Confocal tandem scanning reflected light microscope

• US 5,517,352 A
• Filed: 02/24/1993
• Issued: 05/14/1996
• Est. Priority Date: 12/06/1990
• Status: Expired due to Fees

• Current Assignee: Advanced Scanning Limited
• Original Assignee: Tandem Scanning Corporation
• Inventors: Hill, James D.
• Primary Examiner(s): Phan, James
• Application Number:
  US08/021,600
• Time in Patent Office: 1,175 Days
• Field of Search: 359/368, 359/379-389, 359/900, 359/234-236, 356/399-400
• US Class Current: 359/368
• CPC Class Codes: G02B 21/0044 moving apertures, e.g. Nipkow disks, rotating lens arrays
• CPC Class Codes: G02B 21/0052 Optical details of the image generation
• CPC Class Codes: G02B 21/0056 based on optical coherence, e.g. phase-contrast arrangements, interference arrangements
• CPC Class Codes: G02B 21/0072 details concerning resolution or correction, including general design of CSOM objectives
• CPC Class Codes: Y10S 359/90 Methods

Abstract

An improved method and apparatus for easily and accurately aligning confocal tandem scanning reflected light microscopes having scanning disc hole diameters as small as 20 microns are described. The method involves the observation and analysis of Moire and other patterns of light occurring within the microscope, and using the apparatus to make very sensitive adjustments that result in a fully aligned, rugged, and stable confocal tandem scanning reflected light microscope offering improved resolution, contrast, and optical slicing capability.

Claims

1. A method for aligning an adjustable confocal tandem scanning reflected light microscope having an optical system with an objective lens, a scanning disc and position and size adjustment means, said method comprising the steps of;

(1) passing light through holes in one area of a scanning disc through part of the optical system, and then through holes in a second area of the scanning disc,

(2) observing and analyzing the initial Moire patterns of light passing through said holes in said second area of the scanning disc,

(3) adjusting the microscope in response to the initial Moire patterns observed in said observing step, and

(4) observing the results of said adjusting step by analyzing any change in said Moire patterns as a result of said adjusting step, to determine whether alignment has been achieved.

2. A method according to claim 1, said method further comprising the steps of;

(1) establishing a first surface mirror as a target at or near the focal plane of the objective lens,

(2) varying the position adjustment means of said confocal tandem scanning reflected light microscope,

(3) observing the direction of motion of a bright area in the Moire pattern of light passing through said holes in said second area of the scanning disc in response to said varying of said position adjustment means, and

(4) varying the size adjustment means using the results from said step of observing the direction of motion of a bright area in the Moire pattern of light to achieve correct size adjustment of said confocal tandem scanning reflected microscope.

3. A method according to claim 1, said method further comprising the steps of;

(1) establishing a first surface mirror as a target at or near the focal plane of the objective lens,

(2) varying the size adjustment means of said confocal tandem scanning reflected light microscope,

(3) observing the size of the bright area in the Moire pattern of light passing through said holes in said second area of the scanning device in response to said varying of said size adjustment means, and

(4) using said observation to achieve correct size adjustment of said confocal tandem scanning reflected microscope.

4. A method of centering the disc of a tandem scanning light reflected microscope according to claim 1, said method further comprising the steps of;

(1) establishing a first surface mirror as a target at or near the focal plane of the objective lens,

(2) varying the size adjustment means of said confocal tandem scanning reflected light microscope to achieve a bright area,

(3) observing the motion of said bright area in the Moire pattern of light passing through said holes in said second area of the scanning device, while turning the disc by hand,

(4) using said observation to achieve precise disc centering of said confocal tandem scanning reflected microscope, and

(5) returning the size adjustment to its original position.

5. A method of making an adjustment to the light path of a confocal tandem scanning reflected light microscope according to claim 1 comprising the steps of;

translating a tilt plate on which a beam splitter is mounted relative to the perpendicular axis of the scanning disc of the microscope along an axis parallel to the path of the light reflected from a specimen to a viewing area, viewing through said microscope to establish a field of view,

continuing the translation of the tilt plate until a bright area of the disc as viewed at the viewing location is less than one-third of the diameter of the field of view,

reversing the direction of translation of the tilt plate until the bright area of the disc is one-third of the diameter of the field of view,

centering the bright area of the disc, using position adjustment screws on a compound that moves the scanning disc in x and y directions perpendicular to the axis of rotation of the disc,

rotating one of the position adjustment screws and observing the direction of movement of the bright area, and

rotating the tilt plate until the bright area does not move at an angle when either rotation screw is moved,

re-centering the bright area of the disc, using position adjusting screws,

noting the direction of motion of the bright area in response to the position adjustments,

translating the tilt plate along its axis by turning the size adjusting screw until the bright area fills the whole field of view, and dims uniformly as one of the position adjusting screws is used to move the bright area,

turning the second size adjusting screw clockwise until the bright area is slightly smaller than the field of view,

using the position adjusting screw to re-center the bright area,

rotating the second size adjusting screw counterclockwise until the tilt plate rests against the first size adjusting screw, and,

turning the position adjusting screws so as to achieve maximum brightness of the field of view.