Image Sensor Pixel Output Control for Focus Detection and Imaging
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Solution Overview
Problem
Existing image sensor elements face challenges in efficiently managing signal outputs between focus detection pixels and imaging pixels, leading to differences in output signal values.
Innovation Solution
The image sensor element incorporates a first pixel for imaging and a second pixel for focus detection, each with photoelectric conversion parts, accumulation parts, and output parts. A control unit manages the voltage of the accumulation parts differently for each pixel type, allowing for distinct signal processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If separate output circuits are provided for focus detection pixels and imaging pixels, then signal management becomes complex and device complexity increases, but if shared output circuits are used, then excessive current may be generated causing potential damage
Solution Approach 1:
The patent applies universality by enabling the second accumulation part to serve dual functions: accumulating electric charge for focus detection pixels and controlling voltage for imaging pixels. This multi-functional design allows a single circuit structure to handle both pixel types without requiring separate output circuits, thereby preventing excessive current while maintaining simple device complexity
Solution Approach 2:
The patent employs parameter changes by dynamically adjusting the voltage of the second accumulation part based on the pixel type. The control unit sets the second accumulation part to a first voltage when receiving signals from focus detection pixels and to a second voltage (different from the first) when receiving signals from imaging pixels. This voltage parameter adjustment enables appropriate signal handling for each pixel type using a shared output circuit
2Measurement precision
If different voltage control is applied to accumulation parts for different pixel types, then signal processing accuracy improves, but then device complexity and control complexity increase
Solution Approach 1:
The control unit is designed with multi-functionality to manage voltage control for multiple accumulation parts based on pixel type identification. It automatically determines whether to apply the first voltage or second voltage to the second accumulation part based on whether the input signal originates from a focus detection pixel or imaging pixel, achieving precise signal processing without requiring separate control circuits for each pixel type
Solution Approach 2:
The patent implements parameter changes through dynamic voltage adjustment of the second accumulation part. The control unit changes the voltage parameter of the second accumulation part between two distinct values (first voltage and second voltage) depending on the operational mode (focus detection or imaging), enabling precise signal handling for different pixel types using a single controllable accumulation part
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 configuration enables selective output of signals from various pixels, preventing excessive current generation and potential damage, while maintaining effective focus detection and imaging capabilities.
Implementation Method 1
a first photoelectric conversion part that photoelectrically converts light to generate electric charge
Data Source
AI summary
An image sensor element includes: a first pixel having a first photoelectric conversion part, a first accumulation part which accumulates electric charge generated by the first photoelectric conversion part, and a first output part based on a voltage of the first accumulation part; a second pixel having a second photoelectric conversion part, a second accumulation part wherein electric charge generated by the second photoelectric conversion part, and a second output part which a second signal based on a voltage of the second accumulation part; an output line to which the first and the second output parts are connected and from which the first and second signals are output; and a control unit which is able to control the voltage of the first accumulation part to be a first voltage and ability to control the voltage of the second accumulation part to be a second voltage different from the first voltage.