PHOTOELECTRIC CONVERSION ELEMENT, LIGHT RECEIVING DEVICE, LIGHT RECEIVING SYSTEM, AND DISTANCE MEASURING DEVICE
First Claim
1. A photoelectric conversion element for detecting light and converting the light into photoelectrons, comprising:
- one MOS diode having an electrode formed on a semiconductor substrate with an insulator therebetween; and
plural embedded photodiodes formed in the semiconductor substrate,wherein the electrode of the MOS diode has a comb-like shape when viewed from an upper surface thereof, in which plural branch portions are branched from one electrode portion, andthe plural embedded photodiodes are nested, respectively, between the branch portions of the electrode when viewed from the upper surface thereof.
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Accused Products
Abstract
A first photoelectric conversion element, which detects light and converts the light into photoelectrons has: one MOS diode having an electrode formed on a semiconductor base body with an insulator therebetween; and a plurality of embedded photodiodes formed in the semiconductor base body. The electrode of the MOS diode has, when viewed from the upper surface, a comb-like shape wherein a plurality of branch portions are branched from one electrode portion. Each of the embedded photodiodes is disposed to nest between the branch portions of the electrode when viewed from the upper surface.
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Citations
27 Claims
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1. A photoelectric conversion element for detecting light and converting the light into photoelectrons, comprising:
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one MOS diode having an electrode formed on a semiconductor substrate with an insulator therebetween; and plural embedded photodiodes formed in the semiconductor substrate, wherein the electrode of the MOS diode has a comb-like shape when viewed from an upper surface thereof, in which plural branch portions are branched from one electrode portion, and the plural embedded photodiodes are nested, respectively, between the branch portions of the electrode when viewed from the upper surface thereof. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A light receiving device that acquires luminance information of incident light, comprising:
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a photoelectric conversion element, which detects and converts the incident light into photoelectrons; a charge accumulating unit for accumulating photoelectrons generated by the photoelectric conversion element; a capacitor that stores the photoelectrons at a fixed time period; a charge discharging unit that discharges the photoelectrons; a first MOS-type switching element disposed between the charge accumulating unit and the capacitor for causing the photoelectrons accumulated in the charge accumulating unit to migrate toward the capacitor; and a second MOS-type switching element disposed between the charge accumulating unit and the charge discharging unit for controlling discharge of the photoelectrons from the charge accumulating unit to the charge discharging unit, wherein the photoelectric conversion element comprises; one MOS diode having an electrode formed on a semiconductor substrate with an insulator therebetween; and plural embedded photodiodes formed in the semiconductor substrate, wherein the electrode of the MOS diode has a comb-like shape when viewed from an upper surface thereof, in which plural branch portions are branched from one electrode portion, the plural embedded photodiodes are nested, respectively, between the plural branch portions of the electrode when viewed from the upper surface thereof, and the photoelectrons from the photoelectric conversion element are transferred to the capacitor by selectively controlling opening/closing of the first switching element and the second switching element, whereby luminance information of incident light is acquired based on an amount (charge amount) of the photoelectrons transferred to the capacitor. - View Dependent Claims (9, 10, 11)
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12. A light receiving device that acquires luminance information of incident light, comprising:
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a photoelectric conversion element, which detects and converts the incident light into photoelectrons; a charge accumulating unit for accumulating photoelectrons generated by the photoelectric conversion element; a first capacitor and a second capacitor that store the photoelectrons at a fixed time period; a charge discharging unit that discharges the photoelectrons; a first MOS-type switching element disposed between the charge accumulating unit and the first capacitor for allocating the photoelectrons accumulated in the charge accumulating unit selectively to the first capacitor; and a second MOS-type switching element disposed between the charge accumulating unit and the second capacitor for allocating the photoelectrons accumulated in the charge accumulating unit selectively to the second capacitor; and a third MOS-type switching element for controlling discharge of the photoelectrons from the charge accumulating unit to the charge discharging unit, wherein the photoelectric conversion element comprises; one MOS diode having an electrode formed on a semiconductor substrate with an insulator therebetween; and plural embedded photodiodes formed in the semiconductor substrate, wherein the electrode of the MOS diode has a comb-like shape when viewed from an upper surface thereof, in which plural branch portions are branched from one electrode portion, the plural embedded photodiodes are nested, respectively, between the plural branch portions of the electrode when viewed from the upper surface thereof, and the photoelectrons from the photoelectric conversion element are transferred to the first capacitor and the second capacitor by selectively controlling ON/OFF states of the first through third switching elements, whereby luminance information of incident light is acquired based on an amount (charge amount) of the photoelectrons transferred to the first capacitor and the second capacitor. - View Dependent Claims (13, 14, 15)
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16. A light receiving system comprising:
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a light emitting device that irradiates pulsed light with respect to an object; a light receiving device that receives reflected light of the pulsed light and carries out an output responsive to a received light amount; and a controller that controls the light emitting device and the light receiving device, wherein the light receiving device comprises; a photoelectric conversion element, which detects and converts the reflected light into photoelectrons; a charge accumulating unit for accumulating photoelectrons generated by the photoelectric conversion element; a pair of capacitors that store the photoelectrons at a fixed time period; a charge discharging unit that discharges the photoelectrons; a pair of MOS-type switching elements disposed between the charge accumulating unit and the pair of capacitors for selectively allocating the photoelectrons accumulated in the charge accumulating unit to the pair of capacitors in synchronism with driving of the light emitting device; and a third MOS-type switching element for controlling discharge of the photoelectrons from the charge accumulating unit to the charge discharging unit in synchronism with driving of the light emitting device, wherein the photoelectric conversion element comprises; one MOS diode having an electrode formed on a semiconductor substrate with an insulator therebetween; and plural embedded photodiodes formed in the semiconductor substrate, wherein the electrode of the MOS diode has a comb-like shape when viewed from an upper surface thereof, in which plural branch portions are branched from one electrode portion, the plural embedded photodiodes are nested, respectively, between the plural branch portions of the electrode when viewed from the upper surface thereof, and the controller; turns ON a first switching element from among the pair of switching elements and transfers the photoelectrons from the photoelectric conversion element to a first capacitor from among the pair of capacitors, in a first period that resides within a period in which the pulsed light from the light emitting device is not irradiated, turns ON a second switching element from among the pair of switching elements and transfers the photoelectrons from the photoelectric conversion element to a second capacitor from among the pair of capacitors, in a second period that resides within a period in which the pulsed light from the light emitting device is irradiated, turns ON the third switching element and controls the charge discharging unit to discharge the photoelectrons from the photoelectric conversion element, within a period outside of the first period and the second period, and acquires luminance information of the reflected light based on an amount (charge amount) of the photoelectrons transferred to the first capacitor and an amount (charge amount) of the photoelectrons transferred to the second capacitor. - View Dependent Claims (17, 18, 19, 24)
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20. A light receiving system comprising:
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a light emitting device that irradiates pulsed light with respect to an object; a light receiving device that receives reflected light of the pulsed light and carries out an output responsive to a received light amount; and a controller that controls the light emitting device and the light receiving device, wherein the light receiving device comprises; a photoelectric conversion element, which detects and converts the reflected light into photoelectrons; a charge accumulating unit for accumulating photoelectrons generated by the photoelectric conversion element; first through fourth capacitors that store the photoelectrons at a fixed time period; a charge discharging unit that discharges the photoelectrons; first through fourth MOS-type switching elements disposed between the charge accumulating unit and the first through fourth capacitors for allocating the photoelectrons to the first through fourth capacitors in synchronism with irradiation of the pulsed light; and a fifth MOS-type switching element disposed between the charge accumulating unit and the charge discharging unit for controlling supply of the photoelectrons from the charge accumulating unit to the charge discharging unit wherein the photoelectric conversion element comprises; one MOS diode having an electrode formed on a semiconductor substrate with an insulator therebetween; and plural embedded photodiodes formed in the semiconductor substrate, wherein the electrode of the MOS diode has a comb-like shape when viewed from an upper surface thereof, in which plural branch portions are branched from one electrode portion, the plural embedded photodiodes are nested, respectively, between the plural branch portions of the electrode when viewed from the upper surface thereof, and the controller; controls irradiation of the pulsed light by the light emitting device, and ON/OFF switching of the first through fourth switching elements, turns ON the fifth switching element and discharges the photoelectrons to the charge discharging unit at a time when all of the first through fourth switching elements are OFF, and acquires luminance information of the reflected light based on an amount (charge amount) of the photoelectrons transferred to the first through fourth switching elements. - View Dependent Claims (21, 22, 23)
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25. A distance measuring device comprising:
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a light emitting device that irradiates pulsed light with respect to an object; a light receiving device that receives reflected light of the pulsed light and carries out an output responsive to a received light amount; a controller that controls the light emitting device and the light receiving device; and an arithmetic processor for calculating a distance to the object by a time-of-flight method using the output of the light receiving device, wherein the light receiving device comprises; a photoelectric conversion element, which detects and converts the reflected light into photoelectrons; a charge accumulating unit for accumulating photoelectrons generated by the photoelectric conversion element; first through fourth capacitors that store the photoelectrons at a fixed time period; a charge discharging unit that discharges the photoelectrons; first through fourth MOS-type switching elements disposed between the charge accumulating unit and the first through fourth capacitors for allocating the photoelectrons to the first through fourth capacitors in synchronism with irradiation of the pulsed light; and a fifth MOS-type switching element disposed between the charge accumulating unit and the charge discharging unit for controlling supply of the photoelectrons from the charge accumulating unit to the charge discharging unit, wherein the photoelectric conversion element comprises; one MOS diode having an electrode formed on a semiconductor substrate with an insulator therebetween; and plural embedded photodiodes formed in the semiconductor substrate, wherein the electrode of the MOS diode has a comb-like shape when viewed from an upper surface thereof, in which plural branch portions are branched from one electrode portion, and the plural embedded photodiodes are nested, respectively, between the plural branch portions of the electrode when viewed from the upper surface thereof, and wherein assuming that; an irradiation start time of the pulsed light is taken as time Teu, an irradiation end time of the pulsed light is taken as time Ted, an incidence end time of the reflected light with respect to the photoelectric conversion element is taken as time Trd, ON times of the first through fourth switching elements are taken as times Tg1u, Tg2u, Tg3u, Tg4u, OFF times of the first through fourth switching elements are taken as times Tg1d, Tg2d, Tg3d, Tg4d, a time period from the time Tg1u to the time Tg1d is taken as P1, a time period from the time Tg2u to the time Tg2d is taken as P2, a time period from the time Tg3u to the time Tg3d is taken as P3, a time period from the time Tg4u to the time Tg4d is taken as P4, a time period from the time Tg4u to the time Trd is taken as Psr, an amount of the photoelectrons stored in the first capacitor within the time period P1 is taken as a charge amount Q1, an amount of the photoelectrons stored in the second capacitor within the time period P2 is taken as a charge amount Q2, an amount of the photoelectrons stored in the third capacitor within the time period P3 is taken as a charge amount Q3, an amount of the photoelectrons stored in the fourth capacitor within the time period P4 is taken as a charge amount Q4, a time period from irradiation of the pulsed light to reflection of the pulsed light by the object and until the reflected light returns is taken as a round-trip time period Δ
P, and the distance between the object and the light emitting device and the light receiving device is taken as a distance D,then the controller; controls irradiation of the pulsed light from the light emitting device, and ON/OFF switching of the first through fourth switching elements, such that (1) P1=P3, (2) P2=P4, and (3) Tg1u<
Tg1d≦
Tg2u<
Tg2d≦
Teu<
Tg3u<
Tg3d≦
Tg4u≦
Ted<
Tg4d, or, Teu<
Tg3u<
Tg3d≦
Tg4u≦
Ted<
Tg4d<
Tg1u<
Tg1d≦
Tg2u<
Tg2d, andturns ON the fifth switching element and discharges the photoelectrons to the charge discharging unit at a time when all of the first through fourth switching elements are OFF, and the arithmetic processor; acquires luminance information of the reflected light in the time period P3 based on a difference between the charge amount Q3 that is stored in the third capacitor, which corresponds to ambient light and the reflected light, and the charge amount Q1 that is stored in the first capacitor, which corresponds to the ambient light, acquires luminance information of the reflected light in the time period Psr based on a difference between the charge amount Q4 that is stored in the fourth capacitor, which corresponds to the ambient light and the reflected light, and the charge amount Q2 that is stored in the second capacitor, which corresponds to the ambient light, determines a ratio between the luminance information of the reflected light in the time period P3 and the luminance information of the reflected light in the time period Psr, and calculates the round-trip time period Δ
P based on the ratio between the time period P3 and the time period Psr, andmeasures the distance D based on the round-trip time period Δ
P. - View Dependent Claims (26, 27)
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Specification