Patent ID: 8803805

Claim:
An indexing device, comprising: a first sensing unit, generating a first move detection signal; a second sensing unit, generating a second move detection signal; a control unit, coupled with the first sensing unit and the second sensing unit; and a positioning member; wherein the control unit operates to generate a cursor control signal in response to a variance of the first move detection signal and/or the second move detection signal; wherein one of the first sensing unit and second sensing unit comprises: a sliding member, disposed on a casing of the device, an opening member formed on the sliding member, and a sensing module, slidably disposed on the sliding member; wherein the sensing module outputs a light signal through the opening member for detecting a movement of the casing; wherein the sensing module comprises: a substrate; a lens set, disposed on the substrate, directed toward the opening member; a sensor chip, disposed on the substrate, adjacent to the lens set; and a sliding board, connected with the substrate, slidably connected with the sliding member; wherein the sensor chip outputs the light signal through the lens set to the opening member; wherein the sliding board comprises: a containing member for containing the substrate, the lens set, and the sensor chip, adjacent to the positioning member; and a shelter member, extending to the outside of the containing member and contacted with the casing, for sheltering the opening member between the containing member and the casing; wherein the containing member has a perforating member directed toward the opening member and is formed corresponding to the lens set; and wherein the positioning member is disposed at one side of the sliding member for positioning the sensing module on the sliding member.