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:
Jul. 29, 1997
Filed:
Mar. 27, 1996
Dennis Eugene Baxter, East Rochester, NY (US);
James Vergil Leavy, Churchville, NY (US);
Peter Austin Newman, Rochester, NY (US);
Leonard Richiuso, Rochester, NY (US);
Eastman Kodak Company, Rochester, NY (US);
Abstract
Camera autofocus apparatus and method employing an autoranging device to determine a lens destination focus position in terms of a target number of signal pulses from a lens motion sensor photo-interrupter. A lens drive motor is initially driven at maximum speed by a 100% pulse width modulated drive signal. At a fixed number of signal pulses in advance of the target, the average motor speed is calculated and a reduced pulse with modulated drive signal, determined based on the calculated motor speed, is applied to the drive motor to cause the lens to arrive at a uniform speed at a near destination focus position that is suitable for application of a standard motor stopping routine. During the motor stopping routine, the motor is initially 'plugged' (reverse polarity drive signal) and the signal pulse period is monitored until a predetermined period is reached. At this point, the plug is removed and an electrical brake (short circuit) is applied to the motor to bring the lens to a rest at the destination focus position.