Retinal Image Projection Beam Diameter Control

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Solution Overview

Problem

In Maxwellian view image projection devices, it is challenging to maintain the diameters of multiple light beams on the retina within a predetermined range while ensuring a half angle of the larger angle of view is 10° or greater.

Innovation Solution

The device includes a light source, a scanning unit, and an optical system that converges light beams at a convergence point in the eye, with the diameters of the light beams adjusted to 0.36 mm or greater and 0.46 mm or less when the half angle of the larger angle of view is 10° or greater and 30° or less.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the half angle of the larger angle of view is increased to 10° or greater for wide-angle retinal irradiation, then the coverage area on the retina is improved, but the diameters of the light beams on the retina become difficult to maintain within a predetermined range

Engineering Contradiction:

Improvecoverage area on retinaVSAvoidlight beam diameter uniformity

Core Design Contradiction:

Area of stationary objectVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by precisely controlling the diameter of light beams incident on the cornea within the range of 0.36 mm to 0.46 mm. This parameter control ensures that when the optical system projects images onto the retina with a half angle of view of 10° or greater, the diameters of the light beams on the retina are maintained within 55 μm to 77 μm, thus resolving the contradiction between wide coverage area and uniform beam diameter

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces mechanical adjustment mechanisms with optical parameter control. Instead of mechanically adjusting the optical system to maintain beam diameter, the invention uses controlled light beam parameters (diameter at cornea incident) combined with the optical system's natural convergence properties to achieve consistent beam diameters on the retina across wide viewing angles

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 configuration allows the diameters of the light beams on the retina to be maintained within a predetermined range, ensuring consistent image projection across varying angles of view.

Implementation Method 1

an optical system that converges a plurality of light beams, which are emitted from the scanning unit at different times, at a convergence point in an eye of a user and then irradiates a retina of the user with the plurality of light beams to project an image

Methodology Applied

Scientific EffectLight beam convergence: Focusing

Data Source

PatentUS20250143561A1Image projection device, vision test device, and fundus photography device

Publication Date: 2025.05.08 TDK CORP

AI summary

An image projection device includes a light source, a scanning unit that scans a light beam emitted from the light source, and an optical system that converges a plurality of light beams, which are emitted from the scanning unit at different times, at a convergence point in an eye of a user and then irradiates a retina of the user with the plurality of light beams to project an image, wherein diameters of the plurality of light beams incident on a cornea of the user are adjusted to 0.36 mm or greater and 0.46 mm or less when a half angle of a larger one of a horizontal angle of view and a vertical angle of view of an area where the retina is irradiated with the plurality of light beams at the convergence point is 10° or greater and 30° or less.