Abstract: A driver chip for use in an LED or other multi-element recording printhead includes a plurality of current driver channels. Data for determining recording durations for each of the current driver channels is provided on a data bus. A token bit is shifted through a shift register in association with image data to be latched by registers corresponding to a specific driver channel. The driver chip is operational in different recording resolution modes so that it may be connected to recording arrays of different resolutions. When operational in other than its highest or higher resolution, a by-pass signal is generated causing the token bit to by-pass certain stages of the shift register.

Abstract: A non-impact printhead having a plurality of driver IC chips and and a plurality of recording elements such as LEDs. Each driver IC chip includes a plurality of current-carrying channels that are operative for carrying current to respective recording elements on the printhead and a control for controlling operation of the driver.

Abstract: A method for connecting selected bonding pads of a universal current driver IC supporting a maximum resolution, e.g., 600 DPI, with the appropriate bonding pads of the same or a lower resolution LED chip array. The output pads of the current driver IC and the pads of the LED elements of each LED chip array or segment are matched so that wire bonding takes place between the physically closest pads. Consequently, the universal current driver IC may be employed with LED chips or segments of a certain standardized length that contain 96 LED elements for 300 DPI, 128 LED elements for 400 DPI, and 192 LED elements for 600 DPI or the like. The selection algorithm, in picking the physically closest IC current driver pad to be connected to an LED element pad leaves certain stages of the IC driver unconnected.

Abstract: In an LED printhead or the like, a plurality of LED arrays are arranged in a row. Opposite the LED arrays are driver IC chips providing current in respective current driving channels to respective LEDS. Current to an LED for recording of a pixel will be provided for say a duration related to a multibit image data signal. A data bus is provided for carrying the data signals. The data signals are latched in respective data registers associated with each current driving channel. A token bit shift register is provided for identifying a respective data register for latching of the multibit image data signal presently on the data bus. A direction of shifting of the token bit is determined through automatic self-sensing of the token bit itself as the token bit is moved from a boundary scan register that forms a part of a boundary scan test architecture.

Abstract: A method for producing a calibrated printhead having a plurality of light-emitting recording elements such as LEDs includes the steps of (a) burning-in the recording elements until a further aging characteristic of the recording elements is in a generally linear range; (b) measuring a light intensity emitted by each recording element after the burning-in in step (a); (c) establishing a target value for additional burning-in of at least those recording elements having measured light intensities above a minimum measured light intensity for a recording element; and (d) respectively providing additional burning-in to those recording elements towards the target value. An apparatus including the calibrated printhead has no data provided to the printhead which is corrected for relative non-uniformity of the recording elements to each other.