A method of measuring a distance using a time of flight sensor comprising 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. If the distribution of times comprises only a single peak, the method further comprises analysing the single peak to determine if the single peak includes counts of photons reflected from a target. If the single peak includes counts of photons reflected from a target, the method further comprises measuring the separation between a reference time and a point of the single peak.

A method of measuring a distance using a time of flight sensor comprising 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. If the distribution of times comprises only a single peak, the method further comprises analysing the single peak to determine if the single peak includes counts of photons reflected from a target. If the single peak includes counts of photons reflected from a target, the method further comprises measuring the separation between a reference time and a point of the single peak.

An optical testing apparatus is used in testing an optical measuring instrument that provides incident light from a light source to an incident object and receives reflected light of the incident light at the incident object. The apparatus includes an incident light receiving section, a light signal providing section, an imaging section, and an optical axis misalignment deriving section. The incident light receiving section receives incident light. The light signal providing section provides a light signal to an incident object after a predetermined delay time since the incident light receiving section has received the incident light. The imaging section images the incident light. The optical axis misalignment deriving section derives misalignment of the optical axis of the incident light with respect to the incident light receiving section based on misalignment between the incident light receiving section and the imaging section as well as an imaging result with the imaging section.

An optical testing apparatus is used in testing an optical measuring instrument that provides incident light from a light source to an incident object and receives reflected light of the incident light at the incident object. The apparatus includes an incident light receiving section, a light signal providing section, an imaging section, and an optical axis misalignment deriving section. The incident light receiving section receives incident light. The light signal providing section provides a light signal to an incident object after a predetermined delay time since the incident light receiving section has received the incident light. The imaging section images the incident light. The optical axis misalignment deriving section derives misalignment of the optical axis of the incident light with respect to the incident light receiving section based on misalignment between the incident light receiving section and the imaging section as well as an imaging result with the imaging section.

A method for analyzing backscatter histogram data in an optical pulse runtime method, including the steps of receiving backscatter histogram data; and analyzing the received backscatter histogram data.

Provided are a light receiving device, a light receiving circuit, and a distance measuring device capable of minimizing dead time.

A light receiving device according to the present disclosure may include: a light receiving circuit including a light receiving element; a power supply circuit configured to supply a power supply potential to the light receiving circuit; and a control circuit configured to control the power supply potential supplied by the power supply circuit on the basis of a signal output from the light receiving circuit in a reaction with a photon.

Provided are a light receiving device, a light receiving circuit, and a distance measuring device capable of minimizing dead time.

A light receiving device according to the present disclosure may include: a light receiving circuit including a light receiving element; a power supply circuit configured to supply a power supply potential to the light receiving circuit; and a control circuit configured to control the power supply potential supplied by the power supply circuit on the basis of a signal output from the light receiving circuit in a reaction with a photon.

Provided is a phase difference calculation device including a first light amount acquisition unit that acquires a first light amount of reflected light of light applied in a first time window and received in the first time window and a second light amount of the reflected light received in a second time window, a time window shift control unit that shifts the first and second time windows and a third time window in the negative direction of the time axis to set fourth, fifth, and sixth time windows, and shifts the fourth, fifth, and sixth time windows in the negative direction of the time axis until no reflected light is received in the fourth time window, a second light amount acquisition unit that acquires a third light amount of the reflected light received in the sixth time window, and a phase difference calculation unit that calculates a phase difference between the light and the reflected light on the basis of a first corrected light amount obtained by adding the third light amount to the first light amount and a second corrected light amount obtained by subtracting the third light amount from the second light amount.

LIDAR systems are less accurate in the presence of background light which can saturate the sensors in the LIDAR system. The embodiments herein describe a LIDAR system with a shutter synchronized to a laser source. During a first time period, the laser source is synched with the shutter so that the reflections are received when the shutter is in the process of changing between on and off states, during which time a function of the shutter (e.g., a phase retardation or opacity) monotonically changes so that reflections received at different times have different time-dependent characteristics (e.g., different polarizations). To mitigate the effects of background light, during a second time period, the laser source is synched with the shutter so that the background light is measured (in the absence of the reflections) which can be used to remove the effects of the background light from a range measurement.

LIDAR systems are less accurate in the presence of background light which can saturate the sensors in the LIDAR system. The embodiments herein describe a LIDAR system with a shutter synchronized to a laser source. During a first time period, the laser source is synched with the shutter so that the reflections are received when the shutter is in the process of changing between on and off states, during which time a function of the shutter (e.g., a phase retardation or opacity) monotonically changes so that reflections received at different times have different time-dependent characteristics (e.g., different polarizations). To mitigate the effects of background light, during a second time period, the laser source is synched with the shutter so that the background light is measured (in the absence of the reflections) which can be used to remove the effects of the background light from a range measurement.