Ophthalmic Corneal-Shape Measurement With Reflection-Pattern Lighting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional ophthalmic devices face challenges in uniformly illuminating pattern indices for cornea shape measurement due to complex configurations and non-uniform illumination caused by variations in the position of pattern indices relative to surface light emitting plates.
Innovation Solution
The ophthalmic device employs a surface light emitting panel in a flat plate shape with a light guide plate and an illuminating light source, an index plate with a measurement pattern, and an imaging optical system, adjusting the density of the reflection pattern to ensure uniform illumination across the cornea, using a reflective plate to enhance illumination uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a surface light emitting plate is formed in a substantially spherical shape or using conical shapes to illuminate the pattern index, then the illumination coverage is improved, but the manufacturing complexity increases significantly
Solution Approach 1:
The patent applies curvature by forming the light guide plate into a spherical shape that matches the curvature of the cornea. This curved surface light guide plate provides uniform illumination across the pattern index while maintaining ease of manufacture through a single integrated structure, resolving the contradiction between illumination coverage and manufacturing complexity.
2Illumination intensity
If multiple flat plate surface light emitting plates are divided and configured behind a hemispherical pattern index plate, then the illumination distribution is improved, but the device complexity increases
Solution Approach 1:
The patent merges multiple light emitting elements into a single integrated surface light guide plate. This unified structure simplifies the device configuration while maintaining uniform illumination distribution across the pattern index, eliminating the need for multiple separate plates and reducing overall system complexity.
Solution Approach 2:
The surface light guide plate is formed with a curved surface that matches the corneal curvature, enabling uniform illumination distribution across the entire pattern index area. This curved geometry naturally distributes light evenly without requiring multiple divided plates, thus reducing device complexity while improving illumination uniformity.
3Adaptability or versatility
If the position of the pattern index plate relative to the surface light emitting plates varies, then the adaptability to different eye positions is improved, but the illumination uniformity deteriorates
Solution Approach 1:
The spherical surface light guide plate matches the curvature of the cornea, providing consistent illumination uniformity regardless of the examinee's eye position. The curved geometry ensures that light is distributed evenly across the pattern index plate even when there are variations in positioning, thus maintaining illumination uniformity while accommodating position adaptability.
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 for more uniform illumination of the pattern index on the cornea, simplifying the device structure and ensuring consistent light intensity across the measurement area, thereby improving cornea shape measurement accuracy.
Implementation Method 1
a light guide plate in a flat plate shape and an illuminating light source, the light guide plate having a back surface on which a reflection pattern is formed to reflect illumination light guided inside
Implementation Method 2
a reflection pattern is formed to reflect illumination light guided inside and a front surface from which the illumination light reflected by the reflection pattern is emitted
Data Source
AI summary
An ophthalmic device for measuring a cornea shape of an examinee's eye includes a measurement pattern index plate on which a pattern index for measuring the cornea shape of the examinee's eye is formed, and a surface light emitting panel in a flat plate shape that illuminates the measurement pattern index plate from behind to project the pattern index onto the cornea of the examinee's eye. The surface light emitting panel includes a light guide plate that guides light, an illuminating light source configured at an end portion of the light guide plate, and a reflection pattern configured on a back surface side of the light guide plate to reflect light from the illuminating light source to a front surface side of the light guide plate. A density of the reflection pattern is adjusted corresponding to a positional relationship between the surface light emitting panel and the pattern index.