OST HMD Eye-Tracked Calibration for Precise Virtual Alignment
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Solution Overview
Problem
Existing optical see-through head-mounted displays (OST HMDs) struggle with precise alignment between projected virtual objects and externally viewed objects, leading to misalignment and distortion due to mismatched lens centers and chromatic aberrations, which affects the user's viewing experience.
Innovation Solution
An OST HMD system incorporating an electro-optical display module with a partially reflective partially transmissive optical element and a processor that generates images aligned with eyeball feature position data, using a position determination module and tracking system to ensure precise superimposition of virtual objects with external objects, either partially or fully hidden.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If lens centers of eyepiece optical systems are positioned to match center positions of user's eyes, then alignment precision is improved, but manufacturing and assembly complexity increases due to precise positioning requirements
Solution Approach 1:
The patent introduces an intermediary calibration process using calibration objects and image processing to determine precise optical parameters. Instead of relying solely on mechanical precision during assembly, the system uses software-based calibration to achieve accurate alignment, thereby reducing manufacturing and assembly complexity while maintaining high alignment precision.
Solution Approach 2:
The patent employs parameter estimation through image processing to determine optical characteristics such as lens center positions and distortion parameters. By changing from fixed mechanical positioning to adjustable optical parameters that can be calibrated software-wise, the system achieves precise alignment without the corresponding increase in manufacturing and assembly complexity.
2Manufacturing precision
If chromatic aberrations are corrected through precise optical design, then image quality is improved, but device complexity and cost increase
Solution Approach 1:
The patent converts the harmful effect of chromatic aberrations into a beneficial correction process by capturing images through the optical system and using image processing to measure and compensate for aberrations. Instead of designing a complex optical system to prevent aberrations, the system accepts them as inherent and corrects them computationally, reducing optical complexity while maintaining image quality.
Solution Approach 2:
The patent replaces complex mechanical optical corrections with computational methods. Rather than using sophisticated optical elements to correct chromatic aberrations physically, the system uses image processing algorithms to measure and correct aberrations in software, thereby reducing optical system complexity and cost while maintaining or improving image quality.
3Measurement precision
If eye tracking and calibration systems are added to improve alignment, then alignment precision is improved, but device complexity increases
Solution Approach 1:
The patent makes the camera and image processing system serve multiple functions: capturing images for display, measuring optical parameters, determining eye position, and calculating distortion corrections. By making existing components multi-functional, the system achieves precise alignment without adding separate dedicated hardware for each function, thereby reducing overall system complexity.
Solution Approach 2:
The system uses its own captured images to automatically determine optical characteristics and calibration parameters without requiring external measurement equipment. The camera captures images that are then processed to self-calibrate the optical system, eliminating the need for complex external calibration apparatus and reducing overall system complexity.
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 system enables precise alignment of virtual objects with external objects, enhancing the user's viewing experience by accurately superimposing virtual images over real-world or virtual objects, improving clarity and alignment accuracy.
Implementation Method 1
The electro-optical display module includes at least one partially reflective partially transmissive optical element
Implementation Method 2
The electro-optical display module includes at least one partially reflective partially transmissive optical element
Data Source
AI summary
A method for irradiating an image in an optical see-through (OST) head mounted display (HMD) for viewing through, the OST HMD by a user's eye, an object having at least one of known orientation and position and orientation (O/P&O), associated with a first reference frame, the method comprising: generating and irradiating said image for appearing to said user superimposed in an aligned manner to said object, according to predetermined information, eyeball feature position data, and said O/P&O; said predetermined information relates correction data with a plurality of different respective position data values of at least one eyeball feature position of said eye; said predetermined information further includes display corrections of said electro-optical display module with respect to said position data values of said at least one eyeball feature position, with respect to a second reference frame; and said O/P&O is between said second reference and said first reference frame.