Method of controlling turn-on of light source and image forming apparatus
US6476370B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 27, 2000 |
| Grant date | Nov 5, 2002 |
| Priority date | — |
| Expiry date | May 2, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/04794
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An image forming apparatus and a method of controlling turn-on of light source used therefor are capable of conducting stable image forming operation and maintaining high effective scanning rate while switching the rotation control of the polygonal motor between the internal control by the internal encoder of the motor and the external control by the horizontal synchronous signal outside of the motor. With the apparatus and method, the period of detecting the timing of start of the fast scanning (referred to as SOS period) is T when the driving motor rotates at a predetermined number of revolutions. T becomes shorter by T2 due to the switching from the internal control to the external control. During the shift from the internal control to the external control, the light source is turned on so that the period T1 from turning-on the light source for detecting the SOS timing to the detection of the SOS signal becomes longer than T2. Thereby, turning-on of the light source is surely conducted earlier than the SOS signal detection timing when the rotational control is switched from the internal control to the external control.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.