Method and apparatus for exposure control in light-based measurement instruments
First Claim
1. An apparatus for controlling a light based instrument having a variable intensity light source for providing light and a light sensor adapted for receiving said light provided by said light source, said light sensor having an operating range including a normal operating range and a saturated operating range, the light based instrument being operable over a period of time to define an exposure cycle, comprising:
- a driver circuit operably coupled to said light source for increasing the intensity of light provided by said light source as the time of said exposure cycle elapses;
a light sensor state detector operably coupled to said light sensor for providing a detector signal when said light sensor reaches a predetermined point in said operating range as said intensity of said light source is increased by said driver circuit; and
a control circuit operably coupled to said light sensor state detector and said driver circuit for deactivating said driver circuit in response to said detector signal, whereby said exposure cycle is ended when said light sensor reaches said predetermined point in said operating range.
1 Assignment
0 Petitions
Accused Products
Abstract
A method and apparatus for nearly instantaneous and wide dynamic range exposure control in light-based measurement instruments. The excess charge drained from a CCD array by anti-blooming circuitry is effectively monitored and distinguished from leakage current. Detection of the drained charge generates a signal to deactivate the light source exposing the CCD array. The exposure control device includes a unique circuit for detecting the operating state of an anti-blooming circuit associated with a CCD array, and a unique laser light driver that ramps up the light intensity of the laser light source in an approximately exponential manner.
36 Citations
12 Claims
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1. An apparatus for controlling a light based instrument having a variable intensity light source for providing light and a light sensor adapted for receiving said light provided by said light source, said light sensor having an operating range including a normal operating range and a saturated operating range, the light based instrument being operable over a period of time to define an exposure cycle, comprising:
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a driver circuit operably coupled to said light source for increasing the intensity of light provided by said light source as the time of said exposure cycle elapses; a light sensor state detector operably coupled to said light sensor for providing a detector signal when said light sensor reaches a predetermined point in said operating range as said intensity of said light source is increased by said driver circuit; and a control circuit operably coupled to said light sensor state detector and said driver circuit for deactivating said driver circuit in response to said detector signal, whereby said exposure cycle is ended when said light sensor reaches said predetermined point in said operating range. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method for controlling a light based instrument having a variable intensity light source for providing light and a light sensor adapted for receiving said light provided by said light source, said light sensor having an operating range including a normal operating range and a saturated operating range, the light based instrument being operable over a period of time to define an exposure cycle, comprising:
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increasing the intensity of light provided by said light source as the time of said exposure cycle elapses; providing a detector signal when said light sensor reaches a predetermined point in said operating range as said intensity of said light source is increased by said driver circuit; and deactivating said light circuit in response to said detector signal, whereby said exposure cycle is ended when said light sensor reaches said predetermined point in said operating range. - View Dependent Claims (9, 10)
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11. A method for controlling a light based instrument having a light sensor adapted for receiving light, said light sensor having an operating range including a normal operating range and a saturated operating range, the light based instrument being operable over a period of time to define an exposure cycle, comprising:
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determining when said light sensor reaches a predetermined point in said operating range; and ending the exposure cycle when said light sensor reaches said predetermined point in said operating range. - View Dependent Claims (12)
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Specification