Hoya patented a method for manufacturing thin annular glass plates with precise surface roughness. By irradiating the edges with a laser beam, the outer and inner surfaces are melted to achieve a smooth finish. The inner edge surface has a higher roughness than the outer edge surface. GlobalData’s report on Hoya gives a 360-degree view of the company including its patenting strategy. Buy the report here.

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According to GlobalData’s company profile on Hoya, AI-assisted medical imaging was a key innovation area identified from patents. Hoya's grant share as of January 2024 was 42%. Grant share is based on the ratio of number of grants to total number of patents.

Method for manufacturing annular glass plate with specific surface roughness

Source: United States Patent and Trademark Office (USPTO). Credit: Hoya Corp

A recently granted patent (Publication Number: US11884582B2) discloses a method for manufacturing an annular glass plate with specific characteristics. The method involves irradiating the outer and inner circumferential edge surfaces of an annular glass blank with a laser beam to melt the surfaces and form molten surfaces with a specific surface roughness. The molten surfaces must have an arithmetic average surface roughness Ra not larger than 0.1 µm, with the inner circumferential edge surface having a higher surface roughness than the outer circumferential edge surface.

Furthermore, the patent details additional steps in the manufacturing process, such as controlling the power density of the laser beam emitted to the inner circumferential edge surface relative to the outer circumferential edge surface, ensuring equal relative movement speeds during irradiation, and avoiding bulging of the inner and outer circumferential edge surfaces relative to the main surfaces of the annular glass plate. The method also extends to manufacturing a glass substrate for a magnetic disk by performing polishing processing on the main surfaces of the annular glass plate. Edge surface polishing is specifically excluded from the process, and the final step involves forming magnetic films on the main surfaces of the glass substrate. Overall, the patent outlines a precise and controlled method for manufacturing annular glass plates and glass substrates for magnetic disks, emphasizing specific surface roughness requirements and process parameters to achieve the desired end product.

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GlobalData Patent Analytics tracks bibliographic data, legal events data, point in time patent ownerships, and backward and forward citations from global patenting offices. Textual analysis and official patent classifications are used to group patents into key thematic areas and link them to specific companies across the world’s largest industries.