Patent ID: 7310083

Claim:
A coordinate input device comprising: a housing having a first cover and a second cover which face each other; a movable member which is disposed between the first cover and the second cover and which is slidable along the first cover and the second cover; an endless resilient member; and detectors for detecting a sliding direction and a sliding distance of the movable member, the detectors being disposed inside the housing, wherein one of the first cover and the second cover comprises a supporter for supporting an inner periphery of the resilient member, wherein the movable member in an initial position before a sliding operation is resiliently biased by the resilient member such that the movable member faces the supporter, wherein, when the movable member is slid in a certain direction from the initial position, the resilient member is stretched in the certain direction and the detectors detect the sliding direction and the sliding distance of the movable member, wherein, when the sliding operation of the movable member is finished, a resilient force of the resilient member stretched in the certain direction forces the movable member to return automatically to the initial position, and wherein a top plate of the first cover is provided with an opening such that the movable member is exposed through this opening, and the sliding operation of the movable member is performed through the opening; a cavity is provided between the top plate of the first cover and a surface of the second cover that are disposed facing each other; the movable member is in the form of a circular plate, the movable member being disposed within the cavity and being slidable in arbitrary directions; the supporter has a circular shape; the endless resilient member comprises a coil spring whose opposite ends are connected, the coil spring being disposed within the cavity with an initial state of the coil spring surrounding an outer periphery of the supporter; the detectors are slidable and are provided below the resilient member; and when the movable member at the initial position is slid in a certain direction, one side of the resilient member is stretched by the movable member in the certain direction along the surface of the second cover while the other side of the resilient member is retained by the supporter, the resilient member returning automatically to its initial position when the operation of the movable member is finished.