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. 27, 2001
Filed:
Aug. 27, 1998
Geoffrey L. Barrows, Washington, DC (US);
The United States of America as represented by the Secretary of the Navy, Washington, DC (US);
Abstract
This invention is a one-dimensional optic flow sensor that operates in a small region of the two-dimensional visual field. The heart of the sensor is an linear array of photoreceptors that generates a one-dimensional image representation of the visual field region of interest. The linear photoreceptor array has an orientation in the two-dimensional image space. Information in the two-dimensional image space parallel to the photoreceptor array's orientation is preserved while information in other directions is discarded. The result is that a one-dimensional optic flow algorithm using the photoreceptor array output produces a measurement of the optic flow vector onto the sensor orientation vector. In a preferred embodiment, the photoreceptor array circuitry is implemented on a focal plane chip on which an image is focused by a lens. The focal plane chip is placed slightly off the lens's focal point to blur the image. Each elongated photoreceptor has a long rectangular shaped active area, whose long dimension is perpendicular to the photoreceptor array's orientation. An iris next to the lens controls the “shape” of the blurring by having a transmission function derived from a low-pass spatial filter. The combination of the lens being out of focus and the shading from the iris blur the image in a controlled fashion that implements a low pass spatial filter. This reduces high spatial frequency components in the image that could cause problems due to spatial aliasing from the photoreceptor array.