Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
  • G02B27/0025—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 for optical correction, e.g. distorsion, aberration
  • G02B27/0031—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 for optical correction, e.g. distorsion, aberration for scanning purposes
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
  • G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
  • G02B26/10—Scanning systems

Definitions

• the present invention relates to a scanning unit of the general type used for instance in infrared scanners in which a nodding mirror directs the incoming 5. rays onto a mirror which in turn directs the rays onto a spherical mirror from which the rays are directed to correcting devices such as mirrors or lenses which rotate about an axis and which in turn direct the rays after correction to a detector,
• roof reflectors which, as part of their functions, is to provide a nodding movement perpendicular to the scan.
• the object of the present invention is to provide a simplified and compact form of these earlier devices.
• a further object is to achieve an arrangement in which the aberrations which are to be corrected 5. are uniform across the field and can be removed by the rotating elements.
• a further object is to allow a straight line scan in object space in association with a nodding mirror.
• the invention relates to an improved scanning device which collects an image through a mirror nodding in a first plane and directs it to a focussing collecting mirror scanned in turn by a rotating scanner unit having pairs of optical elements moving in a second
• the focusing collecting mirror aberrations being uniform across the field and corrected symmetrically by the rotating optical correcting mirrors.
• present invention uses a nodding mirror to direct the rays onto a spherical receiving mirror 30. which is a half mirror to allow efficient use of
• OMPI the mirror area provided and to allow the correcting mirrors of the rotating scanning system to be advantage ⁇ ously positioned in relation to the half spherical collecting mirr ⁇ r to give a compact assembly which 5. allows on-axis scanning of a straight line in object space.
• the invention comprises a half spherical collecting mirror associated with a nodding mirror positioned adjacent the collecting
• mirror and to one side of the optical axis of the half spherical collecting mirror characterised by a fixed receiving mirror on the optical axis of the half spherical collecting mirror positioned on the same side of the half spherical collecting mirror as the
• nodding mirror and parallel to the planar edge of the collecting mirror a detector positioned to receive the image projected by the half spherical collecting mirror to the fixed mirror, and a series of aspheric correcting mirrors mounted on a scanner arranged to rotate about an
• the aspheric correcting mirrors are pairs of half spherical mirrors with one mirror of each pair on one side of the optical axis of the half spherical collecting mirror and the other mirror on the opposite 30. side of the optical axis with the planar edges adjacent the optical axis and parallel to the planar edge of the half spherical collecting mirror.
• the fixed mirror is disposed within the circle of rotation of the aspheric correcting mirrors so that the correcting mirrors traverse between the half circular collecting mirror and the fixed mirror to scan the half 5. circular collecting mirror.
• FIG. 1 is a somewhat schematic longitudinal sectional elevation of a unit constructed according to this invention.
• FIG. 2 shows the basic components of the system 15. indicating the position of the optical axis of the half spherical collecting mirror and the rotational axis of the scanner carrying the pairs of correcting mirrors.
• the nodding mirror 1 is supported in any convenient 20. manner in a housing 2 and is provided with a cam
• a fixed mirror 10 directs the rays to the detector 11 which may be of any usual or approved form and may be connected to a visual display or to a mini- processor or the like for image storage or analysing 5. purposes.
• the illustrations shows the compact nature of the device which is arranged in a fold-back pattern with the nodding mirror 1, the half spherical mirror 5, and the detector 11 being arranged in close proximity 10. in a generally stacked formation, allowing the aspheri- cal compensating mirrors 6 and 7 of the scanner 8 to be readily positioned about the optical axis 14.
• a driving motor 16 rotates the scanner 8 which carries the set of aspheric correcting mirrors 6 and 7.
• the axis 4 about which the nodding mirror 1 moves is parallel to the planar edge 15 of the collect ⁇ ing mirror 5 and the axis 9 about which the scanner unit 8 rotates is normal to the plane of the planar edge 15 of the collecting mirror 5 as well as normal to the optical axis of the half spherical collecting mirror 5.
• a relatively horizontal field of view is directed by the nodding mirror 1 to the 15. half-circular collector mirror 5, but the field of view is progressively scanned vertically as the mirror 1 nods.
• the image is then directed by the half spherical collecting mirror 5 generally along the optical axis of 20. the collecting mirror 5 and is directed by the mirror 6 of each set of correcting mirrors to the associated correcting mirror 7 which projects the image to the fixed mirror 10 and thence to the detector 11.
• the scanner rotate about the axis of rotation 9 of the scanner 8 a transverse scan of the image projected from the collecting mirror 5 occurs and, as the aspheric correcting mirrors 6 and 7 are arranged about the
• OMPI optical axis of the collecting mirror 5 enables the collecting mirror aberrations to be uniform across the field and corrected symetrically by the rotating aspheric correcting mirrors.
• an electronics bay is desig ⁇ nated 21 and an output to a display is designated 22.
• An encoder is designated 23 and a window of the housing 1 is designated 24.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Image Input (AREA)
• Lenses (AREA)
• Mechanical Optical Scanning Systems (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=3770211

Family Applications (1)

Country Status (3)

Citations (3)

Family Cites Families (8)

• 1984
  • 1984-06-27 WO PCT/AU1984/000118 patent/WO1985000435A1/en not_active Application Discontinuation
  • 1984-06-27 EP EP19840902573 patent/EP0148229A4/de not_active Withdrawn
  • 1984-06-27 JP JP50258784A patent/JPS61501592A/ja active Pending

Patent Citations (3)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events