Minolta EP1080 Service Manual page 73

Each sensor has two LEDs and one photo receiver. When the Original Cover
is raised, the photo receiver detects light from the two LEDs reflected off the
original to determine whether there is an original placed on the Original
Glass. The combination in which the sensors are activated and deactivated
determines the size of the original, as checked by Original Size Detecting
Board UN2. The original size data is transmitted as 4-bit parallel data to
PWB-A when the Start Key is pressed (Original Cover is raised) or Original
Cover Detecting Sensor PC111 is activated (Cover angle less than 15°).
Original
Photo
Receiver
LED
The number and location of the sensors vary depending on the marketing
area as detailed below.
PC113 (FD2)
PC114 (CD1)
PC115 (FD3) *Area H only
PC116 (CD2) *Area H only
NOTE: Layout of FD Sensors
Area J: A (FD2)
Area H: B (FD2) and C (FD3)
Area O: B (FD2)
CD1
CD2
Original Sizes That Can be Detected:
Area J: A3, B4, A4L, A4C, B5L, B5C
Area H: A3, B4, A4L, A4C, 11" × 17", 8-1/2" × 14", 8-1/2" × 13", 8-1/2" × 11",
11" × 8-1/2"
Area H:
Area O: A3, B4, A4L, A4C, 8-1/2" × 11", 11" × 8-1/2"
Original Size Detecting Sensor
A B C
A5
B5
A4 FLS (8.5" × 13")
LTR (8.5" × 11")
B4
LTR (11" × 85")
M-47
A3