HP (Hewlett-Packard) 5000 User Manual

Functional Overview

10-8

HP DesignJet 5000 Series Printers Service Manual

The APS is the system that provides and controls the pressurization 
of the ink in the Ink Cartridges and is located under the ISS. The key 
purpose of this system is to ensure the minimum required ink 
pressure at the inlet to each Printhead respectively at the required 
print rates. The APS is also used to provide pressure for tube purge 
and as part of the blow prime system operation.

The APS pressurizes the ink in the Ink Cartridge bags by 
pressurizing the air around them. The Printer controls the air 
pressure using the pump with feedback from the sensor; when 
required the valve is opened to depressurize the air circuit. This 
allows control of the ink pressure at the inlet to the Printheads.

The purpose of the Leak Detect System (LDS) is to detect the 
breakage of any of the Tubes that deliver ink from the Ink 
Cartridges to the Printheads.

If a Tube breaks, as the system is pressurized, the ink flows through 
the breakage and gets between the Tube and the Tube Carrier, and is 
forced to go to the Ink Leak Detector where the leaking ink is 
collected. There will be a potential short circuit between the two 
metallic pins, and the ink leak will be detected.