Abstract: An emergency alert communication system comprising a radio frequency receiver. The radio frequency receiver decodes incoming emergency alert signals and demodulates data header signals and emergency alert voice message signals of the emergency alert signals. Included in the data header signals are event and location code signals, which are followed by the emergency alert voice message signals. The demodulated data header signals in the form of digital data header signals are applied to a microcontroller. A telephone keypad of a telephone device is actuated to enter into the microcontroller event and location code signals. Should the event and location code signals demodulated by the receiver and applied to the microcontroller match the event and location code signals entered into the microcontroller by the telephone keypad, the microcontroller routes through an audio switching circuit the emergency alert voice message signals to a speaker, a recording device and a telephone handset of a telephone device.

Abstract: An improved detector system for an optical mouse including an optical mouse housing for supporting a four-by-four array of detector elements, a light source, and a light directing mirror. The light source may be visual, ultraviolet or infrared. The optical detector elements of the array are labeled A through P starting with row 1, column 1 and going left to right. Each element is about one-quarter of a grid period square and capable of producing an electrical output signal corresponding to the amount of light it receives. The elements are grouped into pairs of elements which are located so as to image areas on the grid pattern a distance of an odd multiple of grid periods apart in a direction which is orthogonal to the direction of motion which they detect. Pairs A+C, E+G, I+K, and M+O detect vertical motion and pairs A+I, B+J, C+K, and D+L detect horizontal motion.

Abstract: A cursor position control system in which an optical mouse having a light source and three-by-three detector array moves over a surface having a grid pattern or intersecting orthogonal grid lines of a first color and spaces defined between the grid lines of a second contrasting color. The grid lines are characterized by a line width. Detector cells are grouped into pairs of cells for detecting motion in a particular direction. Cells in a pair are separated so as to image areas an odd multiple of line widths apart in a direction orthogonal to that particular direction. Pairs of cells image areas separated in the particular direction from areas imaged by related pairs of cells by an odd multiple of half line widths. Pairs of electrical signals from pairs of cells are combined then differentiated with respect to time to produce related quadrature signals indicative of the amount and direction of movement of the mouse relative to the surface.