Browse Prior Art Database

Depth Measuring Microscope

IP.com Disclosure Number: IPCOM000084575D
Original Publication Date: 1975-Dec-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 29K

Publishing Venue

IBM

Related People

George, OE: AUTHOR

Abstract

The apparatus as shown schematically is utilized in a method for measuring a depth OA in a workpiece 10.

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Depth Measuring Microscope

The apparatus as shown schematically is utilized in a method for measuring a depth OA in a workpiece 10.

The geometry of the apparatus takes advantage of the fact that there is only a very narrow strip of the vertical object that is in focus, when the microscope is at 45 degrees to the vertical object. This very narrow strip is used as the reference line for measurement. Yet, the range of the measurement is limited only by the field of view of the microscope.

Displacement from the low point O to the high point A of the object, or vice versa, can be measured by using a filar microscope eyepiece or by using a screw micrometer to displace the object horizontally (differential screw micrometer or digital readout micrometer preferred for accuracy).

Horizontal movement of the stage is equal to the vertical height of the object, because both distances are equal legs of a right triangle. Therefore, no correction for cosine error is required using this method.

As shown in the figure, workpiece 10 is attached to positioning table 12. positioning table 12 has freedom of movement along arrow 14. Screw micrometer 16 is positioned so that screw 18 is in contact with positioning table
12. Microscope 20 is positioned at a 45 degrees angle with edge A of workpiece
10.

In operation, microscope 20 is focused so that edge A is clearly seen in the eyepiece. The reading on screw micrometer 16 is noted. The screw micrometer is then rotated until point O of sl...