Patent Document

BACKGROUND OF THE INVENTION  
       [0001]     Laser printers and inkjet printers are commonly used in office settings and smaller document production facilities that require small scale and often numerous printing jobs for day-to-day business. Such small scale, quick demand, and non-repetitive document reproductions are not cost effective to be printed using industrial or commercial-enterprise printing machines such as those found at book publishing companies, newspaper outfits, and generally large-scale document production facilities. Laser and inkjet printers have melded into office settings to provide companies with the ability to produce sharp-looking, high-quality documents at a moment&#39;s notice.  
         [0002]     Some kinds of documents, however, have proven to be difficult to reproduce on laser and inkjet computers. While conventional laser and inkjet printers are well suited to producing documents of printed subject matter, conventional laser and inkjet printers are not as well suited for producing artwork, photographs, and the like. More specifically, laser and inkjet printers are not well suited for producing particular photographic or artistic effects, such as glossy, matte, or satin finish. Furthermore, other effects such as watermarking, three-dimensional effects (3-D), and holography are also difficult, if not impossible, to effectively reproduce using conventional laser and inkjet printers.  
         [0003]      FIG. 1  is a side view diagram of a conventional laser printer  170  that will be used to illustrate the typical workings of a conventional laser printer  170 . Although an inkjet printer is not depicted in  FIG. 1  or in any other figure, the concepts and limitations of a conventional inkjet printer are similar to those of the conventional laser printer  170 .  
         [0004]     The conventional laser printer  170  operates on the principle of static electricity. Briefly, by using a laser  184  to create specific patterns of static electricity on a rotating drum  181 , print may be applied to a sheet of paper according to the specific pattern created. Thus, by controlling the laser  184  in precise detail, virtually anything can be printed to paper by charging the rotating drum  181  with static electricity. Although the workings of a laser printer in well known in the industry, the laser printing concept is described in more detail below.  
         [0005]     The laser printer  170  engages and maneuvers paper through a series of pulleys  192  and a belt  191 . When a document is to be printed, the belt  191  engages a sheet of paper from a paper tray  180  and begins maneuvering the paper toward the rotating drum  181 . The rotating drum  181  is then prepared for receiving a pattern of static charge. Initially, the rotating drum  181  is imparted with a total positive charge by a charge corona wire  187 , a wire with an electrical current running through it. Some laser printers (not shown) use a charged rotating drum  181  instead of a charge corona wire  187 , but the principle of imparting a total positive charge to the rotating drum  181  is the same.  
         [0006]     As the surface of the rotating drum  181  revolves past the charge corona wire  187 , a laser  184  is focused, via a focusing mirror system  183 , across the surface of the rotating drum  181  to discharge certain points according to the specific pattern. In this way, the laser  184  “draws” the letters and images to be printed as a pattern of electrical charges, i.e., an electrostatic image, right on the surface of the rotating drum  181 . In other conventional laser printers (not shown), the charges may be reversed, i.e., a positive electrostatic image on a negative background.  
         [0007]     After the electrostatic image is imparted to the rotating drum  181 , the rotating drum  181  is coated with positively charged toner, most typically a fine, black powder. The toner is applied from a toner roller  182  that includes a toner reservoir. The toner, which typically has a positive charge, clings to the negative discharged areas (the words or images) of the rotating drum  181 , but not to the positively charged areas (the background).  
         [0008]     With the toner pattern applied according to the electrostatic image, the rotating drum  181  continues rotating and rolls over a sheet of paper, which is moving along the belt  191  below. Before the paper rolls under the rotating drum  181 , it is imparted with a negative charge by a transfer corona wire  194  (sometimes called charged roller). The negative charge imparted to the paper is stronger than the negative charge of the electrostatic image imparted to the rotating drum  181  by the laser  184 . Thus, when the paper engages the rotating drum, the positively charged toner is then attracted to the more negatively charged paper, in essence, transferring the electrostatic image from the rotating drum  181  to the paper. Since the paper is moving at the same speed as the drum, the paper picks up the image pattern exactly. To keep the paper from clinging to the rotating drum  181 , the paper is discharged by a detac corona wire  195  immediately after the toner is transferred. The rotating drum  181  continues rotating, now without toner but still with the electrostatic pattern, until the rotating drum  181  surface passes the discharge lamp  188 . Bright light from the discharge lamp  188  exposes the entire rotating drum  181  surface, thereby erasing the electrostatic image. The rotating drum surface is then ready to start the process again by passing the charge corona wire  187 , which reapplies the positive charge.  
         [0009]     The paper, now having toner applied according to the electrostatic image, passes through a fuser  186  which is typically a pair of heated rollers. As the paper passes through the fuser  186 , the loose toner powder melts, fusing with the fibers in the paper to create a printed document. The paper, now a printed document, is then rolled along the belt  191  to the output tray  185 .  
         [0010]     The laser printer  170  includes a controller  190  that is able to receive data from an outside source, e.g., a computer or a portable media card, and store the data in a printing buffer (not shown) and the interpret the data (which corresponds to a document) into an electrostatic image to be imparted by the laser  184 . The controller  190  typically communicates with a computer system via standard, well-known protocols such as through parallel communications ports and/or universal serial bus ports.  
         [0011]     As was discussed briefly above, conventional laser printers are not well suited for producing particular photographic or artistic effects, such as glossy, matte, or satin finish. Furthermore, other effects such as watermarking, three-dimensional effects (3-D), and holography cannot be created using conventional laser and inkjet printers. This is because the toner is typically a colored powder, most often black. Color laser and inkjet computers are able to reproduce colors on a printed document, but doing so uses a large amount of toner or ink when printing. As will become more prevalent in the detailed description of the invention below, other document finishing techniques are also not able to be accomplished with conventional laser and inkjet printers.  
       SUMMARY OF THE INVENTION  
       [0012]     An embodiment of the invention is directed to a system and method for printing a document having one or more document finishes. The method comprises determining an electrostatic image to be applied to a sheet of paper that corresponds to a document finish, applying a finish toner to the sheet of paper corresponding to the electrostatic image, and fusing the finish toner to the sheet of paper. Typically, the finish toner is applied after a non-finish toner and/or a non-finish ink have been applied to the sheet of paper. Thus, the non-finish toner/ink provides the content of the sheet of paper, (i.e., a document pattern) while the finish toner provides a document finish, (i.e., a glossy, matte, or satin finish).  
         [0013]     Such a system is well suited for creating and reproducing documents with finishes because large industrial printers are not required to produce the document finish. Laser printers may use a finish toner cartridge to apply a clear toner to a sheet of paper in order to realize the document finish. As a result, small-number runs or single document productions requiring specific document finishes may be accomplished using small commercial-size desktop printers.  
         [0014]     Furthermore, graphics and art may also be produced using small commercial-size desktop printers as applying non-clear toner may also yield document effects such as watermarking or UV-protection Since the document effects may be produced for short-runs and single document productions, time and money are saved by not having to use large industrial-size printing machines. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]     The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:  
         [0016]      FIG. 1  is a side view diagram of a conventional laser printer that will be used to illustrate the typical workings of a conventional laser printer;  
         [0017]      FIG. 2  is a block diagram of a suitable computing environment in which some embodiments of the invention may be implemented;  
         [0018]      FIG. 3  is a diagram of a portion of the laser printer of  FIG. 2  in the process of imparting toner to a sheet of paper according to an embodiment of the invention; and  
         [0019]      FIG. 4  is an isometric view of a sheet of paper having underlying content and document effects that me be printed using the printer of  FIG. 2  according to an embodiment of the invention. 
     
    
     DETAILED DESCRIPTION  
       [0020]     The following discussion is presented to enable a person skilled in the art to make and use the invention. The general principles described herein may be applied to embodiments and applications other than those detailed above without departing from the spirit and scope of the present invention. The present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed or suggested herein.  
         [0021]      FIG. 2  and the following discussion are intended to provide a brief, general description of a suitable computing environment in which some embodiments of the invention may be implemented. Generally, program modules include routines, programs, objects, components, data structures, etc. that collectively perform particular tasks or implement particular abstract data types. Moreover, those skilled in the art will appreciate that the invention may be practiced with other computer system configurations, including hand-held devices, multiprocessor systems, microprocessor-based or programmable consumer electronics, network PCs, minicomputers, mainframe computers, and the like. The invention may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote memory storage devices.  
         [0022]     With reference to  FIG. 2 , an exemplary system for implementing the invention includes a general purpose computing device in the form of a conventional personal computer  200 , including a processing unit  201 , a system memory  210 , and a system bus  202  that couples various system components including the system memory  210  to the processing unit  201 . The system bus  202  may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. The system memory  210  includes read only memory (ROM)  211  and random access memory (RAM)  212 . A basic input/output system (BIOS)  213 , containing the basic routines that help to transfer information between elements within the personal computer  200 , such as during start-up, is stored in the system memory  210 . The system memory  210  may further include program applications  214  and program modules  215 .  
         [0023]     The personal computer  200  further includes a hard disk drive  241  for reading from and writing to a hard disk (not shown), a magnetic media drive  242  for reading from or writing to a removable magnetic disk (not shown), and an optical media drive  243  for reading from or writing to a removable optical disk (not shown) such as a CD ROM or other optical media. The hard disk drive  241 , magnetic media drive  242 , and optical media drive  243  are connected to the system bus  202  by one or more media interfaces  240  (only one shown). The drives and their associated computer-readable media provide both volatile and nonvolatile storage of computer readable instructions, data structures, program modules and other data for the personal computer  200 .  
         [0024]     Although the exemplary environment described herein employs a hard disk  241 , a removable magnetic disk  242  and a removable optical disk  243 , it should be appreciated by those skilled in the art that other types of computer-readable media which can store data that is accessible by a computer, such as magnetic cassettes, flash memory cards, digital versatile disks, Bernoulli cartridges, random access memories (RAMs), read only memories (ROM), and the like, may also be used in the exemplary operating environment.  
         [0025]     A number of program modules may be stored on the hard disk  241 , magnetic disk  242 , optical disk  243 , ROM  211  or RAM  212 , including an operating system, one or more application programs, other program modules, and program data, all of which are not shown). A user may enter commands and information into the personal computer  200  through input devices such as a keyboard  221  and pointing device  222 . Other input devices (not shown) may include a microphone, joystick, game pad, satellite dish, scanner, or the like. These and other input devices are often connected to the processing unit  201  through an input interface  220  that is coupled to the system bus  202 . The input interface  220  may be a serial port, a parallel port, a game port, a universal serial bus (USB) or any other interface. A monitor  231  or other type of display device may also be connected to the system bus  202  via an interface, such as a video interface  230 . One or more speakers  251  may also be connected to the system bus  202  via an interface, such as an output peripheral interface  250 . In addition to the monitor and speakers, a personal computer  200  typically includes other peripheral output devices, such as printer  270  which is described in greater detail below.  
         [0026]     The personal computer  200  may operate in a networked environment using logical connections to one or more remote computers, such as remote computer  262 . The remote computer  262  may be another personal computer, a server, a router, a network PC, a peer device or other common network node, and typically includes many or all of the elements described above relative to the personal computer  200 , although only a memory storage device, such as a database  263  has been illustrated in  FIG. 2 . The logical connections depicted in  FIG. 2  include a local area network (LAN)  260  and a wide area network (WAN)  261 . Such networking environments are commonplace in offices, enterprise-wide computer networks, intranets and the Internet. As depicted in  FIG. 2 , the remote computer  262  communicates with the personal computer  200  via the local area network  260  via a network interface  235 . The personal computer may also communicate with the remote computer  262  through the wide area network  261  via a modem  255  or other remote communications device.  
         [0027]     When used in a LAN networking environment, the personal computer  200  is connected to the local network  260  through the network interface or adapter  235 . When used in a WAN networking environment, the personal computer  200  typically includes a modem  255  or other means for establishing communications over the wide area network  261 , such as the Internet. The modem  255 , which may be internal or external, is connected to the system bus  202  via the input interface  220 . In a networked environment, program modules depicted relative to the personal computer  200 , or portions thereof, may be stored in the remote memory storage device. It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers may be used.  
         [0028]     The printer  270  operates similar to the conventional printer  170  described above. In one embodiment, the printer  270  is a laser printer  270  and engages and maneuvers paper through a series of pulleys and a belt  291 . When a document is to be printed, the belt  291  engages a sheet of paper from a paper tray  280  and begins maneuvering the paper toward a rotating drum  281 . The rotating drum  281  is then prepared for receiving a pattern of static charge. Initially, the rotating drum  281  is imparted with a total positive charge by a charge corona wire (not shown in detail), a wire with an electrical current running through it.  
         [0029]     As the surface of the rotating drum  281  rotates further, a laser  284  is focused, via a focusing mirror system  283 , across the surface of the rotating drum  281  to discharge certain points according to the specific pattern. In this way, the laser  284  “draws” the letters and images to be printed as a pattern of electrical charges, i.e., an electrostatic image, right on the surface of the rotating drum  281 .  
         [0030]     After the electrostatic image is imparted to the rotating drum  281 , the rotating drum  281  is coated with positively charged toner which may be a black toner, a colored toner, or a clear toner. The aspects of applying different kinds of toner are described below with respect to  FIG. 3 . The toner is applied from a toner roller  282  that may include a toner reservoir. Since the toner typically has a positive charge, the toner clings to the negative discharged areas of the rotating drum  281 , but not to the positively charged areas.  
         [0031]     With the toner pattern applied according to the electrostatic image, the rotating drum  281  continues rotating and rolls over a sheet of paper, which is moving along the belt  291  below. Before the paper rolls under the rotating drum  281 , it is imparted with a negative charge by the transfer corona wire (not shown in detail). The negative charge imparted to the paper is stronger than the negative charge of the electrostatic image imparted the rotating drum  281  by the laser  284 . Thus, when the paper engages the rotating drum  281 , the positively charged toner is then attracted to the more negatively charged paper, in essence, transferring the electrostatic image from the rotating drum  281  to the paper. Since the paper is moving at the same speed as the drum, the paper picks up the image pattern exactly. To keep the paper from clinging to the rotating drum  281 , the paper is discharged by a detac corona wire (not shown in detail) immediately after the toner is transferred. The rotating drum  281  continues rotating, now without toner but still with the electrostatic pattern, until the rotating drum  281  surface passes the discharge lamp (not shown in detail) in order to erase the electrostatic image. The rotating drum  281  surface is then ready to start the process again.  
         [0032]     The paper, now having toner applied according to the electrostatic image, passes through a fuser  286  which may be a pair of heated rollers. As the paper passes through the fuser  286 , the loose toner powder melts, fusing with the fibers in the paper. The paper, now a printed document, is then rolled along the belt  291  to the output tray  285 .  
         [0033]     The laser printer  270  also includes a controller  290  that is able to receive data from and outside source, e.g., the personal computer  200 , store the data in a printing buffer (not shown) and the interpret the data (which corresponds to a document) into an electrostatic image to be imparted by the laser  284 . The controller  290  typically communicates with the computer system  200  via standard, well-known protocols such as through parallel communications ports and/or universal serial bus ports, i.e., output peripheral interface  250 .  
         [0034]      FIG. 3  is a diagram of a portion of the laser printer  270  of  FIG. 2  in the process of imparting toner to a sheet of paper  300  according to an embodiment of the invention. A sheet of paper  300  is shown moving through a portion of the laser printer  270 . Accordingly, different portions of the sheet of paper  300  are in different printing states, i.e., empty at the bottom, toner applied but not fused yet in the middle, and toner fused at the top. When the paper  300  is first staged to be printed, the laser  284  is focused, via the focusing mirror system  283 , across the surface of the rotating drum  281  to discharge certain points according to the specific pattern. Thus, the laser  284  imparts an electrostatic image to the surface of the rotating drum  281 .  
         [0035]     After the electrostatic image is imparted to the rotating drum  281 , the rotating drum  281  is coated with positively charged toner from the toner roller  282 . Since the toner has a positive charge, the toner clings to the negative discharged areas of the rotating drum  281 , but not to the positively charged areas.  
         [0036]     With the toner pattern applied according to the electrostatic image, the rotating drum  281  continues rotating and rolls over a sheet of paper  300 . As described above, before the paper  300  rolls under the rotating drum  281 , it is imparted with a negative charge. The negative charge imparted to the paper  300  is stronger than the negative charge of the electrostatic image imparted the rotating drum  281  by the laser  284 . Thus, when the paper  300  engages the rotating drum  281 , the positively charged toner is then attracted to the more negatively charged paper  300 , in essence, transferring the electrostatic image from the rotating drum  281  to the paper. The paper  300 , now having toner applied according to the electrostatic image, passes through a fuser  286 . As the paper passes through the fuser  286 , the loose toner powder melts, fusing with the fibers in the paper.  
         [0037]     The toner in the toner roller  282  may be supplied from one or more toner hoppers. The embodiment of  FIG. 3  shows three toner hoppers: a black toner hopper  310 , a color toner hopper  311 , and a clear toner hopper  312 . The particular hopper required for a printing job may be chosen through the controller  290  (not shown in  FIG. 3 ) via a toner selector mechanism  315 .  
         [0038]     The choice of toner depends upon the nature of the printing job. Typically, black and colored toner (examples of non-effect and/or non-finish toners) may be imparted to a sheet of paper  300  in conventional ways to print underlying document patterns, i.e., images and words. According to various embodiments of the invention, a finish toner, such as a clear toner, may be imparted to a sheet of paper to create particular document effects and/or document finishes.  
         [0039]     For example, a sheet of paper  300  may first be printed using black toner from the black toner hopper  310 . Then, a particular effect, such as water-resistant sealing, may be achieved by applying a coating of clear toner from the clear toner hopper  312  across the entire sheet of paper  300  on a second pass through the laser printer  270 . The resulting document is a printed document with images or words in black toner underneath a water-resistant coating of clear toner. This document effect and others are described in greater detail below with respect to  FIG. 4 .  
         [0040]     In one embodiment of the invention, the printer  270  is operable to create document effects such that paper  300  is passed by the rotating drum  281  twice. For example, a first pass may impart underlying document content and/or images. Then after the underlying toner (black or colored) is fused to the paper  300  at the end of the first pass, the paper  300  may be fed back for a second pass for imparting additional toner for document effects. Thus, in the second pass, a particular pattern of clear toner is imparted and fused to the paper  300  such that the finished document has a first pattern of black or colored toner underneath a pattern of clear toner fashioned to achieve a particular document effect.  
         [0041]     In another embodiment of the invention, a printer (not shown in any figure) is operable to create document having effects such that the printer includes two stages for imparting toner to a sheet of paper  300 . For example, a first stage may impart underlying document content and/or images. Then after the underlying toner (black or colored) is fused to the paper  300  at the end of the first stage, the paper  300  may be fed to a second stage for imparting additional toner for document effects. Thus, in the second stage, a particular pattern of clear toner may be imparted and fused to the paper  300  such that the finished document has a first pattern of black or colored toner underneath a pattern of clear toner fashioned to achieve a particular document effect.  
         [0042]     Clear toner may be imparted to a sheet of paper  300  to create a number of different document effects according to various aspects of the invention. Such document effects include watermarking, water-resistant coating, UV protection, and others and are discussed below with respect to  FIG. 4 . Additionally, the toner may be translucent or semi-transparent in order to achieve other document effects.  
         [0043]      FIG. 4  is an isometric view of a sheet of paper  300  having underlying content and document effects that me be printed using the printer  270  of  FIG. 2  according to an embodiment of the invention. The sheet of paper  300  includes underlying content, such as an image of a flower  400 , which has been fused to the paper  300  in black and/or colored ink as well as a document effect, such as a water-resistant coating, that has been fused to the paper  300  in a clear toner. Of course, the document effects cannot be seen precisely in  FIG. 4  because the toner is clear. However, the physical effects of the clear toner may be illustrated.  
         [0044]     For example, as described above, the paper  300  may have a water-resistant coating fused to it. Thus, water  420  will not penetrate the paper  300  and will bead up as shown in  FIG. 4 . Such a water-resistant coating may be fused over the entire sheet of paper  300  using a clear toner specifically designed to be water-resistant. As a result, the underlying image  400  may still be seen through the clear toner that covers the entire sheet of paper  300  to provide a water-resistant coating.  
         [0045]     In another example, the paper  300  may have a UV reflective coating fused to it. Thus, UV rays  410  will be reflected by the UV reflective coating on the paper  300  as shown in  FIG. 4 . Such a UV reflective coating may be fused over the entire sheet of paper  300  using a clear toner specifically designed to be UV reflective. As a result, the underlying image  400  may still be seen through the clear toner that covers the entire sheet of paper  300  to provide a protection against fading and discoloration due to UV light exposure.  
         [0046]     In another embodiment of the invention, translucent toner (not shown) may be imparted and fused to the sheet of paper  300  to provide additional document effects. For example, certain artistic effects may be achieved by using translucent toner, such as watermarking effects, 3-D effects, and holography.  
         [0047]     Watermarking is an effect whereby a see-through image appears over the top of an underlying image  400 . Thus, according to an embodiment of the invention, the underlying image may be fused to the paper  300  using black and/or colored toner and then a superimposed second image, meant to be transparent or semi-transparent, may be fused to the sheet of paper  300  using translucent and/or clear toner.  
         [0048]     A 3-D effect is an optical illusion effect whereby an image  400  appears to be “jumping” out of a page when viewed using a specially-prepared viewer, e.g., 3-D glasses. Thus, according to an embodiment of the invention, the underlying image  400  may be again fused to the paper  300  using black and/or colored toner and then a slightly different second image, meant to be transparent or semi-transparent when viewed without the 3-D viewer, may be fused to the sheet of paper  300  using translucent and/or clear toner. Then, when the underlying image is viewed without the 3-D viewer, the image  400  appears incomprehensible or out of focus, but when the 3D viewer is used, the image appears to be lifted off of the paper  300 .  
         [0049]     A holographic effect is another optical illusion effect whereby an image  400  appears to have depth into a page when viewed. Thus, according to an embodiment of the invention, the underlying image  400  may be again fused to the paper  300  using black and/or colored toner and then a slightly different second image, meant to be transparent or semi-transparent, may be fused to the sheet of paper  300  using translucent and/or clear toner. Then, when the underlying image  400  is viewed the image appears to have depth as if one could reach down into the image.  
         [0050]     Other artistic effects may also be created using a finish toner, such as a clear or translucent toner. Additionally, varying sizes of toner particles within the blend of finish toner will yield different document finishes and/or effects. Such artistic finishes include glossy, matte, or satin finishes. By mixing a particular blend of sizes of particles of clear toner and/or translucent toner, different finish effects may be created when imparted to a sheet of paper  300 . That is, the consistency of the toner may be varied from fine to course in order to achieve different document effects in addition to varying the color and/or transparency of the toner.  
         [0051]     For example, applying a certain blend of clear toner to a sheet of paper  300  may impart a glossy finish effect to the underlying image  400 . Likewise, applying a different blend of clear toner and/or translucent toner may impart a matte finish effect to the underlying image  400 . Further yet, applying yet another different blend of clear toner and/or translucent toner may impart a satin finish effect to the underlying image  400 . Other finish effects are contemplated but not disclosed in greater detail herein.  
         [0052]     Different document effects may also be achieved by varying the manner in which the finish toner is fused to the sheet of paper  300 . That is, the temperature and pressure of the fuser  286  may be varied to achieve different document effects and may even be done so in conjunction with varying sizes of particles of toner and blends of clear and translucent toner. For example, if a matte finish is desired, a sheet of paper  300  may be imparted with large toner particles and then fused to the sheet of paper using a lower fuser  286  temperature and pressure that yields a flat or matte finish. However, if a glossy finish is desired, the fuser  286  temperature and pressure may be increased to “melt” the large toner particles all the more, thus creating a very clear and fine looking glossy finish. For a satin finish, an intermediate temperature and pressure setting at the fuser  286  may yield a finish that is neither the fine glossy finish nor the rough matte finish. Other variation of temperature and pressure of the fuser  286  are contemplated but not discussed in greater detail herein.

Technology Category: g