Method of and apparatus for detecting range using multiple range readings

• US 4,470,681 A
• Filed: 09/07/1982
• Issued: 09/11/1984
• Est. Priority Date: 09/07/1982
• Status: Expired due to Term

• Current Assignee: Polaroid Corporation (PLR IP Holdings LLC)
• Original Assignee: Polaroid Corporation (PLR IP Holdings LLC)
• Inventors: Johnson, Bruce K.
• Primary Examiner(s): ADAMS JR, RUSSELL E
• Application Number:
  US06/415,531
• Time in Patent Office: 735 Days
• Field of Search: 354/25 R, 354/25 A, 354/403
• US Class Current: 396/123
• CPC Class Codes: G01S 17/48 Active triangulation systems, i.e. using the transmission and reflection of electromagnetic waves other than radio waves
• CPC Class Codes: G02B 7/32 using active means, e.g. light emitter including both an active and a passive focus detecting device G02B7/285; using ultrasound G02B7/40

Abstract

A method of and system for ranging are disclosed. The method and system transmit ranging energy toward different portions of a scene and sense ranging energy reflected from the different scene portions. Included is a step or means responsive to the sensing for detecting the ranges of the different scene portions.

Claims

1. A ranging system for controlling photographic apparatus as a function of the range of different portions of a photographic scene, said system comprising:

means for transmitting ranging energy along at least a path having different portions of a scene which are generally transverse to the direction of the ranging energy;

means for sensing the presence or absence of ranging energy reflected from said different scene portions along said path; and

,

means responsive to said sensing means for facilitating determination of the range of said different scene portions.

2. A ranging system according to claim 1 wherein said determining means includes means for deriving a selected range signal as a function of the ranges of the different scene portions along said path for facilitating control of the photographic apparatus in accordance with said selected range signal.

3. The system of claim 2 wherein said transmitting means includes means for scanning a narrow beam of energy across a scene for facilitating determination of the range from said system of scene portions lying along a scanning path;

and said sensing means includes means for receiving ranging energy reflected from said scene portions, said receiving means including an energy sensing position sensitive device extended in a direction generally parallel to said scanning path, and means for distributing such ranging energy along said device so that energy reflected from all scene portions substantially equidistant from said system are received at substantially the same location on said device while ranging energy from scene portions non-equidistant from said system are spatially distributed along said extended direction of said device, whereby the distance to any given scene portion which reflects energy is a function of the location of its reflected energy along the extended direction of said device.

4. The system of claim 3 wherein said distributing means includes a device lens mounted over said device for focusing the reflected energy on said array and means for providing relative movement in said extended direction between said device lens and said device in coordinated relation to scanning of said beam to produce said same location of received energy from scene portions equidistant from said system and said distributed locations of energy from non-equidistant scene portions.

5. The system of claim 4 wherein said means for providing relative movement comprises means coupling said device lens to said scanning means to coordinate the relative movement of said device lens with said scanning of said beam.

6. The system of claim 5 wherein said scanning means includes an energizeable source of energy, a source lens for facilitating focusing of said energy in said narrow beam, and said distributing means includes means for providing relative movement in the scanning direction between said source lens and said source so as to scan said beam across said scene, and means for coupling together said source lens and said device lens to coordinate the movement thereof.

7. The ranging system of claim 2 wherein said transmitting means includes a plurality of energizeable sources and at least a corresponding plurality of lenses, each of said lenses being positioned over a respective one of said sources so as to direct ranging energy from the respective one of said sources to a separate portion of the scene;

and said sensing means includes a position sensitive device and a number of lenses corresponding to the lenses of said transmitting means, wherein each of said lenses of said sensing means is positioned over respective said devices;

said sources and said lenses of said transmitting means and said lenses and said arrays of said sensing means being constructed and arranged so that ranging energy directed by any one of said sources is sensed solely by the respective one of said devices.

8. The system of claim 2 wherein said determining means includes means for controlling photographic functions of a photographic apparatus in accordance with said ranges.

9. The system of claim 8 wherein said determining means includes means for deriving a selected range signal as a function of the ranges of the different scene portions for facilitating control of said photographic function control means.

10. The system of claim 9 wherein said means for deriving a selected range signal is operable for deriving said signal as a function of the average of derived ranges of the different scene portions.

11. The system of claim 9 wherein said means for deriving a selected range signal is operable for deriving said signal as a function of the nearest object.

12. The system of claim 9 wherein said means for deriving a selected range signal is operable for deriving said signal as a function of the nearest large object.

13. The system of claim 9 wherein said means for deriving a selected range signal is operable for deriving said signal as a function of the farthest object.

14. The system of claim 9 wherein said means for deriving a selected range signal is operable for deriving said signal as a function of a weighted range signal derived from the ranges of the different scene portions.

15. The system of claim 14 wherein the weighted range signal is a compromise between the range of the nearest and farthest scene portions, but is weighted towards the nearest object.

16. The system of claim 14 wherein the weighted range signal is a compromise between the range of the nearest and farthest scene portions, but is weighted towards the farthest object.

17. The system of claim 14 wherein the weighted range signal is weighted in favor of preselected scene portions along the scanning path.

18. A ranging system for controlling photographic function of a photographic apparatus as a function of the range of different portions of a photographic scene, said system comprising:

means for transmitting ranging energy across a path having different laterally adjacent portions of a scene therealong;

means for sensing the presence or absence of ranging energy reflected from said different scene portions along said path; and

,

means responsive to said sensing means for determining the range of said different scene portions and for controlling photographic functions of a photographic apparatus in accordance with said ranges.

19. A ranging system comprising:

means for scanning a narrow beam of energy across a scene for facilitating determination of the range from said system of scene portions lying along a scanning path; and

,

means for receiving ranging energy reflected from such scene portions, said receiving means including an energy sensing position sensitive device extended in a direction parallel to the scanning path, and means for distributing such ranging energy along said device so that energy reflected from all scene portions substantially equidistant from said system are received at substantially the same location on said device while ranging energy from scene portions non-equidistant from said system are spatially distributed along said extended direction of said device, whereby the distance to any given scene portion which reflects energy is a function of the location of its reflected energy along the extended direction of said device.

20. The system of claim 19 wherein said distributing means includes a device lens mounted over said device for focusing the reflected energy on said device and means for providing relative movement in said extended direction between said device lens and said device in coordinated relation to scanning of said beam to produce said same location of received energy from scene portions equidistant from said system and said distributed locations of energy from non-equidistant scene portions.

21. The system of claim 19 wherein said means for providing relative movement comprises means coupling said device lens to said scanning means to coordinate the relative movement of said device lens with said scanning of said beam.

22. The system of claim 20 wherein said scanning means includes an energizeable source of energy, a source lens for facilitating focusing of said energy in said narrow beam, and said distributing means includes means for providing relative movement in the scanning direction between said source lens and said source so as to scan said beam across said scene, and means for coupling together said source lens and said device lens to coordinate the movement thereof.

23. The system of claim 20 wherein said scanning means includes a source lens mounted over said source and being movable relative to said source so as to effect said scanning, said source lens being generally synchronously movable with said device lens so that reflected beam energy from the different scene portions strike said device in locations which are a function of the distance the reflected pulses travel whereby scene portions equidistant from said system are substantially coincidental on said device.

24. A method of obtaining ranging information comprising the steps of:

transmitting ranging energy across a ranging path having different laterally adjacent portions of a scene to be ranged;

sensing the presence or absence of reflected ranging energy from the different scene portions; and

,

deriving the range of the different scene portions provided by the reflected ranging energy.

25. The method of claim 24 including the step of deriving a selected range signal as a function of the scene portion ranges for facilitating control of a photographic apparatus.

26. A method of obtaining ranging information for controlling photographic functions of a photographic apparatus as a function of the range of different portions of a photographic scene comprising the steps of:

transmitting ranging energy across a ranging path having different laterally adjacent portions of a scene to be ranged;

sensing the reflected ranging energy from the different scene portions; and

,

deriving range information of the different scene portions provided by the reflected ranging energy and controlling the photographic functions in accordance with said range information.

27. The method of claim 26 including the step of deriving a selected range signal as a function of the scene portion ranges for facilitating control of a photographic apparatus.

28. The method of claim 26 wherein said deriving step includes selecting a range signal as a function of the average of the derived ranges of different scene portions.

29. The method of claim 27 wherein said selected range signal is a function of a weighted average of the derived ranges of the different scene portions.

30. The method of claim 26 wherein said deriving step includes selecting a range signal as a function of the nearest object.

31. The method of claim 27 wherein said selected range signal is a function of the nearest large scene object.

32. The method of claim 27 wherein said selected range signal is a function of the farthest object.

33. The method of claim 27 wherein said selected range signal is a compromise between the range of the nearest and farthest scene portions, but is weighted towards the nearest object.

34. The method of claim 27 wherein said selected range signal is a compromise between the range of the nearest and farthest scene portions, but is weighted towards the farthest object.

35. The method of claim 27 wherein said selected range signal is weighted in favor of preselected scene portions along the scanning path.

36. The method of obtaining ranging information comprising the steps of:

scanning a narrow beam of energy across a scene for determining the range from a ranging system of scene portions lying along the scanning path;

receiving ranging energy reflected from such scene portions by an energy sensing position sensitive device extended in a direction generally parallel to said scanning path; and

,

distributing the ranging energy along the extended direction of the device so that energy reflected from all scene portions substantially equidistant from the system are received at the same location on the device while ranging energy from scene portions non-equidistant from the system are spatially distributed along said extended direction of the device, whereby the distance to any given scene portions is solely a function of the location of its reflected energy on the device.

37. The method of claim 36 wherein said distributing step includes:

focusing the reflected energy on the array by means of a lens mounted over the device; and

,

providing relative movement between the lens and the device in coordinated relation to scanning of the beam to produce the same location of energy from scene portions equidistant from the system and distributed location of the energy from non-equidistant scene portions.

38. The method of claim 37 wherein said scanning step includes:

energizing a source of radiant energy;

focusing of said energy in a narrow beam by a lens assembly;

relatively moving the source and the lens so as to scan the beam across the scene; and

,

coupling the scanning step and the distributing step to coordinate relative movement thereof so as to produce the same location of energy from scene portions equidistant from the system and distributed location of the energy from non-equidistant scene portions.