| 摘要 |
PROBLEM TO BE SOLVED: To provide a highly reliable active device for detecting infrared ray capable of avoiding erroneous report as much as possible regardless of whether or not the factor of the attenuation of an infrared beam such as mist or rain exists when it is set outside. SOLUTION: This active device for detecting infrared ray is provided with: a projecting device 10 having a projector 11 for emitting an infrared beam IR, a projector driving part 12 for pulse-driving the projector 11 and a receiver 14; and a light receiving device 20 having a light receiver 21 for receiving the infrared beam IR from the projector 11, a light shielding discriminating part 25 for discriminating that the infrared beam IR has been shielded since at least the predetermined number of pulses are not continuously output from the light receiver 21, a light receiving status detecting part 28 for detecting the light receiving status of the infrared beam IR and a transmitter 29 for transmitting the information of the light receiving status to the receiver 14. The cycle of the pulse driving signal in the projector driving part 12 is changed based on the information to be received by the receiver 14. COPYRIGHT: (C)2006,JPO&NCIPI |
