Safety photoelectric switch
First Claim
1. An optical scanning type photoelectric switch, which performs two-dimensional scanning with light projection pulse to detect an object, and also measures a distance to the object to sense a two-dimensional position of the object, the switch having;
- a storage device for accepting and storing a change in a light projection period of the light projection pulse, a scanning period for scanning with the light projection pulse or a phase of the light projection pulse with respect to the light projection period;
a light projection/reception controlling device for controlling light projection/reception based upon the light projection period or the scanning period stored in the storage device; and
a safety signal output controlling device for switching a safety signal from a permission signal to a non-permission signal when light reflected by the object is received and it is determined that a position of the object is inside a protection area based on at least two scannings in succession.
1 Assignment
0 Petitions
Accused Products
Abstract
There is provided an optical scanning type photoelectric switch capable of preventing interference with another photoelectric switch by use of its own capability, wherein, as for light projection pulse periods of the first and second optical scanning type photoelectric switches, the period is set to 30 μs in the first optical scanning type photoelectric switch while the period is set to 33 μs in the second optical scanning type photoelectric switch 1B, the light projection pulses have the same pulse width, and by setting the light projection periods different between the first and second optical scanning type photoelectric switches, even if mutual interference occurs between any optical axes, a phase difference of 36 degrees in rotation period is generated therebetween in a next scan, thereby preventing occurrence of the interference in succession in a plurality of times of scanning.
-
Citations
6 Claims
-
1. An optical scanning type photoelectric switch, which performs two-dimensional scanning with light projection pulse to detect an object, and also measures a distance to the object to sense a two-dimensional position of the object, the switch having;
-
a storage device for accepting and storing a change in a light projection period of the light projection pulse, a scanning period for scanning with the light projection pulse or a phase of the light projection pulse with respect to the light projection period; a light projection/reception controlling device for controlling light projection/reception based upon the light projection period or the scanning period stored in the storage device; and a safety signal output controlling device for switching a safety signal from a permission signal to a non-permission signal when light reflected by the object is received and it is determined that a position of the object is inside a protection area based on at least two scannings in succession. - View Dependent Claims (2, 3, 4, 5, 6)
-
Specification