The generation unit (2) generates a transmission pulse set so that a time difference between times at which a plurality of transmission pulses are transmitted respectively differs according to the transmitting order of the transmission pulse set. A transmission unit (4) repeatedly transmits the generated transmission pulse set. A reception unit (6) receives reflected pulses of the transmission pulses reflected on a distance-measurement-target object. A specification unit (8) specifies a time difference between times at which a plurality of received reflected pulses are received. A distance calculation unit (10) calculates a distance to the distance-measurement-target object based on a receiving timing of the received reflected pulse and a transmitting timing of the transmission pulse corresponding to the time difference specified for the reflected pulse.

The generation unit (2) generates a transmission pulse set so that a time difference between times at which a plurality of transmission pulses are transmitted respectively differs according to the transmitting order of the transmission pulse set. A transmission unit (4) repeatedly transmits the generated transmission pulse set. A reception unit (6) receives reflected pulses of the transmission pulses reflected on a distance-measurement-target object. A specification unit (8) specifies a time difference between times at which a plurality of received reflected pulses are received. A distance calculation unit (10) calculates a distance to the distance-measurement-target object based on a receiving timing of the received reflected pulse and a transmitting timing of the transmission pulse corresponding to the time difference specified for the reflected pulse.

A self-calibration time-to-digital converter (TDC) integrated circuit for single-photon avalanche diode (SPAD) based depth sensing is disclosed. The circuit includes a SPAD matrix with a plurality of SPAD pixels arranged in m rows and n columns, the SPAD pixels in each column of SPAD pixels are connected by a column bus; a global DLL unit with n buffers and n clock signals; and an image signal processing unit for receiving image signals from the column TDC array. The circuit can also include a row control unit configured to enable one SPAD pixel in each row for a transmitting signal; a circular n-way multiplexer for circularly multiplexing n clock signals in the global DLL unit; a column TDC array with n TDCs, each TDC further comprises a counter and a latch, the latch of each TDC is connected to the circular n-way multiplexer for circular multiplexing.

Time of Flight Sensor A method of measuring optical crosstalk in a time of flight sensor, which comprises a substantially transparent cover covering a light emitter and one or more photodetectors. The method comprises emitting a series of pulses of light from the light emitter; and using the one or more photodetectors to obtain a distribution of times at which at least one photodetector of the one or more photodetectors detected photons after each emission of the series of pulses of light. The method further comprises recording one or more parameters of the earliest peak if the distribution comprises two or more separate peaks.

Time of Flight Sensor A method of measuring optical crosstalk in a time of flight sensor, which comprises a substantially transparent cover covering a light emitter and one or more photodetectors. The method comprises emitting a series of pulses of light from the light emitter; and using the one or more photodetectors to obtain a distribution of times at which at least one photodetector of the one or more photodetectors detected photons after each emission of the series of pulses of light. The method further comprises recording one or more parameters of the earliest peak if the distribution comprises two or more separate peaks.

A selection circuit selects one of digital values respectively output from a TDC 1 and a TDC 2. A histogram generation circuit generates a histogram indicating a relationship between a bin number and a frequency by counting up the frequency of the bin number according to the digital value selected by the selection circuit.

A selection circuit selects one of digital values respectively output from a TDC 1 and a TDC 2. A histogram generation circuit generates a histogram indicating a relationship between a bin number and a frequency by counting up the frequency of the bin number according to the digital value selected by the selection circuit.

Sensors, including time-of-flight sensors, may be used to detect objects in an environment. In an example, a vehicle may include a time-of-flight sensor that images objects around the vehicle, e.g., so the vehicle can navigate relative to the objects. The sensor may generate first image data at a first configuration and second image data at a second configuration. An estimated depth of an object may be determined from the first image data, and an actual depth of the object may be determined from the second image data, based on the estimated depth. In examples, the first and second configurations have different modulation frequencies such that a nominal maximum depth in the first configuration is greater than the nominal maximum depth in the second configuration.

An optical device includes a light receiving element for detecting light reflected and transmitted from a subject; a voltage part for providing a first bias voltage or a second bias voltage to the light receiving element; and a controller for controlling the voltage part so that the second bias voltage provided from the voltage part is synchronized with a light output of a light emitting part to be provided to the light receiving element.

An optical device includes a light receiving element for detecting light reflected and transmitted from a subject; a voltage part for providing a first bias voltage or a second bias voltage to the light receiving element; and a controller for controlling the voltage part so that the second bias voltage provided from the voltage part is synchronized with a light output of a light emitting part to be provided to the light receiving element.