Title:
GAS ZOOM LENS APPARATUS
Document Type and Number:
Japanese Patent JPS63138312
Kind Code:
A
Abstract:
A gass zoom lens (10) of the double Gauss type which, at unity magnification, has cavities (22, 24) between the outer lens elements (A, F) filled with a gas under a first pressure and a central cavity (20) filled with the same gas at a second lower pressure. When the lens is moved to alternate magnification positions, its focal length is adjusted by changing the relative pressure, and hence the refractive index of the gas within the cavities, thereby adjusting the focal length of the lens for the particular magnification.
Inventors:
MAIKERU EDOWAADO HARIGAN
Application Number:
JP28720887A
Publication Date:
June 10, 1988
Filing Date:
November 13, 1987
Export Citation:
Assignee:
XEROX CORP
International Classes:
G02B7/10; G02B3/12; G02B3/14; G02B13/00; G02B15/00; (IPC1-7): G02B3/14; G02B7/10; G02B15/00
Domestic Patent References:
| JPS6078416A | 1985-05-04 | |||
| JPS56130710A | 1981-10-13 | |||
| JPS60181716A | 1985-09-17 |
Attorney, Agent or Firm:
Minoru Nakamura (4 outside)