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:
Jan. 16, 1990
Filed:
Jun. 14, 1988
Andrew A Turnbull, Reigate, GB;
U.S. Philips Corp., New York, NY (US);
Abstract
Each element of an array of infrared detector elements comprises a capacitor formed by a body (11) of pyroelectric or ferroelectric material between a front electrode (14) and a back electrode (12). The elements have individual electrical connections (13) to their back electrode (12) from which there are derived electrical signals which differ as the temperature of the body (11) changes in response to incident infrared radiation (50). These individual electrical connections (13) are provided by a pattern of conductors (13) carried by a support (10) on which the elements are mounted. Each element has at least an infrared-collection area (21) of larger lateral dimensions (x) than at least the electrical connection (13) to the back electrode (12) whereby a peripheral part (23) of each element overhangs and is separated vertically from an underlying part of the support (10). In accordance with the invention, the elements are arranged in a 2-dimensional array with inner elements of the array surrounded by outer elements of the array. The conductors (13 ) to the inner elements extend on a part of the support (10) between the outer elements and below the overhanging peripheral parts (23) of these outer elements. These conductors (13) of the inner elements are separated from the back electrode (12) and overhanging peripheral parts (23) of the outer elements and from the individual electrical connections (13) of these outer elements by a gap (y,z) sufficient to avoid any troublesome parasitic capacitance across a detector element or any significant capacitive cross-talk between the detector elements. The width of the intermediate conductor tracks (13) and the dimensions (y,z) of the surrounding gap may be larger than the spacing between the overhanging peripheral parts (23) of adjacent elements and, for example, as large as or larger than the thickness of the element bodies (11). The array can be fabricated cheaply and reliably using thick-film techniques to form the conductors (13) on a good thermally insulative support (10), so also providing low thermal cross-talk between the detector elements.