Hewlett-packard Development Company, L.p.

Hewlett-packard Corporation

Edward L Feldhousen

Dennis Eugene Ochs

Manlik Kwong

David E Smith

David Lynn Burton

Steven P Downing

Weiyun Sun

Rick Minoru Tanaka

Wade A Powell

Hsue-Yang Liu

Howard E Hilton

Thieu X Dang

Jason Grosse

J Daren Bledsoe

Brian D Setterberg

Brian C Dunn

Jan Elizabeth Casey

A method of registering an image onto a sheet of media on an imaging surface of a printer having a printhead for imaging onto the sheet, comprising: detecting a position of said sheet of media being advanced onto the imaging surface using a first sensor positioned along said media path upstream of the printhead; and firing the printhead at a time based on the detected position and a calibrated distance between the sensor and the printhead.

Method and apparatus for image registration

Embodiments of uniquely spaced markings are disclosed.

Uniquely spaced markings

A belt tracking system for an endless belt having left and right opposed edges, the belt driven in a first direction by a belt drive system. The tracking system includes a set of periodic belt indicia formed on the belt along one or more axes aligned with the first direction. A sensor system tracks movement of the belt in a lateral direction transverse to the first direction and senses the set of belt indicia to provide sensor system signals. An actuator system effects movement of the belt in the lateral direction, the actuator system responsive to the sensor system signals for nominally maintaining a position of the belt relative to the transverse direction. A controller is responsive to the sensor system signals for detecting that the belt has tracked outside an allowable belt movement range and taking protective actions to prevent the belt from damage due to undesired lateral tracking movement. A belt indicia sensor can optionally be employed to calibrate a belt drive system.

Techniques for robust endless belt tracking control

An ECG waveform calibration method combines ECG channel calibration pulses to form combined calibration pulses. The combined channel pulses are filtered to select valid combined pulses. The selected combined pulses are correlated to the corresponding channel calibration pulses to determine valid channel calibration pulses from which a correction scale factor is derived. A valid calibration pulse is determined where a correlation between a combined calibration pulse and a corresponding channel calibration pulse is greater than a predetermined correlation value. The valid channel calibration pulses are then characterized. A set of valid channel calibration pulses is selected for each channel based on the characterization to form an average calibration pulse. The average calibration pulse is used to determine a correction scale factor for each channel which is used to scale the actual channel ECG waveform data. The method also includes a step for adjusting the intra-channel skew.

Ambulatory monitor ECG pulse calibration method

An ECG recorder and playback unit which includes software-implemented digital signal processing filters which compensate for phase and magnitude distortion occurring when an ECG signal is recorded on a Holter recorder and played back. This permits 'tuning' a recorder and playback unit which may be unrelated, as when made by different manufacturers. An impulse or step signal is recorded and played back to provide a system frequency response measurement. Coefficients for a digital correction filter are derived from the discrete Fourier transform of the impulse or step response and a desired system response. When recorded ECG data is played back, it is filtered on a substantially real-time basis with the digital correction filter to compensate for phase and magnitude distortion. Prior to recording, the high frequencies of the ECG signal are boosted to compensate for high frequency losses inherent in the recording and playing back of ECG signals. A calibration pulse and a system characterization pulse are derived by statistically selecting from a plurality of pulses and averaging the selected pulses in order to minimize the effects of noise and tape defects in the pulses. High frequency components of the ECG signal can be amplified prior to recording the signal. This results in decreased amplification, and therefore noise, when the recorded signals are played back. Cardiac pacer pulse detection is performed prior to the step of filtering the played back signal to optimize pulse detection.

ECG recorder and playback unit

Growing community of inventors

Tualatin, OR, United States of America

Edward L Feldhousen