JPH0338963U

JPH0338963U -

Info

Publication number: JPH0338963U
Application number: JP7762189U
Authority: JP
Priority date: 1989-07-03
Filing date: 1989-07-03
Publication date: 1991-04-15

Description

[Brief explanation of drawings]

第１図は本考案の一実施例にかかる原稿読取装
置の搬送系を示す概略図、第２図ａ，ｂはパルス
エンコーダの一例を示す概略側面図および概略部
分断面図、第３図は第１図の装置の制御系を例示
したブロツク図、第４図は同期検出回路の動作を
説明するための動作波形図、第５図は三角波発生
回路の動作を説明するための動作波形図、第６図
ａ，ｂは原稿搬送制御部の処理例を示すフローチ
ヤートである。１……原稿ガイドローラ、３，４……搬送ロー
ラ対、５……等倍センサ、６……排出ローラ、７
……パルスエンコーダ、１１……同期検出回路、
１２……原稿搬送制御部、１３……三角波発生回
路、１４……電圧制御発振器、１５……分周回路
、１６……周波数／電圧変換器、１７……サーボ
モータ駆動回路、１８……直流サーボモータ、Ｓ
１〜Ｓ４……原稿センサ。 FIG. 1 is a schematic diagram showing a conveyance system of a document reading device according to an embodiment of the present invention, FIGS. 2a and 2b are a schematic side view and a schematic partial sectional view showing an example of a pulse encoder, and FIG. 1 is a block diagram illustrating the control system of the device, FIG. 4 is an operation waveform diagram for explaining the operation of the synchronization detection circuit, FIG. 5 is an operation waveform diagram for explaining the operation of the triangular wave generation circuit, and FIG. 6a and 6b are flowcharts showing an example of processing by the document conveyance control section. 1... Original guide roller, 3, 4... Conveyance roller pair, 5... Same size sensor, 6... Ejection roller, 7
...Pulse encoder, 11...Synchronization detection circuit,
12... Original transport control unit, 13... Triangular wave generation circuit, 14... Voltage controlled oscillator, 15... Frequency dividing circuit, 16... Frequency/voltage converter, 17... Servo motor drive circuit, 18... Direct current Servo motor, S
1 to S4... Original sensor.

Claims

[Scope of utility model registration request]

In a document reading device that reads a document image line by line while conveying the document to be read, there are first and second document conveyance rollers arranged before and after the document reading position, and a position immediately before the first document conveyance roller. a document sensor for detecting a read document; a rotation detector for detecting rotation of the first document transport roller; and a speed monitoring based on a detection signal from the rotation detector after the document sensor detects the document to be read. while accelerating the first and second document transport rollers,
The speeds of the first and second document conveyance rollers are increased to the target speed while the leading edge of the document to be read moves to the document reading position, and thereafter the speeds of the first and second document conveyance rollers are increased to the target speed. A document reading device comprising a control means for controlling the speed to a target speed.