Control system for automatic rearview mirrors
US5204778A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 6, 1992 |
| Grant date | Apr 20, 1993 |
| Priority date | — |
| Expiry date | Apr 6, 2012 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60R1/088
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
An improved electronic control system for controlling the reflective state of automatic rearview mirrors for automative vehicles, the system including an electrochromic variable reflectance mirror element the reflectivity of which varies over a reflectance range as a function of electrical signal levels applied thereto. The system also includes a first sensing means effective to sense the ambient light level and produce a first electrical signal which is at least in part logarithmically related to the sensed ambient light level. A second sensing means is also provided which is effective to sense the glare causing light level and produce a second electrical signal which is at least in part logarithmically related to the sensed glare causing light level. Means is provided in the control system for combining the signals derived from the first and second electrical signals to produce a third electrical signal which is at least in part indicative of the severity of the glare, and the system also includes improved means which in response to the third electrical signal controls the reflective state of the electrochromic mirror element.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.