公开(公告)号：US4000397A

公开(公告)日：1976-12-28

申请号：US560979

申请日：1975-03-21

Applicant: Raymond T. Hebert ,  John P. Ekstrand

Inventor： Raymond T. Hebert ,  John P. Ekstrand

IPC: G06K7/10 ,  H03K5/08 ,  G08C9/06

CPC classification number: G06K7/10851 ,  H03K5/082

Abstract: Method and apparatus for processing input binary encoded analog signals to precisely determine the time occurrence of positive-going and negative-going transitions. Such digital signals result, for example, when bar codes (e.g. Universal Product Codes) are optically scanned. Transitions are determined by detecting the zero crossings, at selected gating times, of the second derivative of the input signals. The selected gating times occur whenever the first derivatives of the input signals exceed a threshold level. The threshold level is determined in one embodiment by peak-to-peak detecting the input signals and adding this value to a rectified noise measurement signal.

Abstract translation: 用于处理输入二进制编码的模拟信号以精确地确定正向和负向转换的时间发生的方法和装置。 例如，当条形码（例如通用产品代码）被光学扫描时，这样的数字信号产生。 通过检测输入信号的二阶导数的选定门控时间的过零点来确定转换。 每当输入信号的一阶导数超过阈值电平时，选择的选通时间就会发生。 在一个实施例中，通过峰 - 峰检测输入信号并将该值加到整流噪声测量信号上来确定阈值电平。