Image Sensor A/D Conversion Using Intermittent Reference Signals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional image sensors require prolonged time for analog-to-digital (A/D) conversion due to the need for dual conversions of noise signals, which affects image quality and processing efficiency.
Innovation Solution
An image sensor design incorporating a generator of reference signals with different potential change slopes, a selector to choose the appropriate reference signal, and an analog/digital converter that performs A/D conversion row by row using these signals, allowing intermittent first and second driving modes to optimize noise and photoelectric conversion signal processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If dual A/D conversion of noise signals is performed using multiple reference signals, then image quality is improved, but A/D conversion time is prolonged
Solution Approach 1:
The patent applies periodic action by intermittently performing the first driving mode (dual A/D conversion) rather than continuously. The control unit switches between first driving (intermittent dual conversion) and second driving (single A/D conversion), creating a periodic pattern that balances image quality improvement with time efficiency. This resolves the contradiction by making the quality-enhancing operation periodic rather than continuous.
Solution Approach 2:
The patent implements dynamics by making the A/D conversion process adaptable through two different driving modes. The system dynamically selects between first driving (dual conversion for high quality) and second driving (single conversion for speed) based on intermittent timing, creating a flexible system that adjusts its operation to balance quality and time requirements.
2Measurement precision
If multiple reference signals with different potential change slopes are used, then noise signal conversion accuracy is improved, but device complexity increases
Solution Approach 1:
The patent applies universality by designing a single A/D converter that can perform multiple functions through different driving modes. The same converter handles both first driving (dual conversion using multiple reference signals for high accuracy) and second driving (single conversion for speed), making the device multi-functional and reducing overall system complexity despite using multiple reference signals.
Solution Approach 2:
The patent implements parameter changes by varying the operation mode of the A/D converter between first driving and second driving. By changing the driving mode parameter, the system can switch between using multiple reference signals (for accuracy) and using fewer reference signals (for speed), allowing the same hardware to adapt to different requirements without increasing permanent complexity.
3Loss of time
If first driving is performed intermittently, then A/D conversion time is reduced, but noise signal conversion accuracy may deteriorate
Solution Approach 1:
The patent applies periodic action by intermittently performing first driving (dual A/D conversion) rather than continuously. This periodic execution of the high-accuracy conversion mode ensures that noise signal conversion accuracy is maintained at regular intervals while allowing second driving (faster single conversion) to operate in between, thus reducing overall conversion time while preserving accuracy periodically.
Solution Approach 2:
The patent implements partial action by not performing dual A/D conversion continuously but only intermittently. This partial application of the high-accuracy first driving mode is sufficient to maintain acceptable noise signal conversion accuracy while significantly reducing the total time spent on conversions compared to continuous dual conversion.
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 reduces A/D conversion time while maintaining image quality by intermittently performing dual noise signal conversions and optimizing reference signal usage based on incident light levels.
Implementation Method 1
a photoelectric conversion signal obtained by performing photoelectric conversion on incident light and output from the pixel unit
Data Source
AI summary
An image sensor comprising: a generator that generates a plurality of reference signals having different slopes of potential change; a selector that selects one of the reference signals; and an analog/digital converter that converts an analog signal output from a pixel unit by first or second driving using the selected reference signal into a digital signal. In the first driving, a noise signal is converted into a plurality of first digital signals using the reference signals and a photoelectric conversion signal is converted into a second digital signal using one of the reference signals. In the second driving, the noise signal is converted into the first digital signal using a predetermined one of the reference signals and the photoelectric conversion signal is converted into the second digital signal using one of the reference signals. The first driving is performed intermittently.