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:
Dec. 15, 1987
Filed:
Feb. 18, 1986
Bo Norrgren, Akarp, SE;
Nils Bjelk, Landskrona, SE;
Besam AB, Landskrona, SE;
Abstract
The invention comprises a pulse transmitter (2,3) for infrared light, the reflected radiation from which is received by photo-diodes (5) converting the light pulses to electric pulses (FIG. 3), which are amplified (9) and applied to a balancing circuit (12), which operates digitally and with a given working or threshold level. Applied pulses give the output of the balancing circuit (12) a low state, which is supplied to a first integration circuit (16) having relatively rapid integration time, and which is in series with a second integration circuit (18). The integration circuits each control an input (21,26) of a comparison circuit (22), which generates an operation signal on its output (27,28) when there is a difference in integration conditions, the slower integration circuit (18) controlling the working or threshold level of the balancing circuit (12).