Image forming apparatus and control method therefor

摘要

In an image forming apparatus, a first detection portion includes a pyroelectric sensor and detects the upper half of the human body. A first signal generation portion generates a first signal whose level varies according to the output value of the pyroelectric sensor. A second detection portion includes a pyroelectric sensor and detects a lower area than the first detection portion. A second signal generation portion generates a second signal whose level varies according to the output value of the pyroelectric sensor. A storage portion stores discrimination data including data defining, with respect to the waveforms of the first and second signals, a condition for recognizing a human moving toward the image forming apparatus and a condition for recognizing a human crossing a detection area of the pyroelectric sensors. A recognition portion recognizes the direction of movement of a human.

主权项

1. An image forming apparatus, comprising:
a first detection portion including a pyroelectric sensor and adapted to detect an upper half of a human body; a first signal generation portion adapted to receive an output of the pyroelectric sensor of the first detection portion to generate a first signal whose level varies according to whether or not an output value of the pyroelectric sensor of the first detection portion is greater than a prescribed threshold value; a second detection portion including a pyroelectric sensor and adapted to detect a lower area than the first detection portion to detect a lower half of the human body; a second signal generation portion adapted to receive an output of the pyroelectric sensor of the second detection portion to generate a second signal whose level varies according to whether or not an output value of the pyroelectric sensor of the second detection portion is greater than a prescribed threshold value; a storage portion for storing discrimination data defining, with respect to waveforms of the first and second signals, a relationship between the first and second signals in terms of frequency or cycle and a variation pattern of duty factors of the first and second signals, the discrimination data including data defining a condition for recognizing a human moving toward the image forming apparatus, a condition for recognizing a human moving away from the image forming apparatus, and a condition for recognizing a human crossing a detection area of the pyroelectric sensors; and a recognition portion adapted to calculate a frequency or cycle of the first and second signals and recognize, based on the relationship between the first and second signals in terms of frequency or cycle, the variation pattern of the duty factors of the first and second signals, and the discrimination data, whether a human is moving toward the image forming apparatus, whether a human is moving away from the image forming apparatus, and whether a human is crossing the detection area of the pyroelectric sensors.