| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a low-cost apparatus and a method for detecting an object with a simple structure which facilitates the maintenance and management of the side of the object to be detected and without necessity of a high grade image processor. SOLUTION: A retroreflecting material of a predetermined pattern for retroreflecting the light of a near infrared wavelength band is previously provided at an object to be detected. An emitting unit 1 emits a light of a near infrared wavelength band in a monitoring area. A CCD camera 2 is so exposure regulated to make it possible to discriminate the image of high luminance light. The camera 2 images only the image of the monitoring area by the light of the near infrared wavelength band. The image signal from the camera 2 is binarized by a binarizer 3, and the binary image data is stored in an image memory 4. A discriminator 5 discriminates whether the retroreflecting material is present in the monitoring area or not based on the binarized image data.</p> |
