Abstract: Because laser printers are capable of rendering only a maximum number of characters per unit time, pervious printer would pre-render the entire page prior to print the page. This pre-rendering process greatly increases the memory requirements. To overcome this problem, there is provided a method for reducing memory requirements in a laser printer when printing a page of characters. First, the page is divided into a series of strips. Next, the entire page is scanned strip by strip for any strips that contain an excess number of characters, where the excess number is that number of character that exceeds the maximum number the printer can render in the given time. Assuming a complex strip is found, any common characters in the complex strips are prerendered. If, after pre-rendering the common characters any strip is still complex, then the excess characters are pre-rendered.

Abstract: This is an electronic scheme for correcting mechanical misalignment and electrical delays from laser beam to laser beam in the scan direction of a multiple beam laser scanning system for use in an electrophotographic machine. The position at which a reference beam is turned on is sensed and adjusted to a desired position. Thereafter, the positions at which non-reference laser beams are turned on are sensed and adjusted to the desired position. In one enbodiment, the energization of laser beams is positioned at the trailing edge of the second element of a photodector. In a second embodiment, the point of full laser energy is matched, beam to beam, at the junction of the same two elements in a CCD array. Programmable delay lines are used to obtain sub-pel resolution.

Abstract: This is an electronic scheme for correcting for mechanical misalignment and chromatic aberrations from laser beam to laser beam in the scan direction of a multiple beam laser scanning system for use in an electrophotographic machine. Each beam is first corrected for mechanical misalignment and thereafter for chromatic aberrations. A reference laser beam produces two pulses near the start of scan (SOS) and two pulses near the end of scan (EOS). A non-reference laser beam then produces SOS and EOS pulses from which the mechanical misalignment is calculated. A gated clock is energized by the reference pulse and a tapped delay line is used for nanosecond resolution.

Abstract: Motor test circuit for supplying an error indication signal if the speed variations of a motor under test exceed predetermined limits. The circuit includes a frequency-to-voltage converter or other source of voltage proportional to the motor speed and a reference source derived from the converter's output signal so that the test results are independent from errors due to drift in the converter's parameters caused by time, temperature, or other effects.