| 摘要 |
PURPOSE:To detect contact with high sensitivity, by making three conductive spherical bodies stride obliquely on the outside circumferential surface of a conductive ring, holding a prescribed static position of one specified body, and making the contact tip contact with an object to be measured, so that at least one of the three conductive spherical bodies is separated from the conductive ring. CONSTITUTION:In case when a contact probe is moved in the X(-) axial direction by a probe moving device and the tip of a contact 10 has been made to contact with an object to be measured, the contact 10 is moved in the X(+) direction when the tip of the contact contacts with the object to be measured, spherical bodies 28a, 28b slightly slide on the outside circumferential surface of a ring plate 22, and also a spherical body 28c is separated toward the direction of about 90 deg. against the contact direction of a ring piece 24 and the spherical body 28c as shown by a 2 point chain line. Accordingly, a nonconducting state of the ring piece 24 and the spherical body 28c is detected by a contact detecting circuit, and by reading a coordinate value in this case, the coordinate are measured. |
