Zoom lens, projection display device, and imaging apparatus
AssigneeFUJIFILM Corporation
InventorKazuki INOUE
Life of this patent
Estimating the term…
Abstract
In the zoom lens, a first optical system is formed on the magnification side, and a second optical system is formed on the reduction side, with the intermediate image formed between the first optical system and the second optical system. The first optical system has a 5-group configuration, where the second to fourth lens groups move during zooming. In the first optical system, three or more negative lenses are disposed continuously in order from a position closest to the magnification side. The first optical system has a first cemented lens that is formed by cementing a negative lens and two positive lenses, of which Abbe numbers are larger than that of the negative lens, in order of positive, negative, and positive powers.
Claims17
A zoom lens that forms an intermediate image at a position conjugate to a reduction side imaging plane and causes the intermediate image to be re-imaged on a magnification side imaging plane, the zoom lens consisting of, in order from the magnification side:
- a first optical system;
- and
- a second optical system,
- wherein the intermediate image is positioned between the first optical system and the second optical system,
- wherein the first optical system consists of, in order from the magnification side, a first lens group that has a negative refractive power as a whole, a second lens group, a third lens group, a fourth lens group, and a fifth lens group, and the second lens group, the third lens group, and the fourth lens group move by changing spacings between the groups adjacent to each other in an optical axis direction during zooming,
- wherein the first optical system has three or more negative lenses continuously in order from a position closest to the magnification side,
- wherein the first optical system has a first cemented lens which is formed by cementing a positive lens, a negative lens, and a positive lens in order from the magnification side, and an Abbe number of each of the two positive lenses within the first cemented lens at the d line is larger than that of the negative lens within the first cemented lens, and
- wherein a second cemented lens, which is formed by cementing a negative lens and a positive lens and has a positive refractive power as a whole, is disposed to be closest to the magnification side of the second optical system.
Dependencies are inferred from the claim text.