Abstract: A printhead alignment sensor for an ink jet printer includes two terminals defining a substantially linear gap therebetween. An ink support device supports ink in the gap between the terminals. An electrical measuring device detects a change in an electrical resistance between the terminals when ink is supported in the gap by the ink support device.

Abstract: A method of printing a print image on a print medium using a printer includes providing a text printing mode, wherein a first predetermined number of bits identify a selected character to be printed. A host based printing mode is provided wherein selected bits each indicate whether a corresponding pixel should be printed. The printer is initialized to print in either one of the text printing mode and the host based printing mode. A second predetermined number of bits of a data stream associated with the print image to be printed are received within the printer. The second predetermined number of bits is examined to determine a presence of a command therein. The printer is enabled to print in an enabled printing mode. The enabled printing mode includes either the text printing mode or the host based printing mode, dependent upon the examination of the second predetermined number of bits. The printer is used to print on the print medium in the enabled printing mode.

Abstract: A method of printing a print image on a print medium using a printer includes providing a text printing mode, wherein a first predetermined number of bits identify a selected character to be printed. A host based printing mode is provided wherein selected bits each indicate whether a corresponding pixel should be printed. The printer is initialized to print in either one of the text printing mode and the host based printing mode. A second predetermined number of bits of a data stream associated with the print image to be printed are received within the printer. The second predetermined number of bits is examined to determine a presence of a command therein. The printer is enabled to print in an enabled printing mode. The enabled printing mode includes either the text printing mode or the host based printing mode, dependent upon the examination of the second predetermined number of bits. The printer is used to print on the print medium in the enabled printing mode.

Abstract: The invention described in the specification relates to an ink jet printer with multiple print heads that allows for the less restrictive installation of print head cartridges. The print head carriers are designed so that any of a variety of different types of print head cartridges can be inserted into any of the print head carriers. When image data is received, the ink jet printer's processor determines the appropriate type of print head cartridge that should be used to print the image data. Information electronically stored on the print head cartridges in the form of a read-only memory (ROM), bar code, or optical LED's, identifies the type of each print head cartridge. The printer processor examines this identification information on the installed print head cartridges to determine if one of the print head carriers contains the desired type of print head cartridge.

Abstract: A maintenance station for maintaining either a monochrome or a multi-color printhead in an ink-jet printer includes a single flexible wiper having a first wiping edge for wiping the ink-jet nozzle surface of a monochrome printhead and a plurality of second wiping edges for wiping the ink-jet nozzle surface of a multi-color printhead. Wiping of a monochrome printhead is accomplished by moving the printhead to one side of the wiper, raising the wiper into the path of travel of the nozzle surface, and moving the printhead past the wiper. Wiping of a multi-color printhead is accomplished in a similar manner but the printhead is first positioned on the opposite side of the wiper. The flexibility of the wiper is chosen to apply an optimum wiping force to a multi-color printhead as the printhead is moved past the wiper. A backstop is provided at one side of the wiper to brace it against deflection, so that the wiper applies a greater wiping force to a monochrome printhead than it does to a multi-color printhead.

Abstract: An ink-jet printer is provided with a printhead maintenance system which is capable of providing optimum maintenance for different types of color or monochrome printheads. Dummy heaters are provided in each printhead as a way of identifying the different types of printheads. A maintenance controller is provided in the printer for executing a maintenance program comprising first and second maintenance algorithms for controlling maintenance of monochrome and color type printheads. The controller includes an E.sup.2 PROM memory into which descriptor records are downloaded from a data processor to which the printer is connected. Each descriptor record contains a head detection pattern and various parameters specifying the number and time of wipes, the number of nozzle fires, etc. necessary to maintain a head of the type corresponding to the head detection pattern.

Abstract: A maintenance station for an ink jet printer comprises two modules supported from the printer middle frame by a tongue and groove arrangement and secured in place only by retaining elements integrally formed with the middle frame. The first module includes a wiper element and a cap to provide an air seal around the nozzles. The wiper and cap are mounted on a pivoted rocker element so that as the wiper is moved toward the printhead the cap is moved away therefrom and visa-versa. The second module carries a small DC motor, a nut with a pair of forked arms, and gearing for converting bidirectional rotation of the motor into linear reciprocal motion of the forked arms. The forked arms engage projections on the rocker element so that the wiper or cap is moved toward or away from the printhead depending on the direction of rotation of the motor. In a first position of the rocker element the wiper is positioned in the path of the printhead so as to wipe the nozzles as the printhead is moved back and forth.