Panasonic WORKIO DP-150, Руководство по обслуживанию, Страница: 31 / 136

Mechanism
2-13
2)Photoelectric conversion
•
Photoelectric conversion is to convert optical signals into electrical signals. Pixel
used for photoelectric conversion is called “photoelectric converted pixel”. The
linear type of CCD image sensor for B/W is used here.
3)CCD sensor
The CCD image sensor consists of the photo acceptance unit, transfer unit and
output unit. The sensor is capable of detecting approximately 5,000 pixels.
Optics signals are converted into electrical signals and transferred by the photo diode
before being read out.
Signals of the even and odd pixels are read out independently to speed up the signal
processing.
4)Controlling the exposure lamp switching
When the control signal (LPCNT0) is “L” level at the lamp inverter in the CPU PCB,
the lamp inverter lights the exposure (xenon) lamp at a high-frequency rate.
MOS
Photo acceptance
Pin photo diode array
Transfer
Output
CCD analog shift register
Light
Photo diode
Main body
CPU PCB
Lamp inverter
Exposure lamp
(Fluorescent)
(LPCNT)
Lamp inverter
control signal
LPCNT
(Lamp inverter
control signal) OFF
ON
Electrode