Denso Corporation

Kabushiki Kaisha Toyota Chuo Kenkyusho

Shizuoka University

Toyota Jidosha Kabushiki Kaisha

Isamu Takai

Hiroyuki Matsubara

Teiyu Kimura

Noriyuki Ozaki

Shinji Kashiwada

Kenta Azuma

Shoji Kawahito

Akifumi Ueno

Yoshihide Tachino

Takehiro Hata

Shigeyoshi Hiratsuka

Mitsuhiko Ohta

Makoto Nishida

Masato Rinnai

Seigo Ito

Mineki Soga

Michinori Ando

An optical distance measuring apparatus comprises a laser diode emitting a light pulse, light receiver including a photon-counting light receiver, distance measurement unit including a signal discriminator and propagation estimator, and threshold determiner. The signal discriminator discriminates the signal component, exceeding a threshold, of the signal as a reflected signal resulting from reflection of the light pulse at a measurement object. The propagation estimator estimates a round-trip propagation time of the light pulse to the measurement object using the signal. The threshold determiner sets a boundary level as the threshold, corresponding to a reference level obtained from the signal when the signal discriminator determines the reflected signal, using the relationship between the reference and the boundary level. The reference level is obtained from the average value of a noise probability distribution in the signal. The boundary level represents a predetermined cumulative probability in the noise probability distribution.

Optical distance measuring apparatus

In an optical distance measuring device detecting a distance to an object, a light source is driven at a predetermined timing, and light from the light source is emitted to a predetermined range of a space, and reflected light corresponding to the emitted light is detected by at least one light receiving element. A detection signal corresponding to the reflected light is processed, and an SPAD calculation unit extracts a peak signal corresponding to the reflected light from an object. At this time, the distance to the object is measured according to the time from driving of the light source by an emission unit until output of a peak signal. At this time, performance for measurement of the distance to the object is changed depending on the state of the peak signal. This makes sensitivity appropriate when the distance to the object is optically detected.

Optical distance measuring device and method for the same

An optical distance measuring device includes: a light source unit; a light receiving unit that includes a plurality of light receiving elements; an addition unit that adds the number of pulse signals; a histogram generation unit that generates a histogram that records the addition value for each time of flight; a peak detection unit that determines a distance value from the time of flight corresponding to the peak; an image generation unit that generates signal intensity image data and distance image data; a low signal intensity element detection unit that detects a low signal intensity element from the elements of the signal intensity image data; and an image correction unit that corrects a distance value recorded in a target element corresponding to the low signal intensity element in accordance with a distance value of at least one other element in the elements of the distance image data.

Optical distance measuring device

In an optical distance measuring apparatus, a light source irradiates a target object with a light pulse having a first pulse width. A light receiver outputs a pulse signal that represents reflection light from the target object being incident on the light receiver, and has a second pulse width that is larger than or equal to the first pulse width. A histogram generator records, every predetermined period, a frequency representing the number of outputted pulse signals to thereby generate a histogram. A peak detector detects, from the histogram, an edge point of a peak figure included in the histogram. A distance calculator subtracts, from a time indicative of the edge point of the peak figure, a time length of the second pulse width to thereby calculate a target time, and calculates a distance to the target object as a function of the calculated target time.

An optical detector includes: a light-receiving element that is operated in a Geiger mode by application of a service voltage higher than a breakdown voltage and outputs a pulse signal in accordance with reception of light; a voltage setting unit that is capable of selectively applying any one of the service voltage and a test voltage lower than the breakdown voltage to the light-receiving element; and an abnormality determination unit that performs an abnormality determination process of determining that the light-receiving element is abnormal when the number of pulse signals output from the light-receiving element operated under the test voltage is equal to or greater than a predetermined threshold, and determining that the light-receiving element is normal when the number of pulse signals is smaller than the threshold.

Optical detector and method for controlling the same

In an apparatus, each of light receiving elements outputs an intensity signal based on a corresponding intensity of return light from a measurement space. The return light includes reflected light reflected based on reflection of the measurement light by a target object. An identifying unit identifies a light receiving area in the light detection region as a function of the intensity signals of the respective light receiving elements. The light receiving area is based on specified light receiving elements in the plurality of light receiving elements. The specified light receiving elements are arranged to receive the reflected light. An estimating unit estimates, based on a geometry of the light receiving area, a state of the apparatus including a state of the optical system.

Method and apparatus for optically measuring distance

In an apparatus, each of light receiving elements outputs an intensity signal based on a corresponding intensity of return light from a measurement space. The return light includes reflected light reflected based on reflection of the measurement light by a target object. An identifying unit identifies a light receiving area in the light detection region as a function of the intensity signals of the respective light receiving elements. The light receiving area is based on specified light receiving elements in the plurality of light receiving elements. The specified light receiving elements are arranged to receive the reflected light. A distance measuring unit measures the distance of the target object in accordance with the intensity signals received by the specified light receiving elements.

Method and apparatus for identifying a light receiving area and optically measuring distance

A light detector is provided to include a light receiving array having a plurality of light receivers respectively outputting pulse signals upon incidence of photons. A delay setting value is set which is used to adjust a time interval from when the pulse signals are output from the light receiving array to when a response number, which is a specified number of the light receivers outputting the pulse signals, is acquired.

Light detector comprising a time interval adjusting performance by a delay setting module

A photodetector includes plural detectors. Each of the plural detectors has a single photon avalanche diode (hereinafter referred to as SPAD) which responds to incidence of a photon. The plural detectors include at least a first detector and a second detector. The SPAD has a recovery time period until the SPAD reaches a next photon-responsive state, in response to the SPAD responding to the incidence of the photon. The recovery time period of the SPAD in the first detector is different from the recovery time period of the SPAD in the second detector.

Photodetector and distance measurement apparatus comprising plural single photon avalanche diodes with different recovery time periods

A photodetector includes: a photoreceptor provided with a SPAD that is configured to respond to incidence of a photon, and as the response of the SPAD, configured to output a pulse signal; and a pulse rate control circuit configured to control sensitivity of the photoreceptor to have a pulse rate as the number of pulse signals outputted per unit time from the photoreceptor to be a set value set in advance, (i) in a set range including the set value, (ii) in a set range of the set value or more, or (iii) in a set range of the set value or less.

Photodetector

A light detector is provided to include a detection module, and a monitoring SPAD. The detection module includes an SPAD that is an avalanche photodiode operable in Geiger mode; the detection module is configured to perform light detection by applying, to the SPAD, a reverse bias voltage in a reverse direction. The monitoring SPAD has characteristics identical to characteristics of the SPAD in the detection module. The reverse bias voltage is generated to be applied to the SPAD in the detection module based on (i) a reference breakdown voltage set from a breakdown voltage generated across the monitoring SPAD in Geiger mode and (ii) a predetermined excess voltage.

Light detector having monitoring single photon avalanche diode (SPAD)

A photodetector includes a light receiving part having a plurality of light receiving elements, and a signal processing part that adds outputs from the light receiving elements and outputs the result. A plurality of measurements are performed while combination of effective light receiving elements among the light receiving elements in the light receiving part is changed. The results of the measurements are subjected to a compressive sensing process to determine an output signal of for each light receiving element or for each group of light receiving elements.

Photodetector and optical distance measuring device

A pixelincludes a photodiode PD which is provided between a first barrier regionforming a first potential barrier Band a second barrier regionforming a second potential barrier B, a first floating diffusion region Fwhich is provided adjacent to the first barrier region, and to which a first electric charge generated in the photodiode PD is transferred, and a second floating diffusion region Fwhich is provided adjacent to the second barrier region, and into which a second electric charge generated in the photoelectric conversion region PD flows, and in which a part of the flowing-in second electric charge is accumulated. The second potential barrier Bis lower than the first potential barrier B

Solid state image pick-up device, and pixel

At least one cell implementing a sensor array embraces a photoelectric-conversion accumulation element configured to generate and accumulate signal charges, a potential detection circuit configured to detect the signal charges generated by the photoelectric-conversion accumulation element as a potential change, and an amplification circuit configured to amplify the potential change and to transmit to an output-signal line. The photoelectric-conversion accumulation element and the potential detection circuit are connected in series between a first potential terminal and a second potential terminal, and the potential detection circuit has an insulated-gate transistor, which detects the potential change in a weak inversion state, in a period when an optical-communication signal is received.

Information-acquisition device and optical communication system

The present invention relates to a lane-dividing line detection device and has an object of detecting a lane-dividing line with high accuracy by accurately extracting characteristic points of the lane-dividing line while responding flexibly to road surface conditions. According to the present invention, pixel parts where a brightness variation is larger than a predetermined threshold are extracted from an image picked up by a camera that picks up an area ahead of a vehicle as edge points representing the lane-dividing line on a road surface (step). Next, candidates for the lane-dividing line drawn on a road are generated based on the extracted edge points (step). Then, the predetermined threshold for the brightness variation used to extract the edge points is changed based on the number of the generated candidates for the lane-dividing line (stepsthrough). Specifically, if the number of the candidate lines exceeds a predetermined number, the threshold is changed to a high value so as to increase difficulty in extracting the edge points. On the other hand, if the number of the candidate lines does not reach the predetermined number, the threshold is changed to a low value so as to facilitate the extraction of the edge points.

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Nagakute, Japan

Isamu Takai