Patent ID: 6985137
Filing Date: 2006-01-10
Classification: G06F,H04M,Y02D

Abstract:
1. A method of preventing unintended touch pad input resulting from accidental touching of a touch pad device in an electronic device by an external object when the touch pad device is exposed, said electronic device including a key lock function settable in a first state allowing a user to input into the electronic device one of a plurality of input functions, and settable in a second state allowing the user to input into the electronic device one of a number of selected ones of said plurality of input functions, wherein said touch pad device allows the user to execute a touch-pad function by placing the object at the touch pad device, thereby providing a touch signal for achieving a touch pad input indicative of the touch-pad function, and wherein the touch pad device comprises: a touch pad area having a first side and an opposing second side; a first set of optical sensor components disposed along the first side of the touch pad area; and a second set of optical sensor components disposed along the second side of the touch pad area, each of the first and second sets of optical sensor components including at least two light emitters and one light receiver disposed substantially between the two light emitters to detect the presence of the object at the touch pad device, each of the light emitters located at a location different from other ones of the light emitters and also different from the light receivers, the light emitters emitting light only when activated, such that the light receiver is capable of receiving light emitted from the activated light emitters and reflected by the object for providing an output signal, and wherein the output signal is caused to change due to an increased amount of light received in the light receiver when the object is present, said method comprising the steps of: detecting the change in the output signal for providing the touch signal when the object is present; determining, in response to the touch signal, whether the key lock function is in the first state or in the second state when the touch area is exposed to the external object; and providing the touch pad input indicative of the touch pad function.