Imaging Apparatus Noise Reduction via Vertical Scanning Circuit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing imaging apparatuses face challenges in reducing random noise in correction signals without increasing chip area or requiring multiple frames for image capture, especially when capturing single frames or moving images, as previous methods either require extensive ineffective pixel regions or increase chip area.
Innovation Solution
The proposed imaging apparatus includes an effective pixel region and an ineffective pixel region with a vertical scanning circuit that selects pixels of the same row in the effective region once and in the ineffective region multiple times during one frame, using null or light-shielded pixels to generate correction signals, thereby reducing random noise without increasing chip area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the ineffective pixel region is extended across multiple rows to increase the number of averaging parameters, then random noise in the correction signal is reduced, but the chip area increases
Solution Approach 1:
The patent transitions from increasing the ineffective pixel region across multiple rows (spatial extension) to extending it across multiple frames temporally. This dimensional shift allows the system to achieve the same noise reduction effect without increasing the chip area, as the temporal dimension provides additional averaging opportunities without consuming additional horizontal space.
Solution Approach 2:
The patent makes the ineffective pixel region dynamically extendable across multiple frames rather than being fixed in space. This dynamic approach allows the system to accumulate sufficient averaging parameters over time while maintaining a compact spatial footprint, resolving the contradiction between noise reduction and chip area.
2Measurement precision
If pixel signals from multiple frames are accumulated to generate correction signals, then random noise is reduced, but the imaging apparatus cannot capture single frames and shutter release time lag increases
Solution Approach 1:
The patent performs preliminary action by accumulating pixel signals from multiple frames in advance to generate correction signals. This allows the correction data to be prepared beforehand, enabling the system to capture single frames without introducing time lag, as the correction signals are ready when needed.
Solution Approach 2:
The patent uses copying by creating correction signals through repeated reading of the same ineffective pixel region across multiple frames. This copying process generates sufficient averaging data without requiring the imaging apparatus to wait for multiple frame captures, thus eliminating shutter release time lag while maintaining noise reduction benefits.
3Measurement precision
If a large number of frames are used for averaging pixel signals, then random noise is reduced, but the response time until imaging starts increases
Solution Approach 1:
The patent applies periodic action by repeatedly reading the ineffective pixel region at regular intervals across multiple frames. This periodic sampling strategy accumulates sufficient averaging parameters efficiently, reducing the total time required compared to non-periodic methods, while still achieving the desired noise reduction.
Solution Approach 2:
The patent maintains continuity of useful action by continuously accumulating pixel signals from the ineffective region across multiple frames without interruption. This continuous accumulation process maximizes the efficiency of time utilization, achieving rapid response while gathering sufficient data for noise reduction.
Data Source
AI summary
An imaging apparatus is provided having: a pixel unit including an effective pixel region of multiple pixels accumulating charges generated according to incident light to output signals and an ineffective pixel region of multiple pixels outputting signals not dependent on incident light; a plurality of vertical signal lines provided for each column of pixels of pixel unit; a vertical scanning circuit that scans and selects pixels of pixel unit in row units to output signals of selected pixels of same row to plurality of vertical signal lines; and a horizontal scanning circuit that scans and selects signals of plurality of vertical signal lines to output signals of selected vertical signal lines; wherein the vertical scanning circuit selects pixels of same row of effective pixel region in row units once during one frame and selects pixels of same row of ineffective pixel region in row units multiple times during one frame.