Abstract: An auto-focusing alignment and measurement system for use in precisely positioning a semiconductor substrate with respect to an integrated circuit mask is herein disclosed. This system includes a moveable convergent lens operable with another pair of convergent lenses for alternately focusing images of the mask and the substrate onto a photodiode array. The photodiode array serves as a focus detector and, together with associated signal processing circuitry, provides a feedback signal for controlling displacement of the moveable lens to equal the separation between the mask and the substrate with an accuracy better than the depth of field of the optics. An illumination source and viewing optics provide a magnified view of images of both the mask and the substrate superimposed and in focus, thereby facilitating alignment of the substrate with respect to the mask prior to photolithographic printing.

Abstract: Circular maze game apparatus includes a transparent sphere which encloses another sphere having a maze on its external periphery, with predetermined paths laid out throughout the maze between a predetermined starting point and a predetermined ending point. A rolling element, such as a marble, is disposed on the outer periphery of the inner sphere. The purpose of the game is to move the rolling element along the predetermined path from the starting point to the ending point through the maze by manipulating the game apparatus. At selected locations in the maze, and adjacent to the selected path, apertures extend into the center of the inner sphere so that if the rolling element strays away from the predetermined path, the rolling element may roll into the center of the sphere. In this instance the player must start over.

Abstract: Game apparatus includes a bowl having a sloping floor and a receptacle centered beneath the floor, and a rotating element having an opening therein through which rolling elements may be selectively admitted or dropped into the receptacle, is disposed above the receptacle. At least two different types or colors of rolling elements are disposed on the floor and may be selectively allowed to fall into the receptacle to the intended exclusion of others of the rolling elements, thus comprising a game of skill and coordination.

Abstract: Modular panel apparatus which is particularly useful for providing wall partitions and divider panels of varied sizes and configurations. A panel frame having a rectangular or another polygonal shape is assembled from tubular members that are interconnected together with corner members which lock the tubular members to form a rigid frame. A panel of suitable dimensions is then positioned within the frame, and the panel is held in place by retaining members which removably fit over the frame and secure the panel in place. Panel members of various standard or nonstandard sizes and configurations may be accommodated within corresponding frames.