Imaging Apparatus Defective Pixel Compensation
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Solution Overview
Problem
Conventional camera systems face issues with defective pixels in the focus detection area, leading to errors in focus detection and increased manufacturing costs due to the need to discard entire image sensors, and may focus on incorrect objects if defective pixels are compensated for by shifting the focus area.
Innovation Solution
An imaging apparatus with an image sensor featuring a first pixel group for generating image signals and a second pixel group for focus detection, along with a memory unit to store defective pixel information and a control unit for executing calculations to adjust output signals, allowing the camera to continue functioning even with defective pixels by compensating for their effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pixel set in the focus detection area includes a defect, then the entire image sensor must be discarded to prevent focus detection errors, but this increases manufacturing costs
Solution Approach 1:
The patent extracts and removes only the defective pixel from the focus detection area through software identification and exclusion, rather than discarding the entire image sensor. The control unit identifies defective pixels and excludes them from focus detection calculations, allowing the rest of the sensor to continue functioning normally.
Solution Approach 2:
The patent changes the operational parameters of the focus detection system by dynamically adjusting which pixels are included in calculations based on their defect status. The system modifies the effective pixel set used for focus detection, excluding only those identified as defective while maintaining the overall focus detection function.
2Reliability
If the focus detection area is moved to avoid defective pixels, then focus detection can continue, but the camera may focus on an incorrect object
Solution Approach 1:
The patent implements a feedback mechanism where the control unit continuously monitors focus detection results and adjusts the detection area or parameters based on the presence and location of defective pixels. This feedback loop ensures that focus detection remains accurate by compensating for defective pixel locations rather than simply shifting the entire detection area.
3Ease of manufacture
If defective pixels are used in focus detection, then manufacturing costs decrease, but focus detection accuracy deteriorates
Solution Approach 1:
The patent converts the harmful effect of defective pixels into a beneficial outcome by using the known defect information to improve the overall system reliability. Rather than allowing defective pixels to cause errors, the system proactively identifies and excludes them, turning a manufacturing imperfection into an opportunity for enhanced quality control and cost savings.
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
The solution enables the camera to maintain focus detection accuracy and reduce manufacturing costs by allowing the use of defective pixels, ensuring correct focusing on the intended object while minimizing the impact of defective pixels on image quality.
Implementation Method 1
a first pixel group used for generating an image signal by photoelectrically converting an object image
Data Source
AI summary
An imaging apparatus includes an image sensor including a first pixel group used for generating an image signal by photoelectrically converting an object image and a second pixel group configured to receive a light flux that has passed through divided areas of the exit pupil, a memory unit configured to store information about whether a defective pixel exists in any pixel included in the second pixel group, a control unit configured to execute calculation including combination processing on output signals of the second pixel group existing in a predetermined area, and a controller configured to control a shooting operation according to a result of the calculation by the calculation unit. The calculation unit is configured, if a defective pixel whose information is stored on the memory unit exists in the combination processing, to execute the calculation by using the output signals of the second pixel group.