Back to results
US 4,281,908 AGranted
Tesser type objective lens system having a rear aperture stop
AssigneeMinolta Camera Kabushiki Kaisha
InventorTamikazu Yamaguchi
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeMinolta Camera Kabushiki Kaisha
InventorTamikazu Yamaguchi
Estimating the term…
An improved tesser type objective lens system having a rear aperture stop with a relatively wide field angle of about 60.degree. and an F-number of about F 2.8 is provided. The thickness of the second negative lens in the lens system is increased relative to the total axial distance of the lens system which permits the reduction of the Petzval sum while maintaining a balance correction of spherical aberration and coma.
An improved tesser type objective lens system having a rear aperture stop comprising:
An improved tesser lens system comprising the following design parameters:
An improved tesser lens system comprising the following design parameters:
An improved tesser lens system comprising the following design parameters:
An improved tesser type objective lens system having a field angle of about 60.degree. and a rear aperture stop comprising:
An improved tesser type objective lens system having a field angle of approximately 60.degree. and a rear aperture stop comprising from object to image side:
Dependencies are inferred from the claim text.
No related US applications are recorded in the indexed filing history.
Term ended 4 Apr 1999 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
1. Field of the Invention
The present invention relates to a tesser type lens system having an aperture stop located at the rear of the lens system and more particularly to a lens system of this type having a relatively wide field angle of about 60.degree. and an F-number of about F. 2.8.
2. Description of the Prior Art
FIG. 1 represents a cross sectional view of a first embodiment of the present invention;
FIGS. 2a, 2b, 2c and 2e represent graphic plots of various aberrations of the first embodiment;
FIG. 3 represents a cross sectional view of a second embodiment of the present invention;
The following description is provided to enable any person skilled in the optical art to make and use the invention and sets forth the best mode contemplated by the inventor for carrying out his invention. Various modifications however, will remain readily apparent to those skilled in the art, since the generic principles of the present invention have been defined herein specifically to provide an improved tesser type objective lens system having a rear aperture stop with favorable corrections of various higher order aberrations.
The derivation of the formulae and the relation set forth herein can be accomplished with the assistance of a computer. The present invention represents the parameters of a compromise balance of acceptable aberrations in a relatively easily manufactured and economical lens system for utilization, for example, with a camera.
Various examples of the present invention will hereinafter be described with reference to tabulated physical and optical characteristics in various Tables. The parameters of the lens elements of the present invention are listed in separate embodiments corresponding to the Figures which are illustrated diagrammatically. As usual, in conventional lens diagrams, the light is assumed to travel from left to right. The lenses are disclosed as assembled into three separate optical units. Both in the diagrams and in the Tables the radii of curvature of the lenses are indicated by R, with a subscript corresponding to the consecutive number of the lens element surfaces from object to image side.