US 7,023,629 B2 · Projection lens unit

Abstract

A projection lens unit compensates for thermal expansion and contraction. The unit comprises a coupler at the front surface of a CRT, a lens unit body for projecting an image onto a screen by controlling and magnifying the light from the CRT, a plurality of legs secured to the coupler for supporting the lens unit body at more than three points, a slide mechanism (latch arms and latch engaging slots provided between the legs and the lens unit body for slidably supporting the legs for movement along the optical axis relative to the lens unit body, and expansion/contraction bars provided between the legs and the lens unit body for compensating for the thermally induced expansion/contraction, with one end engaged with a leg and the other end engaged with the base of the lens unit body.

Claims20

Dependent claims

A projection lens unit comprising:

a lens unit body, containing at least one lens, for projecting an image light along an optical axis, from a base end at a side of an image light source;
a plurality of legs for fixing the base end of said lens unit body to the side of the image light source, said legs being attached to the outer peripheral surface of the base end of the lens unit body and each leg defining a holding portion;
and
a plurality of expansion and contraction bars for compensating for thermally induced expansion and contraction, said expansion and contraction bars being housed within respective holding portions, between said legs and said lens unit body, each expansion and contraction bar having one end engaged with a tip end portion of a leg and another end, opposite said one end, engaged with the base end of the lens unit body.

1 more element

Dependencies are inferred from the claim text.

Projection lens unit

Life of this patent

Projection lens unit

Life of this patent

Abstract

Claims20