EC-PACK EC-JET 2000, Manual

Page: 89 / 107

User Manual The1.1 version of 2018 Guangzhou EC-PACK CO.LTD
89
Knocking and Strong Vibration
Strong vibration and knocking to the print head is the most serious vibration problem likely to
occur, since this will affect operation of the printer itself. Severe vibration or knocking will lead to
the printer shutting itself down and displaying one or both of the following fault messages:
“2.01
Deflector Voltage”
“2.03
Velocity of Drop”
It will also be found necessary to clean the print head more often than would be expected.
To understand what is happening, consider that the stream of drops is relatively stable once in
flight. Therefore, if the print head suffers vibration or sudden movement, the drops will be
obstructed either by the VOD sensor or the edge of the gutter. This will cause ink to be splashed
on the VOD sensor and deflector plates, and to build up deposits on the gutter.
10.5.4. Blockage Caused by Knocking and Strong Vibration
FC39 No Print - Print Delay Problem
Normally, when the system detects a product passing the photocell, it will activate a “print go”
signal which causes the current message to be printed immediately. The Print Delay option of the
SETUP menu is used to delay printing to allow the product to travel further before printing, thus
controlling exactly where the message is to be printed. For instance, if the product is a long one
and the message is to be printed in the middle, it will be necessary to set the delay to a value
appropriate to the speed of the conveyor and the length of the message, which will cause printing
to occur at the desired place.
What actually happens is that when the system detects a product passing the photocell, it will
delay printing by counting the number of rasters it would have printed, until that count becomes
equal to the value of the Print Delay option.
However, if the Print Delay value is set to an inappropriate value, it is possible for the next
product to arrive before the delay expires. This resets the delay to begin counting again, and since
the conveyors travelling at the same speed, the next product will once again arrive before printing
has occurred and the delay will be reset; and so on. If this is allowed to continue, printing will
never occur.
The following illustrates this problem :