JPS5881540U

JPS5881540U - Original illumination device

Info

Publication number: JPS5881540U
Application number: JP17825281U
Authority: JP
Inventors: 新名　隆; 史一西川
Original assignee: 株式会社東芝
Priority date: 1981-11-30
Filing date: 1981-11-30
Publication date: 1983-06-02

Abstract

(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Brief explanation of drawings]

第１図は線状光源の輝度分布の一例を示す特性図、第２
図〜第５図は本考案の一実施例を示すもので、第２図は
原稿照明装置を使用したファクシミリ読取走査部の概略
構成図、第３図はシェーディング補正板の配置状態を示
す図、第４図は補助光源の駆動部の構成を示す回路図、
第５図は作用説明に用いるための信号波形図である。２・・・線状光源、３・・・シェーディング補正板、４
・・・光学レンズ、５胃固体撮像素子、１０・・・光度
差検出回路、１３．１４・・・ピークホールド回路、１
５・・・差動増幅器、２０・・・発光駆動回路。Figure 1 is a characteristic diagram showing an example of the luminance distribution of a linear light source.
5 to 5 show an embodiment of the present invention, FIG. 2 is a schematic diagram of a facsimile reading scanning unit using a document illumination device, FIG. 3 is a diagram showing the arrangement of a shading correction plate, FIG. 4 is a circuit diagram showing the configuration of the drive section of the auxiliary light source;
FIG. 5 is a signal waveform diagram for use in explaining the operation. 2... Linear light source, 3... Shading correction plate, 4
... optical lens, pentagastric solid-state imaging device, 10 ... light intensity difference detection circuit, 13.14 ... peak hold circuit, 1
5... Differential amplifier, 20... Light emission drive circuit.

Claims

[Scope of utility model registration request]

(1) In a document illumination device used in a device that illuminates the surface of a document with a linear light source and collects the reflected light to obtain image information of the document, a device is provided at each end of the linear light source. an auxiliary light source that provides auxiliary illumination of the document surface, and a luminance difference between the center and both ends of the linear light source, or an illuminance difference between the center and both ends of the linear light source of reflected light after condensation; and an auxiliary light source drive circuit that drives the auxiliary light source to emit light so as to make the difference to a constant value below a certain value according to the difference information obtained by the detection circuit. lighting equipment.

(2) The document illumination device according to claim 1, wherein the detection circuit detects illuminance difference information from the light reception output of a light receiving element that collects and receives reflected light from the document.