Patent ID: 6927690

Claim:
An apparatus for determining when a door connected to a wall has opened comprising: means for transmitting an optical signal from a first point to a second point, the transmitting means includes a-first optical fiber and at least a-second optical fiber through which the signal is transmitted when the first fiber and the second fiber are in alignment, and through which the signal is unable to be transmitted to the second point from the first point when the first fiber and the second fiber are not in alignment; and means for interrupting the signal from reaching the second point from the first point when the door is opened, the interrupting means contacting the transmitting means, the interrupting means causing the first fiber and the second fiber not to be in alignment when the door is opened, and to be in alignment when the door is closed, the interrupting means includes a block, first optical fiber holder for holding the first optical fiber and a second optical fiber holder for holding the second optical fiber, the first fiber holder positioned next to the second fiber holder so when the door is closed, the first fiber holder and the second fiber holder maintains the first fiber and the second fiber in alignment through which the signal is transmitted, the first fiber holder having a forcing mechanism which moves the first fiber holder so the first fiber and the second fiber are out of alignment when the door is opened.