Image signal sensing process including altering charges of capacitances

US6198086A · kind A · utility

Assignees

• Fraunhofer-Gesellschaft zur förderung der angewandten Forschung e.V. · DE
• Bayerische Motoren Werke Aktiengesellschaft · DE
• Bodenseewerk Gerätetechnik GmbH · DE

Inventors

• Michael Schanz · Gerlingen, DE
• Bedrich Hosticka · Rübhausen, DE
• Reiner Wertheimer · Herrsching am Ammersee, DE
• Hakan Kisakurek · Hersbruck, DE

Key dates

• Filing date: Apr 30, 1999
• Grant date: Mar 6, 2001
• Expiry date: Apr 30, 2019

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04N25/77
• WIPO field: Audio-visual technology
• WIPO sector: Electrical engineering

Abstract

In a method for detecting an image signal by means of an array (30) of photosensitive devices (10) with each of which the charge of a capacitance (12) can be altered, an optical signal (20) of each photosensitive device is first detected by means of the following substeps: creating a charge condition of the capacitance with a predetermined voltage (+U_DD), changing the charge of the capacitance (12) either with a photocurrent generated in the photosensitive device (10) by the optical signal (20) or with a quantity derived from the same and detecting the voltage across the capacitance (12) after a predetermined time period, deciding whether the detected voltage lies within a valid range and, if this is so, determining on the basis of the detected voltage a valid signal which characterizes the detected optical signal, and, if this is not so, repeating the cited steps with a time period which differs from the predetermined time period either a predetermined number of times or until it is determined that the detected voltage lies in a valid range. Subsequently the optical signal detected for each photosensitive device (10) is stored together with the time period for which a valid signa…