AR-P350, AR-P450 (serv.man6). AR350 450 Series Basic Service Manual - Sharp Copying Equipment Service Manual (repair manual). Page 43

Read Sharp AR-P350 / AR-P450 (serv.man6) Service Manual online

AR-350/450 DATA FLOW 7-6
3. Flowchart of image process
(1)
CCD unit
Employs the reduction optical type line CCD 
(Charged Coupled Device) of 7500 pixels.
The scan resolution is 600dpi.
Reflects the copy lamp light onto the 
document.
Light reflected onto the document is passed 
through the reduction lens to form images on 
the photo electric conversion element.
The photo energy is converted into electric 
energy.
The CCD is scanned by every line.
The scan position is shifted sequentially by 
shifting the carriage unit (lamp and mirror) or 
by shifting the document.
(2)
CIS unit
Employs the CIS (Contact Image Sensor) of 
7196 pixels.
The scan resolution is 600dpi.
Reflects the LED light in the unit onto the 
document.
Light reflected on the document is passed 
through the lens to form iamges on the photo 
electric conversion element.
The photo energy is converted into electric 
energy.
The CIS is scanned by every line.
The scan position is shifted sequentially by 
shifting the document.
(3)
Analog process
The photoelectic conversion element outputs 
analog signals.
The analog signals are amplified.
(4)
A/D conversion
The analog image signals are converted into 
digital signals.
Conversion is made in 8bit (256 gradations). 
(0 - 255)
(5)
White balance 
process
Each correction of white level and dark 
composition is performed according to the 
value when the copy lamp is blinked a certain 
times at the white balance position.
(6)
Density 
conversion 
(AE process)
Density correction for the scanner side 
(input side). LUT is sued for density correction.
Four kinds of LUT are used for that operation: 
AE,/TEXT/PHOTO/TEXT-PHOTO.
(7)
Main scan 2 
pixels average
Pixel thin-out is performed depending on the 
mode of scanning.
(8)
Area separation
As shown in the figure, pixels of 5 x 4 are 
sampled and the total value of each side is  
compared. (The difference between the total of 
side A and the total of side B, and the 
difference between the total of side C and the 
total of side D) 
If the difference is great, it is judged as Text, 
and if smaller, Photo.
(9)
Filter process 
(MTF correction)
According to the judgment of images in area 
separation, the gradation is adjusted so  that 
the text area becomes sharp and the photo 
area becomes soft. (Filtering)
(10) Electronic zoom 
process
"Linear interpolation is performed according to 
the zoom ratio of enlargment or redeuction.
(11) Output LUT
Density correction for the scanner side 
(input side). Performed with LUT.
Four kinds of LUT are used: 
AE/TEXT/PHOTO/TEXT-PHOTO.
A
C
D
B
(12) 2-digit error 
diffusion
8bit image data are converted into 2-digit 
image data by using error diffusion.
(13) Pattern matching 
thin out
(14) Data transfer 
block
Serial communication control is performed 
between the CCD PWB and the MFP control 
PWB.
Data are transferred normally by 1 line. When 
zooming, however, since the data size is great, 
transfer is made by 2 lines.
(15) SDRAM
Signals sent to the MFP control PWB in serial 
communication are passed through the 
ICU-ASIC to be stored in the SDRAM.
The storage capacity is 2 pages of A3 paper. 
Then the signals are sent to the ICU-ASIC 
again.
(16) Compression
Image data are sent from the ICU-ASIC to the 
CODEC-IC and compressed.
The compression type at that time is the JPEG 
type.
Then the data are passed through the PCI 
interface of the ICU-ASIC again to the image 
memory block.
(17) Image memory 
block
There are two kinds of image memory blocks: 
the SDRAM and the hard disk.
Use of memory in this area is described later.
In this block, image data are compressed and 
stored.
(18) Expansion
Image data taken from the image memory 
block are passed through the ICU-ASIC again 
to ther CODEC-IC, and decompressed.
(19) Rotation
Image data are rotated acording to the paper 
size.
(20) 2-digit zoom
The zoom block for printing used when 
receiving FAX. Zooming is performed by 2-digit 
data.
(21) Smoothing
Smoothing is performed by the EET 
(Edge Enhancement Technology).
(22) Sync Video 
signal generation
2-digit image data are synchronized with the 
LSU timing.
      0   !"# %&# '()*+
Page of 54
Display

Click on the first or last page to see other AR-P350 / AR-P450 (serv.man6) service manuals if exist.