Kabushiki Kaisha Toyota Chuo Kenkyusho

Toyota Jidosha Kabushiki Kaisha

Toyota Motor Europe Nv/sa

Cristiano Niclass

Mineki Soga

Toshiki Kindo

Radivoje Popovic

Hiromichi Yanagihara

Marc Lany

Edoardo Charbon

Kota Ito

There is provided a light detector having a light-receiving unit including a light-receiving element of a photon-counting type that receives incident light and outputs a binary pulse indicating presence or absence of photon incidence, and an integrating unit that calculates an output value in which a total of pulse widths of pulses is integrated over a measurement period.

Light detector

An optical rangefinder based on time-of-flight measurement, radiates pulsed light toward an object (), and receives reflected light from the object, the receiver operating in a photon counting mode, so as to generate a pulse for a detected photon. There is a variable probability of a photon detection on the receiver, and a controller () controls the photon detection probability of the receiver, based on a light level. By controlling the detection probability according to a light level, the receiver can have an increased dynamic range, and without the expense of using optical components. This can apply even while detecting very weak signals since the receiver can still be in a photon counting mode while the detection probability is controlled. The light level can be indicated by an output of the receiver itself, or by another detector external to the receiver.

Pulsed light optical rangefinder

A first semiconductor layer serves as a first implanted layer of a first conductivity type. A second semiconductor layer of a second conductivity type is provided under the first semiconductor layer. The second conductivity type is opposite to the first conductivity type. The second semiconductor layer is buried in an epitaxial layer grown above a substrate. The second semiconductor layer becomes fully depleted when an appropriate bias voltage is applied to the device.

Single photon avalanche diode with second semiconductor layer burried in epitaxial layer

A photodetector disclosed herein comprises an avalanche transistor having a reference junction structure in which temperature characteristics of a current amplification factor are about the same as those of an avalanche photodiode and which is reverse-biased, and a current injection junction structure which injects a reference current to the reference junction structure and which is forward-biased. Voltages to be applied to the avalanche photodiode and the reference junction structure are controlled so that the amplification factor of the reference current amplified in the reference junction structure is retained at a predetermined value, whereby the temperature characteristics of the photodetector utilizing an avalanche effect can be stabilized.

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Nisshin, Japan

Cristiano Niclass