Abstract:
A protection device for protecting an objective lens and other parts of a microscope from excess immersion oil is provided. The objective lens protector comprising a sheet of absorbent material and a retaining mechanism for releasably securing the sheet of absorbent material to the microscope.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to an objective lens protector and, more particularly, the invention relates to an objective lens protector for protecting an objective lens and other parts of a microscope from excess immersion oil. 
     2. Description of the Prior Art 
     In optics, an objective lens is the lens or mirror in a microscope, telescope, camera, or other optical instrument that gathers the light coming from the object being observed, and focuses the rays to produce a real image. The objective lens is also called the object lens, object glass, and objective glass. 
     Microscope objectives are typically designed to be parfocal, which means that when one changes from one lens to another on a microscope, the sample stays in focus. Microscope objectives are characterized by two parameters, namely, magnification and numerical aperture. The former typically ranges from 5× to 100× while the latter ranges from 0.14 to 0.7, corresponding to focal lengths of about 40 to 2 mm, respectively. For high magnification applications, an oil-immersion objective or water-immersion objective has to be used. The objective is specially designed and refractive index matching oil or water must fill the air gap between the front element and the object to allow the numerical aperture to exceed 1, and hence give greater resolution at high magnification. Numerical apertures as high as 1.6 can be achieved with oil immersion. 
     Unfortunately, excess of immersion oil causes problems to the objective and the microscope, especially objective lenses on inverted microscopes. The immersion oil, if not removed right after use, may glide into the objective lens, causing damages to the optics of the objective lens, which is difficult and costly to repair. 
     SUMMARY 
     The present invention is a protection device for protecting an objective lens and other parts of a microscope from excess immersion oil. The objective lens protector comprises a sheet of absorbent material and a retaining mechanism for releasably securing the sheet of absorbent material to the microscope. 
     The present invention further includes a method for protecting an objective lens and other parts of a microscope from excess immersion oil. The method comprises providing a sheet of absorbent material and releasably securing the sheet of absorbent material to the microscope. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view illustrating a microscope capable of utilizing an objective lens protector, constructed in accordance with the present invention; 
         FIG. 2  is a perspective view illustrating the objective lens protector, constructed in accordance with the present invention, with the protector mounted about the objective lens; 
         FIG. 3  is another perspective view illustrating the objective lens protector of  FIG. 2 , constructed in accordance with the present invention, with the protector mounted about the objective lens; 
         FIG. 4  is still another perspective view illustrating the objective lens protector of  FIG. 2 , constructed in accordance with the present invention, with the protector secured about the objective lens; 
         FIG. 5  is a top plan view illustrating another embodiment of the objective lens protector, constructed in accordance with the present invention, for protecting other parts of the microscope; 
         FIG. 6  is a perspective view illustrating the objective lens protector of  FIG. 5 , constructed in accordance with the present invention, mounted on a Leica microscope objective; and 
         FIG. 7  is a perspective view illustrating the objective lens protector of  FIG. 5 , constructed in accordance with the present invention, mounted on a Nikon Leica microscope objective. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As illustrated in  FIGS. 1-7 , the present invention is an objective lens protector, indicated generally at  10 , for protecting an objective lens  12  of a microscope  14  from excess immersion oil. In an embodiment of the present invention, the objective lens protector  10  of the present invention utilizes a special oil absorbent material  16  to absorb the excess of immersion oil thereby inhibiting potential damages together with an elastic material  18  to releasably secure the objective lens protector  10  to the objective lens. It should be noted that while the objective lens protector  10  has been and will be described as protecting an objective lens  12  of a microscope  14 , it is within the scope of the present invention for the objective lens protector  10  to be used on other parts of the microscope  14  to absorb excess immersion oil and inhibit damage to the microscope  14 . 
     In a preferred embodiment, the absorbent material  16  of the objective lens protector  10  of the present invention is Fisherbrand Oil-Only Sorbent Pads manufactured by Fisher Scientific (Cat #: 19039126) comprised of multilayer, fine fiber polypropylene for cost-effective sorption. Basically, the absorbent material  16  absorbs oil but does not absorb water. It should be noted that any type of absorption material  16  is within the scope of the present invention and should not be limited to any specific type of absorbent material  16  described and illustrated herein. 
     As stated above, the objective lens protector  10  of the present invention includes an elastic material  18  secured to the absorbent material  16 . In a preferred embodiment, the elastic material  18  is cut to a desired length to encompass the circumference of the objective lens  12 . The ends of the elastic material  18  are then connected together by sewing or the like to form a ring. The absorbent material  16  is then measured to the same length as the elastic material  18  and cut to that length. Next, the absorbent material  16  is positioned within the elastic material ring  18  creating the first embodiment of the objective lens protector  10 . The objective lens protector  10  is positioned completely around the objective lens  12  with the elastic material  18  facing outward from the objective lens  12  and the absorbent material directly contacting the objective lens  12 . The objective lens protector  10  snugly hugs the objective lens  12  to absorb any excess immersion oil and inhibit any damage to the objective lens  12 . In a preferred embodiment, the absorbent material  16  and the elastic material  18  have a width of three-eighths (⅜″) inch although using absorbent material  16  and elastic material  18  having greater or lesser widths is within the scope of the present invention. 
     In another embodiment of the objective lens protector  10  of the present invention, the absorbent material  16  is shaped as an O-ring having a top surface  20 , a bottom surface  22 , and an inner edge  24 . The objective lens protector  10  of the second embodiment does not have an elastic material  18  secured thereto, but rather is held in place by the friction of the contact between the inner edge  24  of the absorbent material  16  and the objective lens  12 . 
     With the O-ring embodiment, the objective lens protector  10  of the present invention has a piece of white tape  26  applied to the top surface  20  of the absorbent material  16 . Preferably, the piece of white tape  26  is the same shape as the O-ring absorbent material  16 . As the absorbent material  16  is saturated with immersion oil, the piece of tape  26  will become darker or otherwise change color. The O-ring embodiment of the objective lens protector  10  works well with both standard lenses and specialized lenses such as the Nikon lens shown herein. 
     During use of both embodiments, the objective lens protector  10  of the present invention absorbs excess immersion oil thereby protecting the objective lens  12 . Once the absorbent material  16  of the objective lens protector  10  is saturated, the objective lens protector  10  is removed from about the objective lens  12  and discarded. A new objective lens protector  10  can then be positioned about the objective lens  12 . Oil saturation can typically be determined by either actual viewing of the absorbent material  16 , physically touching the absorbent material  16 , or observing whether the piece of tape  26  has changed color or darkened. 
     In sum, the objective lens protector  10  of the present invention absorbs excess of immersion oil from the objective lenses  12  and other parts of microscopes  14  thereby inhibiting any problems the excess oil may cause. The immersion oil is quickly and efficiently removed thereby keeping the oil from entering the objective lens  12  and causing damages to the optics of the objective lens  12 . 
     The foregoing exemplary descriptions and the illustrative preferred embodiments of the present invention have been explained in the drawings and described in detail, with varying modifications and alternative embodiments being taught. While the invention has been so shown, described and illustrated, it should be understood by those skilled in the art that equivalent changes in form and detail may be made therein without departing from the true spirit and scope of the invention, and that the scope of the present invention is to be limited only to the claims except as precluded by the prior art. Moreover, the invention as disclosed herein, may be suitably practiced in the absence of the specific elements which are disclosed herein.