Electrophotographic printer with media motion motor control
US5185627A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 1, 1991 |
| Grant date | Feb 9, 1993 |
| Priority date | — |
| Expiry date | Oct 1, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G2215/00459
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An electrophotographic printer 10 having a control system 51 for controlling a stepper motor 50. The control system 51 includes a motor speed drive circuit 52, a microprocessor 54, and a clock 58. The motor speed drive circuit 52 has a programmable driver 56 and a logic circuit 60. The microprocessor 54 outputs a speed change value each time a change in the stepper motor is desired. The programmable driver 56 stores the speed change value and incrementally counts down from the speed change value to zero in synchronization with a clock pulse from the clock 58. Upon reaching zero, the programmable divider 56 outputs a speed command signal to the logic circuit 60, which in turn outputs drive signal to control the operation of the stepper motor 50. The microprocessor 54 only outputs a new speed change value when a change in stepper motor operation is desired. If no change is desired, the programmable divider 56 uses the last input speed value to control the stepper motor. As a result, the microprocessor 54 does not constantly interact with the stepper motor 50, and is therefore free to perform other processing tasks.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.