Resin Lens Optical System with Concave Reflection Surface

Solution Overview

Problem

Existing optical systems face challenges with temperature-induced changes in optical properties and manufacturing costs, particularly when using resin lenses, which can expand or melt due to high optical density regions, and glass lenses are heavy and costly.

Innovation Solution

An optical system with a resin lens having a first transmission surface, a concave reflection surface, and a second transmission surface, where the conditional expression 10≤q×Fno/f2≤2989 is satisfied, allowing for the use of resin lenses that suppress expansion and melting while reducing weight and manufacturing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an optical element made of glass is used, then heat resistance and suppression of optical property changes are improved, but weight and manufacturing cost increase

Engineering Contradiction:

Improveheat resistanceVSAvoidweight

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The patent applies parameter changes by controlling the amount of light q and optical system parameters (Fno, f) to satisfy the conditional expression 10≤q×Fno/f2≤2989. This parameter control allows resin lenses to operate within safe thermal limits, preventing expansion and melting while maintaining optical performance. The principle transforms the material selection problem from a binary glass-or-resin choice to a controlled parameter optimization problem.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses resin as a composite material alternative to traditional glass optical elements. By combining resin material with controlled optical system parameters, the invention achieves both the lightweight benefit of resin and the thermal stability traditionally associated with glass, effectively creating a composite solution that merges advantages of both materials.

Inventive Principle:

Principle #40Composite materials

2Reliability

If an optical element made of glass is used, then heat resistance and suppression of optical property changes are improved, but manufacturing cost increases

Engineering Contradiction:

Improveheat resistanceVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies parameter changes by controlling the amount of light q and optical system parameters (Fno, f) to satisfy the conditional expression 10≤q×Fno/f2≤2989. This parameter control allows resin lenses to operate within safe thermal limits, preventing expansion and melting while maintaining optical performance. The principle transforms the material selection problem from a binary glass-or-resin choice to a controlled parameter optimization problem.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses resin as a composite material alternative to traditional glass optical elements. By combining resin material with controlled optical system parameters, the invention achieves both the lightweight benefit of resin and the thermal stability traditionally associated with glass, effectively creating a composite solution that merges advantages of both materials.

Inventive Principle:

Principle #40Composite materials

3Ease of operation

If a concave reflection surface is used in a resin lens, then light deflection and optical path control are improved, but temperature rise and optical property changes occur

Engineering Contradiction:

Improveoptical path controlVSAvoidtemperature rise

Core Design Contradiction:

Ease of operationVSTemperature

Solution Approach 1:

The patent applies parameter changes by controlling the amount of light q and optical system parameters (Fno, f) to satisfy the conditional expression 10≤q×Fno/f2≤2989. This parameter control allows resin lenses to operate within safe thermal limits, preventing expansion and melting while maintaining optical performance. The principle transforms the material selection problem from a binary glass-or-resin choice to a controlled parameter optimization problem.

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The optical system effectively suppresses changes in optical properties and reduces manufacturing costs by using resin lenses, achieving high magnification and resolution while maintaining optical density within the specified range.

Implementation Method 1

the reflection surface has a concave shape. Beams having entered the optical element via the light incident surface are deflected back by the reflection surface

Methodology Applied

Scientific EffectReflection: Reflection

Implementation Method 2

A high optical density region is therefore formed in the optical element. When a high optical density region is formed in the optical element, the temperature in the region rises

Methodology Applied

Scientific EffectOptical absorption heating: Absorption (EM radiation)

Data Source

PatentUS11537031B2Optical system, projector, and imaging apparatus

Publication Date: 2022.12.27 SEIKO EPSON CORP

AI summary

An optical system includes a lens having a first transmission surface, a reflection surface disposed on an enlargement side of the first transmission surface, and a second transmission surface disposed on the enlargement side of the reflection surface. The lens is made of resin. The reflection surface has a concave shape. A conditional expression below is satisfied,10≤q×Fno/f2≤2989where Fno is an F-number of the optical system, f is a focal length of the optical system, and q is an amount of light in an enlargement-side conjugate plane.