Punch Operation; Outline - Sharp AR-FN8 Service Manual

II.

PUNCH OPERATION

A.

Outline

The puncher unit is located on the feed path between the host machine and the finisher, and
successively punches holes when the paper stops temporarily. When the trailing edge of the paper
reaches the puncher unit, the inlet roller of the finisher unit temporarily stops the paper and holes
are punched on the trailing edge of the paper.
The puncher unit consists of a die and hole puncher (punch blade).
The hole puncher is driven by the punch motor (M1P). The hole puncher is attached to the
eccentric cam of the punch shaft, and rotary action of the punch shaft is converted to reciprocal
motion to perform punching.
Punch motor (M1P) is a DC motor. The home position of the punch shaft is detected by punch
home position sensor (PI3P). To stop the DC punch motor accurately at its home position, the
punch motor clock sensor (PI2P) counts a predetermined number of clock pulses to stop the punch
motor. A single punch operation is performed by rotating the punch shaft 180° from its home
position.
Five light sensors (photosensor PCB) are located at the upper side of the inlet paper feed path
of the puncher unit and a set of five LEDs (LED PCB) are located at the lower side. These sensors
and LEDs function as five sensors. The frontmost sensor (LED5, PTR5) are the trailing edge sensor
and are used for detecting the trailing edge of the paper. The remaining sensors (LED1 to LED4,
PTR1 to PTR4) are horizontal registration sensors, and are used for detecting the inner position of
the paper for determining the hole punching position.
The punch motor, puncher unit and above sensors comprise the punch slide unit. This unit
moves backwards and forwards according to the size of the paper. Backward and forward move-
ment is driven by the horizontal registration motor (M2P). The home position of the punch slide
unit is detected by the horizontal registration home position sensor (PI1P). The horizontal registra-
tion motor (M2P) is a 2-phase stepping motor.
The punch motor and horizontal registration motor is driven by the punch driver PCB accord-
ing to control signals from the finisher controller PCB.
Punch scraps caused by punching are stored in the punched scrap container. Scrap full detec-
tion is performed by a reflective sensor (LED6 and PTR6 on the scrap full detector PCB unit).
CHAPTER 4 PUNCHER UNIT (OPTION) BASIC OPERATION
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