Retinal Projection Optical System Using Dual Virtual Planes
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Solution Overview
Problem
Existing image projection devices, such as those using the Maxwellian view method, face challenges in projecting high-quality images on the retina due to limitations in light beam convergence and reflection, resulting in reduced image resolution and quality.
Innovation Solution
An image projection device with a dual optical system that includes a first and second optical system, each comprising multiple curved reflection mirrors, where the scanning light is converged on virtual planes at specific angles to achieve conjugate relationships of equal magnification, ensuring the light beam maintains its diameter and focus, thereby projecting a high-resolution image on the retina.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single reflection mirror is used to reflect scanning light toward the retina, then the device structure is simple, but the image quality and resolution are insufficient
Solution Approach 1:
The optical system is divided into two separate optical systems: a first optical system that converges scanning light from the scan unit onto a first virtual plane, and a second optical system that converges light from the first virtual plane onto a second virtual plane near the pupil. This segmentation allows each subsystem to be optimized independently for specific functions, achieving high image quality while maintaining manageable system complexity
Solution Approach 2:
A first virtual plane is introduced as an intermediary between the scan unit and the final retina projection. The first optical system creates this intermediate image plane, and the second optical system uses it as its input. This intermediary virtual plane enables precise control of light convergence angles and facilitates the conjugate relationship of equal magnification, thereby improving image quality
2Length of stationary object
If the scanning light is converged directly on the retina without virtual planes, then the optical path is short, but the conjugate relationship and magnification control are insufficient for high-resolution projection
Solution Approach 1:
The first virtual plane serves as an intermediary that enables precise conjugate relationship control. By creating an intermediate image plane at a specific location outside the eye, the system establishes a well-defined conjugate relationship between the scan unit and the first virtual plane with equal magnification. The second optical system then establishes another conjugate relationship between the first and second virtual planes, also with equal magnification. This two-stage intermediary approach ensures precise magnification control throughout the optical path
Solution Approach 2:
The system transitions from direct one-to-one mapping to a two-dimensional virtual plane mapping approach. The first virtual plane and second virtual plane are positioned at different locations (one outside the eye, one inside near the pupil), creating additional spatial dimensions for optical control. This dimensional expansion allows independent optimization of convergence angles and magnification relationships
3Manufacturing precision
If curved reflection mirrors are used to achieve equal magnification conjugate relationships, then image resolution is improved, but the device complexity increases
Solution Approach 1:
The complex optical requirements are segmented into two independent optical systems, each with its own curved reflection mirrors. The first optical system contains curved mirrors optimized for creating the first virtual plane, while the second optical system contains curved mirrors optimized for creating the second virtual plane from the first. This segmentation allows each mirror set to be designed and manufactured with focused optimization, balancing complexity with performance
Solution Approach 2:
Curved reflection mirrors are used in both optical systems to achieve the required light convergence and equal magnification relationships. The curvature of these mirrors is specifically designed to create the virtual planes at the correct positions and angles. By using curved surfaces rather than flat mirrors, the system achieves precise control over light path geometry, enabling high-resolution image projection while distributing the optical complexity across two manageable subsystems
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 device provides a good-quality image by maintaining the light beam's diameter and focus, enhancing image resolution and quality, and allowing for the projection of high-resolution images, even for users with varying visual acuity.
Implementation Method 1
the first optical system includes a first curved reflection mirror, and a second curved reflection mirror that is located in a latter stage of the first curved reflection mirror and reflects the scanning light to the first virtual plane
Implementation Method 2
the second optical system includes a third curved reflection mirror, and a fourth curved reflection mirror that is located in a latter stage of the third curved reflection mirror and reflects the scanning light to the second virtual plane
Data Source
AI summary
In the first embodiment and the second embodiment, the case where an image is projected on the retina 52 of one of the eyes 50 has been described, but an image may be projected on the retinas 52 of both eyes 50. In addition, the scan mirror 14 has been described as an example of a scan unit, but the scan unit may be any element as long as it can scan a light beam. For example, other components such as potassium tantalate niobate (KTN) crystal that is an electro-optic material may be used as the scan unit. The case where the light beam is a laser beam has been described as an example, but the light beam may be light other than the laser beam.