Abstract: A robot control apparatus includes a controller that controls a robot including a holder. The controller obtains a first image of at least one holding target. The controller selects, from the at least one holding target recognized in the first image, the at least one holding target to be held by the holder as a selected target. The controller determines a holding position on the selected target on a basis of a second image of the selected target. The controller causes the holder to hold the selected target at the determined holding position.

Abstract: According to one embodiment, in an X-ray tube, an electron convergence cup has a first surface located closer to the anode, and an electron convergence groove opening on the first surface and housing a filament. The first surface has a first edge located on the opening, and a second edge located on the opening and opposite to the first edge in a first direction. The first edge is closer to an outer peripheral part than the second edge is. When the distance between the first edge and the filament in the first direction is defined as a first distance and the distance between the second edge and the filament in the first direction is defined as a second distance, the first distance is shorter than the second distance.