Eye-Imaging Apparatus Synchronized Sequential Illumination
Solution Overview
Problem
Existing eye-imaging systems face challenges in achieving uniform illumination over a wide angular field of view, leading to non-ideal illumination usage efficiency and potential safety hazards due to unnecessary exposure of illumination light to the patient's eye.
Innovation Solution
The proposed solution involves a system with high numerical aperture optical fibers, skewed fiber arrays, and micro-prism array films to redistribute light, combined with synchronized sequential illumination and pulse width modulation to optimize illumination usage and reduce exposure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If continuous illumination light is used, then the image sensor can capture sufficient light signal, but unnecessary exposure of illumination light to the patient eye occurs when the shutter is closed
Solution Approach 1:
The illumination light source is operated in a periodic flashing mode that is synchronized with the image sensor's global shutter operation. The light flashes only during the exposure period when the shutter is open, and remains off during the readout period when the shutter is closed. This periodic action eliminates continuous unnecessary exposure to the patient's eye while ensuring sufficient light signal is provided during the actual image capture, thereby improving illumination light usage efficiency and reducing harmful exposure.
2Loss of energy
If illumination light is synchronized with global shutter, then illumination usage efficiency is improved, but complex synchronization control is required
Solution Approach 1:
The system employs a feedback mechanism where the control of the illumination light source is directly coupled with the global shutter operation of the image sensor. The shutter's open/close state serves as feedback signal that automatically triggers the corresponding on/off state of the illumination light. This feedback-based synchronization eliminates the need for complex external timing circuits or microcontroller-based synchronization logic, as the system self-regulates based on the sensor's operational state, thereby achieving efficient illumination usage with minimal added 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
This approach results in improved illumination uniformity and efficiency, reducing unnecessary exposure of illumination light to the patient's eye while maintaining high color fidelity and reducing system costs.
Implementation Method 1
micro-prism array films to redistribute light
Implementation Method 2
high numerical aperture optical fibers
Implementation Method 3
image sensor for imaging
Data Source
AI summary
An eye-imaging apparatus including red, green, and blue light sources, one or more optical lenses, a light guide cable to transmit light from the light source, a one-chip color image sensor including a shutter, the color image sensor being operable to measure red, green, and blue light in the imaging path and transmit measured colored light in respective red, green, and blue channels. The red, green, and blue light sources are sequentially flashed in synchronization with the operation of the image sensor and the color image sensor captures red, green, and blue images in synchronization with the flashed color. The color image sensor transmits the colored images on respective color channels one at a time.