# US 2008/0186475 A1 · Method and Apparatus for Position Judgment > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2008/0186475 A1 - Document ID: US20080186475A1 - Status: Published application - Kind: A1 - Application number: 11/934,167 - Filed: 2007-11-02 - Published: 2008-08-07 - Earliest claimed: 2006-11-21 - Assignees: Stanley Electric Co., Ltd. - Inventors: Tadashi Kawata; Michinori Ichikawa; Fumio Kubo; Yutaka Ishiyama - Web page: https://patentgrep.com/patent/US20080186475A1 ## CPC - G01B 11/026: {by measuring distance between sensor and object (G01B11/0608 takes precedence)} - G01S 17/58: Velocity or trajectory determination systems; Sense-of-movement determination systems - G01S 17/87: Combinations of systems using electromagnetic waves other than radio waves - G01S 17/89: for mapping or imaging - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES ## Abstract The disclosed subject matter relates to a method and apparatus for position judgment, which can include a plurality of light sources and a photo-detector. The plurality of light sources can be configured to emit a plurality of pulsed lights towards an object from different directions, and a photo-detector can be configured to serially detect the light reflected from the object. A determination of whether the object is moving further away or coming closer to the apparatus can be judged by calculating at least one of a position, an area and a brightness of the object from the reflected light and comparing the data with the previous data for the same value(s). Thus, because the method of the disclosed subject matter does not require a measurement of time as in the conventional methods, the method can result in providing a similar apparatus with a simple configuration and at a low cost, and can be used as a sensor for detecting an obstacle and the like in a vehicle, alarm system, etc. ## Claims ### Claim 1 A method for position judgment, comprising: emitting a first pulsed light that alternates turning on and turning off at a predetermined interval/phase, towards an object from a first direction; emitting a second pulsed light having a different interval/phase from the predetermined interval/phase of the first pulsed light, towards the object from a second direction different from the first direction; detecting reflected light pulses in series from the first pulsed light and the second pulsed light that are reflected from the object; calculating an absolute value of a difference between brightness of each of the reflected light pulses; and comparing the absolute value of a first of the reflected light pulses with the absolute value of a second of the reflected light pulses. ### Claim 2 A method for position judgment, comprising: emitting a first pulsed light that alternates turning on and turning off at a predetermined interval/phase, towards an object from a first direction; emitting a second pulsed light having a different interval/phase from the predetermined interval/phase of the first pulsed light, towards the object from a second direction different from the first direction; detecting reflected light in series, of which one is respectively the first pulsed light and one is the second pulsed light each reflected from the object at different times; forming composite image data that is composed of each reflected light at each different time; calculating at least one of a position, an area and a brightness of the object from the composite image data; and comparing at least one of the position, the area and the brightness with a corresponding previous one of the position, area and brightness. ### Claim 3 (depends on 1) The method for position judgment according to claim 1, wherein each of the first pulsed light and the second pulsed light alternates turning on and turning off with each other. ### Claim 4 (depends on 2) The method for position judgment according to claim 2, wherein each of the first pulsed light and the second pulsed light alternates turning on and turning off with each other. ### Claim 5 (depends on 1) The method for position judgment according to claim 1, wherein each of the first pulsed light and the second pulsed light are turned on simultaneously, respectively. ### Claim 6 (depends on 2) The method for position judgment according to claim 2, wherein each of the first pulsed light and the second pulsed light are turned on simultaneously, respectively. ### Claim 7 (depends on 3) The method for position judgment according to claim 3, wherein each of the reflected light pulses of both the first pulsed light and the second pulsed light is detected when a corresponding light of the first and second pulsed lights is emitted, respectively. ### Claim 8 (depends on 4) The method for position judgment according to claim 4, wherein each of the reflected light pulses of both the first pulsed light and the second pulsed light is detected when a corresponding light of the first and second pulsed lights is emitted, respectively. ### Claim 9 (depends on 5) The method for position judgment according to claim 5, wherein each of the reflected light pulses of both the first pulsed light and the second pulsed light is detected when a corresponding light of the first and second pulsed lights is emitted, respectively. ### Claim 10 (depends on 6) The method for position judgment according to claim 6, wherein each of the reflected light of both the first pulsed light and the second pulsed light is detected when a corresponding light of the first and second pulsed lights is emitted, respectively. ### Claim 11 (depends on 1) The method for position judgment according to claim 1, wherein both the first pulsed light and the second pulsed light are emitted by at least one LED, respectively. ### Claim 12 (depends on 2) The method for position judgment according to claim 2, wherein both the first pulsed light and the second pulsed light are emitted by at least one LED, respectively. ### Claim 13 (depends on 3) The method for position judgment according to claim 3, wherein both the first pulsed light and the second pulsed light are emitted by at least one LED, respectively. ### Claim 14 (depends on 4) The method for position judgment according to claim 4, wherein both the first pulsed light and the second pulsed light are emitted by at least one LED, respectively. ### Claim 15 (depends on 5) The method for position judgment according to claim 5, wherein both the first pulsed light and the second pulsed light are emitted by at least one LED, respectively. ### Claim 16 (depends on 11) A position judgment apparatus using the method for position judgment according to claim 11, comprising: a waveform generator configured to form at least the first pulsed light and the second pulsed light; a driving controller configured to drive at least the first pulsed light and the second pulsed light; a photo-detector configured to detect each reflected light of the first pulsed light and the second pulsed light; an image data former configured to form brightness data from each reflected light detected by the photo-detector; an operating processor configured to calculate an absolute value of a difference between the brightness of each reflected light; and a judging processor configured to judge whether the object is approaching or retreating relative to the apparatus in accordance with the absolute value calculated by the operating processor. ### Claim 17 (depends on 16) The position judgment apparatus of claim 16, wherein the driving controller is configured to drive each of the first pulsed light and the second pulsed light to alternate turning on and turning off with each other. ### Claim 18 (depends on 16) The position judgment apparatus of claim 16, wherein the driving controller is configured to drive each of the first pulsed light and the second pulsed light such that they are turned on simultaneously, respectively. ### Claim 19 (depends on 16) The position judgment apparatus of claim 16, wherein the driving controller is configured to drive each of the first pulsed light and the second pulsed light to alternate turning on and turning off with each other, and the photo-detector is configured such that each of the reflected light pulses of both the first pulsed light and the second pulsed light is detected when a corresponding light of the first and second pulsed lights is emitted, respectively. ### Claim 20 (depends on 16) The position judgment apparatus of claim 16, wherein the driving controller is configured to drive each of the first pulsed light and the second pulsed light such that they are turned on simultaneously, respectively, and the photo-detector is configured such that each of the reflected light pulses of both the first pulsed light and the second pulsed light is detected when a corresponding light of the first and second pulsed lights is emitted, respectively ### Claim 21 (depends on 12) A position judgment apparatus using the method for position judgment according to claim 12, comprising: a waveform generator configured to form at least the first pulsed light and the second pulsed light; a driving controller configured to drive at least the first pulsed light and the second pulsed light; a photo-detector configured to detect each reflected light of at least the first pulsed light and the second pulsed light; an image data former configured to form image data from each reflected light detected by the photo-detector; a composite image data former configured to form composite image data at each timing from the image data outputted from the image data former; an operating processor configured to calculate at least one of a position, an area and a brightness of the object from the composite image data; and a judging processor configured to judge whether the object is approaching or retreating relative to the apparatus in accordance with at least one of the position, the area and the brightness calculated by the operating processor. ### Claim 22 (depends on 21) The position judgment apparatus of claim 21, wherein the driving controller is configured such that each of the first pulsed light and the second pulsed light alternates turning on and turning off with each other. ### Claim 23 (depends on 21) The position judgment apparatus of claim 21, wherein the driving controller is configured such that each of the first pulsed light and the second pulsed light are turned on simultaneously, respectively. ### Claim 24 (depends on 21) The position judgment apparatus of claim 21, wherein the driving controller is configured such that each of the first pulsed light and the second pulsed light alternates turning on and turning off with each other, and the photo-detector is configured such that each of the reflected light pulses of both the first pulsed light and the second pulsed light is detected when a corresponding light of the first and second pulsed lights is emitted, respectively. ### Claim 25 (depends on 21) The position judgment apparatus of claim 21, wherein the driving controller is configured such that each of the first pulsed light and the second pulsed light are turned on simultaneously, respectively, and the photo-detector is configured such that each of the reflected light pulses of both the first pulsed light and the second pulsed light is detected when a corresponding light of the first and second pulsed lights is emitted, respectively.