| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a crime prevention lens which prevents lenses built therein from fogging, and conforms to new environmental conditions. <P>SOLUTION: The crime prevention lens A is formed of: a first cylindrical body (internal cylinder 1) and a second cylindrical body (external cylinder 2) screwed to each other via mounting holes 30, 40 formed in door plates 3, 4 of a double door, respectively; a fitting portion 13 arranged on the internal cylinder 1 and fitted into the mounting hole 30 from outside; an outside flange portion 10 formed on the outside of the fitting portion 13; a male screw portion 10B formed on the inside of the fitting portion 13; a lens system (the lenses 120, 121, 122, 123) arranged in the internal cylinder 1; a hole 17 communicating with a space 16 defined by the lenses 120, 121 and the lens 122; a sealing portion 17A sealing the hole 17; and a defogging gas body 19 sealed in the space 16. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
