Image Sensor Signal-Line Limiting for Stable Capture Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The accuracy of the signal for image generation in image capturing apparatuses is deteriorated due to variations in the potential of the signal line, which depend on whether a signal for focus detection is output, leading to inconsistencies in signal stabilization.
Innovation Solution
Incorporating a limiter circuit that sets and maintains a consistent potential on the signal line during specific periods, ensuring that the signal line's potential starts from the same level regardless of whether a focus detection signal is output, thereby stabilizing the image capturing signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If some pixels output focus detection signal before image capturing signal, then focus detection can be performed, but the potential of the signal line varies depending on whether focus detection signal is output, causing inconsistency in signal stabilization
Solution Approach 1:
The limiter circuit performs preliminary action by setting the signal line potential to a predetermined level during the period when noise signal is output and before image capturing signal is output. This ensures that regardless of whether focus detection signal is output or not, the signal line potential starts from the same predetermined level when image capturing signal is output, thereby eliminating variations in signal stabilization.
2Adaptability or versatility
If different pixels have different output sequences, then both focus detection and image capturing can be achieved, but variations in signal line potential occur, deteriorating image capturing signal accuracy
Solution Approach 1:
The limiter circuit creates equipotentiality by setting the signal line potential to a predetermined level during specific periods. This ensures that all pixels, regardless of their output sequence (whether they output focus detection signal or not), start from the same potential level when outputting image capturing signal, thereby eliminating potential variations and improving signal accuracy.
3Measurement precision
If focus detection signal is output from some pixels, then focus detection is enabled, but the signal line potential varies, leading to deterioration in image quality consistency
Solution Approach 1:
The limiter circuit performs preliminary action by setting the signal line potential to a predetermined level before image capturing signal is output. This preliminary potential setting ensures that the signal line starts from a consistent level for all pixels, thereby maintaining image quality consistency while still allowing focus detection to be performed.
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 the inconsistency in signal stabilization and suppresses the deterioration in image capturing signal accuracy, ensuring consistent image quality across different operational conditions.
Implementation Method 1
A potential of the signal line is set to a predetermined potential by a limiter circuit during a period after a second pixel outputs the noise signal and before the second pixel outputs the image capturing signal
Data Source
AI summary
An image capturing apparatus includes a plurality of pixels, a signal line connected to the plurality of pixels, and a limiter circuit configured to limit an amplitude of the signal at the signal line. A first pixel in the plurality of pixels sequentially outputs a noise signal, a focus detection signal, and an image capturing signal to the signal line. A second pixel in the plurality of pixels sequentially outputs a noise signal and an image capturing signal to the signal line, and wherein a potential of the signal at the signal line is set to a potential by the limiter circuit during a period after the second pixel outputs the noise signal and before the second pixel outputs the image capturing signal.