Browse Prior Art Database

High Resolution X Y Z Theta Mechanism

IP.com Disclosure Number: IPCOM000082461D
Original Publication Date: 1974-Dec-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 2 page(s) / 67K

Publishing Venue

IBM

Related People

Segal, Z: AUTHOR [+2]

Abstract

This mechanism enables achieving high resolution in the X, Y, Z and theta directions. This mechanism will provide resolution to the order of 5-10 microinches with simple electronic control circuitry.

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High Resolution X Y Z Theta Mechanism

This mechanism enables achieving high resolution in the X, Y, Z and theta directions. This mechanism will provide resolution to the order of 5-10 microinches with simple electronic control circuitry.

The high resolution is achieved by a high-reduction harmonic reducer with a typical reduction ratio of 100:1, and a cam which is mounted on its output shaft.

As shown in the drawing, the motor and harmonic reducers may be packaged together as one unit. At the output of this unit is a cam. The X and Y stages are preloaded against the cam. The motion is transmitted from the cam to the slide via a cam follower.

A typical DC or stepping motor has a 2 degree resolution or less. This resolution is reduced 100 times at the output of the reducer to be 0.02 degree. If the total translation required by the stage is +0.050", then a simple eccentric cam can be used to generate the desired displacement.

The Theta stage consists of a motor and a harmonic reducer. The vacuum pencil is mounted at the output of the reducer. A Theta resolution of 0.02 degree can be achieved for a driving motor resolution of 2 degrees. The Z stage is activated by a motor driven harmonic reducer. The output of the reducer is connected to an arm which, when rotated, drives the Theta stage in the Z direction.

The advantages of the mechanism are high resolution, high repeatability and no backlash. Also compact low-torque motors can be used to drive these stages, becaus...