Sony UP-895, Service Manual

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4-5
UP-895/(E)
4-3-1. Reading the Serial Data from System Control
There are eight types of data that a system control (IC304) sends to IC501. Registers for storing each
data exist respectively. The type of a register in which data is stored is selected by combination of “high”
and “low” levels of signals that are input to pins 11, 13, and 14 of IC501.
IC501-11pin IC501-13pin IC501-14pin Register to be selected
L L L Gamma data
L L H Gamma data
L H L Specifies the memory and print ranges.
L H H Emphasizes the edge and sets the memory and print modes.
H L L Count correction data
H L H Sync signal processing parameter
H H L Thermal history correction and other mode setting
H H H Test pattern step width setting
4-3-2. Writing in Frame Memory
The next image data of one frame is written in the frame memory (IC503) when a fetch pulse is input
from a system control (IC304) to pin 1 of IC501. The UP-895 uses a 64M-SDRAM (one word is 8 bits)
as image memory. The sampling frequency is 23 MHz, and the memory space is 4096
x
2048.
4-3-3. Transfer from Frame Memory to Line Memory
IC501 sets a COPYING signal to “L” so as to enter the print operation when a COPY pulse is input from
a system control (IC304) to pin 2 of IC501. To perform printing, the one-line data selected from frame
memory must be transferred to the head line memory in IC501. Data is transferred when a LINEPULS is
input to pin 15 of IC501. IC501 reads necessary print data from the frame memory in the order
corresponding to the print range and print direction specified by the mode setting from a system control.
Next, IC501 stores the print data in the head line memory after edge emphasizing, thermal history
correction, and interpolation.
4-3-4. Thermal Head Control and One-Line Memory
All thermal head controls are performed by IC501. Built-in head line memory is used when transferring
print data to the thermal head. For more details, refer to Section 4-5. Thermal Head Section.
FETCH
EXTV
ODD/EVEN
WE
Image fetching period