Test slide for microscopes and method for the production of such a slide

Abstract

A test slide for the calibration, characterization, standardization, use and study of photon and electron microscopes. The slide is created by forming patterns with specific types of geometries on suitable substrates and these slides provide a standard for comparison of image forming capability of any type of microscope imaging system including, without limitation, light, UV, and X-ray photon microscopical imaging systems operating in transmission or reflection modes, and other microscope techniques. Microscopists can employ one of these slides to compare images of the slide which have been produced by the microscope system under consideration with a known, accurate, image of the slide to better understand the fidelity and accuracy of the microscope system under consideration. The test patterns can also comprise reference images which can be images created by a graphic artist or the like or which can be actual images of samples, these images being either two dimensional or three dimensional.

We claim:  
     
         1 . A test slide comprising: 
 a substrate;    a test pattern formed on said substrate, said pattern comprising at least a diffraction grating and a scale system; and    a locating pattern formed on said substrate to assist an observer to locate said test pattern.    
     
     
         2 . A test slide according to  claim 1  wherein said test pattern includes first and second diffraction gratings, said first diffraction grating oriented orthogonally to said second diffraction grating, and first and second scale systems, said first scale system having an orientation corresponding to the orientation of said first diffraction grating and said second scale system orientated orthogonally to said first scale system.  
     
     
         3 . A test slide according to  claim 2  wherein said calibration and test pattern further comprises header means to identify said calibration and test slide.  
     
     
         4 . A test slide according to  claim 3  wherein said means to identify includes a unique identification number for said slide.  
     
     
         5 . A test slide according to  claim 3  wherein said calibration and test pattern further comprises an offset segment pie star.  
     
     
         6 . A test slide according to  claim 5  wherein said test pattern further comprises at least one series of geometric shapes, each series comprising a geometric shape repeated in said series at different sizes.  
     
     
         7 . A test slide according to  claim 5  wherein said test pattern further comprises at least one geometric shape repeated at at least two scales, each said shape including features to self-identify the scale of the shape.  
     
     
         8 . A test slide according to  claim 7  wherein said geometric shape is an alternating pie shape.  
     
     
         9 . A test slide according to  claim 6  including at least first and second series of geometric shapes, said repeated geometric shape of said first series having different geometric properties from the repeated geometric shape of said second series.  
     
     
         10 . A test slide according to  claim 2  wherein said substrate is a slide base.  
     
     
         11 . A test slide according to  claim 2  wherein said substrate is a cover slip.  
     
     
         12 . A test slide according to  claim 11  wherein said test pattern and said locating pattern are formed on a first side of said cover slip, said cover slip being mounted to a slide base via adhesive means with said first side adjacent said slide base.  
     
     
         13 . A test slide according to  claim 12  wherein a suitable immersion fluid is maintained between said first side and said slide base.  
     
     
         14 . A method of manufacturing a test slide, comprising the steps of: 
 (i) providing a substrate with an image area;    (ii) coating at least a portion of said image area with a resist compound;    (iii) exposing said resist compound to form a test pattern and a locating pattern thereon;    (iv) developing said resist compound and removing portions of said resist compound from said substrate to form said test pattern and a locating pattern thereon.    
     
     
         15 . The method of  claim 14  wherein the exposure of step (iii) is accomplished by optical means.  
     
     
         16 . The method of  claim 14  wherein the exposure of step (iii) is accomplished by focused energy beam means.  
     
     
         17 . The method of  claim 14  wherein step (ii) further comprises the step of metallizing said portion of said image area prior to applying said resist and, in step (iv), said metallization is also removed from said substrate where said resist is removed.  
     
     
         18 . The method of  claim 17  further comprising step (v) wherein said resist is removed and said test pattern and said locating pattern is formed by metallization which remains on said substrate.  
     
     
         19 . The method of  claim 14  wherein step (iv) further comprises the step of removing a selected amount of said substrate where said resist has been removed.  
     
     
         20 . The method of  claim 19  wherein said selected amount of said substrate is removed by chemical etching.  
     
     
         21 . The method of  claim 19  further comprising the steps of: 
 (v) metallizing said portion of said image area;  
 (vi) removing said metallization from the surface of said portion of said area such that metallization remains in depressions formed by said removal of said selected amount of substrate.  
 
     
     
         22 . The method of  claim 21  wherein step (vi) is performed by polishing said portion.  
     
     
         23 . The method of  claim 14  wherein said substrate is a slide base.  
     
     
         24 . The method of  claim 14  wherein said substrate is a cover slip.  
     
     
         25 . The method of  claim 24  wherein said cover slip is mounted on a slide base with said test pattern on a side of said cover slip adjacent said slide base.  
     
     
         26 . The method of  claim 25  wherein an immersion fluid is located between said side and said slide base.  
     
     
         27 . A test slide comprising: 
 a substrate including an image area;    a test pattern formed on said substrate in said image area, said pattern comprising a known image having at least two or more features selected from the group comprising grating-type structures, scale systems, image series, offset segment pie stars and indicia to uniquely identify said slide.    
     
     
         28 . A slide according to  claim 27  wherein a first of said at least two features has an orientation which is substantially orthogonal to a second of said at least two features.  
     
     
         29 . A slide according to  claim 28  wherein said known image comprises first and second grating-type structures and first and second scale systems, said first grating-type structure and said first scale system having a first common orientation, said first common orientation being substantially orthogonal to a second orientation which is common to said second grating-type structure and said second scale system.  
     
     
         30 . A slide according to  claim 27  further comprising a locating pattern to assist in locating said test pattern on said slide.  
     
     
         31 . A slide according to  claim 27  wherein said substrate is a slide base.  
     
     
         32 . A slide according to  claim 27  wherein said substrate is a cover slip which is attached to a slide base.  
     
     
         33 . A slide according to  claim 27  wherein said known image is located substantially at the centre of said image area.  
     
     
         33 . A slide according to  claim 30  wherein said known image is located substantially at the centre of said image area and said locating pattern surrounds said known image.  
     
     
         34 . A slide according to  claim 27  wherein said known image is located at a periphery of said image area.  
     
     
         35 . A slide according to  claim 34  further including a locating pattern located between the centre of said image area and said known image.  
     
     
         36 . A test slide comprising: 
 a substrate;    a test pattern formed on said substrate, said pattern having known shape and size; and    a protective layer on said test pattern, said layer inhibiting inadvertent damage to said test pattern and being non-opaque to an preselected range of wavelengths for which said slide is intended to be used.    
     
     
         37 . A test slide according to  claim 36  wherein said test pattern includes features which are less than one micron in size.  
     
     
         38 . A test slide according to  claim 36  wherein said protective layer of formed via chemical vapour deposition techniques.  
     
     
         39 . A method of forming a test slide for microscopes, comprising the steps of: 
 (i) forming a master test pattern on an information carrier for an injection molding device, said test pattern including patterns of known size and shape;    (ii) inserting said information carrier into said injection molding device;    (iii) cycling said injection molding device to inject liquefied resin into contact with said information carrier and to cool said resin to form a plastic carrier with said test pattern formed in one surface; and    (iv) removing said plastic carrier from said injection molding machine.    
     
     
         40 . The method of  claim 39  wherein said information carrier comprises at least two master test patterns and further comprising step (v) wherein said plastic carrier is cut to separate each of the test patterns thereon.  
     
     
         41 . The method of  claim 40  wherein said plastic carrier is cut to form conventional sized microscope slides with said test patterns being located at an image area thereon.  
     
     
         42 . The method of  claim 39  wherein said master test pattern comprises a collection of reference images.  
     
     
         43 . The method of  claim 42  wherein said images of said reference collection have been originally obtained from visible light microscopy.  
     
     
         44 . The method of  claim 42  wherein said images of said reference collection have been originally obtained from scanning electron microscopy.  
     
     
         45 . The method of  claim 42  wherein said images of said reference collection comprise a montage of images.  
     
     
         46 . The method of  claim 42  wherein said master test pattern further comprises a grid and where said images are arranged in said grid.  
     
     
         47 . The method of  claim 39  further comprising step (v) applying a planar layer of thin film material to at least a portion of said one surface.  
     
     
         48 . The method of  claim 47  wherein said layer is applied to said one surface in areas including image features comprising recesses in said surface such that optical interference in said layer produces colors discernable to a viewer.  
     
     
         49 . A method of forming a test slide for microscopes, comprising the steps of: 
 (i) forming a master test pattern on an information carrier for a mold, said test pattern including patterns of known size and shape;    (ii) inserting said information carrier into a mold;    (iii) adding a substrate material to said mold to contact said information carrier and setting said substrate material to form a carrier with said test pattern formed in one surface; and    (iv) removing said carrier from said mold.