METHOD OF FABRICATING A HIGH-HARDNESS CASE HAVING LOGOTYPES, LETTERS OR FIGURES FOR PORTABLE DEVICES

The present invention concerns a method of fabricating a high-hardness material having logotypes, letters or figures, which comprises the steps of: engraving a polished surface of a high-hardness material like zirconia ceramics or single crystal sapphire so as to form a figure, letter or logotype as an intaglio; filling the intaglio with glass frit; subjecting the surface to heat treatment; and polishing the surface again. The glass surface thus highly polished has hardness lower than the surrounding high-hardness material, thus hardly producing scratches, and the ornamental figure, letter or logotype is strongly united with the surrounding high-hardness material. The method produces variously colored and very beautiful letters, logotypes and figures of a high resolution, and therefore such high-hardness materials may be widely used as a material for covering portable devices or ornaments.