Multiple optical axis photoelectric sensor for muting processing

摘要

A multiple optical axis photoelectric sensor capable of performing muting processing adapted to a plurality of kinds of workpieces having different heights without the need for complicated pre-setting according to the kinds of workpieces, is provided. The multiple optical axis photoelectric sensor is provided with a light projecting device and a light receiving device, which forms a plurality of optical axes together with the light projecting device. In at least one portion of a detection area, which is set according to the optical axes, a muting area for nullifying the result of detection of blocked light is set up. A sensor system acquires a range of blocked light corresponding to the blocked optical axis during passage of a workpiece, and alters the muting area of the multiple optical axis photoelectric sensor from a first range to a second range.

主权项

1. A multiple optical axis photoelectric sensor (SNS) for detecting an object to be detected, which is conveyed by a conveyance device, the multiple optical axis photoelectric sensor (SNS) comprising:
a light projecting device having a plurality of light projecting elements which are arrayed in a line, a light receiving device having a plurality of light receiving elements which are disposed to face the light projecting elements, light blocking determination circuitry configured to perform a light blocking determination of whether or not any optical axes formed between opposed light projecting elements and light receiving elements are in a light blocking state, a controller configured to output a detection signal on the basis of a result of the light blocking determination, and muting processing circuitry configured to perform muting so as not to output the detection signal even though a subset or all of the optical axes are in a light blocking state, wherein the muting processing circuitry comprises: muting initiating circuitry configured to initiate the muting of the optical axes in a first range in response to a signal input from an external muting device indicating that the object to be detected is conveyed toward the multiple optical axis photoelectric sensor (SNS), and muting altering circuitry configured to select, as the optical axis to be muted thereafter, the optical axes in a second range that includes all blocked optical axes of the first range, the muting altering circuitry being configured to select the optical axis in the second range depending on the light blocking state of the optical axes in the first range while the optical axes in the first range are muted, and the muting altering circuitry is configured to acquire the range of the blocked optical axes during an acquisition period for acquiring a blocked light range.