Step motor drive control circuit
US6316902A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 6, 1999 |
| Grant date | Nov 13, 2001 |
| Priority date | — |
| Expiry date | Dec 6, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P8/14
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A step motor drive control circuit, which is suitably employed in an image scanner, reduces the uneven rotation characteristics of a step motor and improves the scanning quality in the image scanner. The step motor drive control circuit generates a phase signal for driving the step motor from a phase signal generator in accordance with a driving pulse signal. The step motor drive control circuit controls switching devices of a driver in accordance with the phase signal so as to perform bipolar driving of the step motor. The step motor drive control circuit includes at least two switching devices with different switching characteristics in order that bipolar driving of the step motor is performed. A constant-current signal from a constant-current signal generator is added to the switching devices, thereby setting switching characteristics of the switching devices to be uniform.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.