Input device with key input and touch input, and operating method thereof

An input device, comprising:

• a controller comprising a drive end configured to output a drive signal and a receiving end configured to receive a detected signal;
• a substrate;
• a first electrode group, a second electrode group and a plurality of ground electrodes arranged at a same level on the substrate, wherein
• the first electrode group comprises at least one first electrode formed on the substrate, the at least one first electrode extending along a first direction of the substrate and configured to receive the drive signal from the drive end,
• the second electrode group comprises a plurality of second electrodes configured to output the detected signal to the receiving end, wherein the plurality of second electrodes are arranged as multiple separated rows which are spaced from each other in the first direction on the substrate, and each of said multiple separated rows includes multiple second electrodes separately arranged along a second direction,
• the plurality of ground electrodes are separately formed on the substrate and not connected to the drive end to receive the drive signal therefrom and not connected to the receiving end to output the detected signal thereto, wherein each of the plurality of ground electrodes is respectively arranged between two adjacent second electrodes in one of said multiple separated rows, and has a width in the first direction smaller than widths of the two adjacent second electrodes in the first direction;
• and
• a plurality of elastic pads each crossing over the at least one first electrode and one of the ground electrodes, which is not connected to the ground electrode under a different elastic pad, along the second direction of the substrate to electrically contact the two adjacent second electrodes in one of said multiple separated rows and at two sides of the first electrode crossed thereby, wherein
• each of the ground electrodes is configured to form an inductive capacitor with a corresponding elastic pad, and
• in response to a press on the corresponding elastic pad, said press decreasing a distance between the each of the ground electrodes and the corresponding elastic pad without causing a contact therebetween,
• the inductive capacitor is configured to generate a capacitance increase, and
• the controller is configured to detect the press based on the capacitance increase.