| 摘要 |
A conventional display device, such as a marking engine for a laser printer or digital copier, having a nominal resolution (where the energy source for the display device can be selectively activated) and a predetermined threshold level for producing output image dots, is modified to a different (higher or lower) resolution or modified to produce output dots along axes different from the axes of the display device (such as for producing halftone screens on angles), by selectively activating the energy source to produce overlap areas that exceed the device threshold and thereby produce dots at positions that are not on the normal resolution positions of the device. Such threshold exceeding overlap areas may be achieved by activating the marking engine's energy source at a plurality of positions, with the energy at some positions being selectively below the threshold level for producing an output dot, but with the combined energy at the desired dot positions being above the threshold level to produce the desired dot. These overlap areas may be produced by modifying the duration that the energy source is activated, by the placement of less than full-extent energy actuation within the pixel extent, by activating the energy source multiple times within a pixel extent, by modulating the intensity of the energy source, and by modulating the shape of the energy cluster that the energy source (or energy beam) produces. For example, a 300x300 laser print engine can be modified to selectively produce 200 or 400 DPI output for fax, 600 or 1200 DPI output for higher resolution printing (as well as the normal 300 DPI printer output). Data compression/decompression techniques can be used to reduce the storage requirements, especially at the higher resolutions.
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