Vision Parameter Measurement Using Lateral Camera Placement
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Solution Overview
Problem
Current systems for determining vision parameters for corrective lenses constrain the subject's gaze and do not allow for a natural posture, leading to inaccurate measurements and discomfort, as they require the subject to view targets close to the camera, which limits space and flexibility.
Innovation Solution
A method and system using a camera placed outside the subject's foveal zone, taking images from different angles without obstructing the gaze, and utilizing an inclinometer to determine the subject's inclination, allowing for natural posture and precise measurement of vision parameters like pantoscopic angle and pupillary distance without visual hindrance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the camera is placed close to the subject to take images, then the image quality and measurement precision are improved, but the subject's gaze is constrained and natural posture cannot be maintained
Solution Approach 1:
The patent positions the camera laterally at the subject's ear level rather than directly in front, utilizing a different spatial dimension. This lateral placement allows the camera to capture facial images without entering the subject's foveal vision zone, thereby maintaining natural gaze direction while achieving sufficient measurement precision through side-view imaging geometry
2Area of stationary object
If visual targets are placed close to the camera for measurement, then the measurement system space requirement is reduced, but the subject cannot adopt natural distance vision posture
Solution Approach 1:
The patent removes the traditional visual target element from the measurement system entirely. Instead of requiring the subject to focus on near targets, the system captures images of the subject's face in natural viewing conditions without any imposed visual targets, thereby eliminating the conflict between compact system design and natural posture maintenance
3Reliability
If the camera obstructs the subject's field of vision to ensure proper framing, then image capture reliability is improved, but visual discomfort and measurement accuracy deteriorate
Solution Approach 1:
The patent applies local quality by positioning the camera specifically in the subject's peripheral vision zone rather than central foveal zone. This localized placement ensures the camera can properly frame facial features for reliable image capture while remaining outside the critical central vision area, thus avoiding visual discomfort and maintaining measurement accuracy
Data Source
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AI summary
The invention concerns a method for helping determine the vision parameters of a subject (100), comprising the following steps: -taking (120) two images (11, 12) from two different angles of the face of the subject by means of a camera (10), the subject (S) being in a natural distant vision position, -determining (130) the inclination of the camera (10) relative to the ground at the time when the images are taken, -deducing therefrom (140) the inclination and the direction of the face of the subject (S), characterised in that the camera is arranged outside a foveal area of the subject when the images (11, 12) are taken (120).