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:
Sep. 04, 1979
Filed:
Dec. 01, 1977
David E Steffen, Chatham, IL (US);
Dickey-john Corporation, Auburn, IL (US);
Abstract
A seed sensor detects seeds passing through a chute or housing forming a path of travel for seeds dispensed from a seed planter. A source of light such as a light emitting diode is optically exposed to the path of travel and a photosensitive element such as one or more photoresponsive transistors is optically exposed to the path of travel for receiving the light from the light source. An electronic circuit is connected with the photosensitive element for producing an electrical signal responsive to the light level incident thereupon and producing a change in the electrical signal in response to a momentary change in light level due to the passage of a seed. The electronic circuit includes a circuit element such as a diode connected with the photosensitive element for maintaining at least a given amount of change in the electrical signal output level in response to a given change of light level corresponding to passage of a seed. The circuit therefore is substantially unaffected by any change in the level of light transmitted from the light source or received by the photosensitive element not caused by passage of a seed, as for example due to the accumulation of dirt or dust partially obscuring either the light source or the photosensitive element.