Temperature compensated optical detector
First Claim
1. An optical detector comprising a photoelectric device that produces a light response signal in response to a characteristic of light incident on said device;
- light means for selectively exposing said device to light from a source;
means for determining a temperature dependent electrical characteristic of said device that is independent of said light characteristic; and
temperature compensating means that produces in response to said light response signal and said device electrical characteristic a detector output that corresponds to said light characteristic and that is compensated for operating temperature of said device.
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Accused Products
Abstract
An optical wavelength detector includes a photoelectric device that produces a signal in response to incident light thereon corresponding to a characteristic of the incident light such as wavelength. A light source is provided that can selectively expose light to the photoelectric device. A memory device stores device characterization data that corresponds wavelength information to current ratio signals from the photoelectric device. The current ratio signals are digitized and form part of the address for the memory. In a temperature compensated embodiment, the optical wavelength detector includes means to determine a temperature dependent electrical characteristic of the photoelectric device. In the preferred embodiment this electrical characteristic is the forward bias voltage detected when a predetermined forward bias current is applied to the photoelectric device in the dark. The temperature dependent forward bias voltage is converted to a digital signal and provides another part of the digital address for the memory. The memory generates a temperature compensated signal that corresponds to the incident light wavelength.
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Citations
28 Claims
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1. An optical detector comprising a photoelectric device that produces a light response signal in response to a characteristic of light incident on said device;
- light means for selectively exposing said device to light from a source;
means for determining a temperature dependent electrical characteristic of said device that is independent of said light characteristic; and
temperature compensating means that produces in response to said light response signal and said device electrical characteristic a detector output that corresponds to said light characteristic and that is compensated for operating temperature of said device. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
- light means for selectively exposing said device to light from a source;
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14. A circuit for determining a characteristic of light comprising:
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a light responsive device that produces a signal in response to the characteristic of incident light thereon; a source of light exposed to said device; addressable memory means for storing data corresponding to said light characteristic as a function of said device optical signal; and means to convert directly said device optical signal to an address for said memory means, said memory means producing in direct response to said address an output that corresponds to said characteristic of light. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21)
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22. A method for determining a characteristic of light comprising the steps of:
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a) providing a light responsive device that produces a temperature dependent optical signal corresponding to the characteristic of incident light thereon; b) exposing said device to incident light from a source and detecting said optical signal; c) interrupting said incident light to said device; d) detecting a temperature dependent electrical characteristic of the dark device; and e) compensating said optical signal as a function of said detected electrical characteristic to provide an output that corresponds to the characteristic of the incident light. - View Dependent Claims (23, 24)
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25. A method for determining a characteristic of light comprising the steps of:
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a) using a light response device to produce an output that corresponds to the light characteristic; b) exposing the device to light; c) using an addressable memory that stores a look-up table of light characteristic data as a function of the device output; d) directly converting the device output to an address for the memory; and e) producing an output from the memory in direct response to said address and that corresponds to the light characteristic. - View Dependent Claims (26, 27, 28)
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Specification