Contact Lens Marking via Rough Surface Light Scattering
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Solution Overview
Problem
Contact lenses with existing marking techniques face challenges in achieving adequate visibility without compromising lens strength or causing eye irritation, as enlarged or deepened marks can lead to diminished durability, irritation, rotation, and vision issues.
Innovation Solution
A contact lens design featuring a concave annular mark with a center projection and a rough flat section, where the radius of curvature of the flat section is significantly greater than the connecting sections, providing enhanced visibility through light scattering and shadow contrast while minimizing the mark's size and depth, thus avoiding the issues associated with larger or deeper marks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the mark is enlarged and deepened to enhance visibility through light reflection, then visibility is improved, but lens strength is diminished and eye irritation increases
Solution Approach 1:
The invention applies a rough surface treatment specifically to the bottom face of the mark, creating localized light scattering properties only where needed for visibility. This allows the mark to be visible without requiring the entire mark structure to be enlarged or deepened, thus preserving lens strength while achieving the visibility enhancement goal.
Solution Approach 2:
The invention changes the surface parameter (roughness) of the mark's bottom face to optimize light scattering. By controlling the surface roughness parameter rather than changing the mark's size or depth parameters, the invention achieves improved visibility while maintaining lens structural integrity and avoiding eye irritation.
2Illumination intensity
If the mark is enlarged to capture more incident light, then reflected light is sufficient, but the mark may catch on the eyelid causing rotation or shifting
Solution Approach 1:
The rough surface treatment is applied locally to the bottom face of the mark, concentrating the light scattering function in a small localized area. This eliminates the need to enlarge the overall mark dimensions, preventing the mark from catching on the eyelid while still achieving sufficient reflected light for visibility.
3Illumination intensity
If the mark is deepened to improve visibility, then light scattering is enhanced, but lens strength is compromised
Solution Approach 1:
The invention creates light scattering properties through surface roughness on the bottom face of the mark rather than through increased mark depth. This localized surface modification achieves enhanced light scattering while keeping the mark depth minimal, thereby preserving lens strength.
Solution Approach 2:
The invention changes the surface roughness parameter of the mark's bottom face to optimize light scattering efficiency. By modifying the surface parameter rather than the depth parameter, the invention achieves improved visibility without compromising lens structural integrity.
4Illumination intensity
If a smooth concave bottom face is used for light focusing, then visibility is improved, but most incident light is transmitted rather than reflected
Solution Approach 1:
The invention applies a rough surface treatment to the bottom face of the mark to convert transmitted light into scattered reflected light. This localized surface modification changes the light interaction from transmission to scattering reflection, improving visibility while reducing energy loss through transmission.
Solution Approach 2:
The invention converts the harmful effect of light transmission (which reduces visibility) into a beneficial effect by using surface roughness to scatter the transmitted light back toward the observer. The rough surface transforms what would be lost transmitted light into useful reflected light for mark visibility.
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 design ensures effective visibility without compromising lens strength or causing eye irritation, reducing the risk of rotation and irritation, and maintaining good wear comfort by limiting the mark's size and depth, thereby addressing the limitations of previous marking techniques.
Implementation Method 1
providing enhanced visibility through light scattering and shadow contrast
Implementation Method 2
laser processing techniques as proposed, for example in Japanese Unexamined Patent Publication No. JP-A-8-194193 have come to be widely used, whereby an engraved marking, produced by directing a laser beam of high-density focused light energy onto the die which is used to mold the resin mold for shaping the contact lens
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A contact lens (10) having a mark (34) on at least one of an anterior face (14) and a posterior face (16) thereof, wherein the improvement including: the mark (34) being defined by a concave annular section (38) having inside and outside peripheral borders of circular shape, and a center projection (36) situated in a center of the concave annular section (38); an outside diameter dimension of the concave annular section (38) is held within a range of 0.1-0.5mm; a widthwise center section of the concave annular section (38) in radial cross section is a flat section (42) having smaller depth change and greater radius of curvature than widthwise side sections; and at least the flat section (42) of the mark (34) has a rough surface. The method of manufacturing the contact lens (10) is also disclosed.