| 摘要 |
PURPOSE:To prevent misirradiation to human bodies by automatically stopping or damping a laser with a photoelectric converter provided at a focusing point according to external infrared rays condensed with a lens to the point as coming at a solid angle including the one at which the laser beam should be emitted. CONSTITUTION:As soon as a laser beam 3 is emitted from a laser 4, it is condensed by a lens system 6 in the range of a solid angle 5 including the one at which the laser beam 3 should be emitted. The beam thus condensed hits a photoelectric converter 8 provided at a focusing point by way of an infrared ray filter 7. The output of the converter is amplified 10 and switches 11 a power source 12 to control the driving 13 of the laser. As soon as any infrared ray comes from an emitting body within the solid angle, it is detected 8 and amplified 10 to open a switch device 11. When the infrared rays passing through the filter 7 is set at a wavelengthe equivalent to the temperature of a human body and amplified 10 sufficiently, the entry of a part of the human body within the solid anble 5 opens the switch device 11. Otherwise, the power of the laser beam can be damped to a danger-free extent. Thus, the safety can be secured. |
