Patent ID: 6875977

Claim:
A method for providing communication of an optoelectronic keypad for a measuring instrument with an external device comprising of the following steps: providing an optoelectronic keypad with a transparent touch screen, at least two touch-sensitive control buttons, at least two light emitters each having an active state, at least two photodetectors, wherein said control buttons are located next to each other on one side of the surface of the touch-screen, the light emitters and the photodetectors being situated next to each other on the other side of the touch screen, and each one control-button, light emitter and photodetector are functionally associated with one another in a way as to constitute on action key, and wherein pressing the control button of an action key causes the light emanating from the light emitter of the pressed action key to be reflected at the actuated key and to impinge on the photodetector of that key; providing a central control and processing unit, wherein light emitters are connected to the central control and processing unit; providing a communication unit, wherein at least one light emitter and/or at least one photodetector is connected to said communication unit; accessing said at least one light emitter and said at least one photodetector by the communication unit in such fashion that light data generated along a predefined format and protocol containing information and transmitted via said at least one light emitter or received by said at least one photodetector is used for communication with the external device; providing a comparator for data evaluation; controlling the at least one light emitter selected for the communication with the external device in such fashion that the light data generated by it is received and read by the external device, and light data transmitted by the external device is received by the at least one photodetector selected for the communication with the external device and is fed to the comparator; evaluating the information contained in the light data transmitted by the external device, and forwarding the information contained in the light data transmitted by the external device to the central control and processing unit.