Pixel Array Select Transistor Bulk Charge Readout
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing imaging devices face challenges in efficiently capturing images and determining distances due to limitations in pixel array design, power consumption, and readout speed, particularly in handling small pixel currents and achieving high-speed temporal and spatial oversampling.
Innovation Solution
The implementation of a pixel array with photodiodes, select transistors, and reset transistors that generate pixel currents based on light detection, combined with a column readout circuit featuring a current source and current mirror for bias current generation, and intermediate memory cells for high-speed readout and post-processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional pixel arrays are used, then image capture is achieved, but power consumption is high and readout speed is limited
Solution Approach 1:
The pixel array is divided into multiple chains, with each chain containing intermediate memory cells that store readout data temporarily. This segmentation allows parallel readout operations across different chains, increasing readout speed while reducing the burden on individual readout circuits, thereby lowering power consumption.
Solution Approach 2:
Intermediate memory cells are used to pre-store readout data before final processing. This preliminary storage enables high-speed readout by decoupling the readout process from the final data processing, allowing the pixel array to operate at higher speeds without proportionally increasing power consumption.
2Productivity
If high readout speed is achieved, then temporal and spatial oversampling is enabled, but device complexity increases
Solution Approach 1:
Multiple intermediate memory cells are combined into chains that can be read out in parallel. This merging approach enables high-speed readout through temporal and spatial oversampling while distributing the complexity across multiple simpler, parallel units rather than requiring a single complex readout system.
Solution Approach 2:
Intermediate memory cells act as mediators between the pixel array and the final output processing. These intermediary storage elements enable high-speed readout by buffering data temporarily, allowing the main processing system to operate at lower complexity levels while still achieving high readout speeds through the intermediary chains.
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 solution enables efficient image capture and ranging by allowing for the reading of small pixel currents with reduced power consumption and facilitates high-speed readout, enhancing temporal and spatial oversampling capabilities.
Implementation Method 1
a photodiode that can generate charges
Data Source
AI summary
In some embodiments, an imaging device includes a pixel array. At least one of the pixels includes a photodiode that can generate charges, and a select transistor that receives the charges in its bulk. When the select transistor is selected, a pixel current through it may depend on a number of the received charges, thus evidencing how much light it detected. A reset transistor may reset the voltage of the bulk.