6570/5570 SCANNER
7 - 14
Mar. 1999 © TOSHIBA TEC
7.7
Automatic Original-Size Detection Circuit
This circuit detects the original size (standard sizes only) using reflection-type photosensors on the base
frame and lens cover of the optical unit.
7.7.1
Principle of original-size detection
The reflection-type photosensors are located on the base frame and lens cover of the optical unit. Each
photosensor comprises an infrared light emitting diode (LED, light-emitting side) and a phototransistor
(light-receiving side). When an original is placed on the original glass, the light emitted by the LEDs is
reflected by the original and led to the phototransistor. In this way, the presence or absence of an original
is detected by whether reflected light exists or not.
Fig. 7.7-1
[A4 Series]
[LT Series]
7.7.2
Original size detection
(1) If the copier is set in the original size detection mode, the carriage is set at its home position.
(2) Detection is performed in an instant when the platen cover is opened, each sensor receive the
reflecting light and the condition of a matrix shown in (4) are satisfied.
(3) Original size detection is performed when the output signals from each sensor are input to the S-
CPU (IC7) on the scanner control PC board.
Original
Original glass
APS
Original
Original glass
APS
Summary of Contents for 4580
Page 1: ...SERVICE MANUAL DIGITAL PLAIN PAPER COPIER 8070 6570 5570 4580 ...
Page 231: ...6570 5570 DEVELOPER UNIT 12 28 Mar 1999 TOSHIBA TEC 3 Draw out the toner filter ...
Page 252: ...8070 6570 5570 4580 FUSER UNIT 14 6A Mar 1999 TOSHIBA TEC ...
Page 369: ...8070 6570 5570 4580 ADF 16 78 Mar 2000 TOSHIBA TEC 16 13 PC Board 1 PWA F LGC 794 ...
Page 370: ...Mar 2000 TOSHIBA TEC 16 79 8070 6570 5570 4580 ADF 2 PWA F SEN 794 ...
Page 374: ...Mar 1999 TOSHIBA TEC 18 1 6570 5570 PC BOARD 18 PC BOARD 1 PWA F SYS 300 ...
Page 375: ...6570 5570 PC BOARD 18 2 Mar 1999 TOSHIBA TEC 2 PWA F MTB 300 ...
Page 376: ...Mar 1999 TOSHIBA TEC 18 3 6570 5570 PC BOARD 3 PWA F LGC 300 ...
Page 377: ...6570 5570 PC BOARD 18 4 Mar 1999 TOSHIBA TEC 5 PWA F MOT 300 4 PWA F ADU 300 ...
Page 378: ...Mar 1999 TOSHIBA TEC 18 5 6570 5570 PC BOARD 6 PWA F SLG 300 7 PWA F SDV 300 ...
Page 379: ...6570 5570 PC BOARD 18 6 Mar 1999 TOSHIBA TEC 8 PWA F PLG 300 ...