Variable Readout Circuitry for Image Sensor Frame Rate
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional image sensors have slower readout circuitry, resulting in a lower-than-desired frame rate due to uniform readout times across all pixel rows, which can lead to inefficiencies in image capture and processing.
Innovation Solution
The implementation of variable timing readout circuitry that adjusts the readout time based on the distance of each row from the column readout circuitry, allowing rows closer to the circuitry to be read faster, thereby increasing the frame rate by reducing settling time and optimizing readout operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If uniform readout time is applied to all pixel rows, then readout simplicity is maintained, but frame rate is reduced due to slower overall readout speed
Solution Approach 1:
The pixel array is divided into multiple segments or groups, each with its own readout path. By segmenting the readout operation into parallel channels, the overall readout time is reduced while maintaining manageable circuit complexity through modular design.
Solution Approach 2:
The readout circuitry transitions from a static, uniform timing approach to a dynamic, variable timing approach where different pixel rows can be read out at different speeds based on their distance from the readout circuitry, optimizing frame rate without excessive complexity.
2Speed
If readout time for distant pixel rows is extended, then readout completeness is achieved, but overall readout speed decreases
Solution Approach 1:
Different regions of the pixel array are assigned different readout qualities or speeds based on their local characteristics, specifically their distance from the readout circuitry. Closer rows use faster readout with less settling time, while distant rows use slower readout with more settling time, optimizing overall speed while ensuring complete readout.
Solution Approach 2:
The readout timing parameters are changed dynamically based on pixel row position. By adjusting the readout time and settling time parameters as a function of distance from the readout circuitry, the system achieves faster overall readout speed while maintaining adequate settling time for accurate signal acquisition.
3Productivity
If faster readout is implemented for all rows, then frame rate increases, but readout accuracy deteriorates due to insufficient settling time
Solution Approach 1:
The readout timing parameters are optimized to achieve the desired frame rate while maintaining signal accuracy. By carefully adjusting the readout time and settling time parameters, the system balances speed and precision requirements.
Solution Approach 2:
The readout system incorporates feedback mechanisms to monitor signal quality and adjust timing parameters accordingly. This ensures that frame rate increases do not compromise readout accuracy, as the system can adapt timing based on actual signal characteristics.
Data Source
AI summary
An imaging device may have an array of image sensor pixels arranged in rows and columns and column readout circuitry coupled to the array. The rows of pixels may receive drive signals from row driver circuitry, and the drive signals may be sent from timing circuitry based on the locations of rows within the array. In particular, rows closer to the readout circuitry may require less settling time and therefore be driven faster than the rows further from the readout circuitry. All of the rows may be driven in a single direction, or the array of pixels may have a cut, in which case rows above the cut may be driven up and rows below the cut may be driven down. A frame buffer may be used to store the signals generated by the rows of pixels and may account for the asynchronous read out of image data.