公开(公告)号：US3774192A

公开(公告)日：1973-11-20

申请号：US3774192D

申请日：1972-03-22

Applicant: INT COMPUTERS LTD

Inventor： BOULTER D

IPC: G06K13/06 ,  G06K13/067 ,  G08B21/00

CPC classification number: G06K13/067 ,  G06K13/06 ,  Y10T307/766

Abstract: In apparatus for detecting the presence of documents on a document support surface, the surface has at least one groove extending from one end of the surface to the other end and aligning with the direction of document feed. The groove is closed at one end and open at the other. A flow of pressurized air is fed from the closed end lengthwise of the groove. A gas pressure dectection means monitors the gas pressure intermediate the ends of the groove and produces an output signal which has a first value when a document covers the groove and a second value when the document is not covering the groove.

Abstract translation: 在用于检测文档支撑表面上的文档的存在的装置中，表面具有至少一个从表面的一端延伸到另一端的凹槽，并与文件进给的方向对齐。 槽在一端封闭，另一端开放。 加压空气流从槽的长度方向的封闭端部供给。 气体压力检测装置监视槽的端部之间的气体压力，并产生当文件覆盖凹槽时具有第一值的输出信号，当文件未覆盖凹槽时产生第二值。