| 摘要 |
PROBLEM TO BE SOLVED: To obtain a compact camera having observation field near to 180 deg. by one single lens by forming a film surface of cylindrical film. SOLUTION: A light beam from A-A on planes X and X is formed into an image on A'-A' on a circumference at the wide angle of visibilityθ1, so that the light beam from B-B in a direction along a Y-axis is formed into the image on B'-B' on a line at the angle of visibilityθ2. Namely, since the width of film (direction Y) is comparatively small, the angleθ2 is small and the curvature of image field in this direction is small and can be omitted, whereby influence exerted on image-formation characteristic is omitted even when B'-B' is on the line along the direction Y. Therefore, as for the shape of the film which can be realized, a spherical surface is made approximate to a narrow cylindrical surface, and the camera is formed is such structure that the cylindrical film 2 is set. Thus, the camera in which the film 2 is set on the cylindrical image-formation surface and which has such an ultra wide-angle that the entire angle of visibility is about 180 deg. by an image-formation optical system using a high-performance aspherical lens and is made light in weight and small in size can be realized.
|
