Systems and methods use a digital microform imaging apparatus for sensing an image mark on the microform containing the image of a document. The use of an area sensor with an adjustable region of interest can be used to improve the detection speed of image marks as a roll of microform is being transported.

Provided are a screen frame and a laser projection display device. The screen frame includes a plurality of side frames that are connected end to end, where a joint of each two of the plurality of side frames is provided with at least two connectors and receiving grooves corresponding to the at least two connectors in a one to one manner, and the at least two connectors have inserting portions extendable into the receiving grooves, at least one inserting portion of the inserting portions is provided with a telescopic engaging member, and a side wall of a receiving groove which is corresponding to an inserting portion having the engaging member is provided with a receiving hole corresponding to the engaging member; the engaging member is configured to extend into the receiving hole for positioning; and the inserting portions are connected to side walls of the receiving grooves by fasteners.

Provided are a screen frame and a laser projection display device. The screen frame includes a plurality of side frames that are connected end to end, where a joint of each two of the plurality of side frames is provided with at least two connectors and receiving grooves corresponding to the at least two connectors in a one to one manner, and the at least two connectors have inserting portions extendable into the receiving grooves, at least one inserting portion of the inserting portions is provided with a telescopic engaging member, and a side wall of a receiving groove which is corresponding to an inserting portion having the engaging member is provided with a receiving hole corresponding to the engaging member; the engaging member is configured to extend into the receiving hole for positioning; and the inserting portions are connected to side walls of the receiving grooves by fasteners.

A handheld projector for visually defining an event zone on a grid mat of a tabletop game to obviate the need to manually make proximity calculations during game play to determine whether players indicated on a game board are located in sufficient proximity to a virtual event to be effected.

A handheld projector for visually defining an event zone on a grid mat of a tabletop game to obviate the need to manually make proximity calculations during game play to determine whether players indicated on a game board are located in sufficient proximity to a virtual event to be effected.

Improved corners for overhead frames having primary and secondary fasteners that are located within the distal rectangular periphery of alpha oriented overhead frame components so that the width of bundled overhead frames is reduced; protrusions leading to snagging are eliminated; obstructions to the preferred, industry-wide, disassembled frame orientation are precluded; and frame components may be rigidly bundled into the alpha orientation without the wasteful and time-consuming use of temporary materials.

Improved corners for overhead frames having primary and secondary fasteners that are located within the distal rectangular periphery of alpha oriented overhead frame components so that the width of bundled overhead frames is reduced; protrusions leading to snagging are eliminated; obstructions to the preferred, industry-wide, disassembled frame orientation are precluded; and frame components may be rigidly bundled into the alpha orientation without the wasteful and time-consuming use of temporary materials.

Improved corners for overhead frames having primary and secondary fasteners that are located within the distal rectangular periphery of alpha oriented overhead frame components so that the width of bundled overhead frames is reduced; protrusions leading to snagging are eliminated; and the preferred, industry-wide, disassembled frame orientation is maintained.

Improved corners for overhead frames having primary and secondary fasteners that are located within the distal rectangular periphery of alpha oriented overhead frame components so that the width of bundled overhead frames is reduced; protrusions leading to snagging are eliminated; and the preferred, industry-wide, disassembled frame orientation is maintained.

Provided are a screen frame and a laser projection display device. The screen frame includes a plurality of side frames that are connected end to end, where each two adjacent side frames of the plurality of side frames are connected by at least two connectors, and the at least two connectors are connected to the each two adjacent side frames by fasteners; the at least two connectors include a first connector and a second connector, and an inserting direction of a fastener on the first connector is perpendicular to a plane where the screen frame is located, and an inserting direction of a fastener on the second connector is parallel to the plane where the screen frame is located. The present disclosure can realize accurate alignment and joining relatively easily.