US 5,064,274 A · Automatic automobile rear view mirror assembly

Abstract

A variable reflectivity automobile mirror assembly is operable by automatic electrical circuitry responsive to variations of incident light upon the mirror and ambient light level about the automobile to provide positions of high and low reflectivity. The assembly also includes a support member or housing, a reflective mirror panel, motor means, actuation means secured to the housing and driven by the drive element of the motor, and a timed-drive circuit for directing the current through the motor in opposite directions to move the mirror between the two positions. the automatic circuitry can include photosensing means and means to combine the output of the photosensing means and to compare it to an independent source. The circuit can position the mirror in response to the output of the comparing means. The circuit can have means to automatically adjust the sensitivity of the circuit so that the incident light level needed to move the panel from the higher or lower reflectivity orientation decreases as ambient light level decreaases. This can be provided by the first and second photosensing means being part of an electrical bridge. Means are also provided to integrate the photosensing signals at different rates. A summer means can add the integrated signals. Means for preventing the mirror switching from a lower to a higher reflectivity position for a short time interval following switching to a lower reflectivity position is also provided. The present invention also includes circuitry for manual actuation of the mirror.

Claims28

Dependent claims

An automobile variable reflectivity mirror assembly for mounting to an automobile structure and for use with an electrical power supply, the assembly being operable to provide at least a relatively higher reflectivity orientation and a relatively lower reflectivity orientation, comprising:

(a) a housing;
(b) a reflective panel associated with said housing for movement between said higher reflectivity and lower reflectivity orientations, said panel providing higher reflectivity in the higher reflectivity orientation, and providing lower reflectivity in the lower reflectivity orientation;
(c) a motor having means to move a drive element in a first or second direction;
(d) means for actuation, said means being associated with said housing, for driving engagement with the drive element to move the panel between the higher and lower reflectivity orientations;
(e) electrical circuit means comprising photosensing means for determining the ambient light level about the automobile and the incident light level upon the reflective panel, and for generating electrical signals proportionately representative of said light levels thereof;
said circuit means further comprising means for comparing the additive sum of said ambient light level signal and said incident light level signal to an independent voltage, the comparing means having an output;
the circuit means having means for directing current through the motor to move the drive element and the actuation means to position the panel in the higher reflectivity orientation or lower reflectivity orientation in response to the output of the comparing means.

4 more elements

(a) a housing;
(b) a reflective panel associated with said housing for movement between said higher reflectivity and lower reflectivity orientations, said panel providing higher reflectivity in the higher reflectivity orientation, and providing lower reflectivity in the lower reflectivity orientation;
(c) a motor having means to move a drive element in a first or second direction;
(d) means for actuation, said means being associated with said housing, for driving engagement with the drive element to move the panel between the higher and lower reflectivity orientations;
(e) electrical circuit means comprising means for detecting the ambient light level about the automobile, for detecting the incident light level upon the reflective panel, and for generating electrical signals proportionately representative of said light levels, said circuit means further comprising means for directing current through the motor to move the drive element to position the reflective panel in the higher or lower reflectivity position, and an electrical bridge portion having means for automatically adjusting the sensitivity of the automatic circuit so that the level of incident light necessary to move the reflective panel from a high to a low reflectivity position decreases as the ambient light level decreases.

2 more elements

(a) a housing;
(b) a reflective panel associated with said housing for movement between said higher reflectivity and lower reflectivity in the higher reflectivity orientation, and providing lower reflectivity in the lower reflectivity orientation;
(c) a motor having means to move a drive element in a first or second direction;
(d) means for actuation, said means being associated with said housing, for driving engagement with the drive element to move the panel between the higher and lower reflectivity orientations;
(e) electrical circuit means comprising means for detecting the ambient light level about the automobile, for detecting the incident light level upon the reflective panel, and for generating electrical signals proportionately representative of said light levels, said detecting means comprises a first photosensor for detecting said ambient light level, and a second photosensor for detecting said incident light striking the reflective panel of said rearview mirror, said first and second photosensors are in an electrical bridge, said electrical bridge further comprises two resistors, said first and second photosensors each having a collector and an emitter, one of said two resistors being electrically connected between the collectors of said first and second photosensors, the other of said two resistors being electrically connected between the emitters of said photosensors.

2 more elements

(a) a housing;
(b) a reflective panel associated with said housing for movement between said higher reflectivity and lower reflectivity orientations, said panel providing higher reflectivity in the higher reflectivity orientation, and providing lower reflectivity in the lower reflectivity orientation;
(c) a motor having means to move a drive element in a first or second direction;
(d) means for actuation, said means being associated with said housing, for driving engagement with the drive element to move the panel between the higher and lower reflectivity orientations;
(e) electrical circuit means comprising photosensing means for determining the ambient light level about the automobile, and the incident light level upon the reflective panel, and for generating electrical signals proportionately representative of said light levels thereof;
said electrical circuit means further comprising determining means which consists one integrated circuit, for with said one integrated circuit when said incident light level is sufficiently high with respect to said ambient light level such that said rearview mirror should be moved from the high reflectivity position to said low reflectivity position, said one integrated circuit of the determining means further being able to prevent switchover from high to low reflectivity during high ambient lighting conditions.

3 more elements

Dependencies are inferred from the claim text.

Automatic automobile rear view mirror assembly

Life of this patent

Automatic automobile rear view mirror assembly

Life of this patent

Abstract

Claims28