The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 06, 2007
Filed:
Jan. 07, 2004
Stephen W. Marshall, Richardson, TX (US);
Stephen W. Marshall, Richardson, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
According to one embodiment, a method for providing position feedback for a device includes providing a photointerrupter having a light-emitting diode, a phototransistor, and an aperture between the light-emitting diode and the phototransistor. For a given size aperture, a current through the phototransistor is a function of a current through the light-emitting diode. The method also includes controlling the current through the light-emitting diode current such that a change in the effective aperture size results in a desired approximately proportional change in current through the phototransistor. While controlling the current through the light-emitting diode, a portion of the aperture is blocked by an arm that has a position indicative of the position of the device. The method also includes providing a signal indicative of the change in current through the photodiode as an indication of the change in position of the device.