Quasi-translator, fourier modulator, fourier spectrometer, motion control system and methods for controlling same, and signal processor circuit

Abstract

A quasi-translator for economically producing pure, smooth translational motion with broad arcuate or error-free motion regardless of orientation, which is useful in numerous interferometer applications including spectroscopy, a Fourier modulator and a Fourier spectrometer are provided. The quasi-translator utilizes a support, an arm including a driving magnet on a first end and a driven element on a second end, an axis for rotation of the arm, a bearing system that controls the rotation of the arm about the axis, a drive coil and a drive amplifier to drive the arm in the arcuate motion. The quasi-translator may be employed in a Fourier modulator to change the optical path difference of the interferometer/quasi-translator at a substantially constant rate of change. The quasi-translator and/or Fourier modulator may be used in a Fourier spectrometer to create an optical spectrum from a light beam and/or electrical signal created from the light beam.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S)[0001]This application is a non-provisional patent application that claims the benefit of the filing date of, and priority to, U.S. Provisional Application No. 61 / 563,109, filed Nov. 23, 2011, the entirety of which is incorporated herein by reference.FIELD OF THE INVENTION[0002]The present invention is in the field of mechanisms for economically producing pure, smooth translational motion, preferably with a broad arc, and substantially error-free motion regardless of orientation and for motion control systems and methods of use thereof. Such substantially smooth translational motion is critical for precision instrumentation applications. One such application is the movement of optical assemblies, such as retroreflectors, mirrors, reflecting panels, etc., in interferometer / spectroscopy applications.BACKGROUND OF THE INVENTION[0003]Fourier transform infrared (“FTIR”) spectrometers are well known in the art. Michelson interferometers function by...

AI Technical Summary

Benefits of technology

[0040]Surprisingly it has been found that employing a driving element that moves, such as, but not limited to a magnet, and that acts as a counterweight while an electromagnetic coil remains static to define the drive motor achieves the desired results of providing a small or broad arc and substantially error-free motion regardless of orientation of the device. Because the electromagnetic coil is fixed, this design achieves the desired results without requiring the use of one or more sliding electrical contacts or flexible leads when connecting the electromagnetic coil to a drive power source.

[0041]Accordingly, it is an object of the invention to provide a quasi-translator f

Problems solved by technology

Any deviation from pure translation may cause slight tilting of a plane mirror, leading to distortion in the detected beam.

Typically, systems relying on either such solution have been difficult to design, relatively large, expensive and present maintenance issues.

However, such devices include structural deficiencies that do not provide pure, smooth translational motion, preferably with a broad arc, and substantially error-free motion regardless of orientation thereof.

For example, the rigid pendulum design of the Burkert device is inherently unbalanced (which leads to various problems, such as, but not limited to, the velocity of the pendulum not being compensated, the pivot point becomes stressed, etc.), and would not operate in any orientation.

While the Brierley device would also not operate in any orientation given the design thereof, further deficiencies of the complex design of the Brierley device requires an inordinate number of components, and unnecessary movement of those components, that add to economic cost and inefficiencies relating to manufacturing and maintaining same.

Additionally, such devices require complex re-calibration when switching those devices from one system to another, and such complex re-calibration can include an inordinate number of steps to perform same.

How

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