Infrared Sensor With Segmented Absorber and Reflector Films
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional infrared sensors face challenges in minimizing size, achieving high sensitivity, and reducing production costs due to high thermal conductivity materials and complex shielding structures, which lead to measurement errors and increased costs.
Innovation Solution
An infrared sensor design utilizing an electrical insulating film sheet with a thermistor element and electrode layers on both surfaces, an infrared absorbing film opposite one temperature sensor, and an infrared reflector film opposite the other, allowing for a large temperature difference and high sensitivity while minimizing size and cost through reduced thermal interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a resin film containing infrared absorbing material (carbon black) is used to shield one side of the temperature sensor devices, then infrared absorption is enhanced, but thermal conductivity becomes high making it difficult to create temperature difference between sensor devices
Solution Approach 1:
The patent divides the film structure into multiple layers: an infrared absorbing film (with carbon black) and a heat insulating film (low thermal conductivity material). This segmentation allows the infrared absorbing film to capture infrared rays while the heat insulating film prevents heat diffusion, maintaining temperature differences between sensor devices.
Solution Approach 2:
The patent uses a composite film structure combining infrared absorbing material (carbon black) with heat insulating material in distinct layers. This composite approach enables simultaneous infrared absorption and thermal insulation, resolving the contradiction between infrared detection capability and temperature differential maintenance.
2Measurement precision
If the distance between temperature sensor devices is increased to create large temperature difference, then temperature measurement accuracy improves, but overall sensor size increases
Solution Approach 1:
The patent changes the thermal conductivity parameter of the film material by introducing a low thermal conductivity heat insulating film. This parameter change allows temperature differences to be maintained over shorter distances, enabling compact sensor design while preserving measurement accuracy.
3Temperature
If a frame body with good thermal conductivity is used, then temperature gradient between sensor devices is reduced, but heat radiation from infrared absorbing film increases reducing sensor sensitivity
Solution Approach 1:
The patent extracts the heat conduction function from the structural frame body and places it in a dedicated heat insulating film layer. This separation allows the frame to provide mechanical support while the film layer controls thermal behavior, preventing heat radiation to the shielded sensor device and maintaining sensitivity.
4Ease of manufacture
If radial leaded type thermistor with directly connected lead wires is used, then manufacturing is simplified, but narrow space between lead wires and thermistor device conducts heat undesirably
Solution Approach 1:
The patent introduces a heat insulating film as an intermediary barrier between the lead wires and the thermistor device. This intermediary prevents direct heat conduction through the narrow space, while the radial leaded type thermistor maintains manufacturing simplicity.
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 design enables high detection sensitivity and quick thermal response with a compact size and lower production costs by using a thin, low thermal conductivity film and reflective materials to manage heat conduction effectively.
Implementation Method 1
an infrared absorbing film which is provided on the other side of the electrical insulating film sheet, and is positioned opposite the first temperature sensor device across the electrical insulating film sheet
Implementation Method 2
an infrared reflector film which is provided on the other side of the electrical insulating film sheet, and is positioned opposite the second temperature sensor device across the electrical insulating film sheet
Implementation Method 3
an electrical insulating film sheet... a thin, low thermal conductivity film
Data Source
AI summary
An infrared sensor comprises: an electrical insulating film sheet; first and second temperature sensor devices which are provided on one side of the electrical insulating film sheet, and are located at a distance from each other; a pair of contact electrodes, with which the first and second temperature sensor devices are attached respectively, formed on one side of the electrical insulating film sheet; an infrared absorbing film provided on the other side of the electrical insulating film sheet opposite the first temperature sensor device; and an infrared reflector film provided on the same side as the infrared absorbing film opposite the second temperature sensor device. The first and second temperature sensor devices respectively comprise: a thermistor element; and a pair of electrode layers, in which one of them is in contact with the contact electrode, formed both on the upper and lower surfaces of the thermistor element.