Patent ID: 7830604
Filing Date: 2010-11-09
Classification: G02B

Abstract:
1. A projection lens configured to project a light flux from an object onto a projection surface, comprising: a negative lens unit having a negative optical power; and a correction mechanism configured to tilt the negative lens unit with respect to an optical axis of the projection lens such that a field tilt is generated in a direction opposite to a direction of a field curvature generated at the projection surface, wherein the projection lens projects the light flux from the object located at one side in a direction orthogonal to the optical axis onto the projection surface located at another side in that direction, and wherein the correction mechanism tilts the negative lens unit in a direction in which a part of an image plane formed by the projection lens approaches a plane orthogonal to the optical axis, the part of the image plane being a part where an amount of the field curvature is largest when the negative lens unit is not tilted with respect to the optical axis.