System and method for controlling an optical filter assembly
First Claim
1. A control system for a variable transmittance optical filter assembly, the optical filter assembly comprising a pair of terminals and an optical filter electrically coupled between the pair of terminals, the control system comprising:
- (a) a controller communicatively coupled to a pair of load terminals for electrically coupling to the terminals of the optical filter assembly; and
(b) a memory communicatively coupled to the controller and having encoded thereon statements and instructions executable by the controller to transition the optical filter assembly between operating states,wherein the controller transitions the optical filter assembly from a first operating state to a second operating state by applying a voltage signal comprising a plurality of pulses across the load terminals, wherein at least one of the pulses comprises a voltage of one polarity, and at least another of the pulses comprises a voltage of an opposite polarity, and wherein the controller maintains the optical filter assembly in a hold mode in which a transmittance of the optical filter assembly is held at a certain average value and variance, the certain average value being less than a maximum transmittance of the optical filter assembly.
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Accused Products
Abstract
A control system for a variable transmittance optical filter assembly includes a controller in communicatively coupled to a pair of load terminals, and a memory communicatively coupled to the controller and having encoded thereon statements and instructions executable by the controller to transition the optical filter assembly between operating states when coupled to the pair of load terminals. The controller is operable to perform any one or more of: allowing the optical filter assembly to transition to a dark state by shorting the load terminals together, maintaining the optical filter assembly in a hold mode by applying a pulse width modulated voltage signal across the load terminals, and transitioning the optical filter assembly between operative states by applying a voltage signal having voltage pulses of opposite polarities to the load terminals.
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Citations
28 Claims
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1. A control system for a variable transmittance optical filter assembly, the optical filter assembly comprising a pair of terminals and an optical filter electrically coupled between the pair of terminals, the control system comprising:
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(a) a controller communicatively coupled to a pair of load terminals for electrically coupling to the terminals of the optical filter assembly; and (b) a memory communicatively coupled to the controller and having encoded thereon statements and instructions executable by the controller to transition the optical filter assembly between operating states, wherein the controller transitions the optical filter assembly from a first operating state to a second operating state by applying a voltage signal comprising a plurality of pulses across the load terminals, wherein at least one of the pulses comprises a voltage of one polarity, and at least another of the pulses comprises a voltage of an opposite polarity, and wherein the controller maintains the optical filter assembly in a hold mode in which a transmittance of the optical filter assembly is held at a certain average value and variance, the certain average value being less than a maximum transmittance of the optical filter assembly. - View Dependent Claims (2, 3, 4, 5, 19, 20)
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- 6. A method for controlling a variable transmittance optical filter assembly comprising a pair of terminals and an optical filter electrically coupled between the terminals, the method comprising transitioning the optical filter assembly from a first operating state to a second operating state by applying a voltage signal comprising a plurality of pulses across the terminals, wherein at least one of the pulses comprises a voltage of one polarity, and at least another of the pulses comprises a voltage of an opposite polarity, the method further comprising maintaining the optical filter assembly in a hold mode in which a transmittance of the optical filter assembly is held at a certain average value and variance, the certain average value being less than a maximum transmittance of the optical filter assembly.
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11. A control system for a variable transmittance optical filter assembly, the optical filter assembly comprising a pair of terminals and an optical filter electrically coupled between the pair of terminals, the control system comprising:
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(a) a controller; (b) switching circuitry communicatively coupled to the controller, the switching circuitry comprising a pair of input voltage terminals for receiving an input voltage, and a pair of load terminals for electrically coupling to the terminals of the optical filter assembly, wherein the controller is configured to;
apply a portion of the input voltage across the load terminals in a forward polarity, apply a portion of the input voltage across the load terminals in a reverse polarity, short the load terminals together, or remove voltage from the load terminals, in response to a control signal received from the controller;(c) a memory communicatively coupled to the controller and having encoded thereon statements and instructions executable by the controller to send the control signal to the switching circuitry according to a desired operating state of the optical filter assembly, to maintain the optical filter assembly in a hold mode in which a transmittance of the optical filter assembly is held at a certain average value and variance, the certain average value being less than a maximum transmittance of the optical filter assembly. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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21. A control system for a variable transmittance optical filter assembly, the optical filter assembly comprising a pair of terminals and an optical filter electrically coupled between the pair of terminals, the control system comprising:
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a controller communicatively coupled to a pair of load terminals for electrically coupling to the terminals of the optical filter assembly; and a memory communicatively coupled to the controller and having encoded thereon statements and instructions executable by the controller to transition the optical filter assembly between operating states, wherein the controller maintains the optical filter assembly in a hold mode by applying a pulse width modulated voltage signal across the load terminals, and wherein in the hold mode a transmittance of the optical filter assembly is held at a certain average value and variance, the certain average value being less than a maximum transmittance of the optical filter assembly. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28)
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Specification