Infrared Sensor Floating Supporter Phononic Crystal Leakage
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Solution Overview
Problem
Infrared sensors face challenges in maintaining high signal-to-noise ratio (S/N) due to reduced power of received infrared light and difficulty in obtaining spatial temperature differences, especially with miniaturized light receivers, leading to leakage issues with semiconductor switches and inaccurate detection signals.
Innovation Solution
The infrared sensor employs a floating supporter with a phononic crystal structure to maintain a temperature difference and uses current-input amplifiers with semiconductor switches to short-circuit thermoelectric converters, reducing leakage and enhancing detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the area of light receiver is reduced to miniaturize the infrared sensor, then the device size is reduced, but the power of received infrared light becomes very weak and S/N ratio decreases
Solution Approach 1:
The infrared sensor is divided into multiple pixels (e.g., 256x256 array) that can be scanned sequentially by a single AFE, reducing the need for each individual light receiver to be large while maintaining overall detection capability through time-multiplexed reading of multiple smaller pixels
Solution Approach 2:
The system uses dynamic pixel selection switching to activate only one pixel at a time for reading by the AFE, allowing miniaturized light receivers to achieve sufficient signal strength through temporal concentration of detection resources rather than spatial enlargement
2Device complexity
If semiconductor switches are used to connect sensor elements to AFE, then integration is improved, but leakage current occurs and detection accuracy deteriorates
Solution Approach 1:
The patent applies preliminary anti-action by using current-input amplifiers that are inherently less sensitive to leakage currents from semiconductor switches, and by designing the switch timing and connection architecture to minimize the impact of leakage on the detection signal, thereby counteracting the harmful leakage effect before it degrades measurement precision
3Device complexity
If one AFE is shared by multiple infrared sensor elements, then device complexity is reduced, but pixel selection switching is required which increases control complexity
Solution Approach 1:
The system implements periodic scanning of pixels through time-multiplexed switching, where each pixel is sequentially connected to the shared AFE in a systematic pattern (e.g., row-by-row or block-by-block scanning), converting the complexity of multiple simultaneous connections into a simpler periodic switching sequence that is easier to control and synchronize
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 improves infrared detection accuracy by effectively canceling offset components and 1/f noise, enabling high-accuracy and high-speed detection operations.
Implementation Method 1
a phononic crystal structure is provided in the floating supporter
Implementation Method 2
high heat insulating properties
Implementation Method 3
an electromotive voltage based on a temperature difference as an infrared detection signal
Implementation Method 4
receives the infrared light
Data Source
Figure 1A~1C
Figure 1D~1F
Figure 2~3A
AI summary
An infrared sensor (201) includes a substrate, an infrared sensor element (10) that generates an infrared detection signal, a parallel switch (SW2) connected to the infrared sensor element (10), and an amplifier (112) that amplifies the infrared detection signal generated by the infrared sensor element (10). The infrared sensor element (10) includes a light receiver, a floating supporter that supports the light receiver in a floating manner so that a gap is formed between the substrate and the light receiver, and a thermoelectric converter that generates the infrared detection signal based on heat generated by the light receiver. The thermoelectric converter includes a first terminal (T1) that outputs the infrared detection signal, and a second terminal (T2) that is maintained at a predetermined potential. The parallel switch (SW2) connects the first terminal (T1) and the second terminal (T2) so that the parallel switch (SW2) is capable of short-circuiting the first terminal (T1) and the second terminal (T2). The amplifier (112) is a current-input amplifier.