Konica 7065 GUIDE MANUAL 7065010e
1
PROCESS
PROCESS
OUTLINE AND COMPOSITION
In this digital copying machine, optical data (light beam) reflected from the original is converted into electrical signals, subjected to
image processing, then converted back into optical data (light beam) and directed onto the drum.
Figure 1 shows the composition of the machine, and Fig.2 an outline of the digital copying process.
Image processing unit
Fixing unit
Cleaning
unit
PCL
PCL
Charging corona unit
Separation
corona unit
TSL
Fig.1
Transfer
corona unit
Image read unit
Image write unit
Polygon mirror
Developing unit
OPC drum
PCL
Cleaning
Fixing
Original
Charging
Optical data
Image write
Image read
Optical data
Developing
Electrical data
Image processing
Separation ← Transfer corona
(Transfer simultaneous
exposure)
Fig.2
Electrical signal
1 - 1
PROCESS
IMAGE READ MECHANISM
Light source (xenon lamp)
Lens1st mirror
CCD image sensor
[1] Outline
A xenon lamp is used as the light source, and the light from the
lamp is directed onto the original.
The light reflected off the original is reflected by the 1st, 2nd and
3rd mirrors shown in Fig.1, then passed through the lens and
directed onto the CCD image sensor.
The CCD image sensor consists of 5000 pixels. One pixel is
7 µm in length, and the length on the original that can be read
by one pixel is 63.5 µm.
2nd mirror
3rd mirror
Fig.3
1 - 2
IMAGE PROCESSING
PROCESS
CCD image
sensor
A/D Board
Image Processing Board
Electronic RDH
Processing Board
A/D
conversion
Error diffusion
processing
Shading correction
Selector/SGU
[1] Outline
The analog signal produced by opto-electric conversion by the
CCD image sensor on the A/D board is subjected to analog
processing, then A/D-converted, and transmitted to image
processing board.
Image processing consists of shading correction, brightness/
density conversion, EE processing, text/dot pattern judgement, filter/magnification change processing, copy γ correction, write density control, and 2-beam control. In addition,
Error diffusion processing and image compression are carried out within Electronic RDH.
[2] Analog Processing
In the analog processing board, the minute image signals from
the CCD image sensor are amplified and also level-shifted into
the A/D conversion range.
Amplification and level-shifting take place automatically at the
shading correction timing by an electronic variable resistor,
hence there is no need to perform manual adjustment.
[3] A/D Conversion
The image signals from the analog processing board are
converted one pixel at a time into 9-bit digital signals.
[4] Shading Correction
Shading correction is done to even out the light distribution of
the CCD image sensor. The following correction takes place
at the specified timing.
Brightness/density
conversion,
EE processing, Text/
dot pattern
judgement, Filter/
magnification
processing
Reversal processing
Write density
Image
compression
Fig.4
1. White correction
The voltage output from each pixel of the CCD image
sensor when the white reference plate is exposed to the
light from the exposure lamp is memorized as the maximum output value for that pixel.
2. Black correction
The output voltage from each pixel of the CCD image
sensor when the exposure lamp is out is memorized as the
minimum output voltage for that pixel.
* Based on the difference between the white and black
data for each pixel memorized in 1 and 2 above, the
calculated result that indicates the number of the step
corresponding to the image data read from the original is
output to an accuracy of 10 bits.
(1)
(2)
(1)····Output before shading correction
(2)····Output after shading correction
control
512
0
1024
0
Copy γ correction
2-beam control
Memory
Before shading correction
Read width
After shading correction
Read width
Fig.5
White
Black
White
Black
1 - 3
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