Encoder with mask spacer contacting the encoder film

US6624407B1 · kind B1 · utility

Assignee

• Lexmark International, Inc. · US

Inventors

• Dariush Aboonasry · Lexington, US
• Christopher Alan Adkins · Lexington, US
• Alexander Chapman · Lexington, US
• Darell D. Cronch · Georgetown, US
• David Michael Cseledy · Lexington, US
• Edmund Hulin James, III · Lexington, US
• Michael Anthony Marra, III · Lexington, US
• Barry Baxter Stout · Lexington, US

Key dates

• Filing date: Jul 3, 2001
• Grant date: Sep 23, 2003
• Expiry date: Jul 3, 2021

Classification

• Technology area (CPC G): Physics
• CPC primary: G01D5/34738
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An encoder including a light source for emitting light, a photodetector for detecting at least part of the light emitted by the light source, and an encoder film including a plurality of alternating bars and windows and being located between the light source and the photodetector. The encoder includes a mask including a plurality of alternating bars and windows, the mask being located between the light source and the photodetector. The encoder further includes a spacer located between the mask and the encoder film, the encoder film contacting the spacer to maintain a predetermined spacing between the mask and the encoder film.