Pixel Sensor Array Layout for Integrated Phase Detection Autofocus
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing camera devices with separate image sensor and autofocus devices face increased complexity, cost, and size due to the need for additional circuitry and separate manufacturing processes, prohibiting size reduction and increasing manufacturing complexity.
Innovation Solution
Integrate autofocus functionality into a pixel sensor array by incorporating autofocus pixel sensors with imaging pixel sensors, using a metal grid structure with grid extensions to shield photodiodes and enable phase detection autofocus (PDAF) within the pixel sensor array.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate image sensor and autofocus devices are used, then autofocus functionality is achieved, but device complexity increases
Solution Approach 1:
The patent combines autofocus pixel sensors and imaging pixel sensors into a single integrated pixel sensor array. The autofocus pixel sensors include photodiodes with metal grid structures that enable phase detection autofocus, while imaging pixel sensors capture image data. Both sensor types share common circuitry including transfer gates, floating diffusion regions, and readout circuitry, eliminating the need for separate autofocus and image sensor devices and their associated interconnection circuitry.
2Reliability
If separate image sensor and autofocus devices are used, then autofocus functionality is achieved, but manufacturing complexity increases
Solution Approach 1:
The patent integrates autofocus and imaging functions into a single pixel sensor array that can be manufactured using standard CMOS image sensor fabrication processes. The metal grid structures are formed using conventional photolithography and etching techniques, and the photodiodes are created through standard semiconductor doping processes. This unified approach allows both autofocus and imaging pixel sensors to be produced in the same manufacturing run on the same substrate, eliminating the need for separate manufacturing processes and subsequent assembly.
3Reliability
If separate image sensor and autofocus devices are used, then autofocus functionality is achieved, but device size increases
Solution Approach 1:
The patent consolidates autofocus pixel sensors and imaging pixel sensors into a single integrated array, eliminating the physical separation between autofocus and imaging devices. The metal grid structures within the pixel sensor array provide both optical shielding and autofocus detection functionality without requiring additional external components. This integration significantly reduces the overall device footprint by removing redundant housing, interconnection circuitry, and separate device assemblies.
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 integration reduces complexity, cost, and size of the camera device while enabling high-speed autofocus performance in various illumination scenarios.
Implementation Method 1
a photodiode configured to convert photons of incident light into a photocurrent of electrons
Data Source
AI summary
Autofocus functionality is integrated into a pixel sensor array of an image sensor device described herein by including autofocus pixel sensors with imaging pixel sensors in the pixel sensor array. A metal grid structure may be included around the autofocus pixel sensors and the imaging pixel sensors in the pixel sensor array. Grid extensions of the metal grid structure extend laterally outward over at least a portion of photodiodes of the autofocus pixel sensors, thereby shielding the portions of the photodiodes from incident light. The autofocus pixel sensors may be arranged in pairs in the pixel sensor array such that opposing sides of the photodiodes of the autofocus pixel sensors in a pair are shielded by grid extensions. This results in a phase difference between the incident light sensed by the autofocus pixel sensors in the pair, which may be used for determining the focus of the pixel sensor array.