Abstract: A portable electronic device including a first body, a second body, and a hinge mechanism is provided. The second body is connected to the first body through the hinge mechanism, and the hinge mechanism has a basis axis located at the first body and a rotation axis located at a lower end of the second body. When the second body rotates with respect to the first body, the rotation axis slides along an arc shaped path with respect to the basis axis to increase or decrease a distance between the rotation axis and the basis axis and increase or decrease a distance between the lower end of the second body and a back end of the first body.

Abstract: A method for treating a mold includes grinding an outer metal surface of a mold body of the mold with a first material; lapping the outer metal surface after the grinding with a second material that is finer than the first material; and polishing the outer metal surface after the lapping to achieve an average surface roughness (Ra) less than or equal to about 0.15 ?m and a waviness height (Wa) less than or equal to about 100 nm. A mold for shaping glass-based material can include a mold body having an outer metal surface, wherein the outer metal surface has an average surface roughness (Ra) less than or equal to about 0.15 ?m and a waviness height (Wa) less than or equal to about 100 nm.

Abstract: A method for treating a mold includes grinding an outer metal surface of a mold body of the mold with a first material; lapping the outer metal surface after the grinding with a second material that is finer than the first material; and polishing the outer metal surface after the lapping to achieve an average surface roughness (Ra) less than or equal to about 0.15 ?m and a waviness height (Wa) less than or equal to about 100 nm. A mold for shaping glass-based material can include a mold body having an outer metal surface, wherein the outer metal surface has an average surface roughness (Ra) less than or equal to about 0.15 ?m and a waviness height (Wa) less than or equal to about 100 nm.

Abstract: A method for treating a mold includes grinding an outer metal surface of a mold body of the mold with a first material; lapping the outer metal surface after the grinding with a second material that is finer than the first material; and polishing the outer metal surface after the lapping to achieve an average surface roughness (Ra) less than or equal to about 0.15 ?m and a waviness height (Wa) less than or equal to about 100 nm. A mold for shaping glass-based material can include a mold body having an outer metal surface, wherein the outer metal surface has an average surface roughness (Ra) less than or equal to about 0.15 ?m and a waviness height (Wa) less than or equal to about 100 nm.