Automatic antiglare mirror
First Claim
1. An automatic antiglare mirror including an electrochromic element wherein its reflectivity is variably controlled by driving the electrochromic element by a pulse voltage and changing a duty factor of the pulse voltage in response at least to quantity of rear light so that, when quantity of rear light is smaller, the amount of coloration of the electrochromic element is smaller whereas, when quantity of rear light is larger, the amount of coloration of the electrochromic element is larger, said automatic antiglare mirror comprising reflectivity change ratio changing means for changing the ratio of change in the reflectivity to the duty factor of the pulse voltage so that, when a duty factor in a color imparting direction is smaller, the ratio of change in the reflectivity to the duty factor is smaller;
- when the duty factor in a color fading direction is larger, the ratio of change in reflectivity to the duty factor is smaller;
when the duty factor in the color imparting direction is larger, the ratio of change in the reflectivity to the duty factor is larger; and
when the duty factor in the color fading direction is smaller, the ratio of change in the reflectivity to the duty factor is larger.
1 Assignment
0 Petitions
Accused Products
Abstract
An automatic antiglare mirror for a vehicle with its reflectivity being variably controlled by an electrochromic element includes a rear light detection circuit for detecting quantity of light in the rear of the vehicle, a coloration amount control circuit for controlling an amount of coloration the electrochromic element and a response speed control circuit for controlling response speed of the electrochromic element. The coloration amount control circuit performs control of the amount of coloration in such a manner that, when quantity of rear light is smaller, the amount of coloration of the electrochromic element is smaller whereas, when the quantity of rear light is larger, the amount of coloration of the electrochromic element is larger. The response speed control circuit performs control of the response speed in such a manner that, when the quantity of rear light is smaller, the response speed of the electrochromic element in a color imparting direction is lower whereas, when the quantity of rear light is larger, the response speed of the electrochromic element in the color imparting direction is higher.
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Citations
4 Claims
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1. An automatic antiglare mirror including an electrochromic element wherein its reflectivity is variably controlled by driving the electrochromic element by a pulse voltage and changing a duty factor of the pulse voltage in response at least to quantity of rear light so that, when quantity of rear light is smaller, the amount of coloration of the electrochromic element is smaller whereas, when quantity of rear light is larger, the amount of coloration of the electrochromic element is larger, said automatic antiglare mirror comprising reflectivity change ratio changing means for changing the ratio of change in the reflectivity to the duty factor of the pulse voltage so that, when a duty factor in a color imparting direction is smaller, the ratio of change in the reflectivity to the duty factor is smaller;
- when the duty factor in a color fading direction is larger, the ratio of change in reflectivity to the duty factor is smaller;
when the duty factor in the color imparting direction is larger, the ratio of change in the reflectivity to the duty factor is larger; and
when the duty factor in the color fading direction is smaller, the ratio of change in the reflectivity to the duty factor is larger.
- when the duty factor in a color fading direction is larger, the ratio of change in reflectivity to the duty factor is smaller;
- 2. An automatic antiglare mirror including an electrochromic element wherein its reflectivity is variably controlled by driving the electrochromic element by a pulse voltage and changing duty factor of the pulse voltage in response at least to quantity of rear light so that, when quantity of rear light is smaller, the amount of coloration of the electrochromic element is smaller whereas, when quantity of rear light is larger, the amount of coloration of the electrochromic element is higher, said automatic antiglare mirror comprising current value control means for controlling the current value of the pulse voltage driving the electrochromic element is such a manner that, when the quantity of rear light is smaller, the current value of the pulse voltage in a color imparting direction is smaller, whereas when quantity of rear light is larger, the current value is larger.
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4. An automatic antiglare mirror including:
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(a) an electrochromic element wherein its reflectivity is variably controlled by driving the electrochromic element by a pulse voltage and changing duty factor of the pulse voltage in response to quantity of rear light so that, when voltage in response at least to the quantity of rear light is smaller, the amount of coloration of said electrochromic element is smaller and when the quantity of said rear light is larger, the amount of the coloration of said electrochromic element is higher; (b) a main drive current circuit driven by said pulse voltage comprising in combination a first transistor (Q1), a second transistor (Q2), a first resistor (R10), a second resistor (R11) and a current supply which supplies a drive current constantly to said electrochromic element; (c) a supplemental drive current circuit comprising a combination of a transistor (Q4) and a resistor (R17) which supply additional drive current to said electrochromic element; and (d) means for supplying drive current to said electrochromic element only from said main drive current circuit when the intensity of the rear light is small and means for supplying current to said electrochromic element both from said main drive current circuit and from said supplemental drive current circuit when the intensity of the rear light is large.
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Specification