Back pressure regulator ink-jet pen

摘要

The present invention relates to free-ink type ink-jet pens. A spring-loaded regulator mechanism is provided within the pen to allow ink from a pressurized ink reservoir to be fed to the pen while maintaining a predetermined set point back-pressure at the printhead as needed for appropriate pen operation. A mechanism in communication with the ambient atmosphere is used in conjunction with a substantially constant force biasing mechanism to maintain the balance between the countervailing forces. Back-pressure is maintained substantially constant regardless of the ink flow rate from the ink reservoir into the pen.