Printer ribbon motor controller
US5366303A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 11, 1993 |
| Grant date | Nov 22, 1994 |
| Priority date | — |
| Expiry date | May 11, 2013 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J33/52
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
This disclosure sets forth a dot matrix printer having an improved ribbon drive. The ribbon drive is provided by two respective stepper motors. When one stepper motor is in a take-up mode, the second is in a feed mode. The process is reversed proximate the end of the tape as it is unwound. A re-generative mode for the feed motor is provided and a resistance bank varies amounts of drag on the ribbon as it is fed from the feed motor spool. Both motors when in the take-up mode are driven by full H bridge drivers and amplifiers controlled by a micro controller through an address and decode input and output latch. In order to provide for a uniform velocity of the print ribbon the angular velocity of the take up motor is controlled by counting the zero crossings of the feed motor, and then loading it into the micro controller to compare it with a look-up table for purposes of providing a proper speed to the take-up motor and the proper peak drag through the resistance bank to the feed motor. All functions are controlled by the micro controller and firmware logic provided thereto.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.