| 摘要 |
PURPOSE:To prevent the unnecessary opening of a door by forming three detection ranges with the approximate center of an entrance and exit as the center and opening the door narrowly when a passing body enters into only the detection range in the center and opening the door to its full width when a passing body enters into detection ranges on both sides. CONSTITUTION:A detector 1 is provided on a transom E on an automatic door D, and detection ranges A, B, and C are formed. When a passing body enters into the central detection range B, infrared rays from the passing body are condensed by the second detecting element 7, and a turn-on signal is sent to a half opening switch 10 of a full/half opening thermic-ray switch converter 9 to open the door D. A flip flop 13 in the circuit is reset still; and when a half opening limit switch 14 is turned on, an NAND gate 15 becomes ''0'', and the door D is stopped in the half opening position. When the passing body enters from the side or plural passing bodies enter into detection ranges, the flip flop 13 is set and its Q becomes ''0'' because passing bodies traverse left and right detection ranges A and C, and the output of the NAND gate 15 is held in ''1'', and the door D is opened to its full width. |
