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：US3387173A

公开(公告)日：1968-06-04

申请号：US52568566

申请日：1966-02-07

Applicant: IBM

Inventor： HALL RICHARD E

IPC: G06K9/20 ,  H01J29/18

CPC classification number: H01J29/18 ,  G06K9/20

公开(公告)号：US3448275A

公开(公告)日：1969-06-03

申请号：US3448275D

申请日：1967-06-07

Applicant: IBM

Inventor： HALL RICHARD E

IPC: H01L27/146 ,  H01J39/12

CPC classification number: H01L27/14643 ,  H04N5/3692