Abstract: A method of calculating at least a component of ink drop velocity in an ink jet printer includes jetting at least one first ink drop from a printhead firing plane. It is detected when the first ink drop is a first predetermined distance away from a reference plane. A first time period between the jetting and the detecting of the first ink drop is measured. At least one second ink drop is jetted from the printhead firing plane. It is detected when the second ink drop is a second predetermined distance away from the reference plane. A second time period between the jetting and the detecting of the second ink drop is measured. A difference between the first predetermined distance and the second predetermined distance is divided by a difference between the first time period and the second time period.

Abstract: An ink detection 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: An encoder including a light source for emitting light, a photodetector for detecting at least part of the light emitted by the light source, and an encoder film including a plurality of alternating bars and windows and being located between the light source and the photodetector. The encoder includes a mask including a plurality of alternating bars and windows, the mask being located between the light source and the photodetector. The encoder further includes a spacer located between the mask and the encoder film, the encoder film contacting the spacer to maintain a predetermined spacing between the mask and the encoder film.

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: An ink detection 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 printhead firing control system for an inkjet printer includes a printhead mounted for movement across a paper path and an encoder for producing a digital output signal indicative of movement of the printhead. A filter circuit is connected to receive the digital output signal for filtering the digital output signal to remove frequency variations which meet at least one predetermined parameter, thereby providing a filtered digital signal. A fire-pulse generation circuit receives the filtered digital signal from the filter circuit and produces printhead heater resistor drive pulses based at least in part upon the filtered digital signal. This arrangement provides for improved printing accuracy by eliminating frequency changes in the digital encoder signal which may erroneously be caused by mechanical vibrations or other noise within the printer. An improved digitally controlled oscillator construction is also described.

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: An analog encoder system repeatedly switches back and forth between monitoring of first and second encoder output signals to track movement of a structure associated with the encoder. Switching between signals is controlled according to an upper intersection amplitude and a lower intersection amplitude of the two encoder output signals.

Abstract: An optical encoder assembly for an optical encoder for determining rotation of a rotatable shaft. An encoder housing is non-engageable with the shaft. A receiver plate is attached to the encoder housing, has a first side and a substantially opposing second side, and has a through hole and a window both extending from the first side to the second side, wherein the through hole is engageable with the shaft. An encoder mask is attached to the first side of the receiver plate, has a shaft hole engageable with the shaft, and has a mask grating positioned over the window. A light emitter is aligned to face the first side of the receiver plate and is positioned over the mask grating. A light detector is attached to the second side of the receiver plate and is positioned over the window.

Abstract: A method of detecting malfunctioning ones of a plurality of nozzles of a printhead in an ink jet printer includes providing a sensor having at least two terminals defining at least one gap therebetween. An attempt is made to jet ink from a first of the nozzles into the at least one gap. A resistance between at least two of the terminals is measured to determine whether the ink has been jetted into the at least one gap. The attempting and measuring steps are repeated for each remaining nozzle.

Abstract: A method of calculating at least a component of ink drop velocity in an ink jet printer includes jetting at least one first ink drop from a printhead firing plane. It is detected when the first ink drop is a first predetermined distance away from a reference plane. A first time period between the jetting and the detecting of the first ink drop is measured. At least one second ink drop is jetted from the printhead firing plane. It is detected when the second ink drop is a second predetermined distance away from the reference plane. A second time period between the jetting and the detecting of the second ink drop is measured. A difference between the first predetermined distance and the second predetermined distance is divided by a difference between the first time period and the second time period.

Abstract: A printhead alignment sensor for an ink jet printer includes at least two terminals defining a gap therebetween. An electrical measuring device detects a change in an electrical parameter between two of the terminals when ink is in the gap between the at least two terminals.

Abstract: A method of analog encoder initialization involves repeatedly adjusting an encoder light element energization level and dc offsets of the encoder channels to produce desired signals.

Abstract: An optical encoder assembly for an optical encoder for determining rotation of a rotatable shaft. An encoder housing is non-engageable with the shaft. A receiver plate is attached to the encoder housing, has a first side and a substantially opposing second side, and has a through hole and a window both extending from the first side to the second side, wherein the through hole is engageable with the shaft. An encoder mask is attached to the first side of the receiver plate, has a shaft hole engageable with the shaft, and has a mask grating positioned over the window. A light emitter is aligned to face the first side of the receiver plate and is positioned over the mask grating. A light detector is attached to the second side of the receiver plate and is positioned over the window.

Abstract: A printer assembly and a method for determining the position of a printer component, such as a printer paper-feed roller, during a move of the printer component from an initial position toward a desired final position. An analog encoder is operatively connected to the printer component, and a threshold device is connected to the analog output of the analog encoder. The position of the printer component is determined from the digital output of the threshold device and a digitization of the analog output of the analog encoder.

Abstract: A method for reducing horizontal banding on media in an ink jet printer involves the step of moving the media repeatedly back and forth along a media movement path during a printing scan of at least one print head, the printing scan defined by movement of the print head across the media movement path as ink is ejected from the print head onto the media.

Abstract: A method of analog encoder initialization involves repeatedly adjusting an encoder light element energization level and dc offsets of the encoder channels to produce desired signals.

Abstract: A method for synchronizing the print start position for a printer carriage on an inkjet printer that includes the steps of: (a) providing an encoder signal indicative of a position of an inkjet printer carriage relative to a substrate being printed upon or a printer platen, where the encoder signal is an alternating voltage signal with an encoder signal frequency; (b) filtering and dividing the encoder signal to provide a fire pulse signal, where the fire pulse signal is an alternating voltage signal with a fire pulse signal frequency that is a multiple of the encoder signal frequency; (c) detecting a rising edge of the encoder signal preceeding a predetermined print start position of the printer carriage; (d) upon detection of the rising edge of the encoder signal in step (c), detecting a next falling edge of the fire pulse signal; (e) upon detection of the next falling edge of the fire pulse signal in step (d), detecting a count of the next rising edges of the fire pulse signal; and (f) assigning a synchron

Abstract: A method is disclosed for treating patients suffering from heart failure to increase cardiac output. The patient's vagus nerve is electrically stimulated or modulated with a sequence of substantially equally spaced pulses by an implanted neurostimulator, and the frequency of the stimulating pulses is adjusted until the patient's heart rate reaches a target rate within a relatively stable target rate range below the low end of the patient's customary resting heart rate. The frequency of the stimulating pulses is maintained at the frequency which ultimately produced the relatively stable target rate range so as not to deviate markedly from the target rate, at least so long as the patient remains at rest. An activity sensor associated with the implanted neurostimulator detects physical activity of the patient and adjusts the frequency of the stimulating pulses accordingly, to elevate the heart rate during periods of physical activity by the patient.

Abstract: A method of analog encoder initialization involves repeatedly adjusting an encoder light element energization level and dc offsets of the encoder channels to produce desired signals.