Optical scanners and signal processors therefor
    1.
    发明授权
    Optical scanners and signal processors therefor 失效
    光学扫描仪和信号处理器

    公开(公告)号:US5734152A

    公开(公告)日:1998-03-31

    申请号:US454830

    申请日:1995-05-31

    IPC分类号: G06K7/10 G06K7/14

    摘要: An optical scanning system is provided for producing a signal representative of a spatial distribution of indicia having different degrees of reflectivity to light, such as a bar code. The system includes an optical scanner for scanning beam of light over the spatial distribution of indicia and for producing an electrical signal corresponding to changes in the degree of reflectivity of the indicia. A digitizer, responsive to detections in a predetermined characteristic of the produced electrical signal is provided. The digitizer converts the detections into digital words, such digital signals having a plurality of bits. The digitizer includes a timing generation circuit for producing a pulse in response to each one of the detections with a time duration representative of the degree of reflectivity of the indicia as the beam of light. A decoder converts the time duration of the pulse into the digital word having a plurality of bits. An enhancement filter is also disclosed. The enhancement filter modifies pulses produced by a differentiator circuit used in the scanner. Such modification includes increasing the rise time, and peak level of, the pulses produced by the differentiator circuit 24.

    摘要翻译: 提供了一种光学扫描系统,用于产生表示具有不同光反射度的标记的空间分布的信号,例如条形码。 该系统包括用于在标记的空间分布上扫描光束并用于产生对应于标记的反射度的变化的电信号的光学扫描器。 提供了响应于所产生的电信号的预定特性中的检测的数字转换器。 数字转换器将检测器转换为数字字,这样的数字信号具有多个位。 数字转换器包括定时产生电路,用于响应于每个检测产生脉冲,其中持续时间代表标记作为光束的反射度。 解码器将脉冲的持续时间转换为具有多个位的数字字。 还公开了增强滤波器。 增强滤波器修改由扫描器中使用的微分电路产生的脉冲。 这种修改包括增加由微分电路24产生的脉冲的上升时间和峰值电平。