Projector comprising an expanding and contracting member having a temperature coefficient that counters the increase and decrease of a focal distance of a projection lens caused by temperature changes
First Claim
1. A projector comprising:
- a display device which modulates illumination light;
a projection lens which projects modulation light produced by the display device;
a holding device which has a holder member supporting the display device;
a frame member supporting the projection lens and functions as a base capable of supporting the holder member; and
an expanding and contracting member disposed between the frame member and the display device, the expanding and contracting member being configured to move the display device relative to the projection lens, whereina temperature coefficient for an expansion and contraction of the expanding and contracting member in a direction of an optical axis of the projection lens corresponds to a temperature coefficient for an increase and decrease of a focal distance of the projection lens such that the increase and decrease of the focal distance of the projection lens caused by temperature changes is countered by the expansion and contraction of the expanding and contracting member.
1 Assignment
0 Petitions
Accused Products
Abstract
A projector includes: a display device which modulates illumination light; a projection lens which projects modulation light produced by the display device; and a holding device which has a holder member supporting the display device, a frame member supporting the projection lens and functions as a base capable of supporting the holder member, and an expanding and contracting member disposed between the frame member and the display device, wherein a temperature coefficient for the expansion and contraction of the expanding and contracting member in the direction of the optical axis of the projection lens corresponds to a temperature coefficient for the increase and decrease of the focal distance of the projection lens.
12 Citations
11 Claims
-
1. A projector comprising:
-
a display device which modulates illumination light; a projection lens which projects modulation light produced by the display device; a holding device which has a holder member supporting the display device; a frame member supporting the projection lens and functions as a base capable of supporting the holder member; and an expanding and contracting member disposed between the frame member and the display device, the expanding and contracting member being configured to move the display device relative to the projection lens, wherein a temperature coefficient for an expansion and contraction of the expanding and contracting member in a direction of an optical axis of the projection lens corresponds to a temperature coefficient for an increase and decrease of a focal distance of the projection lens such that the increase and decrease of the focal distance of the projection lens caused by temperature changes is countered by the expansion and contraction of the expanding and contracting member. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
Specification