公开(公告)号：US20210072076A1

公开(公告)日：2021-03-11

申请号：US16952611

申请日：2020-11-19

Applicant: DENSO CORPORATION

Inventor： Yoshihide TACHINO ,  Isamu TAKAI

IPC: G01J1/44

Abstract: 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.

公开(公告)号：US20200044109A1

公开(公告)日：2020-02-06

申请号：US16598295

申请日：2019-10-10

Applicant: DENSO CORPORATION ,  KABUSHIKI KAISHA TOYOTA CHUO KENKYUSHO

Inventor： Kenta AZUMA ,  Noriyuki OZAKI ,  Shinji KASHIWADA ,  Teiyu KIMURA ,  Isamu TAKAI ,  Hiroyuki MATSUBARA ,  Mitsuhiko OHTA ,  Shigeyoshi HIRATSUKA

IPC: H01L31/107 ,  H01L31/02 ,  H01L27/144

Abstract: 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.

公开(公告)号：US20210373156A1

公开(公告)日：2021-12-02

申请号：US17401014

申请日：2021-08-12

Applicant: DENSO CORPORATION

Inventor： Teiyu KIMURA ,  Noriyuki OZAKI ,  Takehiro HATA ,  Mineki SOGA ,  Hiroyuki MATSUBARA ,  Isamu TAKAI

IPC: G01S17/08 ,  G01S17/931 ,  G01S7/4861 ,  G01S7/484

Abstract: 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.

公开(公告)号：US20190265333A1

公开(公告)日：2019-08-29

申请号：US16282756

申请日：2019-02-22

Applicant: DENSO CORPORATION

Inventor： Akifumi UENO ,  Isamu TAKAI

IPC: G01S7/48 ,  G01S17/08 ,  G01S17/93

Abstract: 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.

公开(公告)号：US20210088663A1

公开(公告)日：2021-03-25

申请号：US17110339

申请日：2020-12-03

Applicant: DENSO CORPORATION

Inventor： Masato RINNAI ,  Isamu TAKAI

IPC: G01S17/42 ,  G01S17/931 ,  G01S7/486 ,  G01S7/484

Abstract: 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.

公开(公告)号：US20190265356A1

公开(公告)日：2019-08-29

申请号：US16282805

申请日：2019-02-22

Applicant: DENSO CORPORATION

Inventor： Akifumi UENO ,  Isamu TAKAI

IPC: G01S17/10 ,  G01C3/08 ,  H05B37/02 ,  G01S17/93

Abstract: 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.

公开(公告)号：US20210088661A1

公开(公告)日：2021-03-25

申请号：US16952616

申请日：2020-11-19

Applicant: DENSO CORPORATION

Inventor： Takehiro HATA ,  Kenta AZUMA ,  Hiroyuki MATSUBARA ,  Isamu TAKAI

IPC: G01S17/14 ,  G01S7/481 ,  G01S7/4863

Abstract: A photodetector and an optical ranging apparatus provided with the photodetector are disclosed. The photodetector includes a pulse output section that changes an output from a light-receiving element to a rectangular pulse having a predetermined pulse width and outputs the rectangular pulse. Further, the photodetector also includes a pulse conversion circuit that converts the rectangular pulse to a rectangular pulse having a pulse width different from the predetermined pulse, based on the rise and fall of the rectangular pulse.

公开(公告)号：US20210018624A1

公开(公告)日：2021-01-21

申请号：US17061239

申请日：2020-10-01

Applicant: DENSO CORPORATION

Inventor： Yoshihide TACHINO ,  Isamu TAKAI

IPC: G01S17/10 ,  G01S17/931 ,  G01S7/4865

Abstract: 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.

公开(公告)号：US20200379111A1

公开(公告)日：2020-12-03

申请号：US16997182

申请日：2020-08-19

Applicant: DENSO CORPORATION

Inventor： Teiyu KIMURA ,  Isamu TAKAI

IPC: G01S17/10 ,  G06T7/50 ,  G01S17/894

Abstract: 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.

公开(公告)号：US20200044098A1

公开(公告)日：2020-02-06

申请号：US16583674

申请日：2019-09-26

Applicant: DENSO CORPORATION

Inventor： Kenta AZUMA ,  Teiyu KIMURA ,  Noriyuki OZAKI ,  Shinji KASHIWADA ,  Takehiro HATA ,  Isamu TAKAI ,  Hiroyuki MATSUBARA

IPC: H01L31/02 ,  H03F3/08 ,  G01S7/486 ,  H01L31/10

Abstract: 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.