Abstract: An imaging apparatus includes a controller executing instructions to form a latent image, and a print engine. The print engine includes a laser source, a micro-electromechanical system (MEMS) device, and a module for mounting the MEMS device. The print engine is communicatively coupled to the controller and configured to form the latent image using the laser source and the MEMS device. The module includes a base having a first support and a second support, the second support having a support guide feature; and a bracket attached to the MEMS device. The bracket has a central axis, a first end, and a second end, the second end having a bracket guide feature, the first end being affixed to the first support to form a cantilever arrangement. The support guide feature engages the bracket guide feature to form a sliding joint having a sliding axis substantially parallel to the central axis.

Abstract: In bi-directional imaging, such as bi-directional printing, a driving mechanism scans a light beam through a scan path across an imaging window. A controller enables transmission of video data to a modulator when the light beam is positioned for imaging on the imaging window. Video data is transmitted to the modulator when the light beam is traveling in a forward direction or a reverse direction across the imaging window, whereby a modulated light beam is capable of producing an image when traveling in the forward or reverse directions. The controller adjusts scan durations or image rasterization rates to ensure that each scan is properly aligned with the prior and subsequent scan.

Abstract: A system for driving a torsion based on frequency, amplitude and offset control signals includes a pulse width modulator subsystem configured to generate output pulses having controlled pulse durations alternately to each of two channels, the output pulses encoding the frequency, amplitude and offset control signals. A driver circuit is configured for driving the torsion oscillator with a voltage of one polarity during a pulse output to the one of the channels, and a voltage of opposite polarity during a pulse output to the other of the channels.

Abstract: A method for operating a torsion oscillator at its resonant frequency. The method performs an open-loop frequency sweep starting with nominal operation parameters saved from the factory or from a previous operation of the torsion oscillator. The sweep determines an open-loop resonant frequency and an open-loop drive level. A closed-loop resonant frequency sweep is performed and a closed-loop steady-state resonant frequency is determined. This frequency is used to calculate a closed-loop overshoot and a closed-loop steady-state drive level. The torsion oscillator is then operated in a closed-loop mode at the closed-loop steady-state resonant frequency and starting at the closed-loop steady-state drive level. Finally, the nominal operation parameters are updated and stored in non-volatile memory. The method minimizes the effects of ambient environmental conditions including air density on the steady-state operation of the torsion oscillator.

Abstract: A module for mounting a micro-electromechanical system (MEMS) device includes a base having a first support and a second support. The second support has a support guide feature. The module also includes a bracket attached to the MEMS device. The bracket has a central axis, a first end, and a second end. The second end has a bracket guide feature. The first end is affixed to the first support of the base to form a cantilever arrangement. The support guide feature engages the bracket guide feature to form a sliding joint having a sliding axis substantially parallel to the central axis.

Abstract: A method for operating a torsion oscillator at its resonant frequency. The method performs an open-loop frequency sweep starting with nominal operation parameters saved from the factory or from a previous operation of the torsion oscillator. The sweep determines an open-loop resonant frequency and an open-loop drive level. A closed-loop resonant frequency sweep is performed and a closed-loop steady-state resonant frequency is determined. This frequency is used to calculate a closed-loop overshoot and a closed-loop steady-state drive level. The torsion oscillator is then operated in a closed-loop mode at the closed-loop steady-state resonant frequency and starting at the closed-loop steady-state drive level. Finally, the nominal operation parameters are updated and stored in non-volatile memory. The method minimizes the effects of ambient environmental conditions including air density on the steady-state operation of the torsion oscillator.

Abstract: A method reduces the Q factor of the resonant frequency response of a torsional oscillator system in a laser printer, where the Q factor is expressed as a function of the resonant frequency and 3 dB bandwidth of the frequency response. The frequency response of the torsional oscillator system is a function of at least a rotational inertia, a spring constant and a damping constant. The method includes the steps of decreasing the rotational inertia of the torsional oscillator system by a first factor, and decreasing the spring constant by a second factor that is substantially equal to the first factor. The method generally increases component yields, thereby reducing component costs. Also, laser printers using torsion oscillators having reduced Q factors may be used over a wider speed range. Conversely, a single laser printer model may be used at a single speed, rather than at speeds that vary due to variations in resonant frequency.

Abstract: A method for determining an operating point of an oscillation controller. The method builds a model of an oscillation device based upon its design parameters. Then the resonant frequency of each specific oscillator is measured in its application environment, and the model, or a table derived from the model is used to define the operating point. The operating point may be expressed in terms of clock counts by factoring in the clock rate of the oscillation controller.

Abstract: A method for improving the operation of an electrophotographic printer. The method includes providing an electrophotographic printer containing a laser scanning unit. A torsion oscillator for the laser scanning unit is enclosed in closed compartment. The closed compartment includes side walls having first and second side wall edges, a bottom wall attached on the first side wall edges, and a cover attached adjacent to the second side wall edges. The closed compartment is sufficient to reduce stray air currents from adjacent the torsion oscillator thereby improving the operation of the electrophotographic printer.

Abstract: A system for driving a torsion oscillator based on frequency, amplitude and offset control signals includes a pulse width modulator subsystem configured to generate a stream of repetitive pulse signals which encodes the frequency, amplitude and offset control signals, a low pass filter for filtering the stream of repetitive pulse signals to provide a filtered output, and a driver circuit for driving the torsion oscillator based on the filtered output.

Abstract: A torsion oscillator (FIG. 1) is stabilized in operation by determining the current resonant frequency (62); in a first procedure, observing the oscillator for change in resonant frequency (64), and then restoring the amplitude and median offset (66) without changing the drive frequency. In an alternative procedure, after determining the resonant frequency (62); setting the drive frequency close to but offset from the current resonant frequency (74), observing the oscillator for change in resonant frequency (76), and the restoring the close offset to the changed resonant frequency (78). By operating slightly off peak, the direction of resonant change is immediately known. The first procedure has less difficulties in implementation, but requires more power.

Abstract: A torsion oscillator (FIG. 1) is stabilized in operation by determining the current resonant frequency (62); in a first procedure, observing the oscillator for change in resonant frequency (64), and then restoring the amplitude and median offset (66) without changing the drive frequency. In an alternative procedure, after determining the resonant frequency (62); setting the drive frequency close to but offset from the current resonant frequency (74), observing the oscillator for change in resonant frequency (76), and the restoring the close offset to the changed resonant frequency (78). By operating slightly off peak, the direction of resonant change is immediately known. The first procedure has less difficulties in implementation, but requires more power.

Abstract: A torsion oscillator (FIG. 1) is stabilized in operation by determining the current resonant frequency (62); in a first procedure, observing the oscillator for change in resonant frequency (64), and then restoring the amplitude and median offset (66) without changing the drive frequency. In an alternative procedure, after determining the resonant frequency (62); setting the drive frequency close to but offset from the current resonant frequency (74), observing the oscillator for change in resonant frequency (76), and the restoring the close offset to the changed resonant frequency (78). By operating slightly off peak, the direction of resonant change is immediately known. The first procedure has less difficulties in implementation, but requires more power.

Abstract: A torsion oscillator (FIG. 1) is stabilized in operation by determining the current resonant frequency (62); in a first procedure, observing the oscillator for change in resonant frequency (64), and then restoring the amplitude and median offset (66) without changing the drive frequency. In an alternative procedure, after determining the resonant frequency (62); setting the drive frequency close to but offset from the current resonant frequency (74), observing the oscillator for change in resonant frequency (76), and the restoring the close offset to the changed resonant frequency (78). By operating slightly off peak, the direction of resonant change is immediately known. The first procedure has less difficulties in implementation, but requires more power.

Abstract: A torsion oscillator (FIG. 1) is stabilized in operation by determining the current resonant frequency (62); in a first procedure, observing the oscillator for change in resonant frequency (64), and then restoring the amplitude and median offset (66) without changing the drive frequency. In an alternative procedure, after determining the resonant frequency (62); setting the drive frequency close to but offset from the current resonant frequency (74), observing the oscillator for change in resonant frequency (76), and the restoring the close offset to the changed resonant frequency (78). By operating slightly off peak, the direction of resonant change is immediately known. The first procedure has less difficulties in implementation, but requires more power.

Abstract: A method of activating an electrophotographic machine includes determining at least one condition of the electrophotographic machine. Power is applied to a polygon mirror. A time period required for the polygon mirror to accelerate from a stationary condition to a target rotational velocity is measured. The measured time period and data associated with the at least one condition are stored in a memory device. The polygon mirror is decelerated back to the stationary condition. Power is reapplied to the polygon mirror at a point in time. The measured time period and the data are used to determine when to begin at least one process in the electrophotographic machine relative to the point in time.

Abstract: A method of aligning print images of an electrophotographic machine on a print medium includes reflecting a first laser beam off of a first rotating reflector to thereby scan the first laser beam across a first photoconductive drum to produce a first scan line in a scan direction. The rotation of the first reflector is cyclically repeated to thereby produce a plurality of substantially parallel first scan lines on the first photoconductive drum. A respective line of first toner is applied to each of the first scan lines. A second laser beam is reflected off of a second rotating reflector to thereby scan the second laser beam across a second photoconductive drum to produce a second scan line in the scan direction. The rotation of the second reflector is cyclically repeated to thereby produce a plurality of substantially parallel second scan lines on the second photoconductive drum. A respective line of second toner is applied to each of the second scan lines.