Abstract: An encoder includes a housing, a light source coupled to the housing, and a light sensor coupled to the housing and positioned to receive a light beam from the light source. The encoder also includes a wheel having opaque and transmissive sections which may be positioned to pass through the light beam before it reaches the light sensor. The encoder further includes a floating aperture piece, which defines at least one aperture. The aperture is positioned so that the light beam must pass through it before reaching the light sensor. The floating aperture piece slidably engages the housing while allowing a loose tolerance between a position of the wheel and a position of the housing, thereby substantially eliminating a positioning error between the aperture and the wheel.

Abstract: A system for ink short protection for signaling to inkjet printheads includes a differential signaling driver having a first and a second terminal, a differential signaling receiver having a first and a second terminal, a first capacitor in series between the first terminals, a second capacitor in series between the second terminals, and circuitry for reducing charge accumulation on the capacitors. A method for ink short protection and a printing mechanism having such an ink short protection system are also provided.

Abstract: A system for ink short protection for signaling to inkjet printheads includes a differential signaling driver having a first and a second terminal, a differential signaling receiver having a first and a second terminal, a first capacitor in series between the first terminals, a second capacitor in series between the second terminals, and circuitry for reducing charge accumulation on the capacitors. A method for ink short protection and a printing mechanism having such an ink short protection system are also provided.

Abstract: An apparatus for detecting ink droplets ejected from ink drop generators has a target holder and a conductive absorbent target supported by the target holder. The apparatus for detecting ink droplets also has standoffs extending from the target holder. The apparatus for detecting ink droplets further has an actuator for moving the target holder towards the ink drop generators such that the standoffs space the target from the ink drop generators.

Abstract: A waste ink removal system cleans ink residue from an ink drop sensor in a printing mechanism when a scraper, supported by a base, is actuated between a retracted position and an engaged position. The system also includes a reservoir defining a plurality of capillary drains onto which the scraper deposits ink residue while moving to the engaged position. A method of cleaning ink residue from an electrostatic sensing element of an ink drop detector, and a printing mechanism having such a waste ink removal system are also provided.

Abstract: A waste ink removal system cleans ink residue from an electrostatic sensing element of an ink drop detector in a printing mechanism when a scraper, supported by a base, is actuated between a retracted position and an engaged position. The system also includes a debris receptacle and/or an absorber which the scraper contacts, after scraping ink from the sensing element, to remove the ink from the scraper surface. A method of cleaning ink residue from an electrostatic sensing element of an ink drop detector, and a printing mechanism having such a waste ink removal system are also provided.

Abstract: A uni-directional waste ink removal system cleans ink residue from an electrostatic sensing element of an ink drop detector in a printing mechanism when the electrostatic sensing element, supported by a base, is actuated between an activated position, a storage position, and back to the activated position. The system also includes a scraper and an absorber which first contact the sensing element when the base is in the storage position, thereby ensuring ink residue may be absorbed, and that ink residue is only scraped from the sensing element in one direction as the base is moved to the activated position. A method of cleaning ink residue from an electrostatic sensing element of an ink drop detector, and a printing mechanism having such a unidirectional waste ink removal system are also provided.