PANORAMIC PROJECTOR AND CAMERA

• US 3,832,046 A
• Filed: 11/13/1972
• Issued: 08/27/1974
• Est. Priority Date: 11/13/1972
• Status: Expired due to Term

• Current Assignee: Cae-Link Corporation
• Original Assignee: Richard A. Mecklenborg
• Inventors: Mecklenborg, Richard A.
• Primary Examiner(s): Hayes, Monroe H.
• Application Number:
  US05/305,792
• Time in Patent Office: 652 Days
• Field of Search: 352/69,132 35/12N
• US Class Current: 352/69
• CPC Class Codes: G09B 9/304 by using a film

Abstract

A panoramic motion picture projector useful in flight simulators and in the entertainment field is shown. A curved cylindrical segment of film which typically subtends 180* at the film gate contains a full 360* of picture information thus enabling projection of a complete panoramic image. The film segment is scanned by a slit of light revolving about the axis of curvature of the segment and the resulting image is converted to a rotating radial pattern having said axis as its center. In one embodiment, the speed of rotation of the radial pattern is increased to cause an input rotation of 180* to cover 360*, and the pattern is then restored to the cylindrical format by a scanning projection head for projection on a cylindrical screen. For use in situations, e.g., in flight simulators, where perspective transformations are required, means are provided to tilt the scanning slit in order to pick up the required image information and then to detilt it afterwards. Translation corrections are then obtained by Scheimpflug and anamorphic correction means and placed in the optical path prior to projection. A panoramic camera is also described.

Claims

1. A method of projecting a panoramic display of an image from an image-bearing transparency onto a curved surface with an apparent first perspective point laterally displaced from a second perspective point from which the image was recorded on the transparency, comprising the steps of:

a. disposing at least a portion of a panoramic image-bearing transparency in a curved configuration with the upright axis of the image on said transparency substantially parallel to the axis of curvature of said transparency while scanning said transparency so disposed with a slit of light having a normal orientation parallel to and rotating about said axis of curvature;

b. skewing said slit of light relative to the axis of curvature prior to scanning the transparency, the degree of skewing being a function of the extent and direction of lateral displacement;

c. restoring the resulting image-bearing light slit to parallelism with said axis of curvature subsequent to scanning the transparency;

d. optically rotating the image-bearing light slit into an image plane perpendicular to said axis of curvature so as to form, as the transparency is scanned, a radial pattern of scanning slit images each with its infinity or horizon point at the center of the pattern and with the slit image produced by scanning the transparency in that direction which coincides with said line of lateral displacement being disposed on a first axis and the slit image produced by scanning that portion of the transparency which extends perpendicular to said line of lateral displacement disposed along a second axis perpendicular to said first axis;

e. performing a Scheimpflug correction on said pattern with the correction axis aligned with said first axis, the amount of correction being a function of the extent of lateral displacement;

f. performing an anamorphic distortion on the result of preceding step (e), as a function of the extent of lateral displacement and with the magnification axis of the anamorphic distortion along said second axis; and

g. rotating said resulting slit images into mutual parallelism.

2. A method according to claim 1 wherein there is a displacement in altitude as well as lateral displacement between the first and second perspective points, the method including the further step of anamorphically distorting said radial pattErn to effect apparent altitude displacement.

3. A method according to claim 2 wherein said further step is performed subsequent to step (f).

4. The method of claim 1 wherein said function of the extent and direction of lateral displacement is a function which varies directly according to the extent of lateral displacement and sinusoidally according to the direction of lateral displacement.

5. The method of claim 1 wherein said function of the extent and direction of lateral displacement is a function of the product of the cosine of the scan angle relative to a plane perpendicular to the line of lateral displacement of the first perspective point from the second perspective point and the arctan of the distance of displacement of the simulated viewpoint from the film viewpoint divided by the altitude of the film viewpoint.

6. A method of recording a full 360* panoramic scene on film comprising the steps of:

rotating a right-angle reflector through 360* to completely scan the scene to be recorded, said reflector having its input axis substantially perpendicular to its axis of rotation and arranged to reflect a continuously changing slit image for forming a full 360* radial image pattern of the scene;

disposing film sensitive to said slit image in the form of a partial cylinder enclosing less than 360*;

orienting the continuously changing slit image which forms the full 360* radial image pattern as slit images which are parallel with the axis of curvature of said cylindrically curved film and which rotate around said axis of curvature; and

directing said rotating and parallel slit image onto a segment of said cylindrically disposed film to record a full 360*panoramic scene on a segment of film disposed as a partial cylinder of less than 360*.

7. A panoramic projector to project from an image-bearing transparency a scene having an apparent perspective point laterally displaced from that at which the image was recorded on the transparency, comprising:

a. a cylindrical transparent gate to support the transparency;

b. means spaced radially on one side of said gate to scan a transparency image supported by said gate with a slit of illumination parallel to the longitudinal axis of said cylindrical gate;

c. means to tilt said slit of light prior to scanning said transparency image supported by said gate, the amount of tilt being a function of the extent and direction of lateral displacement;

d. means spaced radially on the other side of said gate to track said scanning slit of light and to orient the resulting image-bearing slit of light in a plane perpendicular to said longitudinal axis so that, as said slit scans said transparency supported by said gate, a radial pattern of slit images is formed with the infinity or horizon points of all images at its center;

e. means to remove the tilt of said image-bearing slit of light;

f. scanning means synchronized with the forming of said radial image pattern to track said perpendicularly oriented image-bearing slit and orient it to parallelism with said longitudinal axis for projection on a curved screen;

g. means, interposed between said means to remove the tilt and said synchronized scanning means, to perform a Scheimpflug correction; and

h. means, interposed between said Scheimpflug means and said synchronized scanning means, to perform an anamorphic distortion.

8. The invention according to claim 7 wherein said means to track and orient said image-bearing slit of light is disposed radially inwardly of said cylindrical gate and comprises:

a. a right angle reflecting means mounted for rotation about said longitudinal axis; and

b. means for rotating said reflecting means.

9. The invention according to claim 8 wherein said means for rotating said reflecting means is a scan drive motor connected through gearing to rotate said reflecting means at a selected angular rate of omega .

10. The invention according to claim 9 wherein said means to scan said transparency image supported by said gate with a slit of illumination comprises:

a. means to generate a slit of light;

b. means rotatable about said gate to image said generated slit of light on said transparency image; and

c. means to rotate said rotatable means at said selected angular rate of omega .

11. The invention according to claim 10 wherein said means to rotate said rotatable means comprises said scan drive motor connected through gearing to said rotatable means.

12. The invention according to claim 10 wherein said generated slit of light is generated perpendicularly to and along the axis of said gate, and wherein said rotatable means comprise:

a. a Pechan prism disposed remotely from said gate with its optical axis coincident with the axis of said gate and mounted for rotation about said coincident axis;

b. a first right-angle reflector juxtaposed with said first Pechan prism in the optical path between said Pechan prism and said gate and oriented to reflect said slit of light into parallelism with said gate axis;

c. a second right-angle reflector disposed in the optical path between said first right-angle reflector and said gate and oriented to rotate said slit of light into perpendicularity with said gate axis;

d. a third right-angle reflector disposed in the optical path between said gate and said second right-angle reflector to reflect said slit of light into parallelism with said gate axis;

e. means mounted for rotation about said gate axis and supporting said first, second and third reflectors in the aforesaid spatial disposition and orientation;

f. means to rotate said support means at said selected angular scan rate omega ; and

g. means to rotate said Pechan prism at the rate of omega /2 to keep said slit of light aligned with, and stationary with respect to, said first reflector as it rotates.

13. The invention according to claim 12 wherein said means to tilt comprise means to add to said Pechan prism position an angular amount equal to one-half the required tilt and wherein said means to remove said tilt comprise:

a. a second Pechan prism;

b. means to rotate said second Pechan prism at the rate omega /2; and

c. means to subtract from the position of said second Pechan prism an angular amount equal to the amount added to the first-mentioned Pechan prism.

14. The invention according to claim 13 wherein said means to rotate said first and second Pechan prisms at the rate omega /2 comprise said scan drive motor connected through differential gearing to said Pechan prisms, and said means to add and means to subtract comprise a servo motor, whose position is controlled in accordance with said function, coupled to said gearing to provide a second differential input.

15. The invention according to claim 13 wherein said transparency is framed strip film and further including means to move the film into and out of said gate, said film-moving means comprising:

a. means to rotate said gate;

b. supply and take up means to transport film to and from said gate;

c. means to cause said scanning means to scan at said selected angular rate omega plus the rate of rotation of said gate; and

d. means to add to said first and subtract from said second Pechan prism, one-half of said angular rate omega .

16. The invention according to claim 10 wherein said slit of light is generated parallel to said gate axis and said rotatable means comprise:

a. a Pechan prism rotatable about said gate axis;

b. first right-angle reflection means to reflect said slit of light into parallelism with said gate axis;

c. a second right-angle reflecting means to reflect said slit of light into perpendicularity with said gate axis;

d. a mirror coaxially surrounding said gate;

e. third reflecting means to reflect the slit of light from said secOnd right-angle reflector means onto said mirror;

f. annular lens means coaxially disposed between said gate and mirror to image the slit reflected from said mirror onto said gate;

g. rotatable support means to support said first, second and third reflecting means for rotation about said axis;

h. means to drive said support means at the desired angular scan rate omega ; and

i. means to drive said Pechan prism at an angular rate of omega /2.

17. The invention according to claim 16, further including means to move film into and out of said gate comprising means rotatable about said film gate axis, said means containing an endless loop of film and having guides to feed film from said loop onto said gate and to return film coming from said gate to said loop as said means rotates about said gate axis.

18. The invention according to claim 17 wherein said mirror and lens contain openings providing a passageway for film to be supplied to and taken from said gate.

19. The invention according to claim 16 wherein said means to tilt comprises a second Pechan prism and means to position said second prism, and said means to remove said tilt comprises a third Pechan prism and means to drive said third prism.

20. The invention according to claim 19 wherein said second and third prisms are driven in opposite directions by a common servo drive motor.

21. The invention according to claim 10 and further including means to cause said slit to be illuminated only when scanning the frame of film to be displayed.

22. The invention according to claim 21 wherein 360* of image information is stored on film occupying 180* on said gate and said means to cause said slit to be illuminated only when scanning said frame to be displayed comprises:

a. first means providing an output pulse for each 180* of film;

b. a first flip-flop having its trigger input connected to said first output;

c. a second means to provide a second output for each 180* of scan motion;

d. a second flip-flop having its trigger input connected to said second output;

e. a first AND gate having as inputs the true outputs of said first and second flip-flops;

f. a second AND gate having as inputs the not-true outputs of said first and second flip-flops;

g. an OR gate having the outputs of said first and second AND gates as inputs; and

h. light control means operative on said slit generating means and responsive to the output of said OR gate.

23. The apparatus of claim 7 wherein said function of the extent and direction of lateral displacement is a function which varies directly according to the extent of lateral displacement and sinusoidally according to the direction of lateral displacement.

24. The apparatus of claim 7 wherein said function of the extent and direction of lateral displacement is a function of the product of the cosine of the scan angle relative to a plane perpendicular to the line of lateral displacement of the first perspective point from the second perspective point and the arctan of the distance of displacement of the simulated viewpoint from the film viewpoint divided by the altitude of the film viewpoint.

25. In a panoramic projection system having means to support an image-bearing transparency, means to scan the image periodically with a slit of light, means to project the resulting modulated light slit on a curved screen, and means to cause said projected image to scan across said screen, apparatus for altering the image as projected to simulate a display viewing point laterally displaced from the actual or recording viewing point of the transparency, comprising:

a. means to tilt the slit of light prior to scanning the image such that the degree of tilt is a function of the extent and direction of lateral displacement;

b. means to remove the tilt of the resulting image-modulated light slit after the image has been scanned;

c. means to rotate said moDulated slit of light into an image plane such that, as the image is scanned, a radial pattern is formed at said plane with the horizon or infinity point of all slit images at its center and with the slit image produced by scanning a portion of the image in the direction of lateral displacement disposed along a first axis of said pattern and the slit image produced by scanning a portion of the image perpendicular to the direction of displacement disposed along a second axis perpendicular to said first axis;

d. means to perform a Scheimpflug correction on said pattern with the correction axis aligned with said first axis, the amount of correction being a function of the extent of lateral displacement; and

e. anamorphic distortion means operable on the corrected output pattern of said Scheimpflug means with the magnification axis of the anamorphic correction aligned with said second axis and the amount of magnification a function of the extent of lateral displacement.

26. The invention according to claim 25 wherein said means to tilt said light slit comprises a first Pechan prism and said means to remove the tilt of said image-modulated light slit comprises a second Pechan prism.

27. The apparatus of claim 25 wherein said function of the extent and direction of lateral displacement is a function which varies directly according to the extent of lateral displacement and sinusoidally according to the direction of lateral displacement.

28. The apparatus of claim 25 wherein said function of the extent and direction of lateral displacement is a function of the product of the cosine of the scan angle relative to a plane perpendicular to the line of lateral displacement of the first perspective point from the second perspective point and the arctan of the distance of displacement of the simulated viewpoint from the film viewpoint divided by the altitude of the film viewpoint.

29. A projector to project a full 360* panoramic view of a scene stored on a frame of film comprising:

a. a cylindrical transparent film gate to support the film, said gate having a circumference greater than the length of a frame of film and wherein the frame of film when supported on said gate will subtend X degrees;

b. means on one side of said gate to scan said frame of film with a slit of illumination parallel to the axis of said cylinder;

c. means on the other side of said gate to track said scanning slit of light and to orient the resulting image-bearing slit of light in a plane perpendicular to the cylinder axis so that as said slit of light scans said frame of film a radial image pattern is formed;

d. means to adjust the angular rate of forming said radial image pattern with respect to the angular rate of scanning said frame of film by a factor of 360 divided by X to cause a full 360* radial image pattern to form during the scan of the frame of X degrees; and

e. scanning means synchronized with forming of said radial image pattern by said image-bearing slit of light at said adjusted rate to track said perpendicular oriented image-modulated slit of light and return it to parallelism with the cylinder for projection on a cylindrical screen.

30. The invention according to claim 29 wherein X is 180* such that the angular rate of forming said radial image is double the angular scanning rate.

31. The invention according to claim 30 and further including means to cause said slit to be illuminated only when scanning the 180* containing said film frame.

32. The invention according to claim 29 wherein said means to track and image said slit is on the inside of said cylindrical gate and comprises a right-angle reflecting means mounted for rotation about said cylinder axis and means to rotate said reflecting means.

33. The invention according to claim 32 wherein said reflecting means is a prism.

34. The invention according to claim 33 wherein said means to increase rotaTion is a Pechan prism with its axis of rotation on a line perpendicular to said radial image pattern and passing through its center and means to rotate said prism at a selected angular rate of omega times 360 divided by two X where omega is the angular rate at which said scanning means is scanning said frame of film.

35. The invention according to claim 29 wherein said means to scan said frame of film with an illuminated slit comprise:

a. means to generate a slit of light; and

b. means rotatable about said gate to image said slit on said frame of film supported by said gate.

36. The invention according to claim 35 wherein said slit of light is generated perpendicular to and along the axis of said gate and said rotatable means comprise:

a. a Pechan prism rotatable about the axis of said cylindrical gate and spaced from said gate along said axis;

b. a first right-angle reflector to reflect said slit of light into parallelism with said axis;

c. a second right-angle reflector to return said slit of light to perpendicularity to said axis;

d. a third right-angle reflector aligned with said gate to reflect said slit of light into parallelism with said axis;

e. means to support said first, second and third reflectors, said means being mounted for rotation about said axis;

f. means to rotate said support means and the reflectors supported thereon at said selected angular scan rate omega ; and

g. means to rotate said Pechan prism at the rate omega /2 to keep said slit aligned with said reflector as it rotates.

37. The invention according to claim 36 further including means to move film to and from said gate, whereby panoramic motion pictures may be projected.

38. The invention according to claim 36 wherein said means to move film comprise:

means to rotate said gate; and

supply and take up means to supply film to and take up film from said gate.

39. The invention according to claim 35 wherein said slit of light is propagated perpendicular to and along said axis and said rotatable means comprise:

a. a Pechan prism rotatable about said axis;

b. first right-angle reflection means to reflect said slit into parallelism with said axis;

c. a second right-angle reflecting means to reflect said slit into perpendicularity to said axis;

d. a mirror surrounding said gate;

e. third reflecting means to reflect the slit of light output of said second means onto said mirror;

f. annular lens means to image the slit of light reflected from said mirror onto said gate;

g. rotatable support means to support said first, second and third reflecting means for rotation about said axis;

h. means to drive said support means at a selected angular scan rate omega ; and

i. means to drive said Pechan prism at an angular rate of omega /2.

40. The invention according to claim 36 further including means to move film to and from said gate whereby panoramic motion pictures may be projected.

41. The invention according to claim 40 wherein said means to move film comprise means rotatable about said film gate axis, said means containing an endless loop of film and having guides to feed film from said loop onto said gate and to return film coming from said gate to said loop as said means rotates about said gate axis.

42. The invention according to claim 41 wherein said mirror and lens contain openings to allow film to be supplied to and taken from said gate.

43. The invention according to claim 29 further including:

a. means to tilt said slit of light prior to scanning said frame of film;

b. means to remove said tilt after said frame of film is scanned;

c. Scheimpflug correction means interposed in the optical path between said means to adjust the angular rate of forming and said synchronized scanning means;

d. anamorphic distortion means interposed in the optical path between said Scheimpflug means and said synchronized scanning mEans; and

e. means to control said tilting means, said means to remove said tilt, said Scheimpflug means and said anamorphic means as a function of lateral displacement.

44. A method of projecting a full 360* panoramic view of an image recorded on a transparency, comprising the steps of:

a. disposing the transparency in a curved configuration with a first axis of the image on said transparency parallel to the axis of curvature of said transparency, and the radius of curvature of said transparency such that the dimension of the image on said transparency perpendicular to said first axis subtends an angle of X degrees, where X is less than 360*;

b. generating on one side of and directing toward said transparency a slit of light parallel to, and rotating about, said axis of curvature for producing an image-modulated slit of light on the other side of said transparency;

c. optically rotating the image-modulated light slit in an image plane perpendicular to said axis of curvature so as to form, as the transparency is scanned, a 360* radial pattern of image-modulated light slits each with its horizon or infinity point at the center of the pattern;

d. adjusting the rate of said optical rotation of said image-modulated light slit with respect to the rotating of said slit of light about said axis of curvature by a factor of 360 divided by X to cause a full 360* radial pattern to form during X degree scan of the transparency; and

e. restoring the slit images of said pattern to mutual parallelism for projection.

45. A method of projecting a panoramic view, including a full 360* view of an image recorded on a transparency comprising the steps of:

disposing the transparency in a curved configuration with a first axis of the image on said transparency parallel to the axis of curvature of said transparency and the radius of curvature of said transparency such that the dimension of the image on said transparency which is perpendicular to said first axis subtends an angle less than 360*;

scanning said transparency with slit of light parallel to, and rotating about, said axis of curvature for producing an image-modulated slit of light;

optically rotating said image-modulated light slit in an image plane perpendicular to said axis of curvature so as to form, as the transparency is scanned, a radial pattern, up to and including a 360* radial pattern, of image-modulated light slits each with the horizon or infinity point at the center of the pattern;

adjusting the rate of said optical rotation of said image-modulated light slit with respect to the rate of scanning said transparency such that the radial pattern of image-modulated light slits formed by scanning the image on the transparency covers a sector of angular units equivalents to the angular units represented by the panoramic image on said transparency; and

restoring the radial pattern of image-modulated light slits to mutual parallelism for projection.

46. A panoramic projector to project a view, including a full 360* view of a scene stored on a frame of film comprising:

a curved transparent film gate to support the film, said gate having a circumference greater than the length of a frame of film and wherein the frame of film when supported on said gate will subtend an angle less than 360*;

means on one side of said gate to scan said frame of film with a slit of illumination parallel to the axis of said cylinder;

means on the other side of said gate to track said scanning slit of light and to orient the resulting image-modulated slit of light in a plane perpendicular to the axis of curvature of said gate so that as said slit of light scans said frame of film a radial image pattern, up to and including a 360* radial image pattern, is formed, each of said image-modulated light slits forming said radial pattern with the horizon or infinity point at the ceNter of the pattern;

means to adjust the angular rate of forming of said radial image with respect to the angular rate of scanning said frame of film such that the radial pattern of image-modulated light slits formed by scanning the frame of films covers a sector of angular units equivalent to the angular units represented by the panoramic image on said frame of film; and

scanning means synchronized with the forming of said radial image at said adjusted rate to track said perpendicular oriented image-modulated slit of light and rotate it to parallelism for projection on a curved screen.

47. A camera to record a panoramic scene up to and including a full 360* scene, on a frame of film comprising:

a rotating right-angle reflector to scan the scene to be recorded having its input axis substantially perpendicualr to its axis of rotation and arranged to reflect a continuously changing slit image which forms a radial image pattern of the scene to be recorded;

curved transparent film gate means; and

rotating optical means to orient the continuously changing slit image comprising the radial image pattern into parallelism with the axis of curvature of said gate means and to direct said parallel slit image from said radial pattern onto film supported by said film gate means.

48. A panoramic camera to record a full 360* scene on a frame of film comprising:

a rotating right-angle reflector for scanning the scene to be recorded having its input axis perpendicular to its axis of rotation and arranged to reflect a continuously changing slit image to form a 360* radial image pattern of the scene to be recorded wherein the horizon of said scene is at the center of said radial pattern;

cylindrically curved transparent film gate means for supporting film sensitive to said slit image as a partial cylinder;

rotating optical means to orient the continuously changing slit image comprising the radial image pattern into parallelism with the longitudinal axis of said cylindrically curved film gate means and to direct said parallel slit images from said radial pattern onto said film supported by said film gate means; and

means to regulate the rotation rate of said optical means such that a full 360* radial image pattern is oriented and then recorded on a segment of said film supported by said cylindrically curved film gate means which segment is less than a full 360* cylinder.

49. A method of recording a panoramic scene, up to and including a full 360* scene on film comprising the steps of:

rotating a right-angle reflector to scan the scene to be recorded, said reflector having its input axis substantially perpendicular to its axis of rotation and arranged to reflect a continuously changing slit image for forming a radial image pattern of the scene;

disposing film sensitive to said slit image as a partial cylinder enclosing less than 360*;

orienting the continuously changing slit image which forms the radial image pattern as slit images which are parallel with the axis of curvature of said film and when rotate around said axis of curvature; and

directing said rotating parallel slit images on a segment of said cylindrically disposed film.