Patent ID: 9294089
Filing Date: 2016-03-22
CPC Classification: H03K

Claim Text:
1. A method for detecting capacitive touch keys, comprising: when a touch key is being touched, determining change trends of charge amounts in each charge accumulation region corresponding to a touch key, where the change trends comprise increment and decrement; performing charge adjustment to each charge accumulation region corresponding to a touch key until charge amounts in each charge accumulation region corresponding to a touch key reach stability based on the determined change trends, where if the change trend is decrement, charge adjustment is performed to the charge accumulation region until the charge amount in the charge accumulation region reaches a charge balance amount, and if the change trend is increment, charge adjustment is performed to the charge accumulation region until the charge amount in the charge accumulation region reaches a maximum value, where the charge balance amount is the charge amount in the charge accumulation region before the capacitive touch key is touched; calculating charge change amounts in each charge accumulation region when the touch key is being touched according to charge adjustment amounts in each charge accumulation region corresponding to a touch key, and calculating the ratio of the charge change amount to the charge balance amount in each charge accumulation region; when the change trend of charge amount in the charge accumulation region corresponding to the touch key is decrement, and the ratio of the charge change amount to the charge balance amount in the charge accumulation region corresponding to the touch key is greater than a first threshold and less than a third threshold, or is equal to the first threshold and less than the third threshold, determining the touch key is touched; and when the change trend of charge amount in the charge accumulation region corresponding to the touch key is increment, and the ratio of the charge change amount to the charge balance amount in the charge accumulation region corresponding to the touch key is greater than a second threshold and less than the third threshold, or is equal to the second threshold and less than the third threshold, determining the touch key is touched where an insulating dielectric layer is formed on the periphery of each touch key, a metal layer is formed on the periphery of the insulating dielectric layer, metal shield rings are formed between adjacent touch keys, and each touch key is connected with a standard unit capacitor.