Single sensor adaptive drive circuit for rearview mirror system
US5193029A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 19, 1991 |
| Grant date | Mar 9, 1993 |
| Priority date | — |
| Expiry date | Nov 19, 2011 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60R1/088
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
An automatic rearview mirror system having a reflective element that is actuatable between at least two different reflective conditions by a control that discriminates between glare-causing and nonglare-causing light simultaneously sensed by a single light sensor. The control includes a processor that is more responsive to decreasing levels of light than to increasing levels of light to produce a signal that is indicative of the slow-transient characteristic of the light sensed by the single light sensor. The processor may include a very slow signal processor that is always operative and a somewhat faster-slow signal processor, which may be selectively inhibited when the mirror is fully colored, or when a differential circuit indicates that the difference between the glare and the non-glare light sensed by the light sensor exceeds a predetermined level. The differential circuit may additionally limit the differential between the glare and the nonglare lights sensed by the light sensor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.