8. The device according to claim 7 , wherein the processor is further configured to: enlarge the currently displayed font based on one of a parabolic enlargement rule, an elliptical enlargement rule, or a circular enlargement rule, with the first enlargement coefficient configured by the operating system and the second enlargement coefficient configured by the current application.
8. The device according to claim 7 , wherein the processor is further configured to: enlarge the currently displayed font based on one of a parabolic enlargement rule, an elliptical enlargement rule, or a circular enlargement rule, with the first enlargement coefficient configured by the operating system and the second enlargement coefficient configured by the current application. 10. The device according to claim 8 , wherein the processor is further configured to: enlarge the currently displayed font based on the following equation: x 2 k ⁢ ⁢ 1 2 + y 2 k ⁢ ⁢ 2 2 = 1 , ⁢ x < T ; wherein y is a size of the enlarged font, x is the size of the currently displayed font, k1 is the first enlargement coefficient configured by the operating system, k2 is the second enlargement coefficient configured by the current application, and T is the preset maximum threshold.