Optical Member Coating Ink for Refractive Index and Positioning Accuracy
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Solution Overview
Problem
The miniaturization and weight reduction of optical member products, achieved by using high-refractive-index optical members, lead to increased deviation of the condensing position, deteriorating image quality. Additionally, variations in the film thickness of the coating film on the optical member affect positioning accuracy when incorporated into a mirror frame.
Innovation Solution
An ink is developed for forming a coating film on optical members, comprising a black pigment, at least one colored or colorless pigment, a binder, and a volatile component. The ink is formulated to achieve an average refractive index of 1.60 or more and an average attenuation coefficient of 0.10 to 0.15, with a total volume ratio of pigments between 10% to 40% by volume, enhancing light shielding properties and film quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If high-refractive-index optical members are used for miniaturization and weight reduction, then the optical path can be bent to a large extent and the thickness of the optical member can be reduced, but the deviation amount of the condensing position increases and image quality deteriorates
Solution Approach 1:
A coating film is applied to the outer peripheral surface of the optical member to serve as an intermediary element. This coating film provides a reference surface for positioning that is independent of the optical path bending, thereby maintaining positioning accuracy even when the optical member is miniaturized with high refractive index materials.
Solution Approach 2:
The coating film is applied selectively to the outer peripheral surface of the optical member, creating a localized reference region. This local treatment does not interfere with the bulk optical properties needed for miniaturization while providing the necessary positioning reference at the periphery.
2Length of moving object
If the refractive index of the optical member is increased to reduce thickness, then miniaturization is achieved, but the deviation amount of condensing position with respect to assembling position increases
Solution Approach 1:
The coating film acts as an intermediary reference layer on the outer peripheral surface, providing a stable measurement基准 for positioning that is decoupled from the optical path deviations caused by high refractive index materials.
3Object-affected harmful factors
If a coating material containing high blackness metal oxide is used for inner surface reflection prevention, then reflection suppression is achieved, but the coating film may have poor workability during long-term storage
Solution Approach 1:
The coating material is formulated as a composite containing titanium dioxide (35-75% by mass), carbon black (2-20% by mass), and specific dispersants. This composite formulation maintains high blackness for reflection suppression while ensuring stable workability during long-term storage through controlled volatile content and pH.
Solution Approach 2:
The coating material parameters are precisely controlled: titanium dioxide with methanol hydrophobicity of 30-80% and pH of 3.0-8.0, carbon black with volatile content of 0.6-6.0% and pH of 3.0-8.0. These parameter specifications ensure both reflection suppression performance and storage stability.
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 coating film formed with this ink exhibits excellent light shielding properties, inner surface reflection suppression, refractive index, and film quality, thereby improving positioning accuracy and image quality of optical member products.
Implementation Method 1
an average attenuation coefficient k of the coating film of an optical member in the wavelength range of 400 nm to 700 nm is 0.10 to 0.15
Implementation Method 2
an average refractive index n of the coating film of an optical member in a wavelength range of 400 nm to 700 nm is 1.60 or more
Data Source
AI summary
Provided are an ink for forming a coating film of an optical member, containing a black pigment, at least one of a colored pigment or a colorless pigment, a binder, and a volatile component, in which, in a case of forming a coating film of an optical member, an average refractive index n of the coating film of an optical member in a wavelength range of 400 nm to 700 nm is 1.70 or more, and an average attenuation coefficient k of the coating film of an optical member in the wavelength range of 400 nm to 700 nm is 0.10 to 0.15, and a total ratio of the black pigment, the colored pigment, and the colorless pigment in an entire volume of the coating film of an optical member is 10% by volume to 40% by volume; and an application thereof.