Concave-Mirror Ophthalmic Scanning for Wide-Angle Fundus Fixation
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Solution Overview
Problem
Existing ophthalmic devices struggle to provide a fixation target that covers a widened angle of the ocular fundus, leading to interruptions in the presentation of the fixation target due to the limitations of existing optical systems.
Innovation Solution
The ophthalmic device employs a reflecting face that scans light in a specific direction, combined with a concave mirror and multiple light sources, allowing simultaneous incidence of fixation target light and scanning light on the ocular fundus via different optical paths, and includes a moving mechanism for adjusting the light sources' positions to cover a wider angle of the ocular fundus.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single light source is used for fixation target, then the optical system is simple, but the fixation target cannot cover a widened angle of the ocular fundus
Solution Approach 1:
The patent divides the single fixation target function into multiple light sources (first light source and second light source) positioned at different locations. Each light source illuminates a different region of the ocular fundus, enabling wide-angle coverage without requiring a single complex optical path. The first light source covers a first region while the second light source covers a second region, effectively segmenting the illumination task.
Solution Approach 2:
The patent introduces a spatial dimension solution by positioning light sources at different angular locations around the optical axis. Instead of trying to expand the coverage of a single on-axis light source, the invention uses multiple light sources distributed in different angular positions, thereby covering a widened field of view through spatial distribution rather than increasing the power or aperture of a single source.
2Adaptability or versatility
If multiple light sources are used to cover wider angle, then the fixation target coverage is improved, but the optical path becomes more complex
Solution Approach 1:
The patent employs a shared optical system that serves multiple functions: it guides both the imaging light from the emission section and the fixation target light from multiple light sources to the ocular fundus. The same optical components (lenses, mirrors, beam splitters) are used for both imaging and fixation target illumination, eliminating the need for separate dedicated optical paths for each light source and reducing overall system complexity.
Solution Approach 2:
The patent merges the optical paths of multiple light sources into a single shared optical system. Instead of providing separate complete optical paths for each light source, the invention combines them so that they share common components such as the beam splitter, scanning mirrors, and focusing lenses. This merging approach reduces the total number of optical components and simplifies the overall optical architecture.
3Area of stationary object
If light sources are positioned to cover wider angle, then the ocular fundus coverage is improved, but the light sources may interfere with scanning light
Solution Approach 1:
The patent ensures continuous and coordinated operation of multiple light sources with the scanning light. The light sources are positioned and controlled to provide continuous fixation target illumination across different regions as the scanning light moves. The timing and positioning are synchronized so that the fixation target light remains visible throughout the scanning process without interruption or interference, maintaining continuous useful action for both imaging and fixation.
Solution Approach 2:
The patent uses optical components such as beam splitters and dichroic mirrors as intermediaries to separate and guide different light paths. These intermediary elements enable the fixation target light from multiple light sources and the scanning light to coexist in the same optical system without interfering with each other. The intermediaries direct each type of light along its appropriate path to the ocular fundus and back to the detector.
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
Enables continuous presentation of a fixation target across a wider angle of the ocular fundus without interruption, improving the imaging process by ensuring consistent light emission and fixation target visibility.
Implementation Method 1
a reflecting face arranged to reflect the fixation target light, to reflect scanning light emitted by an emission section and incident on the reflecting face via the one of the slit mirror, the angled spherical mirror, the non-spherical mirror, the pair of parabola mirrors, the pair of parabolic mirrors, and the lens system
Implementation Method 2
an ellipsoidal mirror having a mirror face disposed such that the scanning light reflected by the reflecting face is incident on the ocular fundus of a subject's eye when the subject's eye is placed at a focal point of the ellipsoidal mirror
Implementation Method 3
lens system, the light source being adjacent one of a slit mirror, an angled spherical mirror, a non-spherical mirror, a pair of parabola mirrors, a pair of parabolic mirrors, and the lens system
Data Source
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AI summary
The present invention provides an ophthalmic device comprising a light source (82; 84) arranged to emit a fixation target light, and a reflecting face (68A) arranged to reflect scanning light emitted by an emission section and to scan the scanning light in a specific direction by changing orientation, the emission section being a source of the scanning light that is different to the light source. The ophthalmic device further comprises a concave mirror face (70A) disposed such that the scanning light reflected by the reflecting face (68A) is incident on the ocular fundus of a subject's eye (38) when the subject's eye is placed at a focal point of the concave mirror (70) during use of the ophthalmic device, and is arranged such that, when the subject's eye (38) is placed at the focal point of the concave mirror (70) during use of the ophthalmic device and when the light source (82; 84) emits the fixation target light, the fixation target light and the scanning light are simultaneously incident on the ocular fundus via different optical paths both propagating via the concave mirror face (70A) and the focal point, the target fixation light following a predetermined optical path for fixing the gaze of the subject's eye (38).