Non-telecentric projection lens design for an LED projector

Area of Science:

• Optical Engineering
• Miniature Projection Systems

Background:

• Mini-projectors with LED light sources require compact, high-performance projection lenses.
• Existing lens designs may face limitations in zoom ratio, image quality, or cost for business applications.

Purpose of the Study:

• To design and evaluate a novel non-telecentric projection zoom lens for LED mini-projectors.
• To achieve a high zoom ratio, excellent image quality, and low distortion at a competitive cost.

Main Methods:

• A six-element spherical lens design for a non-telecentric projection zoom lens.
• Analysis of optical performance including zoom ratio, F-number, throw ratio, spot size, distortion, and modulation transfer function (MTF).

Main Results:

• Achieved a zoom ratio of 1.1 with a working F/# of 2.4 and throw ratio of 1.23.
• Maintained RMS spot sizes below 15 μm and suppressed optical/TV distortion to <1.5% and <1%, respectively.
• Demonstrated high image quality with MTF values >0.4 at 46 lp/mm, even under tolerance errors (MTF >0.3).

Conclusions:

• The newly designed non-telecentric projection zoom lens delivers sharp images and excellent optical performance.
• The lens's low cost and suitability for business applications make it a viable solution for mini-projectors.