Wide angle scan camera

• US 4,157,218 A
• Filed: 04/14/1977
• Issued: 06/05/1979
• Est. Priority Date: 04/14/1977
• Status: Expired due to Term

• Current Assignee: Perkinelmer Incorporated
• Original Assignee: Perkinelmer Incorporated
• Inventors: Boyan, Gerard E., Gordon, Robert
• Primary Examiner(s): Griffin, Donald A.
• Application Number:
  US05/787,530
• Time in Patent Office: 782 Days
• Field of Search: 355/1, 352/69, 354/65-69, 354/94-96, 354/71, 354/99
• US Class Current: 396/8
• CPC Class Codes: G03B 37/00 Panoramic or wide-screen photography; Photographing extended surfaces, e.g. for surveying; Photographing internal surfaces, e.g. of pipe

Abstract

A wide angle strip camera system which, in combination, includes a wide angle lens, having a curved conjugate focal surface, an image-receiving surface, a curved exposure slit disposed adjacent the image-receiving surface; the lens, image-receiving surface and exposure slit being so mounted that a semicircular strip at a constant preselected field angle in an object field is focused on the image-receiving surface. The system is fixedly supported in a vehicle, such as an aircraft, whereby the forward velocity of the vehicle provides image motion. The exposure slit is curved to correspond to field points of equal range so that there is negligible differential image motion within the slit, the slit being of such width in the direction of vehicle motion to result in uniform exposure; and the image-receiving surface is driven in the direction of vehicle movement at a speed corresponding to the altitude-velocity ratio of the vehicle with respect to the object field.

In a preferred form of the invention, the wide angle lens is a globe lens.

Claims

1. A wide angle strip camera system which, in combination, comprises:

globe lens means;

an image-receiving surface;

curved exposure slit means disposed adjacent said image-receiving surface;

said lens means, image-receiving surface and exposure slit means being so mounted that a curved strip at a constant preselected field angle in an object field is focused on the image-receiving surface;

said system being fixedly supported in a vehicle whereby the forward velocity of the vehicle provides image motion;

said exposure slit means being curved to correspond to field points of equal range so that there is substantially no differential image motion within the slit;

means for moving said image-receiving surface in the direction of vehicle movement at a speed corresponding to the altitude-velocity ratio of the vehicle with respect to the object field; and

said vehicle being an aerial reconnaissance aircraft and said globe lens per se being an interface between the aircraft and the external environment.

2. A wide angle strip camera system which, in combination, comprises:

globe lens means;

an image-receiving surface;

curved exposure slit means disposed adjacent said image-receiving surface;

said lens means, image-receiving surface and exposure slit means being so mounted that a curved strip at a constant preselected field angle in an object field is focused on the image-receiving surface;

said system being fixedly supported in a vehicle whereby the forward velocity of the vehicle provides image motion;

said exposure slit means being curved to correspond to field points of equal range so that there is substantially no differential image motion within the slit;

means for moving said image-receiving surface in the direction of vehicle movement at a speed corresponding to the altitude-velocity ratio of the vehicle with respect to the object field;

said image-receiving surface being curved to substantially closely match the contour of the spherical focal surface of said globe lens; and

air bar means for curving said image-receiving surface.

3. A dual-field globe lens strip camera system which, in combination, comprises:

globe lens means;

a first image-receiving surface;

semicircular exposure slit means disposed adjacent said first image-receiving surface;

said lens means, first image-receiving surface and exposure slit means being so mounted that a semicircular strip at a constant preselected field angle in an object field is focused on the first image-receiving surface;

said globe lens means having a curved second conjugate focal surface;

fold flat means being interposed between said globe lens means and said curved second conjugate focal surface;

a substantially flat second image-receiving surface;

an optical fiber bundle interposed between said curved conjugate focal surface and said flat image receiving surface;

said lens means, fold flat means, second image-receiving surface and optical fiber bundle being so mounted that a strip in the object field is focused on the second image-receiving surface;

said system being fixedly supported in a vehicle whereby the forward velocity of the vehicle provides image motion;

said exposure slit means being curved to correspond to field points of equal range so that there is substantially no differential image motion within the slit;

the elements in said optical fiber bundle being arranged to compensate on the second image-receiving surface for differential image motion corresponding to field points on said strip in the object field; and

means for moving said image-receiving surfaces in the direction of vehicle movement at speeds corresponding to the altitude-velocity ratio of the vehicle with respect to the object field.