course, both coupling surfaces can be provided with a coating.

The peripheral shape of the ring member, and also of the frame member, can be chosen as required. For example, the members may have a circular, oval, elliptical or other closed circumferential shape. The frame member may comprise a rigid transparent window forming a wall of the envelope. The window can be of any suitable material, for example glass, or a plastic material, such as polycarbonate. Of course, for ease of manufacture, the frame member can be made entirely of such transparent material. Alternatively, the rigid advantage may form a part of the frame member, for example that is attached to and / or enclosed by an annular frame. The frame member may be provided with a second coupling surface that engages a second membrane. In this case, a second ring member may be provided with a second coupling surface for coupling to the second membrane. The second engagement surface may be opposite the first engagement surface of the frame member. The second membrane can define a wall of the envelope. Alternatively, the first ring member may be provided with a second coupling surface that engages a second membrane. Again, a second ring member can be provided with a second coupling surface for coupling to the second membrane. The second engagement surface may be opposite the first engagement surface of the first ring member. The second membrane can define a wall of the envelope. The first and second membranes can be formed from a single membrane network, although preferably the first and second membranes are discrete. A conduit can be provided through a wall of the envelope, preferably a radially outer wall, whose conduit is in communication with the envelope. Such a conduit will allow the fluid to be removed from or introduced into the envelope so that the volume and / or pressure of the fluid in the envelope can be varied to vary the power of the lens. The conduit can be formed by a preformed or perforated orifice in one or more of the first or second ring members or the frame member. The conduit may be provided with sealing or sealing means, suitable for preventing leakage of fluid from the envelope through the conduit. Such sealing means may be as described in International Publication W096 / 38744, or may be a rubber or elastomer plug penetrable by a needle of a syringe, and capable of self-sealing upon removal of the needle. Alternatively, a valve can be provided in the conduit, cushioned so that the conduit is normally closed, but is capable of being opened for example by the needle of a syringe. In one embodiment, the valve comprises a ball pushed by a spring against an annular seat. To vary the fluid in the envelope, a needle of a syringe or the like is inserted through the center of the seat, thereby displacing the ball. The fluid can then be introduced into or removed from the envelope to vary the pressure in the envelope. When the needle is retracted, the spring pushes the ball against the seat again to close the valve and seal the duct. It has been found by the applicant that, with the preferred transparent fluids such as silicone oil, which is relatively viscous, such a duct must be relatively large in order to enable efficient filling of the lens. One way in which the effective size of such a duct can be increased is by providing a plurality of ducts in a wall of the envelope. It is believed that this in itself is novel, and thus in accordance with an invention described herein, a variable focusing lens is provided comprising a transparent envelope at least partially defined by a flexible transparent membrane and containing a transparent fluid, and a plurality of conduits provided in a wall of the envelope for introducing fluid into the envelope. The plurality of conduits may be provided with respective sealing means, for example as described above, or may be provided with a simple sealing means for a plurality of conduits. The conduits may be distributed around the periphery of the lens, but in a preferred arrangement the conduits are grouped close to each other. As an alternative to the provision of a plurality of conduits, it is possible to provide a simple conduit having a large cross section. It will be appreciated that the maximum width of the duct in the direction of the lens axis is limited by the thickness of the wall of the envelope forming the lens. However, the cross-sectional area of the duct can be increased by the formation of the duct such that its width perpendicular to the axis of the lens is greater than its width parallel to the axis of the lens. The retaining means may be any suitable means, for example screws, clamps and the like. The respective retaining means may be provided for each of the first and second ring members. In a preferred arrangement, the retaining means takes the form of a deformable portion of one of the frame member and the ring member, accommodated to be deformed, for example bent or folded, on the other of the frame member and the leg member. ring. In this case, the deformable portion may be metal, such as aluminum, stainless steel or titanium. Advantageously, the retaining means can be provided by a pair of spectacles or similar device, in which the lens is to be mounted. The transparent fluid retained within the envelope can be any suitable fluid, for example silicone oil, such as type 703 silicone oil. The fluid can be communicated to the envelope by means of a suitable pump, for example a syringe. However, the applicant has realized that a simple syringe is not ideal as a pump to vary the focus of the lens. One reason for this is that the plunger of the syringe is difficult to control accurately. For example, the static friction between the piston and the barrel of the syringe must be overcome before the piston moves, such that the pressure applied to the piston tends to be constituted until the static pressure is exceeded, at which point the piston It moves relatively quickly. Thus, according to an invention described herein, there is provided a pump for a variable focusing lens comprising a fluid chamber having an outlet gate and a linearly movable member accommodated to vary the effective volume of the fluid chamber, wherein positioning means are provided for positioning the movable member in a plurality of discrete positions. In a simple arrangement the positioning means may be in the form of two stoppers arranged to limit the movement of the movable member, for example a piston or plunger, to a range or interval. which has endpoints defined by the respective stops. The end points may correspond respectively to a first predetermined power of the lens, for example for the correction of the myopia of a user, and a second predetermined power of the lens, for example for the correction of the hyperopia or presbyopia of a user. In this way a bifocal lens can be produced which can be adjusted by the user for reading and viewing for close or remote work. The stops can be variable in their positions, for example for the initial adjustment of the two power levels for the lenses, and can be insurable in a selected position. The positioning means may comprise a series of indicators, for example teeth of a frame or the like, which can be coupled by a suitable coupling member, in order that the movable member is adjustable gradually. The Applicant has also found that it is preferable that users of variable focus lenses, for example users of lenses incorporating variable focus lenses, control lens focusing by a rotational movement rather than a linear movement such as that of the lens. piston of a syringe. Thus, according to an invention described herein, there is provided a pump for a variable focusing lens comprising a fluid chamber having an outlet gate and a means for linearly varying the volume of the fluid chamber in response to a rotational movement of a control member.

The pump may comprise a pinion engaged for rotation with a control knob, and coupling a frame coupled for linear movement to a piston provided in the fluid chamber. Alternatively, a piston received within the fluid chamber can be provided on a threaded shaft, the shaft being coupled with a complementary threaded collar, such that the collar or shaft can be rotated to cause the piston to move linearly within the chamber of fluid. Alternatively, the interior of the fluid chamber may be threaded, and the periphery of the piston may be provided with a complementary thread such that rotation of the piston causes linear movement thereof within the fluid chamber. In a presently preferred arrangement, a barrel member having a threaded exterior, the circumferential wall, and a fluid gate defined in an end wall thereof is provided. The barrel member is received within a lid member provided with a complementary interior thread and an end wall opposite the end wall of the barrel member. The fluid chamber is defined by the volume enclosed by the connected barrel and the lid members. According to this arrangement, as the lid member and the barrel member are rotated relative to one another the lid moves away from or towards the end face of the barrel member, thereby linearly increasing or reducing the volume of the barrel member. fluid chamber. The cap member may optionally be provided with a piston mounted in fixed relation to its end face, and received within the barrel member. In this case, the fluid chamber is defined between the end face of the barrel member and the piston, and the relative rotation of the barrel member and the cap member causes the piston to reduce the effective volume of the fluid chamber. Placement or indication means may be provided, as described above, in the context of a rotational control member. According to an invention described herein, a variable focusing lens is provided in combination with a pump as described herein. In a preferred arrangement, two variable-focus lenses are provided in a goggle frame. A simple pump may be provided, although it is preferred that a respective pump be provided for each lens, so that each lens is independently variable. The pump (s) can be provided on the arms of the frames of the glasses, for example at the ends of the arms, so that they are hidden by the ears of the user. Channels can be provided in the eyeglass frame, for example in the arms, for fluid communication between the lenses and the pump (s). The pump (s) may be arranged to be detachable from the glasses, for example permanently uncoupled after an initial adjustment operation of the lens focus. The pump (s) may be arranged to be detachable from the glasses, such that when the pump (s) are disengaged, the fluid communication channels are automatically closed, for example by means of a valve. In a preferred embodiment, a pair of eyeglasses has two pumps, one for each lens, with each pump that is removably coupled to an arm of the eyeglasses. Fluid communication between each pump and its respective lens is achieved by means of flexible tubing extending from the pump to the lens. The flexible pipe is received in a channel in the frame of the glasses for at least part of its length. When the user has adjusted the focus of the lens, the pipe is closed and cut, and the pump and the portion of the pipe coupled to it is detached and discarded. In a particularly preferred form, a part of the pipe connecting the lens and the pump is received in a channel formed in the main frame of the glasses, preferably on the side facing the user. The pipe projects from this gap beyond the side of the glasses to join the pump attached to the eyeglass arm. The pipe _ can be closed in any suitable way. However, it is preferred that the pipe be clamped or clamped to close, for example by means of a screw that pushes the sides of the pipe with one another. In a preferred form, a screw is provided in a passage in the frame of the goggles, perpendicular to and intercepting the channel in which the pipe is received. On the opposite side of the channel from the screw is a member that extends through the channel in the shape of a bridge. When it is desired to close the pipe, the screw is screwed into the passage, and the end of the screw compresses the pipe against the member to close it. The part of the pipe projecting beyond the end of the channel can then be removed, for example by cutting it so that its end lies flush with the side of the frame. In a particularly preferred embodiment, the member is formed by a part of the hinge that couples the arm to the main frame. This helps retain the pipeline in the channel, and avoids the need to provide a separate member. As an alternative, the pipe could be closed by compression means other than a screw. For example, the frame can be provided with a button, which when pressed compresses the pipe against a member, to close it. The button may be arranged such that it locks when depressed, to ensure that the pipe remains closed. In addition, the button may be provided with means to retain it in its original position, to prevent accidental operation. These means may take the form of a protrusion on the button, which fits within a corresponding recess in the frame. In addition, means may be provided in the goggles to allow the pipe to be cut. For example, a button having a razor can be provided, this dividing the pipe when the button is depressed. This button can be provided separately; however, it is preferred that the button that closes the pipe and the button that cuts it are combined, so that the pipe can be closed and cut in a simple movement. This simplifies the process of adjusting the glasses to a desired focus. As mentioned in the International publication W096 / 38744, the lenses can be pre-filled with fluid, during their manufacture. The pumps then need to contain only a sufficient amount of fluid to allow adjustment of the focus of the lenses. It will be appreciated that it is very important that the lenses are completely filled with the fluid, with no air bubbles in the lens. The presence of air bubbles is extremely distracting to the user of the glasses.

A number of procedures can be taken to fill the lens, to avoid the presence of air bubbles in the filled lens. For example, in a method that has proven to be effective, some of the air in the lens envelope is first sucked out, and then a similar amount of fluid is injected. The air removal cycle followed by the injection of the fluid is then repeated as necessary until the lens is filled with fluid. In an alternative method, a needle whose external diameter is smaller than the internal diameter of the duct, is used to inject the fluid. The empty space between the needle and the needle allows the air in the lens to escape as the fluid is injected. The fluid can still be injected through the needle while it is being withdrawn from the conduit. It is also preferred that the fluid used to fill the lens be degassed prior to filling, to reduce the likelihood of bubbles forming in the lens after filling. The filling of the lens will normally involve the injection of a relatively viscous fluid through a narrow passageway. The filling process can be facilitated by heating the fluid before injection, to reduce its viscosity. The variable focus lens described herein may be provided with at least one protective cover, transparent to the or each flexible membrane. The cover can be, for example, a rigid sheet of transparent material, for example glass or a plastic material such as polycarbonate. The protective cover can be mounted, for example attached, to the ring member or to the frame member. As mentioned above, the applicant has found that in order to obtain a desired optical quality of a variable focusing lens, it is important that the membrane is maintained under tension. For this purpose it is advantageous to form the membrane from a heat shrinkable plastic material. Thus, according to an invention described herein, there is provided a method for making a variable focusing lens having a transparent, flexible membrane, supported on a frame, wherein the membrane is treated with And heat while it is kept in the frame to increase the tension in the membrane. The applicant has found that, at least with the preferred materials for the membrane, for example Mylar, the heat treatment of the membrane causes the membrane material to contract and thereby increase the tension in the membrane. The membrane can be treated using any suitable source of heat, and in a preferred arrangement the heat is provided by a hot air source, such as a hair dryer, a hot air gun or a fan type heater. According to an invention described herein, there is provided a method for manufacturing a variable focusing lens having a flexible transparent membrane supported on a frame, wherein the membrane is pre-tensioned, and the frame is mounted to the membrane, while the membrane is pre-stressed. In this way, a convenient method is provided to ensure that the membrane is in tension on the frame. Any suitable means can be provided to pre-tension the membrane. For example, the principles for tensioning the membrane described in the British patents GB-2184562 and GB-2183059 can be applied in this novel form to the pre-tensioning of the membrane. The frame may be a frame as described hereinafter. The variable focus lens described above is of course suitable for use in glasses or spectacles. However, this can also be used on any form of optical article where it may be desired to incorporate corrective optical elements, including, but not limited to sunglasses, goggles or swimming goggles., glasses or goggles for skiing, squash lenses, sports glasses in general, sun masks, welding goggles, glasses or goggles for laboratory and in general optical protective devices. The lens can be provided as an insert, or it can have means for coupling to the outside of the telescope. If the lens is to be used in lenses against the sun, then the material of the membranes or the fluid itself could be dyed. In addition, it is possible to use metallic Mylar, which reflects a portion of the light incident on it, and transmits the rest, such as the material of the outer membrane, thereby providing reflector lenses against the sun. A variable focus lens and glasses that embody many of the advantageous features described herein and to which the other features described herein can be applied will now be described in detail, by way of example only, with reference to the drawings. annexes, in which: Figure 1 shows an axial section of a portion of a variable focus lens during its construction. Figure 2 shows a section similar to that of Figure 1, but showing the lens completed. Figure 3 is a partial sectional view of a variable focus lens. Figure 4 is a sectional view of a pump for a variable focusing lens. Figure 5 is a sectional view of another pump for a variable focusing lens. Figure 6 is a sectional view of yet another pump for a variable focusing lens.

Figure 7 is a perspective view of part of a pair of spectacles. Figure 8 is an enlarged view of a part of the glasses. Figure 9 is a sectional view of part of the glasses. Figure 10 is a sectional view of part of an alternative pair of glasses. The lens described and illustrated herein may be used in an optical apparatus constructed and accommodated to be adjusted as described and as claimed in the publication International W096 / 38744. The lens shown in Figure 2 comprises first and second membranes 2, flexible, transparent, which are tensioned, and which define between them a sheath 30 in which a transparent fluid 4, such as silicone oil, is contained. In the illustrated embodiment, the membranes 2 are Mylar, for example, Mylar Type D of 23 μm. The membranes 2 are held in tension by a support 6. The support 6 defines the periphery of the lens, and of the casing 30, and is arranged to retain the flexible membranes 2 under tension.

The support 6 is also accommodated to seal the lens. As can be seen from FIG. 1, the support 6 is formed by the coupling of a frame member 8 and first and second aluminum ring members 10, 12. In this regard, the frame member 8 has a radially extending flange 14, which is stepped as indicated at 16. The frame member 8 also has an axially extending flange 18. The first ring member 10 has a portion 20 projecting radially outward, defining a first step 22 cooperating with the step 16 of the frame member 8, and a second step 24 cooperating with a step 26 of the second leg member. ring 12. The second ring member 12 has a recess 28 arranged radially outwardly therein. Where the completed lens will have a generally circular periphery, for example, a first membrane 2, which is circular, is positioned to extend within the frame member 8, such that its periphery extends along the radial flange 14 of it. The first ring member 10 is then supported within the frame member 8 such that the complementary steps 16 and 22 thereof are interengaged. This interengagement places the first ring member 10 relative to the frame member 8. The interengagement also flexes the peripheral circumference of the first membrane 2 through two different directions as is clearly shown in Figure 1. A second circular membrane 2 is then placed through the frame member 8, such that its periphery extends along the radially extending upper surface of the first ring member 10. After this, the second ring member 12 is positioned such that the steps 24 and 26 of the first and second members 10, 12 cooperate to retain the second ring member 12 in position within the frame member 8, and to flex the periphery of the second membrane 2 through two directions. The tolerances of members 8, 10, 12 are chosen such that even when the arrangement is in the interengaged position shown in Figure 1, the two membranes 2 are firmly held by the interengaged members.

The construction has the considerable advantage that the circular membranes 2 do not have to be produced to narrow tolerances. Each circular membrane 2 can be cut to be generally circular and have a diameter that is somewhat larger than what is required. In turn, each membrane 2 is placed as described above and maintained by the interengagement of the ring members 10, 12. Any material in excess of the membrane 2 can then be trimmed simply by using a blade or razor with the ring members 10, 12 that act as guides. To complete the construction of the lens it is necessary to ensure that the frame member and the first and second ring members 8, 10, 12 are secured to each other, such that the peripheries of the membranes 2 are firmly retained to seal the lens and to prevent any leakage from the sheath 30 defined between the two membranes 2. In the illustrated embodiment, the retention of the membranes 2 is achieved by the folding and deformation of the frame member 8. In this regard, the vertically extending vertical free end of the arm 18 of the frame member 8 is inclined to be received within the recess 28 of the second frame member. ring 12. Any excess deformed material of the ring 8 during this folding operation is received within an annular space 32 which is defined between the peripheries radially outwardly of the first and second ring members 10 and 12, and the inner periphery of the arm 18 of the frame member 8. Once the lens has been constructed, as shown in Figure 1, and with the frame member 8 deformed to secure the structure, a conduit 34 is pierced through the frame 6 within the envelope 30. The envelope 30 can then be filled with the transparent fluid 4 through the conduit 34. With the silicone oil 703 as the fluid, the resulting lens achieves a range of focal length of at least -6 to +10 diopters, and the range of -10 to +10 diopters must be achievable. Of course, it will be appreciated that, in an alternative embodiment, the rings are formed with conduits before they are assembled. Fluid may be introduced into the envelope 30 via conduit 34 and retained therein by the use, for example, of conduits, plugs and sealing means as described in International publication W096 / 38744. In one embodiment, the lens is pre-filled at this stage with the fluid 4 and an appropriate material is provided in the conduit 34 to seal the envelope 30. However, the material sealing the conduit 34 is preferably penetrable by a syringe, for example, so that the pressure of the fluid 4 within the envelope 30 can be adjusted. As an alternative, a self-sealing valve could be placed in the conduit, as described above. In the embodiment shown, the two axially outer surfaces of the lens are each protected by a sheet 36 of a polycarbonate. Each polycarbonate sheet 36, for example, can be approximately 1/2 millimeter thick. It will be appreciated that these sheets 36 are arranged to extend substantially parallel to one another. The circumferential periphery of each of the sheets 36 can be fixed to the annular frame 6 in any appropriate manner. For example, the sheets 36 can be adhered to the frame 6. In addition and / or alternatively, a plastic frame (not shown) of a pair of glasses, for example, can be accommodated to receive the annular frame 6 in a manner to retaining the leaves 36 against the annular frame 6 in the position of Figure 2. Figure 3 shows a lens filled with fluid, according to a different arrangement. In this case there is only a single ring member 12 having an oblique coupling surface 38, complementary to the oblique engagement surface 40 of the frame member 8. A simple flexible membrane 2 is maintained between these coupling surfaces 38, 40, which are pushed together by the retaining means in the form of a folded arm of the frame member 8. A wall of the envelope containing the transparent fluid 4 is provided by a polycarbonate wall 42 received by the annular portion 44 of the cover member. frame 8. Figure 4 shows a pump for a variable focusing lens in the form of a modified syringe having a barrel 45 and a piston 48 mounted on a piston rod 50. The rod 50 of the piston is provided along one side with a frame or row of teeth. A collar 52 is attached to the barrel flange 46, and the shaft 50 passes through a central opening defined in the collar. A collar tooth projects into the opening and engages the teeth of the shaft 50, such that the shaft 50, and therefore the piston 48, is movable gradually through a series of discrete sites defined by the teeth of the shaft 50. The stops 56 are firmly clamped to the shaft 50 and have complementary teeth that engage with the teeth of the shaft 50, and keep the stops 56 in position relative to the axis. The stops 56 engage the collar 52 when the shaft 50 is at either end of the range of movement defined by the stops 56. Figure 5 shows yet another pump for a variable focus lens. The pump comprises a cylindrical barrel 58 with a threaded exterior and the lid 60 with a complementary threaded interior, which engages the thread of the barrel 58. Between the barrel and the lid a fluid chamber 62 is defined. According to the barrel and the The lid is rotated relative to the other the effective volume of the fluid chamber 62 is varied so that the fluid can be forced out of or sucked through a fluid gate 64, defined on one end face of the barrel 58.

Figure 6 shows an additional pump use with a variable focusing lens. Again, this pump is in the form of a modified syringe, having a barrel 70 and a piston 72 mounted on a rod 74 of the piston, having a frame 76 of teeth on one side. Passing through the barrel is an axle 78, on which a pinion gear 80 is mounted. The pinion 80 engages with the frame 76. Coupled to one end of the shaft, which projects beyond the barrel, is a wheel 82 (partially shown in dashed lines), which can be rotated by a user. The rotation of the wheel 82 in turn rotates the pinion 80, which drives the frame 76 and thus moves the piston 72 in the barrel 70. The fluid can thus be. forced out of and sucked into the barrel, to vary the pressure in the lens, simply by rotating the wheel. Of course, other gear shapes can be used to connect the wheel to the piston rod. Figure 7 shows a part of a pair of eyeglasses 100 employing two variable focus lenses. As will be seen, one of the lenses 102 is connected to a pump 104, removably coupled to an arm 106 of the glasses, by a length of the pipe 108. The other lens is also provided with a pump in an analogous manner. The pumps may be of the form described above, although it will be appreciated that any suitable pump form may be used. The coupling area between the main frame 110 of the glasses and the arm 106 is shown in more detail in Figure 8. It will be noted that the pipe 108 extends from the lens through a channel 112 formed in the frame 110 and is opens towards the back (for example, the side facing the user) thereof. Part of the hinge (shown schematically as 114) is fixed to either side of the channel, and extends through it in the. shape of a bridge. The frame also includes a threaded passage 116, as shown in Figure 9, which accommodates a screw 118. The threaded passage 116 opens within the channel 112, and is aligned with the part 114 of the hinge that forms a bridge with the channel . In use, the pressure within the lens, and thus its focus, is adjusted by means of the pump 104. When the desired focus has been achieved, the screw 118 is screwed into the passage 116 to close the pipe 108. In particular, the end of the screw 118 holds or hugs the pipe 108 against the part 114 of the hinge bridging the channel. The screw is preferably screwed in and out by means of an Allen key, although of course any other screw form can be used. Once the pipe 108 is tightened until closed, the pump 104 is detached from the arm 106 of the goggles, and the pipe is cut as indicated at 120, level with the edge of the frame 110. The same process is repeated for the another lens. An alternative arrangement for closing and cutting the pipe 108 is shown in Figure 10. Here, the pipe is closed by means of a projection 122 coupled to a button 124, which slides in an opening in the frame. When the button 124 is depressed, the projection 122 presses the tubing against the part 114 of the eyeglass hinge, closing it in this way. The button may be provided with means for locking it in its closed position, as shown at 126 and 128. The button may also be provided with means (not shown) for retaining it in its original position until it is pressed. In addition, the button 124 may be provided with a blade or knife 130 to cut the pipe. The knife 130 and the pipe 108 are arranged such that the knife only cuts the pipe after the pipe has been closed by the projection 122. A simple depression of the button serves in this way to close the pipe and cut it. The button 124 has been shown on the front face of the frame 110 of the glasses. However, it will be appreciated that this could also be accommodated on the upper face of the eyeglass frame. The member could then lean against a side wall of the channel 112 to close the pipe. The features described herein may be used either separately or in any suitable combination. It will be appreciated that alterations and modifications to the embodiments described and illustrated herein may be made within the scope of this application.

For example, although there has been much mention here of variable focus lenses, the advantageous features described herein may also be applied to other optical devices. For example, by providing a suitable silver surface in the lens described herein, a variable focusing mirror can be manufactured in accordance with the present disclosure. The silver surface can be applied to the flexible membrane, or it can be applied to a rigid surface observed through the flexible membrane. Of course, in the case of a flexible silver membrane, it is not necessary that the fluid within the envelope be transparent, since light is not required to pass through it in use. Of course, the optical properties of the fluid in this case are irrelevant and the fluid may be opaque.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (107)

CLAIMS Having described the invention as above, the content of the following claims is claimed as property:

1. A variable focusing lens, characterized in that it comprises a transparent envelope at least partially defined by a flexible transparent membrane, and containing a transparent fluid, a frame member that engages a face of the flexible membrane and a ring member that is Assembled to an opposite face of the flexible membrane, the ring member and the frame member are pushed towards each other by the retaining means, wherein the respective surface of the frame member and the ring member which engage the Flexible membranes are substantially complementary and shaped to cause a peripheral region of the flexible membrane to change direction more than once.

2. A variable focusing lens according to claim 1, characterized in that the profiles of the coupling surface are staggered.

3. A variable focusing lens according to claim 1, characterized in that the profiles of the coupling surface comprise one or more projections and one or more complementary recesses.

4. A variable focusing lens according to claim 1, characterized in that the coupling surfaces comprise at least one oblique surface that increases in radial extent towards the frame member.

5. A variable focus lens according to any preceding claim, characterized in that the ring member and the frame member are of a material or materials that is / are rigid enough to positively inter-engage with each other and to ensure that the ring member and the frame member can keep the flexible membrane under tension.

6. A variable focus lens according to claim 5, characterized in that the material of the ring member and the frame member is also of light weight.

7. A variable focusing lens according to claim 6, characterized in that the ring member and the frame member are made of a high impact resistant plastic material.

8. A variable focusing lens according to claim 7, characterized in that the ring member and the frame member are made of aluminum.

9. A variable focusing lens according to claim 7, characterized in that the ring member and the frame member are made of titanium.

10. A variable focusing lens according to any preceding claim, characterized in that at least one of the surfaces is a high friction surface.

11. A variable focusing lens, characterized in that it comprises a transparent envelope, at least partially defined by a flexible transparent membrane and containing a transparent fluid, a frame member that engages a face of the flexible membrane and a ring member that is Assembled to an opposite face of the flexible membrane, the ring member and the frame member are pushed towards each other by the retaining means, wherein the respective surface of the frame member and the ring member which engage the Flexible membranes are substantially complementary and at least one of the surfaces is a high friction surface.

12. A variable focus lens according to claim 10 or claim 11, characterized in that one or more of the frame member and the ring member is made of a material having a high coefficient of friction on its surface.

13. A variable focusing lens according to claim 10 or claim 11, characterized in that at least one of the coupling surfaces has been roughened or expanded to increase its surface friction.

14. A variable focusing lens according to claim 10 or claim 11, characterized in that at least one of the coupling surfaces is provided with a coating of high friction material.

15. A variable focus lens according to claim 14, characterized in that the coating is made of rubber or a synthetic elastomer.

16. A variable focusing lens, characterized in that it comprises a transparent envelope at least partially defined by a flexible transparent membrane and containing a transparent fluid, a frame member that engages a face of the flexible membrane and a ring member that engages on one opposite face of the flexible membrane, the ring member and the frame member are urged towards each other by the retaining means, wherein at least one of the coupling surfaces is provided with a rubber or elastomer coating synthetic

17. A variable focus lens according to any of claims 14 to 16, characterized in that the coating has a thickness of less than 100 μm, preferably less than 50 μm, more preferably less than 20 μm, and most preferably less than 10 μm.

18. A variable focusing lens according to any of claims 14 to 17, characterized in that the coating is provided on the coupling surface which engages the face of the membrane which also forms an internal surface of the envelope, so that the interface of Sealing helps contain fluid.

19. A variable focusing lens according to claim 18, characterized in that the coupling surfaces are provided with a coating.

20. A variable focus lens according to any preceding claim, characterized in that the ring member and the frame member have a circular, oval, elliptical or other closed curve peripheral shape.

21. A variable focus lens according to any preceding claim, characterized in that the frame member comprises a rigid transparent window forming a wall of the envelope.

22. A variable focusing lens according to claim 21, characterized in that the rigid window is made of a suitable material, such as glass or a plastic material such as polycarbonate.

23. A variable focusing lens according to claim 22, characterized in that the frame member is made entirely of such transparent material.

24. A variable focus lens according to claim 21 or claim 22, characterized in that the rigid window forms a part of the frame member, for example that is attached to and / or enclosed by an annular frame.

25. A variable focusing lens according to any preceding claim, characterized in that the frame member is provided with a second engaging surface that engages a second membrane.

26. A variable focusing lens according to claim 25, characterized in that the second ring member is provided with a second coupling surface for coupling to the second membrane.

27. A variable focus lens according to claim 25 or claim 26, characterized in that the second engagement surface is opposite the first engagement surface of the frame member.

28. A variable focusing lens according to any of claims 25 to 27, characterized in that the second membrane defines a wall of the envelope.

29. A variable focusing lens according to any one of claims 1 to 24, characterized in that the first ring member is provided with a second coupling surface that engages a second membrane.

30. A variable focusing lens according to claim 29, characterized in that a second ring member is provided with a second coupling surface for coupling to the second membrane.

31. A variable focusing lens according to claim 28 or claim 29, characterized in that the second engagement surface is opposite the first engagement surface of the first ring member.

32. A variable focusing lens according to any of claims 29 to 31, characterized in that the second membrane defines a wall of the envelope.

33. A variable focus lens according to any of the claims 25 to 32, characterized in that the first and second membranes are formed from a simple membrane network.

34. A variable focusing lens according to any of claims 25 to 32, characterized in that the first and second membrane are discrete.

35. A variable focusing lens according to any preceding claim, characterized in that a conduit is provided through a wall of the envelope, which conduit is in communication with the envelope.

36. A variable focusing lens according to claim 35, characterized in that the wall is a radially outer wall.

37. A variable focusing lens according to claim 34 or claim 35, characterized in that the duct is formed by a perforation preformed in one or more of the first or second ring members or of the frame member.

38. A variable focusing lens according to claim 34 or claim 35, characterized in that the conduit is drilled in one or more of the first or second ring members or of the frame member.

39. A variable focus lens according to any of the claims 35 to 38, characterized in that the conduit is provided with suitable sealing means to prevent leakage of liquid from the envelope through the conduit.

40. A variable focusing lens according to claim 39, characterized in that the sealing means takes the form of a plug of rubber or elastomer penetrable by a needle of a syringe, and capable of self-sealing when removing the needle.

41. A variable focusing lens according to claim 39, characterized in that a valve is provided in the conduit, accommodated so that the conduit is normally closed, but capable of being opened, for example, by the needle of a syringe.

42. A variable focusing lens according to claim 41, characterized in that the valve comprises a ball pushed by a spring against an annular seat.

43. A variable focusing lens according to any of claims 35 to 42, characterized in that a plurality of conduits are provided in a wall of the envelope.

44. A variable focusing lens, characterized in that it comprises a transparent envelope at least partially defined by a flexible transparent membrane and containing a transparent fluid, and a plurality of conduits provided in a wall of the envelope for the introduction of fluid into the envelope.

45. A variable focusing lens according to claim 43 or claim 44, characterized in that the plurality of conduits are provided with respective sealing means.

46. A variable focus lens according to claim 43 or claim 44, characterized in that the plurality of ducts are provided with a simple sealing means.

47. A variable focusing lens according to any of claims 43 to 46, characterized in that the conduits are grouped close together.

48. A variable focus lens according to any of claims 35 to 42, characterized in that a single conduit having a large cross section is provided.

49. A variable focusing lens according to claim 48, characterized in that the cross-sectional area of the duct is increased by the formation of the duct, such that its width perpendicular to the axis of the lens is greater than its width parallel to the axis of the lens.

50. A variable focusing lens according to claim 26 claim 30, or any claim dependent therefrom, characterized in that respective retaining means are provided for each of the first. and second ring members.

51. A variable focus lens according to claim 1, claim 11, claim 16, or any claim dependent therefrom, characterized in that the retaining means takes the form of a deformable portion of one of the structural member and the ring member , accommodated to be deformed, for example folded, on the other of the frame member and the ring member.

52. A variable focusing lens according to claim 51, characterized in that the deformable portion is made of metal, such as aluminum, stainless steel or titanium.

53. A variable focus lens according to any preceding claim, characterized in that the transparent fluid retained within the envelope is silicone oil, such as type 703 silicone oil.

54. A variable focusing lens according to any preceding claim, characterized in that the fluid is communicated to the envelope by means of a suitable pump, for example a syringe.

55. A pump for a variable focusing lens comprising a fluid chamber having an outlet gate and a linearly movable member accommodated to vary the effective volume of the fluid chamber, characterized the pump because positioning means are provided for positioning the mobile member in a plurality of discrete positions.

56. A pump according to claim 55, characterized in that the positioning means is in the form of two stops arranged to limit the movement of the movable member, for example a piston or piston, to a range or position having end points defined by buffers. respective.

57. A pump according to claim 56, characterized in that the stops are variable in their positions.

58. A pump according to claim 57, characterized in that the stops are insurable in a selected position.

59. A pump according to any of claims 55 to 58, characterized in that the positioning means comprises a series of indicators that can be coupled by a suitable coupling member, in order that the movable member is adjustable gradually.

60. A pump according to claim 59, characterized in that the series of sites are in the shape of the teeth of a frame or the like.

61. A pump for a variable focusing lens, characterized in that it comprises a fluid chamber having an outlet gate and means for linearly varying the volume of the fluid chamber in response to a rotational movement of a control member.

62. A pump according to claim 61, characterized in that the pump comprises a pinion engaged for rotation with a control knob and coupling with a frame coupled for linear movement to a piston provided in the fluid chamber.

63. A pump according to claim 61, characterized in that a piston received inside the fluid chamber is provided on a threaded shaft, the shaft coupling with a complementary threaded collar, such that the collar or shaft can be rotated to cause the piston moves linearly within the fluid chamber.

64. A pump according to claim 61, characterized in that the interior of the fluid chamber is threaded, and the periphery of the piston is provided with a complementary thread, such that the rotation of the piston causes the linear movement thereof within the chamber of the piston. fluid.

65. A pump according to claim 61, characterized in that it comprises a barrel member with a threaded exterior, a circumferential wall, and a fluid gate defined in an end wall thereof, which barrel member is received within a cover member provided with a complementary internal thread and an end wall opposite the end wall of the barrel member, the fluid chamber is defined by the volume enclosed by the connected barrel and the lid members.

66. A pump according to claim 65, characterized in that the lid member is provided with a piston mounted in fixed relation to its end face and received inside the barrel member, such that the fluid chamber is defined between the end face of the member of barrel and piston, and relative rotation of the barrel member and cap member causes the piston to reduce the effective volume of the fluid chamber.

67. A pump according to any of claims 61 to 66, characterized in that positioning means are provided for positioning the movable member in a plurality of discrete positions ..

68. A variable focusing lens, characterized in that it is in combination with a pump according to any of claims 55 to 67.

69. One eyeglasses, characterized in that two variable focus lenses are provided in accordance with claim 68, in a spectacle frame.

70. The glasses according to claim 69, characterized in that a single pump is provided.

71. The spectacles according to claim 69, characterized in that a respective pump is provided for each lens, so that each lens is independently variable.

72. The glasses according to any of claims 69 to 71, characterized in that the pump (s) are provided on the arms of the eyeglass frames, for example at the ends of the arms, so that they are hidden by the ears on the arms. use.

73. The glasses according to any of claims 69 to 72, characterized in that channels are provided in the frame of the glasses, for example in the arms, for fluid communication between the lenses and the pump (s).

74. The goggles according to any of claims 69 to 73, characterized in that the pump (s) are arranged to be detachable from the glasses after an initial adjustment operation of the focus of the lenses.

75. The glasses according to claim 74, characterized in that the pump (s) are permanently uncoupled.

76. The glasses according to claim 74 or claim 75, characterized in that the pump (s) are arranged to be detachable from the glasses, such that when the o. the pumps are / are detached the fluid communication channels are automatically closed.

77. The spectacles according to claim 76, characterized in that the channels are automatically closed by means of a valve.

78. The spectacles according to claim 71 or any claim dependent thereto, characterized in that they comprise a pair of spectacles with two pumps, one for each lens, each pump being removably coupled to an arm of the spectacles, wherein the fluid communication between each pump and its respective lens is achieved by means of flexible tubing extending from the pump to the lens, the tubing being received in a channel in the eyeglass frame for at least a part of its length, the tubing being closed and cut off after a user has adjusted the focus of the lens, and the pump in the coupled portion of the pipe is then detached and discarded.

79. The goggles according to claim 78, characterized in that a part of the pipe connecting the lens and the pump is received in a channel formed in the main frame of the goggles.

80. The glasses according to claim 79, characterized in that the channel is on the side of the main frame facing the user.

81. The goggles according to any of claims 78 to 80, characterized in that the pipe is closed when firmly tightened.

82. The glasses according to claim 81, characterized in that the pipe is firmly tightened by means of a screw that pushes the sides of the pipe together.

83. The glasses according to claim 82, characterized in that a screw is provided in a passage in the frame of the glasses, perpendicular to and intersecting the channel in which the pipe is received, wherein a member is provided on the side of the opposite channel the screw extending through the channel in the shape of a bridge, and wherein the screw can be screwed into the passage to compress the pipe against the member, to close it.

84. The glasses according to claim 83, characterized in that the member is formed by a part of the hinge that couples the arm of the glasses to the main frame.

85. The glasses according to claim 81, characterized in that the pipe is closed by tightening by means of a button which, when pressed, compresses the pipe against a member, to close it.

86. The glasses according to claim 85, characterized in that the button is arranged to engage when pressed, to ensure that the pipe remains closed.

87. The spectacles according to claim 84 or claim 85, characterized in that the button is provided with means to retain it in its original position, to prevent accidental operation.

88. The spectacles according to claim 88, characterized in that the means take the form of a protuberance on the button, which fits inside a corresponding recess in the frame.

89. The spectacles according to any of claims 78 to 88, characterized in that means are provided in the spectacles to allow the pipe to be cut.

90. The glasses according to claim 89, characterized in that a button is provided that has a knife, dividing the pipe when the button is depressed.

91. The glasses according to claim 90. when it is dependent on any of claims 85 to 88, characterized in that the button that closes the pipe and the button that cuts it are combined, so that the pipe can be closed and cut in a single movement.

92. A method for filling with transparent fluid a variable focus lens housing, characterized in that it includes the steps of sucking out some of the air in the envelope, injecting a similar amount of fluid into the envelope, and repeating the cycle of Air removal, followed by injection of fluid until the envelope is filled with the fluid.

93. A method for filling with transparent fluid a wrapping of a variable focusing lens, characterized in that a needle is used to inject fluid into the shell through a conduit, wherein the outer diameter of the needle is smaller than the inner diameter of the duct, such that the air in the envelope can escape as the fluid is injected.

94. A method for filling with transparent fluid a wrap of a variable focusing lens, characterized in that the fluid used to fill the envelope is degassed before filling.

95. A method for filling with transparent fluid an envelope of a variable focusing lens, characterized in that the fluid is heated before filling, to reduce its viscosity.

96. A variable focusing lens according to any of claims 1 to 54, characterized in that the lens is provided with at least one transparent protective cover for the or each flexible membrane.

97. A variable focus lens according to claim 96, characterized in that the cover is a rigid sheet of transparent material.

98. A variable focusing lens according to claim 97, characterized in that the material is glass or a plastic such as polycarbonate.

99. A variable focus lens according to any of claims 1 to 54 or 96 to 98, characterized in that the or each flexible membrane is formed from a heat shrinkable plastic material.

100. A method for manufacturing a variable focusing lens having a transparent, flexible membrane supported on a frame, characterized in the method because the membrane is heat treated while being held in the frame, to increase the tension in the membrane.

101. A method according to claim 100, characterized in that heat is provided by a source of hot air, such as a hair dryer, a hot air gun or a fan type heater.

102. A method for manufacturing a variable focusing lens having a transparent, flexible membrane supported on a frame, characterized in that the membrane is pretensioned, and the frame is mounted to the membrane while the membrane is pre-tensioned.

103. A goggle incorporating a variable focus lens according to any of claims 1 to 54 or 96 to 98, characterized in that the goggles are in the form of sunglasses, goggles for swimming, glasses or goggles for skiing, squash lenses, sports glasses in general, masks for welding, goggles or goggles for welding, goggles or glasses for laboratory, and protective devices for the 5 eyes in general.

104. The glasses according to claim 103, characterized in that the lens is provided as an insert.

105. The spectacles according to claim 103, characterized in that the variable focusing lens is coupled to the outside of the spectacles. 15

106. A variable focusing lens, characterized in that it comprises a transparent fluid envelope defined between two membranes, at least one of which is flexible, wherein one or both of the membranes or the fluid is dyed.

107. A variable focusing lens, characterized in that it comprises a transparent fluid envelope defined between two membranes, at ____ tt -__ fc __ «-» «- > «-» - »» _ », ,, .. *, l __» «& _, ~ < , except one of which is flexible, the flexible Mylar membrane being formed metalized