Patent ID: 8548625

Claim:
An optical sensing system, comprising: a row of light emitters on a first side of a region through which a product falls during delivery and a row of light detectors on a second side of the region, each light detector substantially aligned with a corresponding one of the light emitters, each light emitter, when activated, emitting light across the region and directly incident upon at least one of the light detectors, each light detector substantially aligned with a corresponding one of the light emitters, each light detector detecting light emitted from any of two or more of the light emitters when the respective light emitter is activated; an optical detection aperture located in front of each light detector and between the respective light detector and the light emitters, each optical detection aperture constraining a range of incident angles of light that may be detected by the respective detector and allowing light from a larger range of horizontal angles to reach a respective light detector than light from a range of vertical angles that reaches the respective light detector to permit direct light from the light emitters to reach the light detectors while blocking light from the light emitters reflected from adjacent reflective surfaces; a controller sequentially activating each one of the light emitters on the first side of the region through which the product falls for a first period of time then deactivating the one of the light emitters and, for each light emitter when activated, monitoring at least two light detectors for detection of light from the activated light emitter when the activated emitter is an end emitter within the row of emitters and monitoring at least three light detectors for detection of light from the activated light emitter when the activated emitter is not an end emitter within the row of light emitters; and a reporting circuit coupled to the light detectors and, responsive to detection of light from the activated light emitter at fewer than all of the at least two monitored light detectors, generating a signal indicating delivery of a product.