Infrared Imaging Element with Shared Read Circuits to Reduce Chip Area
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Solution Overview
Problem
The existing thermal infrared solid-state imaging elements have a large chip area and high manufacturing costs due to identical numbers of read circuits and pixel columns, which restricts the layout and increases costs.
Innovation Solution
The infrared imaging element design includes a pixel array unit with diodes as temperature detection pixels, connected by drive and signal lines, with a vertical scanning circuit and signal line selection circuit, where the number of read circuits is fewer than the number of signal lines, allowing for a reduced chip area and lower costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If identical numbers of read circuits and pixel columns are disposed, then each pixel column can be read independently, but the layout area occupied by read circuits increases and manufacturing cost increases
Solution Approach 1:
Multiple pixel columns share a single read circuit through time-division multiplexing. The read circuit sequentially reads signals from different pixel columns by switching between signal lines, allowing one read circuit to serve multiple columns and reducing the total number of read circuits required.
Solution Approach 2:
The system dynamically switches between different signal lines corresponding to different pixel columns during the reading process. By making the read circuit adaptable and capable of switching its connection target, the system achieves flexible reading of multiple columns with a single read circuit.
2Productivity
If identical numbers of read circuits and pixel columns are disposed, then signal reading can be performed for all columns, but the chip area increases
Solution Approach 1:
Multiple pixel columns share a single read circuit through time-division multiplexing. The read circuit sequentially reads signals from different pixel columns by switching between signal lines, allowing one read circuit to serve multiple columns and reducing the total number of read circuits required.
Solution Approach 2:
The system transitions from a spatial arrangement where each column has its own read circuit to a temporal arrangement where a single read circuit serves multiple columns through time-division multiplexing, effectively adding a time dimension to the reading process.
3Manufacturing precision
If identical numbers of read circuits and pixel columns are disposed, then complete pixel array coverage is achieved, but circuit configuration freedom is restricted
Solution Approach 1:
A single read circuit is designed to perform multiple functions by reading signals from different pixel columns through time-division multiplexing. The read circuit becomes a universal component that can handle any pixel column signal by switching between signal lines, increasing configuration flexibility.
Solution Approach 2:
The system dynamically switches between different signal lines corresponding to different pixel columns during the reading process. By making the read circuit adaptable and capable of switching its connection target, the system achieves flexible reading of multiple columns with a single read circuit.
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 shrinks the chip area, reduces manufacturing costs, and enhances the degree of freedom in circuit configuration, improving performance by enabling high-frame-rate reading and signal-to-noise ratio improvements through intermittent output and averaging.
Implementation Method 1
a plurality of temperature detection pixels 3 each of which includes a diode 1 and generates an electric signal in accordance with infrared rays received from an outside
Implementation Method 2
Outputs of the pixels are transmitted to an integrating circuit via the signal lines, after which the outputs are integrated and amplified by the integrating circuit
Data Source
AI summary
A thermal infrared imaging element includes: a pixel array unit (100) that includes a plurality of temperature detection pixels (3) each of which includes a diode (1) and generates an electric signal in accordance with infrared rays received from an outside, the temperature detection pixels being arrayed in a two-dimensional fashion in a row and column directions; a plurality of drive lines (12) that are provided in rows and that commonly connect one ends of the temperature detection pixels (3) in units of the rows; a plurality of signal lines (13) that are provided in columns and that commonly connect the other ends of the temperature detection pixels (3) in units of the columns; a vertical scanning circuit (4) that sequentially selects the drive lines; a signal line selection circuit (6) that sequentially selects the signal lines; and one or more read circuits (7) that amplify an electric signal from a temperature detection pixel connected to both one of the drive lines which is selected by the vertical scanning circuit and one of the signal lines which is selected by the signal line selection circuit. The number of the read circuits (7) is smaller than the number of the signal lines provided in the respective columns.