Electrochromic Lens Surface Control for Uniform Coloring
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Solution Overview
Problem
The heating process during the production of electrochromic elements causes undulations on the surface, leading to significant differences in light and dark shading between lenses, making them defective, especially when applied to spectacles.
Innovation Solution
The electrochromic element is designed with controlled undulations by adjusting the difference in reflection power and maximum height undulation within specific ranges, ensuring uniformity and reducing shading variations between lenses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If heating is applied during preforming or injection molding to shape the electrochromic element, then the lens substrate can be formed, but undulations are caused on the surface of the electrochromic element due to heat influence
Solution Approach 1:
The patent applies preliminary anti-action by pre-forming the electrochromic film with a specific curvature radius (R1) that is different from the final lens curvature radius (R2). This pre-applied curvature counteracts the thermal deformation that occurs during heating, so that when the heating process is completed, the electrochromic film naturally settles into the desired flat or uniformly curved surface without significant undulations. The curvatures are specifically designed so that R1 < R2, creating a preliminary distortion that compensates for thermal expansion effects.
Solution Approach 2:
The patent implements preliminary action by performing the electrochromic film formation and initial curvature application before the heating process. The film is laminated onto the lens substrate with a predetermined curvature while in a controlled state, and then the entire assembly undergoes heating. This sequence allows the thermal processing to occur on a pre-configured structure, minimizing the development of undulations during the heating phase.
2Ease of manufacture
If the electrochromic film is preformed in a curved surface shape and then injection-molded, then the lens substrate can be produced, but light and dark shading appears on the surface when coloring is applied
Solution Approach 1:
The patent uses preliminary anti-action by designing the pre-forming curvature radius (R1) to be smaller than the final lens curvature radius (R2). This creates an intentional preliminary distortion that counteracts the thermal effects during injection molding. When the electrochromic film is subsequently colored, the uniformity of the surface ensures even light reflection and consistent color appearance without light and dark shading variations.
Solution Approach 2:
The patent applies parameter changes by controlling the curvature radius as a critical parameter throughout the manufacturing process. The curvature radius is changed from R1 during preforming to R2 in the final lens product. By carefully selecting and controlling this parameter at each stage, the patent achieves both ease of manufacture through injection molding and manufacturing precision in terms of color uniformity, as the controlled curvature change prevents surface undulations that would cause shading variations.
3Ease of manufacture
If heating temperature is increased to ensure proper molding, then the lens substrate can be formed, but the undulation on the surface increases
Solution Approach 1:
The patent implements preliminary anti-action by pre-curving the electrochromic film with a specific radius (R1) that compensates for thermal deformation. This allows the use of higher heating temperatures for proper molding without excessive undulation, as the pre-applied curvature counteracts the thermal effects. The preliminary curvature acts as a buffer that absorbs the thermal expansion and contraction stresses.
Solution Approach 2:
The patent applies preliminary action by establishing the correct curvature geometry before the high-temperature molding process. The electrochromic film is pre-formed and laminated with the appropriate curvature (R1 < R2) prior to heating, so that when high temperatures are applied for proper molding, the surface undulation is minimized because the structure is already pre-configured to accommodate thermal changes.
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 approach suppresses differences in light and dark shading, improves yield, and ensures consistent coloring without warping in the field of vision when applied to spectacles.
Implementation Method 1
electrochromic elements that utilize an electrochromism phenomenon in which a voltage is applied to cause a reversible oxidation-reduction reaction and colors are reversibly changed
Implementation Method 2
The heating condition during the above-described preforming or injection molding is, for example, 100° C. or higher, and an undulation is caused on the surface of the electrochromic element due to the influence of heat
Data Source
AI summary
An electrochromic element, a lens for spectacles or the like wherein an undulation is controlled by adjusting the difference in reflection power within a predetermined range. An electrochromic element wherein a lens substrate and an electrochromic film are laminated together, wherein an absolute value of a difference in reflection power in 30% or more of spaces between local regions adjacent to each other among individual local regions obtained by splitting a 40 mm×40 mm range a surface center into 5 mm× 5 mm regions is 0.05 D or more and 0.5 D or less, a surface of the electrochromic film has an undulation, and a maximum height undulation (Wz) in 30% or more of the individual 5 mm×5 mm local regions obtained by splitting the 40 mm×40 mm range the surface center is 6 μm or more and 30 μm or less.