Abstract: An eye refractometer is provided with a projection optical system for projecting test beams forming test patterns such that the central ray of each test beam passes through the pupil of the eye to be inspected while being spaced apart from the optic axis in order to form test patterns corresponding to three meridians forming 60.degree. with each, a focusing lens disposed in the projection optical system and movable only in one direction during one measurement, and a beam detecting device for detecting the reflected images of the test patterns by the retina of the eye and generating electrical signals corresponding to the three meridians.

Abstract: An increment type position control apparatus is adapted to evaluate a numerical value concerning a positional point by making subtraction between the data in a position feedback counter for counting a feedback pulse from an incremental encoder and the data in a commanded position buffer from a processor. Upon depression of an origin return command button provided on a control panel, the position feedback counter and the commanded position buffer are each loaded with a predetermined value, whereupon a pitch is given, whereby an object being controlled is controllably moved in the direction toward the origin. If and when the object being controlled exceeds the origin position, the same is stopped and the counter and the buffer are each again loaded with an appropriate numerical value, whereupon a given pitch is provided, whereby the object being controlled is moved in the direction toward the origin and comes to a point to almost exceeding the origin position.

Abstract: A method and system of velocity control for an automatic welding apparatus, wherein at least either a welding torch or a workpiece is movable in the directions of the three rectangular axes and point-to-point (PTP) position control of the torch and workpiece is effected between two preset positions at a preset relative velocity. In effecting the PTP position control, the direction of movement is determined based on information about the two preset positions, and the components of the preset velocity in the directions of the three rectangular axes are determined based on the direction of movement thus found and also based on information about the preset velocity, these components being used as instruction velocities in the respective axes.

Abstract: An automatic welding apparatus comprising a workpiece fixture carried by a moving member for rotation about a horizontal axis extending in a back and forth direction, said moving member being provided on a carriage for sliding movement in a lateral direction, said carriage being provided for sliding movement in said back and forth direction, and a torch fixture carried by an arm for rotation about a vertical axis, said arm being provided for sliding movement in the vertical direction. In another embodiment, the workpiece fixture is provided only for rotation about a horizontal axis extending in the back and forth direction, and the torch fixture is carried by the arm for rotation about the vertical axis, which arm is provided at the end of a column for sliding movement in said lateral direction, which column is provided on a sliding member for sliding movement in the vertical direction, which sliding member is provided on a guide for sliding movement in said back and forth direction.