Soft-starting system for a lamp in an image forming device or the like
US6034790A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 24, 1997 |
| Grant date | Mar 7, 2000 |
| Priority date | — |
| Expiry date | Oct 24, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B39/08
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A lamp power supply circuit for an image forming device, which is not provided with a full-wave rectifier and any additional noise reducing circuit but is capable of effectively suppressing inrush current not to produce noise that may cause erroneous operation of the image forming device and affect any external appliance. A lamp lighting control system for use in an image forming device, which can realize soft-starting of an exposure lamp or a fixing heater-lamp by gradually increasing a conducting angle .beta..sub.i (i=0, 1 . . . ) for applying a voltage to a lamp through phase control of an AC power-supply voltage V.sub.AC for an initial period of energizing the exposure lamp or the fixing heater-lamp. Wherein, the conducting angle is gradually increased per even-number unit of cycles of AC power-supply voltage V.sub.AC on the condition that even numbers of cycles in the same unit have the same conducting angle, e.g., .beta..sub.0 =.beta..sub.1 <.beta..sub.2 =.beta..sub.3 <.beta..sub.4 =.beta..sub.5 <.beta..sub.6 =.beta..sub.7 < . . . <.beta..sub.16 =.beta..sub.17.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.