Pixel Drive Control for Solid-State Imaging Dynamic Range
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Solution Overview
Problem
Conventional solid-state imaging devices face challenges in expanding dynamic range for objects moving at high speeds or with large luminance differences, leading to potential signal saturation and increased motion artifacts, especially when exposure time control is performed in units of rows rather than pixels.
Innovation Solution
A solid-state imaging device with a pixel drive control unit that individually controls exposure timing, including start, end, and reset timings, and the number of exposure periods for each pixel, allowing for precise control of exposure periods at equal intervals, and switching control timing tables based on user operations or predetermined intervals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If exposure time is shortened to expand dynamic range for high-speed moving objects, then motion distortion is reduced, but signal saturation occurs in high illuminance regions and dynamic range expansion is insufficient
Solution Approach 1:
The imaging device divides the pixel array into multiple regions (first region and second region) with different exposure time settings. The first region uses a first exposure time while the second region uses a second exposure time, allowing simultaneous capture of both high-speed moving objects and high illuminance objects without signal saturation in either region.
Solution Approach 2:
Different regions of the pixel array are assigned different exposure time characteristics tailored to their specific imaging needs. The first region is optimized for high-speed moving objects with shorter exposure time, while the second region is optimized for high illuminance objects with longer exposure time, achieving local optimization of image quality.
2Device complexity
If exposure control is performed in units of rows, then device complexity is reduced, but high dynamic range cannot be obtained in entire region and motion artifacts increase
Solution Approach 1:
The pixel array is segmented into multiple independent regions that can be controlled separately. Each region can have its own exposure time settings, allowing the first region to capture high-speed moving objects while the second region captures high illuminance objects, achieving high dynamic range across the entire image sensor.
3Device complexity
If all short exposure times are time-shared, then device complexity is reduced, but motion artifacts occur in high illuminance objects and unexposed periods cannot capture moving objects
Solution Approach 1:
The imaging device simultaneously performs short exposure imaging in the first region and long exposure imaging in the second region, eliminating the need for time-sharing. This allows continuous capture of both high-speed moving objects and high illuminance objects without motion artifacts or unexposed periods.
Solution Approach 2:
Both short exposure and long exposure imaging operations are performed continuously and simultaneously in different regions, ensuring that no useful imaging action is interrupted or delayed, thereby capturing all moving objects without motion artifacts.
4Reliability
If multiple short exposure images are generated in accumulation period, then dynamic range is expanded, but memory storage requirements increase
Solution Approach 1:
The imaging device captures images with different exposure times in different regions simultaneously, generating one image per region per accumulation period instead of multiple images per region. This reduces the number of images requiring storage while maintaining dynamic range expansion through regional exposure differentiation.
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 approach effectively expands the dynamic range, reduces motion distortion, and prevents unexposed periods, enabling reliable capture of objects with high illuminance while minimizing memory storage increases.
Implementation Method 1
a pixel array unit (22) including a plurality of pixels (21)
Data Source
AI summary
The present disclosure relates to a solid-state imaging device and a method of controlling a solid-state imaging device, and an electronic device for enabling appropriate expansion of a dynamic range with respect to an object moving at a high speed or an object having a large luminance difference between bright and dark to reduce motion distortion (motion artifact). Exposure of a plurality of pixels is individually controlled in units of pixels. The present disclosure can be applied to a solid-state imaging device.