Abstract: Several different methods of testing the integrity and proper operation of the drive and sense electrodes in a mutual capacitance sensing device such as a touchscreen or touchpad are disclosed herein. According to one embodiment, measured values of mutual capacitance corresponding to individual cells in a mutual capacitance sensing device are compared to one another and to predetermined thresholds. The results of the comparison are employed to determine whether any of the traces forming the electrodes in the device are defective. By way of example, traces can be defective if they are broken, too thin, too thick, or shorted together. The various embodiments of the methods disclosed herein may be used for touchscreen or touchpad quality control in a manufacturing setting, or may be used to test touchscreens or touchpads that have already been incorporated into electronic devices. The various methods disclosed herein lower manufacturing costs, increase product quality and yield, and may be carried out quickly.

Abstract: An optical encoder includes an optical encoder pattern of alternating light elements and dark elements, and an optical unit, including an optical emitter providing light to the encoder pattern, and an optical sensor including a photo-detector receiving the light from the optical encoder pattern and in response thereto outputting a sinusoidal signal indicating relative movement between the optical sensor and the encoder pattern. In one embodiment, the photo-detector has a diamond shape, a modified-diamond shape, or an hourglass shape. In another embodiment, at least one of the light elements and the dark elements of the optical encoder pattern has a diamond shape, a modified-diamond shape, or an hourglass shape.

Abstract: A system and method for preventing unauthorized installation of a software program utilizes an activation key that is based on a hardware key and a software key. The hardware key is associated with a particular hardware device, while the software key is associated with the software program to be installed. Installation of the software program in a hardware device is enabled to proceed only if the software key extracted from the activation key matches the software key of the software program.

Abstract: An I/O module for use with I/O devices such as pumps, valves, thermocouples, and mass flow controllers includes I/O interface software pre-programmed within the I/O module. The pre-programmed I/O interface software enables a user to remotely configure the I/O module to support an I/O device by selecting an I/O device from a menu of pre-programmed I/O devices. Once an I/O device is selected and the I/O module is configured to support the selected I/O device, a user can utilize pre-programmed interfaces to remotely monitor a parameter of the I/O device and to control the operation of the I/O device. Because the I/O module includes configuration, monitoring, and control capability pre-programmed within the I/O module, no additional I/O software is required to configure an I/O module, to begin monitoring a parameter of an I/O device, and/or to control a parameter of an I/O device.