Abstract: A robot arm mechanism has a plurality of joints. Of the plural joints, a first joint is a rotational joint that rotates on a first axis, a second joint is a rotational joint that rotates on a second axis, and a third joint is a linear motion joint that moves along a third axis. The second axis is perpendicular to the first axis and is a first distance away from the first axis. The third axis is perpendicular to the second axis and is a second distance away from the second axis.

Abstract: A purpose is to prevent a first connection piece string from colliding against a second connection piece string in a robot arm mechanism including a linear extension and retraction joint.

Abstract: An extendable and retractable arm mechanism includes a first structure group formed by coupling a plurality of first structures and a second structure group formed by coupling a plurality of second structures. Each of the first structures includes lock part for fixing the second structures. When the first structure group and the second structure group extend, the lock part fixes the second structures to the first structures.

Abstract: An object of the present invention is to prevent unnecessary driving stop of a stepping motor. A robot arm section includes a robot arm, a stepping motor 31a, a motor driver 31b, an encoder 31c and a step-out detection section 31e. The robot arm has a joint J1. The stepping motor generates power for operating the joint. The motor driver drives the stepping motor according to a target angle. The encoder outputs an encoder pulse every time a drive shaft of the stepping motor rotates by a predetermined angle. The step-out detection section detects a step-out of the stepping motor based on the target angle and a current angle of the stepping motor that is identified based on the encoder pulse. When the stepping motor does not recover from the step-out before a predetermined grace time elapses from a time at which the step-out is detected, the motor driver stops driving the stepping motor at the time point at which the grace time elapses.

Abstract: A multi-joint arm mechanism includes an arm supporting member a first, second and third joints. The third joint has a linear extension and retraction axis. The third joint includes flat-shaped first structures bendably coupled to one another, second structures having a C-shaped section and bendably coupled to one another, a supporting member supporting the stiffened first and second structures, and a drive member sending and drawing the stiffened first and second structures. The first and the second structures are linearly stiffened by being in contact with each other and return to a bent state by being separated from each other. The second structures are bent toward the bottom parts and conveyed into the arm supporting member. The first structures are bent in a same direction as the second structures and conveyed into the arm supporting member. The first structures are stored in the arm supporting member along the second structures.