Curved Optical Slit Module for Linear Sensor Wide Field of View
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical systems for linear imaging, particularly in motion tracking applications, face challenges in accurately capturing a wide field of view with minimal distortion and rotation errors, especially when the tracking unit moves with the object, as conventional lenses suffer from image distortion and poor focus at large angles.
Innovation Solution
A sensing module comprising a linear image sensor and an optical unit with a curved surface featuring a slit or a freeform aspheric lens, which maintains constant magnification and minimizes distortion by focusing light onto a single pixel, regardless of the angle of incidence, using a monolithic, domed, or toroidal lens configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional lenses are used to focus light onto a linear sensor, then the system can capture a limited field of view, but the measurement precision and image quality deteriorate at large angles due to distortion and poor focus
Solution Approach 1:
The patent employs a curved optical surface (cylindrical or freeform) instead of a conventional flat lens surface. This curvature is specifically designed to map a wide angular field of view onto the linear sensor while maintaining constant magnification across all angles, thereby eliminating the distortion and focus degradation that occur with conventional lenses at large angles.
Solution Approach 2:
The patent utilizes variable optical power across the optical surface, where the focal length or refractive power changes as a function of position or angle. This parameter variation allows the optical system to maintain consistent image quality and constant magnification across the entire wide field of view, resolving the contradiction between measurement precision and field of view area.
2Area of stationary object
If a wide field of view is captured using conventional optical systems, then more scene information is obtained, but image distortion and rotation errors increase
Solution Approach 1:
The curved optical surface is specifically shaped to provide a distortion-free mapping of the wide field of view onto the linear sensor. The curvature profile is designed to compensate for angular variations, ensuring that objects at different angles are imaged with consistent scale and orientation, thereby capturing a wide field of view without introducing image distortion.
Solution Approach 2:
By varying the optical power across the surface, the system maintains constant magnification for all incident angles. This parameter change ensures that the scaling factor remains uniform across the entire field of view, eliminating the distortion that would otherwise occur when capturing wide-angle scenes with conventional lenses.
3Device complexity
If multiple pixels are used to capture angular information, then computational requirements increase, but using a single pixel reduces processing complexity
Solution Approach 1:
The optical system extracts and separates angular information spatially before it reaches the sensor. The curved optical surface maps different incident angles to different lateral positions on the linear sensor, allowing angular information to be captured in a single exposure without requiring complex computational processing to separate angular from radial components.
Solution Approach 2:
The curved optical surface creates a specific geometric mapping where the lateral position on the sensor directly corresponds to the incident angle. This geometric encoding of angular information allows the system to use a single pixel (or a linear array) to capture angular data without the need for multiple pixels performing computational analysis, thereby reducing device complexity while maintaining measurement precision.
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 solution provides accurate and fast angular location information with reduced computational requirements and minimal distortion, suitable for tracking applications in various environments, including virtual reality and outdoor settings, by effectively compressing a two-dimensional scene onto a linear sensor.
Implementation Method 1
an optical element having a curved, outward surface and a covering on the curved surface. The covering has a slit formed therein. The optical unit faces the sensor with the slit perpendicular to a longitudinal axis of the linear sensor and images a wide field of view onto a single pixel of the linear sensor
Implementation Method 2
The surface focuses light incident on the slit at each vertical elevation angle across a linear sensor and the optical power of the lens varies to maintain a constant magnification
Data Source
AI summary
A sensing module includes a linear image sensor and an optical unit. The unit includes an optical element having a curved, outward surface and a covering on the outward surface. The covering has a slit formed therein. The optical unit faces the sensor with the slit perpendicular to a longitudinal axis of the sensor and images a wide field of view onto a single pixel of the linear sensor, wherein light impinging normal to the slit, at any location along the slit, is imaged on a central pixel of the sensor while light impinging one of a plurality of non-normal angles to the slit is imaged on an associated one of a plurality of non-central pixels of the sensor.