Azbil Corporation

Shun Onuma

Raita Mori

To calculate a probability of an optical sensor's irregular discharge, a light detection system includes an optical sensor, an application voltage generating circuit that applies a drive pulse voltage to the optical sensor, a discharge determining portion that detects the optical sensor's discharge, a discharge probability calculating portion that calculates a discharge probability in a first state in which light from an additional light source having a known light quantity is incident on the optical sensor or the additional light source is turned off, and in a second state in which the additional light source's turning-on/turning-off state is different from the first state and the drive pulse voltage's pulse width is the same as the first state, a sensitivity parameter storing portion that stores the optical sensor's sensitivity parameters, and another discharge probability calculating portion that calculates a discharge probability of the optical sensor's irregular discharge.

Light detection system and discharge probability calculating method

A flame detection system includes: an optical sensor that detects light generated from a light source; an applied voltage generating circuit that periodically applies a drive pulse voltage to the optical sensor, discharge determining portion that detects a discharge from the optical sensor, a discharge probability calculating portion that calculates a discharge probability based on a number of times of application of the drive pulse voltage and a number of times of discharge detected in the a first state in which the optical sensor is shielded from light and a second state in which the optical sensor can receive light, a sensitivity parameter storing portion storing known sensitivity parameters of the optical sensor; and a received light quantity calculating portion that calculates the received light quantity by the optical sensor in the second state based on the sensitivity parameters and the discharge probabilities calculated in the first and second states.

Flame detection system and received light quantity measuring method

To calculate a probability of an optical sensor's irregular discharge, a light detection system includes an optical sensor, an application voltage generating circuit that applies a drive pulse voltage to the optical sensor, a discharge determining portion that detects the optical sensor's discharge, a discharge probability calculating portion that calculates a discharge probability for each of first and second states in which the optical sensor is shielded from light and the drive pulse voltage's width in the second state is different from the first state, a sensitivity parameter storing portion storing the drive pulse voltage's reference pulse width as the optical sensor's sensitivity parameter, and another discharge probability calculating portion that calculates an irregular discharge's probability that occurs without depending on the optical sensor's received light quantity, based on the sensitivity parameter, and the discharge probabilities calculated and the drive pulse voltage's widths in the first and second states.

Light detection system, discharge probability calculating method, and received light quantity measuring method

To calculate received light quantity even when part of noise component's discharge probability is unknown, a light detection system includes a discharge probability calculating portion that calculates discharge probabilities for a first state in which a source's light with known light quantity impinges on an optical sensor, a second state in which the source's turning-on/turning-off state is the same as the first state with a drive pulse width applied to the optical sensor different from the first state, a third state in which the source's turning-on/turning-off state is different from the first and second states with the same pulse width as the first state, and a fourth state in which the source's turning-on/turning-off state is the same as the third state with the same pulse width as the second state, another discharge probability calculating portion that calculates regular and irregular discharges' probabilities, and a received light quantity calculating portion.

For calculating an optical sensor's regular-discharge probability, a light detection system includes the optical sensor, an application voltage generating circuit for applying a drive pulse voltage to the optical sensor, a discharge determining portion for detecting the optical sensor's discharge, a first discharge probability calculating portion, a sensitivity parameter storing portion for storing the optical sensor's sensitivity parameters, and a second discharge probability calculating portion for calculating a discharge probability of the optical sensor's regular discharge. The first discharge probability calculating portion calculates a discharge probability in: a first state in which light from an additional light source having a known light quantity is incident on the optical sensor or the additional light source is turned off; and a second state in which the additional light source's turning-on/turning-off status is different from the first state, with the drive pulse voltage's pulse width being the same as the first state.

A flame detection system includes: an optical sensor that detects light emitted from a light source; an applied voltage generating circuit that applies a drive pulse voltage to the optical sensor; a discharge determining portion that detects a discharge from the optical sensor; a discharge probability calculating portion calculates discharge probabilities in a first state and a second state in which the optical sensor is shielded from light and a pulse width of the drive pulse voltage is different; a storing portion storing a reference pulse width as a sensitivity parameter; and a discharge probability calculating portion that calculates a discharge probability of an irregular discharge occurring without depending on the received light quantity by the optical sensor based on the sensitivity parameter, the discharge probabilities calculated in the first and second states and the pulse widths of the drive pulse voltage in the first and second states.

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Tokyo, Japan

Shun Onuma