Image Sensor Column Line Switching for Vertical Stripe Suppression
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Solution Overview
Problem
Existing image sensors are prone to vertical stripes in images due to signal corruption from column amplifiers, which can be noticeable and affect image quality, especially with a high number of pixels and frame rates.
Innovation Solution
The image sensor is designed with a switching mechanism that allows column lines to be connected to multiple column amplifiers, with a control device managing the switching to distribute signal disturbances across multiple columns, effectively scrambling or blurring vertical brightness disturbances and potentially bypassing defective amplifiers, while maintaining a simple structure with fewer column amplifiers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single column amplifier is assigned to each column line, then the structure is simple and the number of column amplifiers is minimized, but vertical stripes become visible in the image due to signal corruption from defective amplifiers
Solution Approach 1:
Each column amplifier is designed to handle multiple column lines (e.g., 4-8 lines), transforming a single-function amplifier into a multi-functional component. This reduces the total number of amplifiers needed while providing redundancy - if one amplifier fails, its column lines can be reassigned to other amplifiers, preventing visible vertical stripes in the image.
Solution Approach 2:
The patent changes the assignment parameter from one-to-one (one amplifier per column line) to one-to-many (one amplifier serving multiple column lines). This parameter change allows the system to tolerate amplifier failures and redistributes the signal paths, eliminating the vertical stripe artifact while maintaining structural simplicity.
2Quantity of substance
If column amplifiers are assigned to multiple column lines, then the number of column amplifiers can be reduced, but the switching control complexity increases
Solution Approach 1:
The patent segments the column lines into groups that are assigned to different amplifiers. Each amplifier serves a specific segment of column lines, and the switching device selectively connects these segments. This segmentation reduces the total number of amplifiers needed while organizing the switching control into manageable segments rather than requiring complete reconfiguration of all amplifiers.
Solution Approach 2:
The switching assignments are predetermined and configured in advance during system initialization or manufacturing. The control device stores pre-calculated assignment patterns that map column lines to amplifiers, eliminating the need for real-time complex decision-making. This preliminary configuration simplifies the runtime control complexity while maintaining the ability to redistribute signals dynamically.
3Reliability
If overlapping assignment column groups are used to blur vertical disturbances, then image quality improves, but the switching control becomes more complex
Solution Approach 1:
The patent merges multiple assignment column groups that overlap in their coverage of column lines. Instead of maintaining separate non-overlapping groups, the system combines the assignment patterns so that adjacent amplifiers share common column lines in their assignments. This overlapping merge creates a buffer zone that blurs vertical disturbances across column boundaries while using a unified switching control mechanism rather than separate controls for each group.
Data Source
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AI summary
The sensor has a set of light-sensitive pixels (P) arranged in rows and columns, where signals of the pixels are conducted via a set of column lines to column amplifiers. One of the amplifiers is associated with one of the column lines with a switching device, where the device selectively switches the column line to the associated column amplifier. A control device (23) i.e. microcontroller, controls the switching device, such that such that connection association of the column lines to the column amplifiers varies from row to row. An independent claim is also included for a method for reading out of an image sensor.