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US 6,208,470 B1Granted
Telecentric projection lens
AssigneeTexas Instruments Incorporated
InventorsDouglas W. Anderson, D. Scott Dewald
Life of this patent
Estimating the term…
Abstract
A projection lens (400) having a BFD:EFL, ratio in the range of 0.80:1 to 1.60:1, an air equivalent BFD of at least 4.3 inches, a throw ratio in the range of 3:1 to 6:1, and lateral color correction of one-quarter pixel when used with an SXGA modulator having pixels on 0.17 μm centers, and operating with its chief rays telecentric at the plane of the modulator. The projection lens comprises an objective lens group (402), a telecentric lens group (404), and an aperture stop (414) between the objective lens group and the telecentric lens group.
Claims5
A projection lens assembly comprising:
- an objective lens group, said objective group comprising:
- a first lens at an end of said objective lens group opposite said aperture
- stop, said first lens being a positive lens;
- and
- a second lens adjacent to said first lens, said second lens being a positive lens:
- a telecentric lens group;
- and
- an aperture stop between said objective lens group and said telecentric lens group, said projection lens having an object plane, a BFD:EFL ratio in the range of 0.80:1 to 1.60:1, an air equivalent BFD of at least 4.3 inches, a throw ratio in the range of 3:1 to 6:1, and operating with its chief rays telecentric at said object plane.
5 more elements
Dependencies are inferred from the claim text.