On demand media web electrophotographic printing apparatus

A single pass serial color printer including an electrophotographic imaging apparatus;

• a recording medium guide path, said imaging apparatus comprising a plurality of compact, modular, removable color imaging development cartridge units, closely spaced in serial alignment;
• said cartridge units, equally arranged, radially and equiangularly, parallel to each other, and aligned parallel with a shared common transfer roll;
• each cartridge unit including a photosensitive drum contacting said common transfer roll at a nip between the photosensitive drum and transfer roll;
• wherein the uniformly offset cartridges are commanded to print with a simple fixed time delay electronic control from a processor for causing the plural color images to align precisely on the common transfer roll, wherein a final color toned image is transferred to said common transfer roll;
• whereby said final color toned image is subsequently transferred to said recording medium against a recording transfer roll at a nip between the common transfer roll on said guide path in a serial transfer process during a continuous rotation controlled by the processor of said common transfer roll and said recording transfer roll in the single pass of the recording medium relative to said plurality of color cartridges, and wherein a fuser unit fuses the final color toned image onto the recording medium.

A single pass serial color media web printer comprising a registration apparatus and an electrophotographic imaging apparatus;

• said imaging apparatus having a plurality of compact, modular, removable color imaging development cartridge units, closely spaced in serial alignment;
• said cartridge units, equally arranged, parallel to each other in a short, straight, horizontal media web guide path;
• each cartridge unit aligned with a unit transfer roll and each cartridge unit including a photosensitive drum contacting said unit transfer roll at a nip between the photosensitive drum and the unit transfer roll along the guide path;
• wherein the uniformly offset cartridges are commanded to print with a simple fixed time delay electronic control from a processor for causing the plural color images to have precisely aligned registration on the recording medium, wherein a final color toned image is sequentially formed from a plurality of electrostatic latent toned images corresponding with a plurality of predetermined colors respectively, and serially transferred unidirectionally to said media web at a nip between each said unit transfer roll and respective photosensitive drum;
• wherein the continuous media web registration apparatus precisely feeds and cuts the media web to a desired length, the desired length produced by the registration apparatus controlled by the processor, and wherein a fuser unit fuses the final color toned image onto the media web.

A color serial traversing printhead printer means including a color serial electrophotographic imaging unit;

• wherein the full color serial electrophotographic cartridge imaging unit may comprise simple, compact precision alignment of a closely spaced plurality of serial color cartridges, mounted on a carriage with a separate cooperating image transfer/fuser unit located for operating on the underside of a recording medium, and confronting the color serial imaging unit whereby the carriage is supported on and guided by parallel transport shafts, and the moving the image transfer/fuser unit is supported and guided by separate parallel transport shafts;
• wherein said transport shafts are supported on both sides of the color electrophotographic printing apparatus with side plates along the media feed;
• the carriage and the separate transfer/fuser unit are driven synchronously at the same speed by a main stepper motor through a carriage belt drive unit mechanically coupled to an image transfer/fuser belt drive unit which moves the carriage and the image transfer/fuser unit in a main scan printing direction with a predetermined scan print width, whereby the cartridges are arranged in line side-by-side and parallel to each other, but each with a transfer roll and each with a photosensitive drum/transfer roll nip, the uniformly spaced cartridges are commanded to print with a simple desired time delay electronic control from processor to cause the plural color images to have precisely aligned registration with each respective transfer roll and photosensitive drum/transfer roll nip;
• wherein the complete toned image is transferred and fused onto the stopped recording medium;
• the plurality of colors are laid down on the on the recording medium in serial or sequential fashion in a non-repeating printing process during a single print scan of the stopped recording medium;
• the printing process and the printing direction are perpendicular to the recording medium;
• wherein at the end of each print scan the recording medium located between the carriage and image transfer/fuser unit is advanced the scan width for the next print scan by two media feed transport rollers driven by a media feed stepper motor, whereupon the completion of each traverse print scan, the carriage and unit are reversed, and returned to a home position and made ready for the next print scan.

An improved method of printing of the type wherein an image is formed by an imaging member and a print medium is presented to the imaging member to transfer the image thereto and produce a print wherein the method is characterized by the steps of:

• providing said medium as a continuous web of material,
• driving the web with a first driver along an infeed path past a cutter assembly to a second driver not operating, whereby a web buckle is formed at a position following the cutter assembly,
• upon detection of the buckle by a buckle sensor, separately driving said web synchronously along a print path with the second driver operating to present a portion of the web to the imaging member and receive an image transferred there from, and
• operating the cutter assembly to cut the web in coordination with a defined position of the imaging member, the cut being coordinated to produce a trailing edge of said portion between the first and second drivers such that the portion of the web driven by the second driver receives the transferred image with the trailing edge of said portion without loss of web material.

An improved method of printing of the type wherein an image is formed by an imaging member:

• and a print medium is presented to the imaging member to transfer the image thereto and produce a print wherein the method is characterized by the steps of:
• providing said medium as a continuous web of material,
• driving the web with a first driver along an infeed path past a cutter assembly to a second driver not operating, whereby a web buckle is formed at a position following the cutter assembly, and upon detection of the web buckle by a buckle sensor, separately driving said web synchronously along a print path with the second driver, while maintaining the web buckle between the first and second drivers, and operating to present a portion of the web to the imaging member and receive an image transferred therefrom, and
• operating the cutter assembly to cut the web, before the web buckle sensor and said web buckle in coordination with a defined position of the imaging member, the cut being coordinated to produce a trailing edge of said portion between the first and second drivers such that the portion of the web driven by the second driver receives the transferred image with the trailing edge of said portion without loss of web material.

An improved method of printing of the type wherein an image is formed by an imaging member and a print medium is presented to the imaging member to transfer the image thereto and produce a print wherein the method is characterized by the steps of:

• providing said medium as a continuous web of material,
• driving the web with a first driver along an infeed path past a cutter assembly.
• at a position following the cutter assembly, separately driving said web along a print path with a second driver to present a portion of the web to the imaging member and receive an image transferred therefrom, and
• operating the cutter assembly to cut the web in coordination with a defined print line position of the imaging member, the cut being coordinated to produce a trailing edge of said portion between the first and second drivers such that the portion of the web driven by the second receives the transferred image with a defined margin without loss of web material.

An improved method of printing of the type wherein an image is formed by an imaging member and a print medium is presented to the imaging member to transfer the image thereto and produce a print wherein the method of online operating setup is characterized by the steps of:

• the registration rolls stopped, the cleanly cut leading edge of the web is advanced a distance Z by the feed rolls to the registration roll nip by the media feed stepper motor.
• counting motor steps to conform Z or sensed by the registration roll nip sensor, the web is advanced a distance P to form the web buckle.
• the web buckle sensor is actuated, the media feed rolls stop, and the apparatus waits for a print command.
• on a print command both the media feed and registration rolls start simultaneously and feed the web at the same speed while maintaining the web buckle.

An improved method of printing of the type wherein an image is formed by an imaging member and a print medium is presented to the imaging member to transfer the image thereto and produce a print wherein the method of online operating setup is characterized by the steps of:

• the registration rolls stopped, the cleanly cut leading edge of the web is advanced a distance Z by the feed rolls to the registration roll nip.
• sensed at the registration roll nip by the registration roll sensor, the media feed rolls stop;
• the apparatus on the subsequent print command, only the media feed rolls start and advance the web a distance P to form a web buckle.
• upon actuation of the web buckle sensor, the registration rolls start to feed at the same speed as the media feed to maintain the buckle.