Abstract: The data required to specify an image which is to be printed by a printing device, such as an ink-jet or laser printer, can be substantially reduced by omitting the data specifying the dot size or amplitude modulation (AM). Instead, the processor of the printing device determines the dot density in the immediate vicinity of each dot and, from that density measurement, calculates the appropriate dot size and modulates the dot size accordingly when driving the print head or print laser.

Abstract: The method of the invention enables a printer to interpret received page description data and to generate a series of corresponding graphics commands that enable graphic objects to be printed. During the interpreting action, memory resources are allocated for storage of the graphics commands, which are then arranged into a display list. The printer's personality maintains a measure of available memory for allocation and, upon sensing a low memory level, causes a compression of the series of graphics commands in the display list to achieve a more efficient use of the available memory assets.

Abstract: In a device including a replaceable cartridge containing a consumable material, the cartridge having at least one moving part, a system for estimating the use of consumable material from the cartridge is disclosed. The system includes an information storage medium secured to the moving part of the cartridge. A read-write head is mounted in the device in proximity with the information storage medium, and is adapted and constructed to write information on and read information from the information storage medium. The storage medium can be provided as a magnetic storage medium, which may be configured as an annular disc. The moving part can be provided as a generally cylindrical roller assembly including a drive gear. The drive gear can include an end surface to which the storage medium may be secured. The device itself can be any suitable printing device, such as a laser printer. The cartridge may be provided as a toner cartridge, in which instance the consumable material would be toner.

Abstract: Image data such as text or half-tone images is compressed and decompressed. A compressor has three phases: a bit-run length phase that counts the length of each run of consecutive identical pixels; a pairs-repetition phase that compresses repeated pairs of pixel run values to one copy of the repeated pair and a repeat count; and an optional dictionary-based micro-table encoder. The micro-table, which may be used in any application calling for a least recently used (LRU) mechanism, has multiple qualification layers, with elements within a qualification layer being promoted to the next higher qualification layer upon the occurrence of a table hit for that element, and being demoted to the next lower qualification layer by being bumped by elements promoted up from below. The result is a table that is weighted both by frequency and recency of hits.

Abstract: The output of a conventional laser printer having a resolution of 300.times.300 dots per inch (DPI), and a predetermined threshold level for forming image dots, is enhanced by selectively providing interleaved image dots between the normal scan lines of the laser printer. Such interleaved image dots between scan lines may be achieved by appropriately energizing the two pixels directly above and directly below that desired interleaved dot, with the energizations at one or both pixels being selectively below the threshold level for producing a dot on the scan line, but with the combined energization at the desired interleaved point being above the threshold level to produce the desired interleaved dot. An input 600.times.

Abstract: 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.

Abstract: An improved method and apparatus for the creation and application of visual images such as textual characters is provided, which preferably makes use of a digital computer (12) and laser printer (16). In the preferred method, a desired image is developed using the computer (12), typically with specific selection of font style, image orientation and size of characters; the final image is then printed using printer (16) on a substrate (18) presenting a release surface (20). An image-removing web (22) is then applied over the printed image, causing the printed image to adhere to the web (22). The web (22) is then stripped from the substrate (18) and can be applied to any selected support surface.