Optical inserts manufactured through Nittoh’s mastery of optics
Optical inserts are important mold pieces used to form the surfaces of lenses in lens molds, and the shape accuracy and surface roughness of these optical inserts are the most important aspects of our lens molds. Advanced manufacturing technologies are required to manufacture these high precision optical inserts.
Over many years, Nittoh has gained experience and developed technologies through the manufacture of lens molds and mass production of lenses, and this enables us to manufacture the optimum optical inserts for lens molds.
In addition to manufacturing our own accurate, high precision optical inserts plated with thick electroless Ni-P plating and optical inserts finished by direct lapping, we also manufacture and deliver optical inserts based on drawings provided by the customer.
High precision proven through measurement data
Nittoh manufactures high precision optical inserts machined with the optimum diamond cutting tools for achieving the required characteristics, and finished by direct lapping.
Shape accuracy of optical surfaces is generally expressed as a PV value (peak to valley). This PV value represents the maximum error between the machined surface and the design surface, which means the difference between the highest point (peak) and the lowest point (valley) within a specified measurement area.
Measurement examples of products machined with diamond cutting tools
【Large diameter product】
Machined product
Stainless steel material plus Ni-P plating
Size: 60mm diameter
Tool: Diamond cutting tool
Time: 12 hrs
Application: Projector lens
Shape accuracy: 0.299 µm PV
【Small diameter product】
Machined product
C5191 phosphor bronze
Size: 2mm diameter (aspherical surface measurement area: 0.55mm dia.)
Tool: Diamond cutting tool
Time: 4 hrs
Application: Cell phone lens
Shape accuracy: 0.0452 µm PV
Measurement: UA3P
【Measurement example of direct lapped product using hand polishing】
Average roughness of 1.12nm for measurement area of 0.9×0.9 mm
Peak to valley of 13.11nm for same measurement area
（1nm＝0.001μm＝0.000001mm）
Nittoh has confidence in delivery time and quality
Nittoh employs a comprehensive range of technologies cultivated through the development, design and manufacture of lenses and cameras to manufacture high precision optical inserts, and we can manufacture those optical inserts with thick electroless Ni-P platings in as little as three weeks.
We also manufacture optical insert blanks plated with thick electroless Ni-P coatings, and if the customer provides us with their own blanks, we can create a lapped mirror finish on the inserts or adjust them according to the customer’s correction value instructions.
●Workpiece materials and sizes
Nittoh has experience with optical inserts from 1mm to 100mm in diameter.
Ask us about other sizes as well.
Materials include SUS 420J2, brass, aluminum, phosphor bronze and other nonferrous metals, and carbide.
●Machined shapes
Aspherical, spherical, cylindrical, and Fresnel. Ask us about other special shapes as well.
Molds for glass molding
Nittoh’s glass molding technology consists of placing optical glass in heat-resistant molds with mirror-finish surfaces and then heating the material at high temperature and pressing under high pressure to mold the lenses.
When manufacturing our molds, we generally use binderless carbide that we accurately machine with ultraprecision processing machines and then polish. We can also use mold drawings provided by the customer to either manufacture the entire inserts or just the aspherical surfaces.
Machined size: Spherical, aspherical or other surfaces 5mm to 45mm in diameter
Mirror-finish inserts manufactured through ultraprecision machining: concave lenses, convex lenses, Fresnel lens, etc.
4529 Konami, Suwa City, Nagano Prefecture 392-0131 Japan