Paper Size Detection Control; Paper Empty Detection Control; Remaining Paper Detection Control; Dehumidification Heater Control - Konica Minolta BIZHUB 750 Service Manual

Theory of Operation Ver1.0 Aug.2005
15.3.3

Paper size detection control

A. Size detection in the main scan direction
The size detection of paper in the main scan direction is made according to the position of the guide plate con-
nected to the paper size VR/1 (VR3) and /2 (VR4).
B. Size detection in the sub scan direction
The size detection of paper is made by the combination of the paper size sensors /Fr1 (PS17) and /Fr2 (PS23)
and the paper size sensors /Rr1 (PS18) and /Rr2 (PS24) that turn ON and OFF.
Original size
8.5 x 11 or less
A4R to B5R
8 x 13 or more
15.3.4

Paper empty detection control

The paper empty detection in the tray is made by the paper empty sensors /3 (PS15) and /4 (PS21).
15.3.5

Remaining paper detection control

The remaining paper in the tray is detected according to the time required for the lift plate to be brought up by
the paper lift motors /3 (M18) and /4 (M19) when the tray is set. The time required for this up operation (operat-
ing time of M18 and M19) is stored in the printer control board (PRCB) and the remaining paper after that is
detected by subtracting a value shown on the paper feed counter.
The paper remaining thus detected is shown on the operation panel in 5 steps.
15.3.6

Dehumidification heater control

A. Purpose
To keep the humidity in the tray at a fixed state, the dehumidification heaters /1 (HTR1) and /2 (HTR2) are pro-
vided.
B. Operation timing
The dehumidification heaters /1 (HTR1) and 2 (HTR2) operate when the dehumidification heater switch (SW3) is
ON and the power switch (SW2) is OFF.
15. PAPER FEED SECTION (trays 3 and 4)
PS17, PS23
ON/OFF
OFF
ON
ON
PS18, PS24
ON/OFF
OFF
OFF
ON
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