| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for detecting a transparent body without comprising specially high detection performance necessary to capture subtle attenuation of the amount of light due to light transmission through the transparent body in transparent body detection by the photoelectric switch. ! SOLUTION: A photoelectric switch comprises: a light projection unit 2 which projects light; a light-receiving unit 3 which is arranged side by side with the light projection unit 2 and receives light; a regression reflection plate 4 which is arranged facing the light projection unit 2 and the light-receiving unit 3 and reflects light; and a detection unit 7 which detects whether a transparent body 50 exists in a detection region on the basis of the amount of light. The photoelectric switch further includes a first circular polarization filter 5 which is provided on a light projection surface of the light projection unit 2 and a light-receiving surface of the light-receiving unit 3, and transmits only |
