Image Sensor Pixel Group Control for Dynamic Range Readout
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Solution Overview
Problem
In imaging units with backside irradiating type imaging chips, the accumulation period and readout of pixel signals cannot be finely controlled on a cell-by-cell basis due to the grouping of two-dimensionally adjacent pixels, limiting the control over electrical charge accumulation and signal readout for different cells.
Innovation Solution
An imaging element comprising a plurality of pixel groups with a control unit to manage the accumulation period and a readout unit for each group, allowing independent control and readout of pixel signals, enabling tailored accumulation periods for different image information and improved dynamic range management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If pixels are grouped into cells for readout control, then the readout structure is simplified, but the control precision of charge accumulation period deteriorates
Solution Approach 1:
The imaging device divides the pixel array into multiple independently controllable regions (first region and second region), allowing separate control of charge accumulation periods for each region. This segmentation enables precise control while maintaining simplified readout through regional grouping.
Solution Approach 2:
The invention implements dynamic control where the charge accumulation period can be independently adjusted for different regions based on imaging requirements. The control unit can set different accumulation times for the first and second regions, enabling adaptive control precision without fixed cellular constraints.
2Device complexity
If a single accumulation period is used for all pixels, then the control system is simplified, but the adaptability to different image information deteriorates
Solution Approach 1:
The control system is segmented into region-specific control units that can independently manage charge accumulation for the first and second regions. This allows the system to maintain relative simplicity while gaining the adaptability to apply different accumulation periods to different regions based on their specific imaging requirements.
Solution Approach 2:
Different regions of the pixel array are assigned different charge accumulation periods according to their specific imaging needs. The first region may use a longer accumulation period for low-light conditions while the second region uses a shorter period for bright conditions, optimizing image quality locally without requiring complete system redesign.
3Ease of operation
If cell-by-cell control is implemented, then regional control is enabled, but the ability to control individual pixels or sub-regions within cells is lost
Solution Approach 1:
The invention implements a hierarchical segmentation strategy where the pixel array is divided into regions that can be further subdivided into pixel groups. This allows control at multiple levels: regional control for broad adjustments and pixel-group control for fine-tuned adjustments, providing both ease of operation and control granularity.
Solution Approach 2:
The control structure adds a dimensional layer by organizing pixels into groups within regions. This creates a multi-level control hierarchy where control can be applied at the region level for coarse adjustments and at the pixel-group level for fine adjustments, effectively adding a control dimension without increasing operational complexity.
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 allows for precise control of electrical charge accumulation and readout for each pixel group, enhancing image quality by differentiating accumulation periods based on image information and independently reading pixel signals, thus widening the dynamic range and improving image fidelity.
Implementation Method 1
a plurality of pixel groups including a plurality of pixels which output pixel signals according to incident light
Data Source
AI summary
An imaging element includes: an imaging unit in which a plurality of pixel groups including a plurality of pixels that output pixel signals according to incident light are formed, and on which incident light corresponding to mutually different pieces of image information is incident; a control unit that controls, for each of the pixel groups, a period of accumulating in the plurality of pixels included in the pixel group; and a readout unit that is provided to each of the pixel groups, and reads out the pixel signals from the plurality of pixels included in the pixel group.