Thermal Lens Set Defogging via Segmented Heater and Sensor Isolation

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Solution Overview

Problem

Optical imaging lenses face challenges with fogging and frosting due to temperature changes and moisture condensation, leading to reduced image clarity, and existing defogging or defrosting solutions using sensing chips can be inaccurate and damaging.

Innovation Solution

A thermal lens set with a heater and a lens barrel that includes a non-thermal zone and a thermal zone with a heating element, where the heating element is in direct contact with the outer lens group to create a temperature difference that effectively removes moisture, and a sensing chip is used to control the heating process, ensuring the sensor is protected from thermal influence.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a sensing chip (NTC or PTC) is set on the heating element or in an exposed environment for defogging or defrosting, then the defogging function is provided, but the sensing accuracy becomes inaccurate and the NTC may be damaged

Engineering Contradiction:

Improvedefogging functionVSAvoidsensing accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The heating element is divided into two distinct portions: a thermal zone that directly contacts the lens group for heating, and a non-thermal zone that houses the sensing chip away from thermal influence. This segmentation allows the sensing chip to accurately detect temperature without being exposed to excessive heat that would cause damage or inaccurate readings.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The conductive element serves as an intermediary that thermally connects the heating element to the lens group while electrically connecting the sensing chip to the power supply source, while isolating the sensing chip from direct thermal exposure. This intermediary structure enables temperature sensing without subjecting the sensor to damaging thermal conditions.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If the heating element is placed in direct contact with the lens group for effective heating, then the defogging efficiency is improved, but the risk of thermal damage to the lens increases

Engineering Contradiction:

Improvedefogging efficiencyVSAvoidthermal damage risk

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The heating element is designed with localized heating zones that concentrate thermal energy precisely where needed on the lens group surface, rather than uniformly heating the entire lens assembly. This localized approach improves defogging efficiency while minimizing overall thermal exposure and potential damage risk.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The heating element operates in periodic cycles controlled by the sensing chip, alternating between heating phases and cooling phases. This periodic operation prevents continuous thermal exposure that could cause lens damage while maintaining effective defogging during active heating periods.

Inventive Principle:

Principle #19Periodic action

3Stability of the object's composition

If multiple glass lenses are used to reduce temperature effects on lens shape, then the imaging stability is improved, but the manufacturing cost and weight increase

Engineering Contradiction:

Improveimaging stabilityVSAvoidmanufacturing cost

Core Design Contradiction:

Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The patent changes the material parameter of the lens from glass to plastic, and compensates for plastic's higher temperature sensitivity by introducing active thermal control through the heating element. This parameter change allows use of cheaper plastic materials while maintaining imaging stability through active temperature management rather than relying solely on passive glass material properties.

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 thermal lens set effectively removes moisture from the lens surface, maintaining image clarity by creating a significant temperature difference between the thermal and non-thermal zones, thereby preventing fogging and frosting, and ensuring the sensor's accuracy and longevity.

Implementation Method 1

a heating element is arranged between at least one optical lens and the lens barrel

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Implementation Method 2

the heating element is in direct contact with the outer lens group to create a temperature difference

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

a sealing element is arranged between the heating element and the lens barrel

Methodology Applied

Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentUS20240361499A1Thermal lens set, use of thermal lens set and method to remove mist from lens set

Publication Date: 2024.10.31 ETERGE OPTO ELECTRONICS CO LTD

AI summary

A thermal lens set includes an imaging lens group including an inner lens group and an outer lens group. The outer lens group includes at least one outer lens element. A heater is used to heat the imaging lens group and includes at least two portions. One of the at least two portions is in direct contact with the imaging lens group. A lens barrel is used to accommodate another one of the at least two portions.