Patent ID: 8260568

Claim:
A moving direction detector comprising: first and second groups of sensor elements that face a moving body to be detected, arranged in a row along a moving direction of the moving body, and output detection signals in accordance with travel of the moving body, each of the first and second groups including one or more sensor elements; signal processing units that convert output signals of the first and second groups of sensor elements into rectangular waves; a moving direction detection unit that outputs a signal corresponding to a moving direction of the moving body, based on the detection signals from the first and second groups of sensor elements; output processing units that output signals with which a moving direction of the moving body can be determined, based on output signals of the signal processing units and an output signal of the moving direction detection unit; and an output determination unit that determines an output value of the output processing unit, wherein the moving direction detection unit has a delay function of generating an output signal at a time instant that is delayed by a predetermined time from a time instant when a moving direction of the moving body is changed, and wherein the duration of the high level or the low level of the rectangular wave is fixed to duration a 1 or duration a 2 , and even in the case where a moving direction reverses during the duration a 1 or the duration a 2 , the output processing unit outputs a rectangular wave having a fixed width of the duration a 1 or a 2 in accordance with a moving direction of the moving body, at a time instant that is delayed from the reversal by the duration a 1 or a 2 .