公开(公告)号：US3544994A

公开(公告)日：1970-12-01

申请号：US3544994D

申请日：1967-10-02

Applicant: IBM

Inventor： HANSON CHARLES C ,  HO JOSEPH P L ,  SEGAR LAWRENCE P

IPC: H03M1/00 ,  H03K13/04 ,  H03K17/16 ,  H03K17/60

CPC classification number: H03M1/00 ,  H03M1/50

公开(公告)号：US3533007A

公开(公告)日：1970-10-06

申请号：US3533007D

申请日：1969-10-09

Applicant: IBM

Inventor： SEGAR LAWRENCE P

IPC: H03F3/45 ,  H03F3/68

CPC classification number: H03F3/45071

公开(公告)号：US3701099A

公开(公告)日：1972-10-24

申请号：US3701099D

申请日：1971-06-08

Applicant: IBM

Inventor： HALL RICHARD E ,  SEGAR LAWRENCE P

IPC: G06K9/38 ,  G06K9/00 ,  G06K7/14

CPC classification number: G06K9/38 ,  G06K2209/01

Abstract: A discrimination reference level generator which provides a dynamically adjustable reference level for discriminating between the white background of a document and black characters imprinted on the document. The maximum contrast signal from document areas on either side of the document area being scanned are used to control the black-white discrimination level of the scanned area. Furthermore, correlation between the discrimination reference levels of adjacent document areas prevents a sudden decrease in the discrimination reference level between two adjacent document areas. The discrimination reference level is not permitted to fall below a predetermined minimum level which is constant for normal contrast but which is automatically raised when there is an extremely high contrast between the document and the characters imprinted thereon.

Abstract translation: 鉴别参考电平发生器，其提供用于区分文档的白色背景和印在文档上的黑色字符的动态可调参考电平。 被扫描的原稿区域两侧文件区域的最大对比度信号用于控制扫描区域的黑白区分等级。 此外，相邻文件区域的鉴别参考水平之间的相关性可以防止两个相邻文档区域之间的鉴别参考水平的突然降低。 鉴别参考电平不允许低于正常对比度恒定的预定最小电平，但是当文档与其上印有字符之间存在非常高的对比度时，识别参考电平自动升高。

公开(公告)号：US3662377A

公开(公告)日：1972-05-09

申请号：US3662377D

申请日：1970-04-30

Applicant: IBM

Inventor： DYM HERBERT ,  MAZZA ROBERT V ,  SEGAR LAWRENCE P

IPC: G06F3/033 ,  G06F3/041 ,  H03M1/00 ,  G01R17/06

CPC classification number: G06F3/041 ,  H03M1/00 ,  H03M1/50

Abstract: An analog-to-digital converter that eliminates dynamic coupling errors in a system where the measured signal and the reference signal are subject to such variations. This device sequentially samples an analog unknown voltage and a reference voltage and converts the sampled signals into digital information representative of the unknown voltage. Sampling and conversion is achieved in a three step process which alternates the reference and unknown signal inputs to an integrator and level holding circuits. The integrator output controls the duration of a digital counter which runs until the integrator output crosses a zero value. The result in the digital counter provides the binary value representative of the analog unknown signal. Dynamic coupling errors which occur during the reference and unknown signal sample times are eliminated by dividing the sample time of the unknown signal in two segments, a first sampling segment prior to sampling the reference signal, and a second sampling segment after the reference signal.

Abstract translation: 一种模数转换器，消除了测量信号和参考信号受到这种变化的系统中的动态耦合误差。 该装置顺序采样模拟未知电压和参考电压，并将采样的信号转换成代表未知电压的数字信息。 采样和转换是通过将参考和未知信号输入交替到积分器和电平保持电路的三步骤过程来实现的。 积分器输出控制运行的数字计数器的持续时间，直到积分器输出跨越零值。 数字计数器的结果提供代表模拟未知信号的二进制值。 在参考和未知信号采样时间期间发生的动态耦合误差通过将未知信号的采样时间除以两个段，在对参考信号进行采样之前的第一采样段和参考信号之后的第二采样段来消除。