Function-oriented Knowledge Base \ Optical Mouse Cord
Capacitive coupling transmits cursor control signals to computer
Use Play, Pause, Rewind
to control the animation of the image.
These controls work for Internet Explorer only. If you use another
web browser, right-click the image and select the Play
option.
Introduction A conventional computer mouse is normally connected
to a computer via a connection cord. A problem associated
with a corded mouse is that the cord often serves as an undesirable
barrier, which is annoying. Also, it can be broken or operate
intermittently. Because the cord is a required element, the
operational range of the mouse is limited. A method for providing
a mouse or other pointing device without a corded connection
to a computer is needed.
Description To transmit a cursor control signal, the use
of a capacitive coupling is proposed. The casing of a mouse
houses a double-head trigger circuit, which converts square-wave
signals from an interior circuit into pulse signals. On the
bottom of the mouse, there are several pulse-transmitting
electrodes. When the user's hand moves the mouse, the pulse-transmitting
electrodes generate pulse signals that contain cursor control
information. A mousepad contains a flexible pad and a metal
sheet coated with an insulating pad. Each pulse-transmitting
electrode has a capacitive coupling with the metal sheet through
the insulating pad. Due to this capacitive coupling, the transmitting
electrodes induce pulse signals in the metal sheet. The metal
sheet outputs these signals through a wire into a demodulating
circuit installed in the computer case. The demodulating circuit
restores the normal square-wave shape of the cursor control
signals. Thus, a capacitive coupling transmits cursor control
signals to the computer.
Additional information The transmitted pulse signals generate a low
energy electric field and have a low frequency. Therefore,
a high-frequency radio signal is non-existent and will consequently
not be generated and interfere with other electrical devices.
