Thermopile Sensor Field of View Narrowing via Integrated Light Blocker
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Thermopile sensors in mobile devices face challenges in accurately measuring temperature due to limited sensor-to-aperture distance, which reduces measurement accuracy and requires narrowing the field of view to prevent interference from nearby objects, but existing methods either reduce light power or do not sufficiently limit the field of view.
Innovation Solution
An integrated light blocking layer with an aperture is placed on the thermopile membrane, combined with a lens in the package lid to direct light, effectively maximizing the field of view and allowing only specific light to reach the thermopile, while maintaining thermal conductivity and light power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the sensor-to-aperture distance is limited in mobile devices, then the device size is reduced, but the temperature measurement accuracy deteriorates
Solution Approach 1:
The patent introduces a light blocking layer with an aperture positioned above the thermopile membrane, creating a new spatial dimension for field of view control. This vertical layering approach allows FOV narrowing without increasing the horizontal device footprint, thus maintaining compact size while improving measurement accuracy by blocking stray light from nearby objects.
Solution Approach 2:
The light blocking layer acts as an intermediary element between the aperture and the thermopile sensor. It selectively blocks unwanted light paths while allowing desired light to reach the sensor, thereby improving temperature measurement accuracy without requiring a larger sensor-to-aperture distance.
2Measurement precision
If the field of view is narrowed to prevent interference from nearby objects, then the temperature measurement accuracy is improved, but the light power reaching the thermopile is reduced
Solution Approach 1:
The light blocking layer features a selectively positioned aperture that provides different optical properties in different regions. The aperture is strategically located to block light paths from nearby objects while maintaining an open path for light from the target object, thus achieving FOV narrowing without proportionally reducing the light power reaching the thermopile.
Solution Approach 2:
The patent optimizes the aperture size, shape, and position parameters of the light blocking layer to achieve the desired field of view narrowing while maximizing light transmission. By carefully adjusting these geometric parameters, the system achieves accurate temperature measurement with sufficient light power for the thermopile to generate adequate output voltage.
3Reliability
If an existing light blocking method is used, then the field of view can be limited, but the light power reaching the sensor is significantly reduced or the field of view is not sufficiently narrowed
Solution Approach 1:
The optical path control is segmented into multiple functional elements: the package lid aperture, the light blocking layer with its specific aperture, and the thermopile membrane. This segmentation allows each element to contribute to field of view control in a coordinated manner, achieving sufficient FOV narrowing while preserving adequate light power through the integrated structure.
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
This configuration enhances temperature measurement accuracy by effectively narrowing the field of view and maximizing light power incident on the thermopile, improving the accuracy of temperature measurements in mobile devices.
Implementation Method 1
a lens configured to direct light to the thermopile device
Implementation Method 2
A thermopile can include an electronic device that converts thermal energy into electrical energy. It is composed of several thermocouples often connected in series or in parallel.
Implementation Method 3
Thermopiles do not respond to absolute temperature, but generate an output voltage proportional to a local temperature difference or a temperature gradient.
Implementation Method 4
a light blocking layer disposed proximate to the thermopile membrane, the light blocking layer including an aperture disposed proximate to the thermopile
Data Source
AI summary
A sensor device, a sensor package, and method for fabricating a sensor device are described that include an integrated light blocker disposed on the thermopile device and a lens configured to direct light to the thermopile device. In an implementation, the thermopile device includes a substrate; a thermopile membrane disposed on the substrate, the thermopile membrane including at least one passivation layer; a thermopile disposed within the thermopile membrane, the thermopile including at least one thermocouple; and a light blocking layer disposed proximate to the thermopile membrane, the light blocking layer including an aperture disposed proximate to the thermopile.