Olivetti JP 90, Руководство по обслуживанию

Страница: 19 / 63

681640J
1-13
JP 90 - Service Manual
Ink-Jet Printing
Turn to section 1.8 for a full explanation on ink-jet printing.
Print Nozzles
A total of 51 print nozzles are arranged on two vertical rows of 25 and 26 nozzles and are divided
horizontally in three groups, one for each color.
Figure 1-8 shows how the nozzles are placed on each row.
YELLOW
MAGENTA
BLUE
2
4
6
8
1
3
5
7
19
21
23
25
20
22
24
26
45
47
49
51
44
46
48
50
Fig.1-8 Nozzle Matrix
Information on the Heating Element Activation Circuitry
The heating elements are divided into four groups. Two groups have 12 elements and the other two groups
have 13. Only one element can be activated at each time in each group, and therefore no more than four
elements can be activated simultaneously.
To avoid induction between adjacent elements, each element will be activated according to a specific
sequence (see figure 1-9).
Each group of heating elements is controlled by an 18.8 V driver circuit. This voltage must be regulated
in order to guarantee correct print head operation.
The most typical faults that may occur with lower voltages are the following: lack of ink bubble expulsion
if the print head is not used for a determined period of time, lack of bubble expulsion in low temperatures.
Higher voltages, on the other hand, can cause the generation of incorrect ink bubble control commands
or no command at all due to the possible deterioration of the heating element.