DAY-NIGHT MIRROR FOR VEHICLES
First Claim
1. A day-night mirror for a vehicle, comprising an enclosure having side, bottom and top walls, one of said side walls including a pane of glass stationary with respect to said enclosure, an oscillatory mirror having two surfaces and located interiorly of said enclosure, one of said surfaces being, in one orientation of said mirror, parallel with an immediately adjacent surface of said pane of glass but displaced therefrom by a distance of the order of 0.015 inch, said one of said surfaces of said mirror being coated with a reflective surface, means for rotating said mirror through an angle of substantially 45* with respect to said surface of said pane of glass and back to parallelism with said pane of glass, and means located within the enclosure for totally absorbing light reflected by said mirror while at said angle of 45*.
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Accused Products
Abstract
A system for simultaneously sensing, by means of photoresistors, ambient light and light from an energized headlamp from a vehicle following a vehicle, and in response to the signal outputs of the photo-resistors causing an oscillatory mirror to move selectively into proximity and parallel with a sheet of glass facing always rearwardly of the truck, or, into 45* relation to the pane of the glass. In the latter condition the mirror reflects light into a black absorbing surface, while the sheet of glass reflects light with low efficiency to the eyes of the driver of the truck, whereas in the former condition mirror reflects light with high efficiency to the eyes of the driver. The mirror is in the parallel position during daylight and at night if no following vehicle is close, but goes to the 45* position at night if a following headlamp is sensed. To avoid plural images, the mirror is made of a sheet of glass which is aluminum coated on its front surface, so that light does not pass through the glass of the mirror in proceeding from the following headlamp to the eye of the driver. Electric current is passed through the aluminum coating of the mirror to generate heat and thus to maintain the mirror and the inner surface of the first mentioned sheet of glass free of ice and fog.
28 Citations
21 Claims
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1. A day-night mirror for a vehicle, comprising an enclosure having side, bottom and top walls, one of said side walls including a pane of glass stationary with respect to said enclosure, an oscillatory mirror having two surfaces and located interiorly of said enclosure, one of said surfaces being, in one orientation of said mirror, parallel with an immediately adjacent surface of said pane of glass but displaced therefrom by a distance of the order of 0.015 inch, said one of said surfaces of said mirror being coated with a reflective surface, means for rotating said mirror through an angle of substantially 45* with respect to said surface of said pane of glass and back to parallelism with said pane of glass, and means located within the enclosure for totally absorbing light reflected by said mirror while at said angle of 45*.
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2. The combination according to claim 1, wherein said means is a photo-cell controlled reversible rotatable motor system for selectively rotating said mirror between said first and second positions according to the intensities of light sensed from two approximately orthogonal directions.
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3. The combination according to claim 2, wherein said photo-cell controlled motor system includes an ambient light sensing photo-resistor and a further light sensing photo-resistor looking backwardly of said vehicle, wherein said motor of said system is a DC rotatable motor, and wherein is provided transistor logic circuitry for directing direct current reversibly to said motor according as ambient light is at high level or as ambient light is at low level and the headlamp of a following vehicle is directed against said further photo-resistor.
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4. The combination according to claim 3, wherein is provided means for adjusting said level.
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5. The combination according to claim 1, wherein said means for totally absorbing light is a blackened coating on an interior of a wall of said enclosure making an angle of 90* with said plate of glass and of 45* with respect to said mirror while said mirror is at said angle of 45*.
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6. A day-night mirror for a vehicle, comprising an enclosure having side, bottom and top walls, one of said side walls including a pane of glass stationary with respect to said enclosure, an oscillatory mirror having two surfaces and located Interiorly of said enclosure, one of said surfaces being, in one orientation of said mirror, parallel with an immediately adjacent surface of said pane of glass but displaced therefrom by a distance of the order of 0.015 inch, said one of said surfaces of said mirror being coated with a reflective surface, means for rotating said mirror through an angle of substantially 45* with respect to said surface of said pane of glass and back to parallelism with said pane of glass, and means for totally absorbing light reflected by said mirror while at said angle of 45*, wherein said means for rotating said mirror includes a photo-cell circuit for detecting whether a source of illumination is closely following said vehicle at night and a reversible DC motor responsive to said photo-cell circuit for rotating said mirror in alternative senses of rotation according as said source of illumination is or is not closely following said vehicle at night.
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7. The combination according to claim 6, wherein said means responsive to said photo-cell circuit includes two transistor switching circuits arranged to deliver current to said motor in respectively opposite directions, and means for rendering said switching circuits alternatively conducting according as said source of illumination is or is not closely following said vehicle at night.
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8. The combination according to claim 7, wherein said photo-cell circuit includes one photo-cell oriented to sense the amplitude of light arriving from rearwardly of said vehicle and one photo-cell for sensing the amplitude of ambient light, a flip-flop, means responsive to the relative amplitudes of said lights as sensed by said photo-cells for transferring said flip-flop from one of its states to the other of its states, and means responsive to the state of said flip-flop for alternatively rendering said switching circuits conducting according to the state of said flip-flop.
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9. The combination according to claim 8, wherein said electronic switches each comprises a pair of transistors of opposite conductivity types and a drive transistor for rendering said pairs of transistors alternatively conductive and non-conductive, said motor being connected between said transistors of opposite conductivity types of each said pairs and in series therewith.
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10. The combination according to claim 9, wherein said drive transistors are connected in cascade as switching transistors and are of the same conductivity types, whereby said drive transistors are alternatively always one conductive and the other non-conductive.
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11. The combination according to claim 8, wherein is included manually operative means for at will setting said flip-flop in either of its states.
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12. The combination according to claim 7, wherein is provided means for by-passing transients from said switching circuits.
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13. A day-night mirror for a vehicle, comprising an enclosure, said enclosure including in a vertical one of its walls a flat pane of glass, means mounting said pane of glass in resilient material at all its edges to forestall bending of said pane of glass, a front coated mirror, a vertical pivot, means securing said front coated mirror to said vertical pivot for rotating with said vertical pivot, resilient means securing said mirror to said last mentioned means to forestall bending of said mirror, means for accurately positioning said mirror parallel to the plane of said sheet of glass and separated therefrom by about 0.015 inch, wherein said coated mirror has a reflective coating of metal and means for passing electrical heating current through said reflective coating of metal in uniform current density in the plane of said coating.
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14. A day-night mirror system for a vehicle, comprising an enclosure, a stationary pane of glass included in one vertical wall of said enclosure, said stationary pane of glass having precisely flat parallel surfaces capable of reflecting light impinging on each of said surfaces, said pane of glass beinG about 1/8 inch thick, a front coated mirror, means pivotally mounting said mirror for rotation about an axis adjacent one of its vertical edges, means for rotating the plane of said mirror about said means pivotally mounting said mirror, two normally open switches closable in response respectively to attainment by said mirrors of angles of 0* and 90* with respect to the plane of said pane of glass, a reversible DC electric motor, means responsive to closures of said switches for terminating current flow to said motor regardless of the direction in which it is rotating, and photosensitive means for rotating said motor in one direction or another as a function of ambient and directive luminous intensities at said pane of glass.
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15. The combination according to claim 14, wherein is included a switch actuator, means driven by said motor for moving said switch actuator, said switches being located relative to said switch actuator such that said switches are open selectively by said switch actuator according as said mirror is in its 0* or its 90* orientation.
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16. The combination according to claim 15, wherein said photosensitive means includes a solely ambient light sensing photoresistor, a directed light sensitive resistance, means connecting said light sensitive resistances in series with each other across a voltage source, and means responsive to the level of voltage at a point located circuitwise between said photosensitive resistances for establishing the direction of rotation of said DC motor by establishing the direction of current flow to said DC motor.
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17. The combination according to claim 16, wherein are provided mechanical stops for said mirror located to assure precision of ultimate angular relation of said mirror at said 0* and 90* orientations.
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18. The combination according to claim 17, wherein is provided a mechanical linkage having a rotatable shaft driven by said motor, an arm rigidly secured to said shaft and extending radially therefrom, and a flexible connection between said mirror and said arm.
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19. The combination according to claim 18, wherein said flexible connection includes a hinge having one member secured to said mirror, a rigid bar rotatably secured at one of its ends to the free end of said arm and having its other end secured to another member of said hinge.
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20. The combination according to claim 19, wherein said hinge is fabricated solely of flexible material.
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21. The combination according to claim 19, wherein said switch actuator is rigidly related to said rotatable shaft and rotates therewith in equal angular relation.
Specification