摘要 |
A constant pressure mechanism of a probe (2A, 2B) for unidirectionally urging the probe in a predetermined direction by virtue of elastic force of a spring (10A, 10B, 14D, 14E) is provided, the constant pressure mechanism comprising: a first pulley (6A, 5B, 6C to 6E) rotatably supported around a central axis (4A, 4B) by an instrument stationary portion (3A, 3B); a rotation force urging mechanism (15) for urging the first pulley in a predetermined rotation direction; and a first wire (8A, 7B, 8C to 8E) having a first end fixed to the first pulley and a second end jointed to the probe. <IMAGE> |