We polish glass spherical lenses and prisms used in optical products such as automotive lenses, lenses for projectors, interchangeable lenses for cameras. Among the required specifications for glass polishing, the evaluation item that has the greatest impact on the optical performance of the product is the shape error, so it is critical to minimize the difference from the required shape in the effective area of the polished surface. In glass polishing, processing conditions vary depending on the shape, glass material, and required accuracy, and it is necessary to find the processing know-how for each lens. In particular, spherical lenses for cutting-edge objective lenses require an extremely high accuracy of λ/40 (approximately 16 nm), so if, for example, the lens diameter is the height of Tokyo’s Sky Tree (634m), the shape error is controlled with an accuracy of about the thickness of a one-yen coin (1.5mm).

Examples of mass production processing results:
・Spherical lens outer diameter size from a few millimeters to 150 mm.
・Materials: In addition to ordinary glass, special glass materials, such as soft glass fluorite and hard synthetic quartz, can be processed.
・Surface accuracy: λ/2(approx. 316nm) for Φ150mm, λ/10(approx. 63nm) for Φ30mm, λ/20(approx. 32mm) forΦ5mm external diameter lenses

We can produce minute rectangular lenses (double-sided aspheric shapes are also possible) used in telecommunication optics and other applications by molding without external processing or by secondary cutting from array-molded lenses.
The technology that makes this possible is our droplet glass mold, a proprietary glass molding method.

Example: 1mm x 0.8 mm(cut product) as the smallest size rectangular lens, 1mm x 0.6mm for single lens molding without secondary cutting process.
Dimensional tolerance: ±0.01mm or less for the outer shape, ±0.005mm for the positional accuracy between the outer shape and center of the optical surface.
Performance: Products with transmitted wavefront accuracy of 50 mλrms or less (@1310 nm) are available.

By utilizing the high degree of geometric freedom on the glass drop receiving-side, which is a feature of Konica Minolta’s unique droplet glass mold technology, we can manufacture glass lenses with inflection points on both sides (commonly known as gull lenses), which are difficult to mold using conventional reheat molding.
While these lenses are essential for low-profile cameras, by manufacturing them with glass, an all-glass, ultra-low-profile camera module that is resistant to temperature changes can be realized.

Example of results:
・External size: Up to Φ 9 mm
・Surface decenter is 5 μm or less (precision), 7.5 μm (general purpose).
・Center thickness accuracy is ±0.005 mm (precision) and ±0.01 mm (general purpose) for external sizes up to Φ 5mm, and ±0.009 mm (precision) and ±0.015 mm (general purpose) for Φ 5 to Φ 9mm.
・Surface accuracy (PV) is 0.3 μm or less (precision) and 0.9 μm or less (general-purpose) for external sizes up to Φ 5, and 0.4 μm or less (precision) and 1 μm or less (general-purpose) for Φ 5 to Φ 9mm.