Apparatus for sensing operation of air cushion and method therefor

An input device for a computer, the input device comprising:

• an air cushion, an inside of which is filled with air, the air cushion having a plurality of patterns arrayed on an inner surface thereof;
• a pneumatic pressure sensor sensing a pneumatic pressure in the air cushion to output a corresponding pneumatic pressure sensing signal;
• a temperature sensor sensing a temperature in the air cushion to output a corresponding temperature sensing signal;
• a capturing unit positioned in a bottom portion of the air cushion, capturing the plurality of patterns, and outputting a pattern image for each captured pattern;
• and
• a controller connected to the pneumatic pressure sensing unit, temperature sensing unit, and capturing unit, determining the pneumatic pressure in the air cushion by using the pneumatic sensing signal, determining the temperature in the air cushion by using the temperature sensing signal, comparing the captured pattern image with an initial pattern image to determine an area of a contact surface between the air cushion and a pressure applying unit, which applies pressure to an outer side of the air cushion, and movement amounts in X- and Y-directions, determining a magnitude of a force applied to the air cushion in the Y-direction by using the determined temperature, pneumatic pressure, and area of the contact surface, and determining a magnitude of a force applied to the air cushion in the X-direction by using the determined movement amount of the contact surface,
• wherein the computer determines a motion direction of an object or a cursor of a display device according to the determined magnitude of the force applied in the Y-direction and the determined magnitude of the force applied in the X-direction.