摘要:
An add-on alarm system for use in conjunction with an audio detector. The system includes an indoor unit that is audibly coupled to the detector and an outdoor unit containing an independent power supply that communicates with the indoor unit to provide an alert signal for directing rescue operations. The outdoor unit includes a relay which is energized by a signal from the indoor unit to close a contact in an alarm circuit and thus generate an alert signal. The relay is held energized by the outdoor power supply so that the alert signal persists in the event the detector or the indoor unit becomes disabled.
摘要:
An apparatus providing a substantially fixed length cable drive comprises a motor-driven capstan having a helical groove. The groove on the capstan is sized to receive opposite ends of a cable for simultaneously letting out and taking up the cable. The cable passes over a fixed pulley and is attached to a carriage at a point intermediate the capstan and pulley. The carriage is guided along a rail defining a fixed mass path. The section of cable between the carriage and pulley is parallel to the mass path. The cable ends on the capstan are disposed on opposite sides of a plane containing the parallel cable section during travel of the carriage along the mass path.
摘要:
A print head (216) positioner (260) includes a stepper motor (264) that is coupled by a substantially friction- and backlash-free taut metal band (266) to a lever arm (268) that imparts precise lateral motion to a positioning shaft (220) that is rigidly attached to the print head assembly. Each step of the stepper motor is translated by the lever arm into one pixel (0.085 millimeter) of lateral movement of the shaft. The exact amount of translation per step of the stepper motor is adjustable by an eccentrically mounted ball (272) that is minutely positionable (274) on the lever arm. The ball couples angular motion of the lever arm to lateral motion of the shaft such that adjusting the ball position on the lever arm provides a-variable scale factor adjustment that compensates for tolerance buildups and exact inter-nozzle spacing on the print head. The shaft is biased toward the ball by a spring (284). The shaft further allows the print head to swing away from a print media support, such as a drum (202), for maintenance.
摘要:
Disclosed are methods for compensating for failed ink jets in an ink jet apparatus. The method in embodiments determines if one or more ink jets are nonfunctioning or have failed and substitutes for the one or more nonfunctioning ink jets by using one or more operational ink jets. The operational ink jets used are neighboring operational ink jets that fill in for the one or more failed ink jets. The one or more failed ink jets are disabled wherein a primary image pass is performed followed by one or more additional imaging passes to fill in for the one or more disabled ink jets by enabling the one or more neighboring operational ink jets. The additional imaging passes may be a right fill imaging pass, a left fill imaging pass or a combination of both.
摘要:
An image transfer ink-jet printer employs an image receiving drum that rotates relative to an ink-jet array print head spanning the full width of the drum. A print head positioner moves the print head in precise increments to position adjacent scan lines of ink drops. Without affecting the overall scale of the image, adjacent pairs of scan lines are spaced at distances less than one nominal pixel width. Pairings within the range of 0.2 to 0.5 pixel widths are used, with optimal spacing at 0.35 pixel widths.
摘要:
A voltage mode drive for a servo system builds a drive matrix from an error signal, which is the difference between a measured value for a parameter of the servo system, such as the position of a rotating drum, and a reference signal, a voltage control signal for the servo system, and an estimated set of parameters for the servo system, the parameters including drive current. The outputs from the drive matrix are a new estimated set of parameters for the servo system which are multiplied by appropriate system constants to produce the voltage control signal. The voltage control signal is amplified by a voltage amplifier and applied to drive the servo system.
摘要:
The present invention provides a stable, high performance system for driving one or more masses in precise incremental movements. More particularly, the present invention provides a method and system for deriving and implementing motion profiles that govern the movement of one or more masses, such as a printer drum as it is indexed along a rotational path by a stepper motor.
摘要:
A compact ink jet printer is described utilizing a small drum for carrying a sheet of record medium during the printing operation. In one embodiment, the drum has an exterior surface with a high coefficient of friction with a contact roller retaining the record medium against the drum as the drum is rotated. Printing is accomplished as by jetting ink from an ink jet print head onto the medium while the medium is backed up by a fixed platen. A fusing mechanism may be utilized to flatten ink drops on the printed medium. A drive mechanism for an ink jet printer may include a stepper motor coupled by timing belt sprockets and a timing belt to the drum of the printer. These components may be selected such that the drum is incremented a multiple of a pixel height during each step of the stepper motor. The record medium may also be clamped to a drum by a clamping mechanism and rotated through plural revolutions of the drum during respective printing and fusing steps.
摘要:
A motion controller for the head carriage of an ink jet printer comprises a target signal generator providing constant velocity reference input to a servo loop controller. Also, two levels of current are applied to the drive motor during direction reversal, a lower one during deceleration of the carriage, and a higher one during acceleration of the carriage. The timing of the two current levels is determined by inputting a rectified velocity signal into a slope detector. A comparator converts the output of the slope detector into a binary signal for controlling the motor current level.
摘要:
A control topology for a servo motor carriage drive includes a strain gauge coupling the carriage to a motor-driven belt to provide a signal representative of the flexure of the belt. A velocity signal is taken from a linear encoder on the carriage. These signals are used in inner and outer feedback loops for controlling the velocity of the carriage as it travels along a predetermined path.