Optical: systems and elements – Protection from moisture or foreign particle
Reexamination Certificate
2000-03-02
2001-05-29
Shafer, Ricky D. (Department: 2872)
Optical: systems and elements
Protection from moisture or foreign particle
C359S512000, C359S846000, C359S872000
Reexamination Certificate
active
06238052
ABSTRACT:
BACKGROUND OF THE INVENTION
A. Field of the Invention
The present invention relates to mirrors of the type used by people to facilitate performance of personal care functions such as shaving, applying cosmetics, and the like. More particularly, the invention relates to a novel mirror having a magnification that may be readily varied by a user, and which also resists formation of water condensation droplets or fog on the viewing surface thereof, thus permitting the mirror to function effectively in humid environments such as shower enclosures and bathrooms.
B. Description of Background Art
A substantial number of people utilize mirrors while showering to facilitate performance of personal care functions such as shaving. However, the use of mirrors in showers was formerly relatively limited, because the warm moist air within a shower enclosure tends to quickly condense on the surface of any mirror used in the shower, obscuring an image of a person's face reflected from the mirror surface so completely as to render the mirror practically useless within a few minutes after a shower has begun.
In response to the problem of moisture condensing on a mirror surface and thereby limiting the usefulness of mirrors in high humidity environments, such as shower enclosures and other locations within a bathroom, the present inventor disclosed in U.S. Pat. No. 4,733,468, issued Mar. 29, 1988, a “fogless” mirror which is highly resistant to formation of condensation droplets on the surface of the mirror. The fogless mirror disclosed in the '468 patent utilizes warm water tapped from the warm water supply pipe to a shower head, to heat the surface of the mirror. Since water vapor in a shower produced largely by evaporation, the water vapor is always somewhat cooler than the warm water supplied to the shower head. And, since water vapor will condense only on surfaces which are at lower temperature than the vapor, heating the surface of the mirror precludes fogging of the mirror. Therefore, the fogless mirror disclosed in the present inventor's '468 patent proved to be a highly effective solution to the problem of bathroom mirror fogging, and mirrors utilizing the teachings of that patent have been widely marketed and used.
The disclosure of a practical and effective fogless mirror in the present inventor's '468 patent solved the problem of providing a bathroom mirror of unity magnification which is non-fogging. However, there are a variety of circumstances in which it would be desirable to have available a face mirror that has a variable magnification. For example, detailed hygienic or cosmetic functions which involve eyebrows or eye lashes benefit from the use of a concave magnification mirror. But, since the field of view of a magnifying mirror of a given size is inherently smaller than that of a flat, unity-magnification mirror, a magnifying mirror may be unsuitable for performing other functions, such as shaving, which preferably employs a mirror having a larger field of view which encompasses the entire face. Therefore, shaving and performing other such tasks related to personal hygiene or beautification would oftentimes be facilitated by the use of a mirror having multiple discrete or continuously variable magnifications. In response to this need, the present inventor disclosed a Variable Magnification Mirror in U.S. Pat. No. 5,900,996, which issued on May 4, 1999. That patent disclosed a variable magnification mirror having a thin diaphragm provided with a reflective front surface and includes a mechanism for deforming the diaphragm from a flat shape, yielding unity magnification of images formed by the reflective surface, to adjustably greater curvatures yielding adjustably larger magnification factors. The mechanism includes a screw-driven, flexible circular puller plate fastened to a rear central portion of the rear surface of the reflective diaphragm, the outer peripheral edge of the diaphragm being held axially fixed with respect to the screw. In the preferred embodiment, the puller plate is so constructed as to have greater flexibility at outer radial portions thereof to accommodate larger angular defections of the outer radial portions of the diaphragm, thereby aiding in maintenance of substantially spherical, distortion free contour. The increased flexibility of outer radial portions of the puller plate is preferably effected by a radial taper provided in the puller plate cross section, the outer radial portions of the plate being progressively thinner than the central radial portion of the puller plate. Preferably, the puller plate is fastened to the rear surface of the reflective diaphragm by means of a resilient adhesive member, the elastic deformability of the member further aiding in maintenance of a substantially spherical diaphragm contour.
Although the variable magnification mirror disclosed in the '996 patent has proved to be a highly effective and widely accepted solution to the problem of providing a variable magnification mirror useful for personal hygiene tasks, there is no obvious practical way to incorporate a flow of warm water through the device to heat the mirror surface and thereby resist formation of condensation droplets on the mirror surface. Thus, a problem still persisted, particularly for people who are unable to wear eyeglasses or contact lenses while showering, yet wish to shave or perform other personal hygiene tasks in the shower. For such individuals, it would be highly desirable to have available a mirror of adjustable magnification to compensate for vision difficulties experienced with their eyeglasses or contact lenses removed. In view of the foregoing facts, the present inventor conceived of a fogless variable magnification mirror having a highly novel construction and function.
OBJECTS OF THE INVENTION
An object of the present invention is to provide a mirror having a magnification that is smoothly and readily variable over a substantial range of magnifications, and which resists formation of condensation fogging on image viewing surfaces thereof.
Another object of the invention is to provide a variable magnification fogless mirror which utilizes warm water to heat optical surfaces of the mirror above ambient atmospheric temperature, thereby minimizing condensation of water vapor droplets from the atmosphere onto the optical surfaces.
Another object of the invention is to provide a variable magnification fogless mirror which utilizes hydrostatic fluid pressure supplied by condensation-inhibiting warming water to deform a flexible reflective diaphragm into a concave reflecting surface.
Another object of the invention is to provide a variable magnification fogless mirror which utilizes warm water flowing in a chamber formed between a front viewing window and a rear flexible diaphragm having a mirrored surface to heat the viewing window and thereby minimize condensation fogging of the front surface of the viewing window.
Another object of the invention is to provide a variable magnification fogless mirror including a frame forming a heated interior plenum space between a front viewing window and a circular rear flexible diaphragm having a mirrored surface, the frame having an inlet port for receiving warm water under pressure, and an outlet port provided with an adjustable flow-rate valve, whereby hydrostatic pressure within the plenum may be varied by adjustment of the flow-rate valve to thereby vary concave deformation of the diaphragm, and thereby vary its magnification to a selected value.
Various other objects and advantages of the present invention, and its most novel features, will become apparent to those skilled in the art by perusing the accompanying specification, drawings and claims.
It is to be understood that although the invention disclosed herein is fully capable of achieving the objects and providing the advantages described, the characteristics of the invention described herein are merely illustrative of the preferred embodiments. Accordingly, I do not intend that the scope of my exclusive rights
Chapin William L.
Shafer Ricky D.
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