Electrophotography – Document handling – Original and copy
Reexamination Certificate
2000-12-18
2001-12-18
Eickholt, Eugene (Department: 2854)
Electrophotography
Document handling
Original and copy
C400S639000, C400S692000, C400S578000, C399S367000, C399S401000, C399S110000, C399S111000, C399S113000, C355S024000
Reexamination Certificate
active
06332068
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates generally to methods and apparatus for printing on two sides of a media sheet, and more particularly, to a media handling system which first feeds a media sheet with a first side exposed to a print source, then feeds the media sheet with a second side exposed to the print source.
Printing to two sides of a media sheet, referred to as duplex printing, is a desirable feature in printing systems. The advantages of duplex printing include reducing the amount of paper required compared to one-sided (simplex) printing, and generating print sets with layouts resembling that of professionally printed books. Conventional duplex printing devices employ complex paper handling mechanisms. Typically, an extra tray is used for temporary storage of pages having printing on a first side. In an alternative approach a second paper path is provided to route a first printed page around the existing paper supply.
Similarly, duplex copying typically is accomplished by either one of two methods. In one method, first side copies are stacked in a duplex tray. When a set of first side copies is complete, the copies are fed out of the duplex tray and returned with an odd number of inversions along a duplex path to receive second side imaging. In an alternative method first side copies are returned directly to receive second side imaging without stacking.
Conventional devices tend to have long paper paths and many parts. A substantial challenge with systems having these complex duplex printing paper paths is handling paper jams. Accordingly, there is a need for a simplified method and apparatus for duplex media handling at a desktop print recording device.
SUMMARY OF THE INVENTION
According to the invention, a modular duplex media handling system is used in conjunction with a simplex media handling print recording apparatus. The simplex media handling system includes firmware for operating either in a simplex mode or in a duplex mode, (where the modular duplex media handling system is installed to operate in duplex mode).
According to one aspect of the invention, the duplex media handling system is removable to allow for easy cleaning of the simplex media handling system, the print recording system, and the duplex media handling system. Another benefit is that the modular duplex media handling system can be used with different print recording systems. A pivoting cover also is included to allow access into the duplex handling paper path to clear paper jams.
The host print recording system includes the simplex media handling system and a recording print source. The simplex media handling system includes feed rollers and metering rollers. A media sheet is fed from an input tray along a first media path from the feed rollers to the metering rollers, onward into a print zone adjacent to the print recording source. The media sheet is fed through the print zone into an output tray.
During duplex operations, the metering roller stops prior to releasing the media sheet into the output tray. While the metering roller still engages a trailing edge of the media sheet, the metering roller reverses direction to move the media sheet back along the first media path onto the feed roller. According to another aspect of the invention, the feed roller, rotating with the metering rollers in the reverse direction, moves the media sheet into the modular duplex handling system. The media sheet is flipped by the modular duplex handling system, which feeds the media sheet back to the feed roller. The feed roller rotating once again in the forward direction moves the flipped media sheet along the first paper path to the metering roller and into the print zone for second side printing. The flipped media sheet is fed through the print zone and released into the output tray.
According to another aspect of this invention, the feed roller and metering roller are commonly linked to rotate only in the same direction. An advantage of such a common rotational direction is that the gearing for the rollers is simple and less costly than for systems where the feed rollers and metering rollers rotate in a common direction at one time and in opposite directions at another time.
According to another aspect of the invention, the modular duplex media handling system includes a pair of drive rollers defining a loop media path. Both the entrance and the exit to the duplex media handling system are located adjacent to the feed roller of the print recording system.
According to another aspect of the invention, the modular duplex handling system also includes linkage to the print recording system drive motor. The drive motor drives all of the feed roller, the metering roller and the pair of duplex handling drive rollers. In addition, the duplex media handling system includes a transmission apparatus which allows the drive rollers to be disengaged, engaged for rotation in the same direction as the feed roller, or engaged for rotation in the opposite direction as the feed roller. The drive rollers rotate in a common direction (not opposing directions), relative to each other.
According to another aspect of the invention, the media sheet is moved through the duplex media handling system in a one-way path, (i.e., the loop media path). Thus, the duplex handling system rollers rotate in one direction. However, at one point during the media flipping process, the duplex handling system rollers are rotating in the same direction as the feed roller, while at another point during the media flipping process, the duplex system rollers are rotating in the opposite direction as the feed roller. The transmission operates to determine whether the drive rollers rotate in the same direction as the feed rollers, or in the opposite direction of the feed rollers.
According to another aspect of this invention, for an inkjet printing embodiment the media dry time for second side printing is the summation of the first and second side printing times of the next sheet.
According to another aspect of the invention, a humidity sensor is included with the modular duplex media handling system. Such a sensor also serves to signify to the print recording system whether the duplex handling system is installed or not installed. When installed, the print recording system reads the humidity sensor allowing determination of a sufficient dry time during first side printing (before allowing the media sheet to be fed through the duplex handling system for media flipping). First side drying time is dependent upon the media, the environment and the amount of ink. An advantage of the humidity sensor's dual functions is that the print recording system firmware may be the same for systems with and without the modular duplex handling system installed.
One advantage of the invention is that automatic media flipping is accomplished without user intervention. Another advantage is that the duplex handling system can be removed and installed as desired. Another advantage is that additional motors are not needed for the module. The duplex module is powered by the simplex media handling system. Another advantage is that additional media position sensors are not required for the duplex module. The media position sensors of the simplex media handling system are provide the sensing for controlling media moving through the duplex module. These and other aspects and advantages of the invention will be better understood by reference to the following detailed description taken in conjunction with the accompanying drawings.
REFERENCES:
patent: 3972612 (1976-08-01), Komori et al.
patent: 4327905 (1982-05-01), Schonfeld
patent: 4348101 (1982-09-01), Schonfeld et al.
patent: 4362379 (1982-12-01), Tiek et al.
patent: 4607948 (1986-08-01), Naito
patent: 4645195 (1987-02-01), Scranton et al.
patent: 4674857 (1987-06-01), Satomura et al.
patent: 4777498 (1988-10-01), Kasamura et al.
patent: 4787616 (1988-11-01), Sasaki et al.
patent: 4811049 (1989-03-01), Honjo
patent: 4825245 (1989-04-01), Fukae et al.
patent: 4845528 (1989-07-01), Aoki et al.
patent: 4855790 (
Blackman Jeffrey R.
Jackson Larry A.
McCue, Jr. Thomas E.
O'Hara Kevin
Ruhe Thomas W.
Eickholt Eugene
Hewlett--Packard Company
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