Tilt-Shift Lens for Off-Axis Iris Imaging
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Solution Overview
Problem
Current iris recognition systems require user cooperation and on-axis alignment with the imaging device, making them slow and unsuitable for quick identification and head-mounted applications, where field of view is obstructed.
Innovation Solution
Off-axis iris imaging systems using a tilt-shift lens to adjust the focal plane parallel to the iris plane, allowing for accurate imaging without blocking the user's view, with the lens tilt ranging from 2.0 to 8.5 degrees and shift offset from 1.0 to 2.5 mm, integrated into head-mounted devices like eyeglasses or binoculars.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If on-axis imaging is used with adjustable swivel, then clear iris image can be obtained, but user cooperation and slow identification process are required
Solution Approach 1:
Instead of requiring the user to align their iris with the camera (on-axis imaging), the patent inverts the approach by using off-axis imaging where the camera captures iris images from a side angle. This eliminates the need for user cooperation and self-alignment while maintaining sufficient image quality for iris code generation.
2Measurement precision
If on-axis camera is placed in front of eye, then iris imaging is achieved, but user's view of actual world is blocked
Solution Approach 1:
The patent moves the camera from the on-axis position (directly in front of the eye) to an off-axis position (side angle). This dimensional change in camera placement allows the camera to capture iris images without blocking the user's forward view, eliminating the harmful obstruction effect while maintaining imaging capability.
3Measurement precision
If multiple images are taken for remote iris, then identification accuracy improves, but processing time increases
Solution Approach 1:
The off-axis imaging geometry is pre-configured to capture the iris at an optimal angle from the side, eliminating the need to take multiple images to achieve proper focus and alignment. The preliminary setup of the off-axis camera position ensures that a single image capture is sufficient for accurate iris code generation, reducing identification time.
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
Enables rapid, accurate, and non-intrusive iris imaging, maintaining a clear field of view while generating high-quality iris codes for identity verification, suitable for both access control and identification applications.
Implementation Method 1
the lens of the off-axis imager has a tilt ranging from about 2.0 to about 8.5 degrees and a shift offset ranging from about 1.0 to about 2.5 mm
Data Source
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AI summary
This application relates to systems and methods for imaging the iris of an individual. The iris images may be taken with an off-axis imager and may be attached to a head-mounted system such as a pair of eyeglasses. In some instances, the iris images may be used for biometric recognition and identification.