Wrist-worn input device

A wrist-worn input device measuring a biopotential for use in inputting a gesture, comprising:

• a band that forms at least part of a tubular structure having a first opening and a second opening at two ends thereof in an axial direction thereof;
• one or more electrodes open to an internal surface of the band;
• a first position determiner that is located close to the first opening and has a shape to be engaged with at least part of the periphery of the styloid process of ulna of a user;
• a sensor that measures the biopotential of the user using the one or more electrodes;
• and
• a communication device that transmits the biopotential of the user measured by the sensor,
• wherein the one or more electrodes include at least one measurement electrode, and
• wherein the at least one measurement electrodes is located at a center point between the first opening and the second opening along the axial direction or located at a point closer to the second opening than to the center point along the axial direction.

A wrist-worn input device, comprising:

• a band in a rectangular development shape, except a cutout, extending along a first longitudinal line and a second longitudinal line, and having the cutout extending along the first longitudinal line;
• and
• a plurality of electrodes including one or more measurement electrodes, one or more reference electrodes, and one or more ground electrodes, each of the electrodes open to an internal surface of the band,
• wherein a center line extends along the internal surface between the first longitudinal line and the second longitudinal line,
• wherein the one or more measurement electrodes are located in an area between the center line and the second longitudinal line,
• wherein one or more potentials measured by using the one or more measurement electrodes are normalized by using one or more potentials measured by the one or more reference electrodes,
• wherein a longest distance between the cutout and the one or more reference electrodes is shorter than a shortest distance between the cutout and the one or more measurement electrodes, and
• wherein the one or more reference electrodes and the one or more ground electrodes are located in an area between a line running from a first intersection of the cutout and the first longitudinal line in perpendicular to the second longitudinal line and a line running from a second intersection of the cutout and the first longitudinal line in perpendicular to the second longitudinal line.