Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
  • F21V5/00—Refractors for light sources
  • F21V5/04—Refractors for light sources of lens shape
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
  • G01C3/00—Measuring distances in line of sight; Optical rangefinders
  • G01C3/02—Details
  • G01C3/06—Use of electric means to obtain final indication
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • 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
  • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
  • G01S17/88—Lidar systems specially adapted for specific applications
  • G01S17/89—Lidar systems specially adapted for specific applications for mapping or imaging
  • G01S17/894—Three-dimensional [3D] imaging with simultaneous measurement of time-of-flight at a two-dimensional [2D] array of receiver pixels, e.g. time-of-flight cameras or flash lidar
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • 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
  • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
  • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
  • G01S7/481—Constructional features, e.g. arrangements of optical elements
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • 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
  • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
  • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
  • G01S7/483—Details of pulse systems
  • G01S7/484—Transmitters
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B3/00—Simple or compound lenses
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B3/00—Simple or compound lenses
  • G02B3/10—Bifocal lenses; Multifocal lenses

Definitions

• the present invention relates to an optical system device.
• the above sensor system consists of a light irradiation unit that irradiates light onto the target object, a camera unit that detects the light reflected from each point on the target object, and a calculation unit that calculates the distance to the target object from the signal received by the camera.
• Non-Patent Document 1 optical devices utilizing the Lau effect have been known to convert incident light into a dot pattern.
• This is composed of a diffraction grating with a predetermined pitch P and a light source, and is arranged so that the distance L0 between the diffraction grating and the light source satisfies the following formula A, where ⁇ is the wavelength of the light from the light source and n is a natural number of 1 or more.
• a device in which the diffraction grating is replaced with a microlens is under consideration (for example, Patent Document 2).
• Figure 3 shows the results of a simulation of the contrast ratio when the light from the light source is irradiated onto an optical element with ⁇ changed from 10 to 90 ⁇ m in 10 ⁇ m increments.
• the present invention aims to provide an optical system device that can emit high-contrast light even when emitting a non-circular dot pattern.
• an optical system device of the present invention comprises an optical element in which aspherical lenses that transmit light of wavelength ⁇ are periodically arranged, and an irradiation unit having a light source that irradiates a plurality of the lenses with light of wavelength ⁇ , wherein m and n are natural numbers of 1 or more, a focal length of a cross-sectional shape of the aspherical lens perpendicular to the y direction is f 1 , a focal length of a cross-sectional shape perpendicular to the x direction is f 2 (f 1 ⁇ f 2 ), a magnitude of the pitch of the aspherical lens in the x direction is P 1 , and a magnitude of the pitch in the y direction is P 2 , a distance L 1 between the irradiation unit and a first focal plane of the aspherical lens, and a distance L 2 between the irradiation unit and a second focal plane are expressed by the following formulas 1 and 2:
• the distances L 1 and L 2 are expressed by the following formulas 3 and 4. It is preferable to satisfy the following.
• planar shape of the lens is rectangular or hexagonal.
• FIG. 13 is a diagram showing the orientation distribution at the far end of the irradiation unit used in the simulation.
• 1A is a schematic cross-sectional view taken along an xz plane
• FIG. 1B is a schematic cross-sectional view taken along a yz plane
• FIG. 1C is a perspective view showing an aspheric lens, showing a conventional optical system device.
• 1 is a graph showing the contrast of a conventional optical system device.
• 1 is a projection diagram of a dot pattern of a conventional optical system device.
• 1A and 1B are schematic cross-sectional views showing an optical system device of the present invention
• 3A to 3C are schematic cross-sectional views illustrating a method for producing an optical element of the present invention.
• the optical system device of the present invention is mainly composed of an optical element 1 and an irradiation unit 2.
• the mutually perpendicular directions are defined as the x-direction, y-direction, and z-direction
• the optical axis direction of the optical element 1 is defined as the z-direction.
• FIG. 5(a) is a view of the optical system device as viewed in the y-direction
• FIG. 5(b) is a view of the optical system device as viewed in the x-direction.
• the optical element 1 is a periodic arrangement of aspheric lenses 11 that transmit mainly light of wavelength ⁇ .
• the aspherical lens 11 is a lens whose focal length f1 is determined by a cross-sectional shape perpendicular to the y direction, whose focal length f2 is determined by a cross-sectional shape perpendicular to the x direction, whose pitch in the x direction is P1 , and whose pitch in the y direction is P2 .
• the aspherical lens 11 has a focal length f1 that is different from the focal length f2 (i.e., f1 ⁇ f2 ).
• the focal length means the distance between the lens surface closest to the focal point and the focal point, as shown in FIG. 5.
• the aspherical lens 11 is disposed so that both the focal point determined by the cross-sectional shape perpendicular to the y direction and the focal point determined by the cross-sectional shape perpendicular to the x direction are located on the irradiation unit 2 side of the aspherical lens 11.
• the optical element of the present invention can also be used for wide-angle lenses whose focal lengths f1 and f2 are smaller than 20 ⁇ m, 15 ⁇ m, and 10 ⁇ m, respectively, and narrow-angle lenses whose focal lengths are larger than 60 ⁇ m, 65 ⁇ m, and 70 ⁇ m, respectively.
• the aspherical lens 11 may have any shape as long as it can focus light. In addition to common lenses such as convex and concave lenses, Fresnel lenses, DOE lenses, metalenses, etc. can also be used. In the case of a convex lens, it is preferable that the convex lens portion faces the irradiation unit 2.
• the planar shape of the lens can be rectangular or hexagonal.
• An anti-reflection coating that prevents light from the irradiation unit 2 from being reflected may also be formed on the aspherical lens 11.
• the pitches P1 and P2 should be sufficiently larger than the wavelength ⁇ of the light from the light source 7, for example, 5 times or more, and preferably 10 times or more.

Landscapes

• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• General Physics & Mathematics (AREA)
• Radar, Positioning & Navigation (AREA)
• Remote Sensing (AREA)
• Computer Networks & Wireless Communication (AREA)
• Electromagnetism (AREA)
• Optics & Photonics (AREA)
• General Engineering & Computer Science (AREA)
• Lenses (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=91717734

Family Applications (1)

Country Status (3)

Cited By (1)

Citations (3)

• 2023
  • 2023-12-26 JP JP2024567901A patent/JPWO2024143433A1/ja active Pending
  • 2023-12-26 CN CN202380087343.3A patent/CN120380370A/zh active Pending
  • 2023-12-26 WO PCT/JP2023/046826 patent/WO2024143433A1/ja not_active Ceased

Patent Citations (3)

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