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:
Nov. 09, 1993
Filed:
Sep. 16, 1991
Carver A Mead, Pasadena, CA (US);
Federico Faggin, Los Altos Hills, CA (US);
Synaptics, Incorporated, San Jose, CA (US);
Abstract
A bipolar phototransistor comprises both an integrating photosensor and a switching element. The base terminal of the bipolar phototransistor is utilized as the switch-control node for the pixel and its emitter is the output node of the integrating photosensor. A plurality of integrating photosensors may be placed in an array of rows and columns, wherein the bases of all bipolar phototransistors in a row are capacitively coupled together to a common row-select line, and the emitters of all bipolar phototransistors in a column are connected together to a column sense line. The input of a sense amplifier is connected to the sense line of each column of integrating photosensors. An integrating sense amplifier according to the present invention includes an amplifying element having an inverting input connected to the sense line. A capacitor, preferably a varactor, is also connected between the inverting input and output of the amplifying element. An exponential feedback element may be provided in the sense amplifiers for signal compression at high light levels.