Drive circuit for an electro-optic rearview mirror system
First Claim
1. An electro-optic rearview mirror system comprising:
- an inside electro-optic rearview mirror element;
an outside electro-optic rearview mirror element electrically connected with the inside electro-optic rearview mirror element such that at least a portion of current flows from the inside electro-optic rearview mirror element to the outside electro-optic rearview mirror element via a line connecting the inside and outside electro-optic rearview mirror elements; and
a drive circuit in electrical communication with the inside electro-optic rearview mirror element and the outside electro-optic rearview mirror element and comprising a first power operational amplifier and a second power operational amplifier, both of which are configured as voltage followers, wherein the first power operational amplifier is configured to provide a current to the inside and outside electro-optic rearview mirror elements, and wherein the second power operational amplifier is electrically connected to the line connecting the inside and outside electro-optic rearview mirror elements and is configured to control a voltage at a center point of the inside and outside electro-optic rearview mirror elements.
1 Assignment
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Accused Products
Abstract
An electro-optic rearview mirror system is provided. The electro-optic rearview mirror system includes an inside electro-optic rearview mirror element and an outside electro-optic rearview mirror element in series with the inside electro-optic rearview mirror element. A drive circuit is in electrical communication with the inside electro-optic rearview mirror element and the outside electro-optic rearview mirror element and includes a first power operational amplifier and a second power operational amplifier, both of which are configured as voltage followers. The drive circuit is configured to apply overvoltage to the inside electro-optic rearview mirror element if the outside electro-optic rearview mirror element is shorted.
16 Citations
20 Claims
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1. An electro-optic rearview mirror system comprising:
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an inside electro-optic rearview mirror element; an outside electro-optic rearview mirror element electrically connected with the inside electro-optic rearview mirror element such that at least a portion of current flows from the inside electro-optic rearview mirror element to the outside electro-optic rearview mirror element via a line connecting the inside and outside electro-optic rearview mirror elements; and a drive circuit in electrical communication with the inside electro-optic rearview mirror element and the outside electro-optic rearview mirror element and comprising a first power operational amplifier and a second power operational amplifier, both of which are configured as voltage followers, wherein the first power operational amplifier is configured to provide a current to the inside and outside electro-optic rearview mirror elements, and wherein the second power operational amplifier is electrically connected to the line connecting the inside and outside electro-optic rearview mirror elements and is configured to control a voltage at a center point of the inside and outside electro-optic rearview mirror elements. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An electro-optic rearview mirror system comprising:
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an inside electro-optic rearview mirror element; an outside electro-optic rearview mirror element electrically connected with the inside electro-optic rearview mirror element such that at least a portion of current flows from the inside electro-optic rearview mirror element to the outside electro-optic rearview mirror element via a line connecting the inside and outside electro-optic rearview mirror elements; and a drive circuit in electrical communication with the inside electro-optic rearview mirror element and the outside electro-optic rearview mirror element and comprising a first power operational amplifier and a second power operational amplifier, wherein the first power operational amplifier is electrically connected to the inside electro-optic rearview mirror element and the second power operational amplifier is electrically connected to the line connecting the inside and outside electro-optic rearview mirror elements, and wherein the drive circuit is configured to differentially sense a voltage associated with the inside electro-optic rearview mirror element such that if the outside electro-optic rearview mirror element is shorted, a voltage associated with the inside electro-optic rearview mirror element remains substantially unchanged. - View Dependent Claims (8, 9, 10, 11, 12, 13)
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14. An electro-optic rearview mirror system comprising:
a drive circuit for driving an inside electro-optic rearview mirror element and at least one outside electro-optic rearview mirror element of a vehicle, the vehicle having an ambient light sensor and a glare light sensor, the drive circuit comprising; a controller responsive to outputs of the ambient light sensor and the glare light sensor for generating voltage control signals, the controller further generating a selection signal for alternatingly selecting one of the inside and outside electro-optic rearview mirror elements; a variable voltage source for generating a drive voltage by discharging a capacitor; and a selection circuit coupled to the variable voltage source for receiving the drive voltage, the selection circuit also coupled to the controller for receiving the selection signal, the selection circuit comprising a first selection switch disposed between the capacitor and the inside electro-optic rearview mirror element and a second selection switch disposed between the outside electro-optic rearview mirror element and ground, wherein the first selection switch selectively enables the drive voltage to be applied across the inside electro-optic rearview mirror element and the second selection switch selectively enables the drive voltage to be applied across the outside electro-optic rearview mirror element. - View Dependent Claims (15, 16, 17, 18, 19, 20)
Specification