High speed printing system for printing magnetic ink

High speed printing system for printing magnetic ink systems and associated methods are disclosed. A color of the magnetic ink may be designed to resemble one of the non-magnetic inks so that instead of ejecting the one non-magnetic ink, the printing system ejects the magnetic ink. Nozzles in a printhead may also be arranged to be adjacent to each other and may be appropriately spaced without causing the inks to be mixed in the printhead. Additionally, a color transform system may be provided to transform a sheet image in accordance with ejecting at least the magnetic and the non-magnetic ink from the printhead.

BACKGROUND

1. Field of the Invention

The invention is related to the field of printing systems, and in particular, to a high speed printing system for printing magnetic ink.

2. Statement of the Problem

Magnetic Ink Character Recognition (“MICR”) is a technology that allows a machine to read characters printed on a print medium. For example, the bottom line of a check is typically printed using a MICR ink so that the check can be processed automatically by a machine. Traditionally, a magnetic ink is printed using an offset printing press in which an inked image (that has the magnetic ink) is first transferred/offset to a rubber blanket, and then from the rubber blanket to paper. Many types of document production have recently moved to using high speed printing systems that are more customizable than the offset printing press. Such high speed printing systems usually use inkjet technologies to produce full colored documents.

Full colored documents are typically produced using inkjet technologies by ejecting varying amounts of inks of four colors: cyan, magenta, yellow, and black. Either dye-based inks or pigment-based inks are usually used. Meanwhile, a magnetic ink used for MICR printing is usually a hybrid ink with dye colorant and ferrite particles. However, it is generally believed that inks of different types should not be mixed. A dye-based ink has dye colorant, while a pigment-based ink has colored particles. Mixing them may cause undesired chemical reactions and/or plug up the nozzles (a printhead has a number of nozzles for ejecting ink from the printhead onto paper).

To reduce the possibility of mixing the magnetic ink with another ink, the magnetic ink is usually ejected from an additional printhead that is separate from the printhead(s) used for regular color printing. However, adding an additional printhead adds complexities to the printing systems, which is not desirable. Some high speed printing systems also use a series of printheads arranged in a column so that a large area of the print medium can be covered simultaneously. Retrofitting such high speed printing systems is even more difficult and costly because a series of printheads for printing the magnetic ink would need to be added.

Additionally, these high speed printing systems may eject inks of more than one color concurrently from each printhead to speed up printing. However, as more than one ink is ejected from each printhead with possible mixing of the inks, it is generally believed that all inks need to be switched to the same pigment-based type because the magnetic ink, with its ferrite particles, is more akin to a pigment-based ink. However, it would not be practical to completely switch from a dye-based printing system to a pigment-based printing system whenever the printing system needs to print the magnetic ink.

SUMMARY

Embodiments provided herein enable a high speed printing system in which printing a magnetic ink does not cause undesired chemical reactions and do not plug up the nozzles more than printing non-magnetic inks. A color of the magnetic ink may be designed to resemble one of the non-magnetic inks so that instead of ejecting the non-magnetic ink, the printing system ejects the magnetic ink. For example, a color of the magnetic ink may resemble black and the printing system ejects the magnetic ink instead of a black ink. Thus, no additional printhead needs to be added to print the magnetic ink. Additionally, nozzles in a printhead may be arranged to be adjacent to each other and may be appropriately spaced. Accordingly, a magnetic ink and a non-magnetic ink may be ejected from adjacent nozzles of the single printhead without causing the inks to be mixed in the printhead. The non-magnetic ink may thus remain as a dye-based ink (or be switched to a pigment-based ink if a customer so chooses).

The color of the magnetic ink may not exactly match the non-magnetic version. Accordingly, a color transform system may be provided to transform a sheet image in accordance with ejecting the magnetic and the non-magnetic ink from the single printhead. One embodiment comprises a printing system that includes the color transform system. The color transform system is operable to transform a sheet image to generate a first bitmap for printing magnetic ink and a second bitmap for printing non-magnetic ink in accordance with ejecting, from a single printhead, the magnetic ink and the non-magnetic ink. The printing system also includes the single printhead operable to receive the first bitmap and the second bitmap, and to concurrently eject the magnetic ink based on the first bitmap and the non-magnetic ink based on the second bitmap.

Other embodiments may be provided below.

DESCRIPTION OF EMBODIMENTS

FIG. 1is a block diagram illustrating a printing system130in an exemplary embodiment. A host system110is in communication with the printing system130to print a sheet image120onto a print medium180. Part of the sheet image120is printed using a magnetic ink. For example, the resulting print medium180may include a check with a MICR line (i.e., the bottom line of a check) that is printed using the magnetic ink so that the MICR line is readable by a machine. The resulting print medium180may be printed in color or in any of a number of gray or black-and-white shades.

The host system110may comprise any computing device including a personal computer or a server. The sheet image120may comprise any file or data that describes how an image on a sheet of print medium should be printed. For example, the sheet image120may comprise PostScript data, Printer Command Language (“PCL”) data, and/or any other printer language data. The printing system130may comprise a high-speed printer. The high-speed printer may be operable for volume printing including printing at least 100 pages per minute. The print medium180may comprise continuous form paper, cut sheet paper, and/or any other medium suitable for printing.

The printing system130, in one generalized form, include a printhead160that includes a number of nozzles, jets, and/or any other similar element for ejecting ink or another substance onto the print medium180. The printhead160may include at least one nozzle plate on which holes or orifices are formed as openings through which the ink exits from the nozzles of the printhead160. For example, the single printhead160may includes a first series of nozzles163(for ejecting magnetic ink), a second series of nozzles167(for ejecting non-magnetic ink), and/or other nozzles (e.g., for also ejecting the magnetic ink and/or the non-magnetic ink). A nozzle for ejecting the magnetic ink and a nozzle for ejecting the non-magnetic ink may each have an opening on a single nozzle plate of the printhead160. It is noted that the word “single” (e.g., as in the “single” printhead160) is denoted to mean that the printhead by itself can eject the magnetic ink and the non-magnetic ink. The word “single” does not imply that a printing system includes only one printhead. Rather, the printing system may include multiple printheads and each printhead by itself can eject the two inks.

When the print medium180is passed underneath or near a nozzle, an ink droplet can be ejected from the nozzle to be deposited onto the print medium180, thus printing a dot on the print medium180. Using a series of nozzles speeds up printing by ejecting a number of ink droplets onto the print medium180concurrently. Having multiple series of nozzles further speeds up printing by ejecting ink droplets of different colors and/or characteristics concurrently. To avoid undesired mixing of inks, nozzles (and/or nozzle openings on the nozzle plate) of each series may be arranged to be adjacent to each other and may be appropriately spaced. Additionally, a distance between the nozzle plate (having the nozzle openings) and the print medium180may also be appropriately spaced so that ink droplets do not intermix after they are ejected. After the ink droplets are ejected, they may be absorbed into the print medium180and dry almost instantly without any mixing due to having low moisture/water content.

One or more bitmaps150may be generated to indicate which nozzle should eject an ink droplet at what time. For example, a particular bitmap may be generated to indicate that a dot should be printed at a particular coordinate. When the print medium180passes underneath or near a nozzle such that ejecting an ink droplet from the nozzle would be deposited at the particular coordinate, the ink droplet would be caused to be ejected from the nozzle. The bitmaps150may be generated using at least a color transform system140. The color transform system140may comprise any system, device, software, circuitry and/or other suitable component operable to transform the sheet image120for generating the bitmaps150in accordance with ejecting at least a magnetic and a non-magnetic ink from the printhead160. The color transform system140may comprise part of a print controller of the printing system130, part of a printhead controller for the printhead160, and/or any other portion of the printing system130. In some embodiments, the color transform system140may also comprise part of the host system110.

The printing system130may comprise additional components to enable high-speed color printing.FIG. 2is a block diagram illustrating the printing system130in another exemplary embodiment. The host system110is still in communication with the printing system130to print the sheet image120. In addition to the (first) printhead160, the printing system130may include a second printhead262for ejecting inks of additional colors and/or characteristics. To further speed up printing, the printing system130may also include a third printhead263that is arranged in an array (e.g., arranged along a length of the print medium180) with the first printhead160. The first series of nozzles163of the first printhead160may thus eject ink droplets concurrently with nozzles of the third printhead263to cover an even larger area of the print medium180. Similarly, the printing system130may further include a fourth printhead264arranged in an array with the second printhead262so that nozzles of both printheads may eject ink droplets concurrently.

The array formed by the first printhead160and the third printhead263may be operable to print a magnetic ink and a cyan ink. The magnetic ink may be supplied from a magnetic ink reservoir273storing a magnetic ink such that the magnetic ink reservoir273is coupled with at least a nozzle of the first series of nozzles163(for ejecting magnetic ink). Similarly, the cyan ink may be supplied from a cyan ink reservoir277such that the cyan ink reservoir277is coupled with at least a nozzle of the second series of nozzles167(for ejecting the non-magnetic cyan ink). To speed up printing, each of the first printhead160and the third printhead263may include another series of nozzles for printing the magnetic ink and yet another series of nozzles for printing the cyan ink. The series of nozzles may be adjacent to each other and may be interlaced with appropriate spacing between each other. Because of the appropriate spacing, inks do not intermix after they are ejected even though it is generally believed that inks of different types should not be ejected from a single printhead.

The array formed by the second printhead262and the fourth printhead264may be operable to print a magenta ink and a yellow ink. The magenta ink may be supplied from a magenta ink reservoir275storing a magenta ink such that the magenta ink reservoir275is coupled with a least a nozzle of the second printhead262and the fourth printhead264. Similarly, the yellow ink may be supplied from a yellow ink reservoir279storing a yellow ink such that the yellow ink reservoir279is coupled with at least a nozzle of the second printhead262and the fourth printhead264. A color of the magnetic ink may resemble black and the first printhead160and the third printhead263eject the magnetic ink instead of a black ink. The printing system130is thus capable of printing inks of four colors (cyan, magenta, yellow, and black) while also being capable of printing the magnetic ink without adding additional printheads.

The magnetic ink may include dye colorant and ferrite particles and may be suitable for MICR printing. Among a wide variety of possible formulations, the magnetic ink may include color pigments and ferrite particles. The ferrite particles may be smaller than colored particles (of a pigment-based ink). Each of the non-magnetic inks (e.g., cyan, magenta, and yellow) may include one of a pigment-based ink with colored particles and a dye-based ink with dye colorant. In other words, the non-magnetic inks may be all dye-based, all pigment-based, or a mix of the two.

In some embodiments, the magnetic ink may resemble another color (i.e., a color other than black). Accordingly, rather than ejecting the other color, the magnetic ink would be ejected without adding additional printheads. In another embodiment, the printing system130may also be able to print inks of other colors and/or other characteristics. For example, the color model may be extended to CcMmYK to include light cyan and light magenta inks. Additionally, the ink or the substance printed may be ultraviolet or may reflect another wavelength not visible to the human eye. Besides pigment-based ink and dye-based ink, the ink or the substance printed may be of yet another characteristic. For example, the ink or the substance may include both dye-colorant and colored particles. Indeed, the printing system130is not limited to printing the magnetic ink. Rather, the printing system130is capable of printing inks or substances of different characteristics from a single printhead (and/or a single nozzle plate) even though it is generally believed that inks of different types should not be ejected from a single printhead.

Because a color of the magnetic ink (or another ink or substance to be printed) may not exactly match the non-magnetic version (or the original ink replaced by the magnetic ink), the printing system130also comprises the color transform system140operable to transform the sheet image120in accordance with printing the magnetic ink (or the another ink or substance). The color transform system140may comprise part of a print controller135. The print controller135may comprise any system, device, software, circuitry and/or other suitable component operable to interpret, render, rasterize, and/or otherwise convert the sheet image120into the bitmaps150for printing. For example, the bitmaps150may comprise a first bitmap251, a second bitmap252, a third bitmap253, and a fourth bitmap254. The first bitmap251and the second bitmap252may be generated by the print controller135and sent to a first printhead controller283to be printed using the array of the first printhead160and the third printhead263. Similarly, the third bitmap253and the fourth bitmap254may be generated by the print controller135and sent to a second printhead controller287to be printed using the array of the second printhead262and the fourth printhead264.

The four bitmaps may each indicate that dots of a particular color should be printed at particular coordinates. For example, the first bitmap251may indicate that black dots should be printed at particular coordinates, and the magnetic ink (which may be black) would be ejected at the particular coordinates. The second bitmap251may be used for printing cyan dots. Similarly, the third bitmap253may be used for printing magenta dots and the fourth bitmap254may be used for printing yellow dots. Accordingly, each of the first printhead controller283and the second printhead controller287may comprise any system, device, software, circuitry and/or other suitable component operable to receive the bitmaps (251,252,253,254) and control nozzles of the printheads (160,262,263,264) for ejecting inks based on the bitmaps. It is noted that a printhead may sometimes be seen as including a printhead controller in some embodiments. For example, the (first) printhead controller160in the embodiment ofFIG. 1may be seen as including a printhead controller.

The color transform system140may process an International Color Consortium (“ICC”) profile215in order to transform the sheet image120. The ICC profile215may be sent from the host system110in conjunction with sending the sheet image120. The ICC profile215may also be stored within the printing system and may be selected when the printing system130is administered/configured to print the magnetic ink. The ICC profile215comprises a set of data characterizing the printing system130for printing the magnetic ink (and the remaining colors) in accordance with standards promulgated by the International Color Consortium (“ICC”). The ICC profile215may have been provided by a manufacturer of the printing system130and/or a provider of the magnetic ink printing solution. The ICC profile215may have been provided using a computer readable medium and/or otherwise distributed electronically (e.g., downloaded over a network).

As noted above, a color of the magnetic ink may not exactly match the non-magnetic version. However, the color transform system140is operable to adjust the bitmap(s) for printing the magnetic ink such that the resulting print medium180may still appear as though it has been printed with the original non-magnetic ink.FIG. 3is a flow chart illustrating a method of printing magnetic ink in an exemplary embodiment. The steps of the flow chart inFIG. 3are not all inclusive and may include other steps not shown. The host system110has sent the sheet image120to the printing system130. In step310, the color transform system140transforms the sheet image120to generate bitmaps150. For example, the color transform system140(and/or other components of the print controller135) may be operable to generate the first bitmap251for printing the magnetic ink and the second bitmap252for printing the non-magnetic ink (e.g., the cyan ink). The two bitmaps are generated in accordance with ejecting at least the magnetic ink and the non-magnetic ink from the single first printhead160(and the single third printhead263).

It is noted that the magnetic ink has replaced another non-magnetic ink so that the printing system130ejects the magnetic ink instead of the other non-magnetic ink. However, a color of the magnetic ink may not exactly match the other non-magnetic ink. For example, the other non-magnetic ink may resemble black, but the magnetic ink may not be of the same black color (e.g., the magnetic ink may appear more reddish because of the ferrite particles). Generating the bitmaps using the color space that corresponds with the other non-magnetic ink would produce a resulting print medium180that does not match the intended color(s). Thus, the color transform system140may be operable to compensate for a difference between a color of the magnetic ink and a color of another non-magnetic ink in some embodiments. In one embodiment, the color transform system140may increase the density of dots to be printed using the magnetic ink to better match black. Alternatively or in addition, the color transform system140may add inks of other colors (e.g., one or more of cyan, magenta, and yellow) to a dot printed with the magnetic ink to better match black in another embodiment. In yet another embodiment, the color transform system140may alternatively or additionally vary a size of ink droplets.

In other embodiments, the color transform system140may be operable to separate a particular color plane from the sheet image120. For example, the magnetic ink may resemble black, and the color transform system140would separate a black color plane from the sheet image120in order to generate the first bitmap251for printing the magnetic ink. Magnetic ink would then be printed based at least on the first bitmap251that corresponds with the black plane. If the magnetic ink is of another color, the color transform system140would generate a corresponding bitmap by separating the color plane of the other color. As noted above, in some embodiments the color transform system140may add inks of other colors (e.g., one or more of cyan, magenta, and yellow) to a dot printed with the magnetic ink to better match black. The color transform system140may thus generate the bitmap of another color (e.g., the second bitmap252for cyan) based on color planes of both black and the other color (e.g., both the black color plane and cyan color plane).

In some embodiments, the color transform system140is further operable to transform the sheet image120based on the ICC profile215that corresponds with at least the magnetic ink. For example, the color transform system140may process the ICC profile215to compute a transformation from a profile connection space (“PCS”) into a color space that corresponds with the magnetic ink. The transformation is different from another transformation that the color transform system140would compute for another ICC profile that corresponds with another ink that the magnetic ink replaces.

After generating the bitmaps (251,252,253,254) based on operations of the color transform system140, the print controller135sends the bitmaps to the printhead controllers (283,287) to be received by the printheads and/or the printhead controllers. In step323, the first printhead controller283may receive the first bitmap251. In step327, the first printhead controller283may receive the second bitmap252. It is noted that the first printhead controller283may receive the bitmaps in parallel or sequentially, and the bitmaps may be received through a proprietary bus/communication channel and/or one that is standard-based including IEEE 1394 and Universal Serial Bus (“USB”). Additionally, as noted above, a printhead may sometimes be seen as including a printhead controller in some embodiments. Accordingly, when such a printhead receives a bitmap, the bitmap may more specifically be received by a printhead controller of the printhead to cause nozzles of the printhead to eject ink.

In step333, the first printhead controller283may cause the magnetic ink to be ejected based on the first bitmap251. For example, the first printhead controller283may control the first series of nozzles163(for ejecting magnetic ink) of the first printhead160based on a portion of the first bitmap251, and control another series of nozzles (also for ejecting magnetic ink) of the third printhead263based on another portion of the first bitmap251. These nozzles would cover different areas of the print medium180as indicated by the first bitmap251. Similarly, in step337, the printhead controller283may cause the non-magnetic cyan ink to be ejected based on the second bitmap252.

The remaining colors may be printed in a like manner. For example, the color transform system140may also transform the sheet image120to generate the third bitmap253for printing the magenta ink and the fourth bitmap254for printing the yellow ink. The print controller135then sends the third bitmap253and the fourth bitmap254to be received by the second printhead controller287. The second controller287then causes the second printhead262and the fourth printhead264to eject the magenta ink based on the third bitmap and the yellow ink based on the fourth bitmap.

In another embodiment, the front side of a sheet may be printed with the magnetic ink, while the back side of the sheet may be printed with non-magnetic/regular black ink. The sheet image120may thus comprise a front sheet image, and the host system110may also send a back sheet image to the printing system130. The printing system130transforms the back sheet image for printing in accordance with ejecting the non-magnetic/regular black ink. Accordingly, to transform the front sheet image, the color transform system140would compensate for a difference between a color of the magnetic ink and a color of the non-magnetic/regular black ink.

Embodiments of the invention can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment containing both hardware and software elements. In one embodiment, the invention is implemented in software, which includes but is not limited to firmware, resident software, microcode, etc.FIG. 4is a block diagram depicting a computer system400operable to provide features and aspects hereof by executing programmed instructions and accessing data stored on a computer readable storage medium412.

A computer system400suitable for storing and/or executing program code will include at least one processor402coupled directly or indirectly to memory elements404through a system bus450. The memory elements404can include local memory employed during actual execution of the program code, bulk storage, and cache memories which provide temporary storage of at least some program code and/or data in order to reduce the number of times code and/or data must be retrieved from bulk storage during execution.

Input/output or I/O devices406(including but not limited to keyboards, displays, pointing devices, etc) can be coupled to the system either directly or through intervening I/O controllers. Network adapter interfaces408may also be coupled to the system to enable the computer system400to become coupled to other data processing systems or storage devices through intervening private or public networks. Modems, cable modems, IBM Channel attachments, SCSI, Fibre Channel, and Ethernet cards are just a few of the currently available types of network or host interface adapters. Presentation device interface410may be coupled to the system to interface to one or more presentation device such as printing systems and displays for presentation of presentation data generated by processor402.