OTCCD Controller for Motion-Compensated Iris Imaging
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Solution Overview
Problem
Conventional image stabilization methods for capturing high-quality iris or face images of moving subjects are limited by the need for short exposures and flash illumination, which can be unsafe and introduce motion blur, and existing solutions with mechanical parts are not suitable for military and security applications.
Innovation Solution
An image acquisition system utilizing an orthogonal transfer charge-coupled device (OTCCD) with a controller that estimates and compensates for lateral velocity vectors by shifting the array of pixels electronically, eliminating the need for mechanical parts and allowing for extended exposure without motion blur.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If extremely short exposures are used to freeze subject motion, then motion blur is eliminated, but flash illumination is required which becomes eye unsafe at larger distances
Solution Approach 1:
The patent applies dynamics by using an Orthogonal Transfer CCD (OTCCD) device that can dynamically shift its pixel array during exposure. This allows the sensor to track moving subjects in real-time, enabling long exposures without motion blur while eliminating the need for flash illumination, thus resolving the eye safety issue at larger distances
Solution Approach 2:
The patent replaces mechanical image stabilization systems with an electronic pixel-shifting mechanism in the OTCCD. Instead of using moving lenses or mirrors to compensate for motion, the pixel array itself is electronically shifted to track the subject, eliminating mechanical parts and enabling long exposures without flash
2Object-affected harmful factors
If image exposure is extended to avoid flash illumination, then eye safety is improved, but motion blur is introduced degrading image quality
Solution Approach 1:
The OTCCD device dynamically shifts its pixel array during the extended exposure period to track the moving subject. This dynamic tracking capability allows the sensor to maintain sharp focus on moving subjects even with long exposures, eliminating motion blur while avoiding flash illumination
Solution Approach 2:
The system performs preliminary tracking of the subject's motion trajectory before and during exposure. By predicting and compensating for subject motion in advance, the pixel array is positioned to continuously track the subject throughout the extended exposure, preventing motion blur
3Reliability
If moveable lenses or tip-tilt mirrors are used for image stabilization, then camera motion is compensated, but mechanical parts are used making the system unsuitable for military and security applications
Solution Approach 1:
The patent replaces mechanical image stabilization components (moveable lenses, tip-tilt mirrors) with an all-electronic solution. The OTCCD's pixel array is shifted electronically using voltage control, eliminating mechanical moving parts while maintaining image stabilization capability, making the system rugged and suitable for military and security applications
Solution Approach 2:
The OTCCD device performs self-stabilization by using its own pixel array to track and compensate for motion. The same sensor that captures the image also performs the stabilization function through electronic pixel shifting, eliminating the need for separate mechanical stabilization subsystems
4Reliability
If conventional image stabilization methods are used, then some motion is compensated, but very fast motions cannot be tracked
Solution Approach 1:
By replacing mechanical stabilization systems with electronic pixel shifting in the OTCCD, the system achieves much faster response times. Electronic switching and pixel shifting can occur at microsecond timescales, enabling tracking of very fast motions that would be impossible with mechanical systems limited by inertia and mechanical response times
Data Source
AI summary
An apparatus includes a video sensing device, a velocity vector estimator (VVE) coupled to the video sensing device, a controller coupled to the velocity vector estimator, and an orthogonal transfer charge-coupled device (OTCCD) coupled to the controller. The video sensing device transmits a plurality of image frames to the velocity vector estimator. The controller receives a location of an object in a current frame, stores locations of the object in one or more previous frames, predicts a motion trajectory and the predicted location of the object on it in a subsequent frame as a function of the locations of the object in the current frame and the one or more previous frames, and transmits the predicted location of the object to the OTCCD. The OTCCD shifts its image array of pixels as a function of the predicted location of the object.