US 7,485,841 B2
Multi-optical axis photoelectric sensor
Tetsu Inoue, Osaka (Japan); and Tsuyoshi Tagashira, Osaka (Japan)
Assigned to Keyence Corporation, Osaka (Japan)
Filed on Jan. 24, 2008, as Appl. No. 12/18,839.
Claims priority of application No. 2007-015006 (JP), filed on Jan. 25, 2007.
Prior Publication US 2008/0179505 A1, Jul. 31, 2008
Int. Cl. G08B 13/18 (2006.01)
U.S. Cl. 250—221  [340/556] 20 Claims
OG exemplary drawing
 
1. A multi-optical axis photoelectric sensor comprising:
a light emitting unit having an elongated first casing along a longitudinal direction of said first casing and a plurality of light emitting elements being equally spaced from each other from one end portion of said first casing to another end portion of said first casing in a first row;
a light receiving unit having an elongated second casing along a longitudinal direction of said second casing and a corresponding number of light receiving elements as the number of the light emitting elements being equally spaced from each other from one end portion of said second casing to another end portion of said second casing in a second row;
a light emitting circuit installed into said light emitting unit for driving said light emitting elements forming optical axes; a light receiving circuit installed into said light receiving unit for processing a first signal from said light receiving elements forming said optical axes with said light emitting elements; a status output means for outputting a binary signal corresponding to each of a first status being a light through status to all of the optical axes and a second status being a light blocked status to at least one optical axis based on a second signal from said light receiving circuit;
a diagnosis means for diagnosing a malfunction of said light emitting circuit, said light receiving circuit and said status output means;
an indicating portion disposed at each of said light emitting and receiving units comprising a plurality of indicating elements being in the same row of each of said light emitting and receiving elements with no-interference to each of said light emitting and receiving elements;
an indicating control portion for turning on said plurality of said indicating elements of said indicating portion as a first turn on pattern to show said first and second rows of said units when said binary signal indicating said first status is output by said status output means and turning on with a predetermined turn on pattern being different from said first turn on pattern when it is diagnosed said malfunction by said diagnosis means.