Image Sensor Signal-Line Control for Faster AF Pixel Readout

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Solution Overview

Problem

Existing image sensors face challenges in speeding up signal reading for focus detection and image generation, which affects the overall performance and efficiency of imaging devices.

Innovation Solution

The image sensor incorporates a unique configuration with first and second pixels for focus detection and imaging, respectively, along with a control unit that manages signal output to dedicated signal lines, allowing for simultaneous and efficient reading of signals from different pixel types.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If signals from all pixels are read out through a single signal line, then device complexity is reduced, but signal reading speed decreases

Engineering Contradiction:

Improvesignal line configurationVSAvoidsignal reading speed

Core Design Contradiction:

Device complexityVSSpeed

Solution Approach 1:

The patent divides the pixel array into multiple regions (first region with first pixels, second region with second pixels, third region with third pixels, fourth region with fourth pixels) and assigns different signal lines to different regions. This segmentation allows parallel signal reading from multiple regions simultaneously, increasing overall reading speed while maintaining manageable device complexity through organized regional distribution.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces a spatial dimension to signal line assignment by distributing pixels and signal lines across multiple regions in a two-dimensional arrangement. Instead of a single centralized signal line, the system uses multiple signal lines positioned at different locations, enabling parallel processing paths and increasing reading speed without proportionally increasing complexity.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Device complexity

If focus detection pixels and imaging pixels share the same signal line, then device complexity is reduced, but measurement precision of focus detection decreases

Engineering Contradiction:

Improvesignal line configurationVSAvoidfocus detection accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent segments the signal reading paths by assigning focus detection pixels (first and second pixels) to separate signal lines from imaging pixels (third and fourth pixels). This segmentation ensures that focus detection signals are read out independently without interference from imaging signals, maintaining high measurement precision for autofocus operations while keeping the overall device complexity manageable through systematic regional organization.

Inventive Principle:

Principle #1Segmentation

3Speed

If multiple pixels output signals simultaneously to different signal lines, then signal reading speed increases, but device complexity increases

Engineering Contradiction:

Improvesignal reading speedVSAvoidsignal line configuration

Core Design Contradiction:

SpeedVSDevice complexity

Solution Approach 1:

The patent merges pixels with identical structural characteristics (first pixels with first photoelectric conversion units, second pixels with second photoelectric conversion units) into groups that share common signal lines. This merging strategy allows simultaneous signal output to multiple signal lines while reducing complexity by creating standardized pixel types with uniform connection patterns, making the system more manageable despite the increased parallelism.

Inventive Principle:

Principle #5Merging (Combining)

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 faster readout of AF pixel signals and improved accuracy of imaging pixel signals, thereby enhancing the speed and accuracy of focus detection and image generation.

Implementation Method 1

a first photoelectric conversion unit that photoelectrically converts light to generate an electric charge

Methodology Applied

Scientific EffectPhotoelectric conversion: Photoelectric Effect

Data Source

PatentUS12244949B2Image sensor and imaging device with vertical controller performing first control and second control

Publication Date: 2025.03.04 NIKON CORP

AI summary

An image sensor, includes: a first pixel and a second pixel, in a first direction, each including a first photoelectric conversion unit and a light-shielding unit and outputting a signal; a third pixel and a fourth pixel, in the first direction, each including a second photoelectric conversion unit and outputting a signal; a first signal line and a second signal line, in the first direction, each of which can be connected to the first pixel, the second pixel, the third pixel and the fourth pixel; and a control unit that performs a first control in which a signal of the first pixel is output to the first signal line and a signal of the second pixel is output to the second signal line, and a second control in which a signal of the third pixel and a signal of the fourth pixel are output to the first signal line.