Patent Publication Number: US-8971747-B2

Title: Image forming apparatus and method for controlling image forming apparatus, which includes fixing and decolorizing section

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a Continuation of application Ser. No. 13/494,128 filed Jun. 12, 2012, which is based upon and claims the benefit of U.S. Provisional Application No. 61/496,699, filed on Jun. 14, 2011; the entire contents of both of which are incorporated herein by reference. 
    
    
     FIELD 
     Embodiments described herein relate generally to an image forming apparatus and a method for controlling an image forming apparatus including a fixing and decolorizing section. 
     BACKGROUND 
     There are known an image forming apparatus that performs image formation using a decolorizable toner and an erasing device that changes an image from a color developed state to a decolored state. The decolorizable toner used in such an image forming apparatus is decolorized when a color former compound and a color developer are disconnected by heat. 
     The erasing device is provided separately from the image forming apparatus. However, there is known a fixing device in the image forming apparatus also used as the erasing device taking into account space saving. In general, temperature necessary for decolorizing a toner is higher than temperature necessary for fixing the toner. Therefore, the fixing device also functioning as the erasing device operates as the erasing device by raising the temperature of the fixing device when the fixing device is about to perform an erasing operation. 
     However, if the temperature of the fixing device is once raised, since the fixing device is formed of a material having high heat accumulation properties such as rubber, it takes time to lower the temperature to the temperature suitable for fixing again. On the other hand, if the fixing is performed in a state in which the temperature does not sufficiently drop, excessive melting of the toner called high-temperature offset occurs. Therefore, even if a user attempts to perform copying or the like while a erasing operation is performed, the user has to wait until the temperature of the fixing device drops, leading to poor operability. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a sectional view of an image forming apparatus according to an embodiment; 
         FIG. 2  is a configuration diagram of a fixing and decolorizing device according to the embodiment; 
         FIG. 3  is an external view of an operation section in the embodiment; 
         FIG. 4  is a block diagram of the configuration of a control panel of the image forming apparatus; 
         FIG. 5  is a diagram of an example of a screen displayed on a control panel in the embodiment; 
         FIG. 6  is a flowchart for a decolorizing operation; and 
         FIG. 7  is a flowchart for an image forming operation performed after the decolorizing operation. 
     
    
    
     DETAILED DESCRIPTION 
     According to one embodiment, an image forming apparatus includes, an image forming section configured to form an image on a medium with a decolorizable toner, a fixing and decolorizing section configured to fix the image formed on the medium and to decolorize the image on the medium selectively, a heat generating section configured to heat the fixing and decolorizing section to first temperature during the fixing and to heat the fixing and decolorizing section to second temperature higher than the first temperature during the decolorizing, a count section configured to count time during which the image forming section doesn&#39;t perform an image forming after the image formation on the medium is finished through the fixing and a control section configured to control the heat generating section to heat the fixing and decolorizing section to the second temperature, when the time counted by the count section reaches the a predetermined threshold time. 
     An embodiment is explained below with reference to the accompanying drawings. 
       FIG. 1  is a schematic configuration diagram of an MFP (Multi Function Peripheral)  1 , which is an image forming apparatus according to this embodiment. The MFP  1  includes a scanner section  2  that scans an original document during copying or the like and a printer section  4  functioning as an image forming section. The MFP  1  includes, below the printer section  4 , paper feeding cassettes  21  and  22  and a recycle paper feeding cassette  23  that store sheets to be fed to the printer section  4 . There is provided a fixing and decolorizing device  5  that fixes an image, which is formed by the printer section  4 , on a sheet and decolorizes or erases the image fixed thereon. There is provided further a discharging section  30  that discharges the sheet having the image fixed thereon by the fixing and decolorizing device  5  downstream of the printer section  4  along a traveling direction of the sheet. 
     The printer section  4  includes a rotating photoconductive drum  12 . The printer section  4  includes, around the photoconductive drum  12 , a charging device  13  that uniformly charges the photoconductive drum  12  to negative polarity and a laser exposure device  14  that irradiates a laser beam, which is based on image data or the like from the scanner section  2 , on the charged photoconductive drum  12  and forms an electrostatic latent image on the photoconductive drum  12 . The printer section  4  includes a developing device  15  that supplies a toner serving as an image forming material to the electrostatic latent image on the photoconductive drum  12 , a transfer device  16  that transfers a toner image formed on the photoconductive drum  12  onto a sheet P, which is an image recording medium, and a cleaner  17  that removes an untransferred toner remaining on the photoconductive drum  12 . 
     The developing device  15  stores a two-component developer, which is a mixture of a toner and a magnetic carrier and supplies the toner to the electrostatic latent image on the photoconductive drum  12 . The toner is a toner that is decolorized or erased by being heated to predetermined temperature. This decolorizable toner contains binder resin and a color material. The color material includes a color assuming compound and a color developing agent. When the decolorizable toner is fixed on a sheet, the color assuming compound and the color developing agent combine and develop a predetermined color, for example, blue. On the other hand, if an image formed with the decolorizable toner is heated to temperature higher than temperature during the fixing processing, the color assuming compound and the color developing agent are dissociated. The color assuming compound and the color developing agent lose the color and become invisible on the sheet. As an example, a toner that is fixed at 80° C. to 100° C. and decolorize by being heated to 130° C. to 150° C. is used. 
     In this embodiment, a capsule type thermal decolorizable toner formed by a chemical method explained below is used as the decolorizable toner. 
     (1) Binder Resin, WAX Atomized Liquid 
     Polyester resin was used as the binder resin. Resin atomized liquid was formed using polyester resin, an anion emulsifier, and a neutralizer and using a high-pressure homogenizer. 
     (2) Preparation of WAX Dispersing Liquid 
     Atomized liquid was obtained by a method same as the method for the resin using rice WAX. 
     (3) Preparation of a Toner 
     Leuko die: CVL (crystal violet lactone), color developing agent; 4-hydroxybenzonic acid benzyl, temperature control agent: lauric acid-4-benzyloxy phenyl ethyl 
     The binder resin, the WAX atomized liquid, the WAX dispersing liquid, and the toner were heated and melted and encapsulated by a well-known coacervation method. The encapsulated color material, toner binder resin dispersing liquid, and WAX dispersing liquid were condensed and fused using aluminum sulfate [Al2(SO4)3] and further cleaned and dried to obtain a toner. Silica and titanium oxide were externally added to the toner. 
     The explanation is continued with reference to  FIG. 1 . The paper feeding cassette  21 , the paper feeding cassette  22 , and the recycle paper feeding cassette  23  have substantially the same configuration. Whereas unused sheets are stored in the paper feeding cassettes  21  and  22 , used sheets, i.e., sheets having toner images formed thereon are stored in the recycle paper feeding cassette  23 . However, the recycle paper feeding cassette  23  can store unused sheets as well. 
     The paper feeding cassette  21  includes a pickup roller  24  that feeds a sheet at the top of the sheets stored in the paper feeding cassette  21 . A separating and conveying roller  27  is provided to separate two or more sheets, which are fed by the pickup roller  24 , one by one and conveys. Like the paper feeding cassette  21 , pickup rollers  25  and  26  and separating and conveying rollers  28  and  29  are also respectively provided in the paper feeding cassette  22  and the recycle paper feeding cassette  23 . 
     A sheet residual quantity sensor  150  is provided at the recycle paper feeding cassette  23  as shown in  FIG. 4 . The sheet residual quantity sensor  150  detects whether the sheets are stored in the recycle paper feeding cassette  23  or not. A sheet residual quantity sensor  150  can also detect whether the sheets stored in the recycle paper feeding cassette are equal to or more than a predetermined threshold quantity or not. 
     The fixing and decolorizing device  5  includes a heat roller  51 , which is a fixing member formed in a cylindrical shape, and a pressurizing belt  52 , which is a pressurizing member that endlessly turns. The pressurizing belt  52  comes into contact with the outer circumferential surface of the heat roller  51  over a predetermined range and forms a fixing nip portion. As shown in  FIG. 2 , the heat roller  51  incorporates, for example, a halogen lamp  53  on the inside as a heating source. The diameter of the heat roller  51  is, for example, 45 mm. The diameter of the pressurizing belt  52  is, for example, equivalent to a diameter of 47 mm in terms of a circle. In this embodiment, the length in a conveying direction of the fixing nip portion is, for example, about 27 mm. 
     As shown in  FIG. 1 , the pressurizing belt  52  is looped around a belt heat roller  54  located on an upstream side in the conveying direction, a pressurizing roller  55  located on a downstream side in the conveying direction, and a tension roller  56 . The pressurizing belt  52  forms fixing nip portions between the belt heat roller  54  and the pressurizing roller  55 . The pressurizing roller  55  brings the pressurizing belt  52  into pressurized contact with the heat roller  51  and forms an outlet of the fixing nip portion. A pressurizing pad  58  is held by a pressurizing pad holder  57  arranged on the inner side of the pressurizing belt  52 . The pressurizing pad  58  is pressed against the inner circumferential surface of the pressurizing belt  52  in the center of the fixing nip portion. The pressurizing belt  52  is brought into pressurized contact with the heat roller  51 . 
     The belt heat roller  54  is formed in a hollow roller shape. A halogen lamp  59  is incorporated in the belt heat roller  54 . 
     In this embodiment, the diameter of the belt heat roller  54  is set to 20 mm, the diameter of the pressurizing roller  55  is set to 18 mm, and the width of the pressurizing pad  58  is set to 10 mm. 
     The surface temperature of the heat roller  51  is detected by a thermistor  61  set in contact with the outer circumferential surface of the heat roller  51 . The surface temperature of the pressurizing belt  52  at the belt heat roller  54  is detected by a thermistor  62  set in contact with the outer circumferential surface of the pressurizing belt  52 . 
     The heat roller  51  comes into contact with an unfixed toner image born on a sheet. Therefore, the heat roller  51  includes, for example, a fluorine resin PFA (tetrafluoroethylene perfluoroalkyl vinyl ether copolymer) layer having thickness of about 25 μm as a release layer on a roller substrate made of aluminum having thickness of 1.0 mm. The pressurizing belt  52 , which is a pressurizing member, includes a silicone rubber layer having thickness of 200 μm on a belt substrate made of nickel having thickness of about 40 μm and includes a fluorine resin PFA layer having thickness of about 30 μm as a release layer on the silicone rubber layer. 
     As shown in  FIG. 2 , the heat roller  51  is driven by a not-shown driving source to rotate. The pressurizing belt  52  is driven to rotate following the heat roller  51 . 
     The halogen lamp  53  incorporated in the heat roller  51  includes two lamps, i.e., a center lamp  53 A that heats the center in the length direction of the heat roller  51  and a side lamp  53 B that heats both the ends in the length direction of the heat roller  51 . The lamp  59  incorporated in the belt heat roller  54  heats the belt heat roller  54  over the entire length in the length direction. The center lamp  53 A corresponds to, for example, the sheet width of an A4 portrait size long in the conveying direction. The heat roller side lamp  53 B corresponds to, for example, the sheet width of an A4 landscape size long in a direction orthogonal to the conveying direction. The power of these three lamps is, for example, 300 W. 
     A center lamp switching element  63 A, a side lamp switching element  63 B, and a pressurizing belt lamp switching element  64  are respectively subjected to ON and OFF control, whereby electricity is supplied from a commercial alternating-current power supply to the center lamp  53 A, the side lamp  53 B, and the lamp  59 . 
     The center lamp switching element  63 A, the side lamp switching element  63 B, and the pressurizing belt lamp switching element  64  are subjected to ON and OFF control by a control section  65 . 
     The thermistor  61  includes a center thermistor  61 A that detects the surface temperature of the center portion in the elongated direction of the heat roller  51  and a side thermistor  61 B that detects the surface temperature of one side end in the elongated direction of the heat roller  51 . The thermistor  61  inputs temperature detection information of the center thermistor  61 A and the side thermistor  61 B to the control section  65 . If a sheet on which a toner is fixed is, for example, a sheet of the A4 portrait size, an OFF period of the side lamp  53 B is set long to prevent the temperature of both the ends of the heat roller  51  from rising more than necessary. 
     The thermistor  62  detects the surface temperature of the center portion in the width direction of the pressurizing belt  52  and inputs temperature detection information to the control section  65 . The thermistors  61 A,  61 B, and  62  are connected to the control section  65  respectively via A/D converters not shown. 
     The set temperature of the heat roller  51  during fixing is 100° C. and the set temperature of the heat roller  51  during decolorizing is 130° C. The set temperature of the pressurizing belt  52  during fixing is 80° C. and the set temperature of the pressurizing belt  52  during decolorizing is 110° C. 
     The sheet having the toner fixed thereon by the fixing and decolorizing device  5  is nipped by a paper discharge roller pair  20  and discharged to the paper discharge section  30 . 
       FIG. 3  is an external view of a control panel  100  functioning as an operation section included in the MFP  1 . The control panel  100  includes various input keys  102  and a liquid crystal panel  104 . The input keys  102  include, besides a start key and a numeric keypad, a decolorizing key  106  pressed by the user when the user desired to perform erasing of a sheet. 
     A main configuration of a control system of the MFP  1  according to this embodiment is shown in  FIG. 4 . 
     The MFP  1  further includes a CPU  65 , which is a control section, a ROM  202 , a RAM  204 , and a timer  206  besides the scanner section  2 , the printer section  4 , the control panel  100 , the paper feeding cassettes  21  and  22 , the recycle paper feeding cassette  23  and the sheet residual quantity sensor  150 . These sections are connected via a system bus. 
     The CPU  65  controls the sections connected via the system bus. The ROM  202  has stored therein various control programs necessary for the MFP  1  to operate. The control programs are executed by the CPU  65 . The RAM  204  is a memory that temporarily stores data generated during the execution of the control programs. The timer  206  counts time according to the execution of the control programs. The timer  206  counts, for example, an idle time that elapses after the MFP  1  finishes the image formation. In other words, the timer  206  counts time during which the printer section doesn&#39;t perform a new image forming operation after the MFP  1  finishes the previous image forming operation. 
     An image forming process and a decolorizing process by the MFP  1  are explained. 
     According to the start of the image forming process, in the printer section  4 , the photoconductive drum  12  rotating in an arrow s direction at circumferential speed of 215 mm/sec is uniformly charged to −750 V by the charging device  13 . A laser beam corresponding to document information is irradiated on the photoconductive drum  12  by the laser exposure device  14  to form an electrostatic latent image on the photoconductive drum  12 . Subsequently, the electrostatic latent image is developed by the developing device  15  using the decolorizable toner. A toner image formed of the decolorizable toner is formed on the photoconductive drum  12 . 
     On the other hand, a sheet is fed from the paper feeding cassette  21 . The sheet is sent to the transfer device  16  by a registration roller pair  6  in synchronization with the formation of the toner image on the photoconductive drum  12 . The toner image on the photoconductive drum  12  is transferred onto the sheet. 
     The sheet having the toner image transferred thereon is peeled off the photoconductive drum  12  and then sent to the fixing and decolorizing device  5 . The surface temperature of the heat roller  51  of the fixing and decolorizing device  5  is controlled to be 100° C. The sheet is inserted through between the heat roller  51  and the pressurizing belt  52 . The toner image is heated, pressurized, and fixed on the sheet. After the fixing and decolorizing device  5  finishes the fixing of the toner image formed with the decolorizable toner, the sheet is discharged to the paper discharge section  30  by the paper discharge roller pair  20 . 
     After the transfer ends, a residual toner on the photoconductive drum  12  is cleaned by the cleaner  17 . Residual charges on the photoconductive drum  12  are removed by a charge removing LED  18 . 
     The decolorizing process is explained with reference to  FIGS. 5 and 6 . 
     When the user presses the decolorizing key  106  of the control panel  100  shown in  FIG. 3 , the decolorizing process is started. When the user presses the decolorizing key  106 , a decolorizing mode setting screen shown in  FIG. 5  is displayed on the liquid crystal panel  104 . 
     The decolorizing mode setting screen displays a message for requesting the user to select any one of three modes explained below. 
     A first mode is an automatic decolorizing mode in which, if MFP  1  does not perform image forming for a fixed time, for example, 30 minutes, the MFP  1  automatically conveys the used sheet from the recycle paper feeding cassette  23  to the fixing and decolorizing device  5  and performs decolorizing in the fixing and decolorizing device  5 . If the user selects the automatic decolorizing mode, the user can input, from the liquid crystal panel  104 , time from the end of the image forming until shift to a decolorizing mode and change the time. In this embodiment, the time for shift is 30 minutes. 
     A second mode is an interrupt decolorizing mode for performing decolorizing if the decolorizing is necessary. For example, if the user selects the interrupt decolorizing mode during copying, the decolorizing is started without delay after a copying job ends. 
     A third mode is a time designated decolorizing mode for designating time when decolorizing is started and time when the decolorizing is finished and performing the decolorizing in a designated period at night or the like. 
     Not only one mode but also plural modes among the three modes can be selected. 
     Processing at the automatic decolorizing mode is explained. 
     In  FIG. 6 , when the image formation is instructed in accordance with an image forming signal or a print signal from a not-shown external computer (Y in ACT  2 ), the CPU  65  sets the surface temperature of the heat roller  51  to 100° C., checks the temperature of the center thermistor  61 A, and heats the heat roller  51  on the basis of a result of the check (ACT  3 ). The CPU  65  also heats the belt heating roller  54  to heat the pressurizing belt  52  to 80° C. When the temperature of the heat roller  51  reaches 100° C. and the temperature of the pressurizing belt  52  reaches 80° C., the CPU  65  shifts to an image print mode and executes the image formation. When a sheet is discharged to the paper discharge section  30 , an image forming process ends, and the rotation of the photoconductive drum stops, the timer  206  starts count (ACT  4 ). 
     For five minutes after the image forming process ends, the CPU  65  sets the MFP  1  in a ready mode and maintains the surface temperature of the heat roller  51  at 100° C. and maintains the temperature of the pressurizing belt  52  at 80° C. If the CPU  65  determines that five minutes elapses (Y in ACT  5 ), the CPU  65  ends the ready mode and shifts to an energy saving mode (ACT  6 ). The energy saving mode is a mode for maintaining the temperature of the heat roller  51  and/or the pressurizing belt  52  lower than temperatures in a fixing mode and the ready mode to lower the temperature of the fixing and decolorizing device  5 . In this embodiment, the CPU  65  stops the heating of the heat roller  51  and continues the heating of only the belt heat roller  54  to heat pressurizing belt  52  (ACT  7 ). The temperature of the pressurizing belt  52  is 80° C. 
     If twenty-five minutes further elapse after the shift to the energy saving mode while a print signal is not received, i.e., thirty minutes elapse after the print ends (Y in ACT  8 ), the CPU  65  determines that time during which image formation is not performed exceeds a threshold of 30 minutes set in advance and detects, with a sheet residual quantity sensor  150 , whether sheets are stored in the recycle paper feeding cassette  23 . As a result of the detection, if the CPU  65  detects that used sheets are stored in the recycle paper feeding cassette  23  (Y in ACT  9 ), the CPU  65  ends the energy saving mode (ACT  10 ) and starts heating of the heat roller  51  and the belt heat roller  54  in order to switch the energy saving mode to the automatic decolorizing mode (ACT  11 ). If sheets are absent in the recycle paper feeding cassette  23  (N in ACT  9 ), the CPU  65  ends the processing without shifting to the decolorizing mode (ACT  15 ) and switches the MFP  1  to, as a sleep mode, a mode for stopping the heating of the pressurizing belt  52  as well. In other words, the CPU  65  prohibits a temperature rise of the heat roller  51  if sheets are absent in the recycle paper feeding cassette  23 . 
     The CPU  65  may execute decolorizing processing when the sheets are present in equal to or more than a fixed quantity. 
     As explained above, according to a detection result of the sheet residual quantity sensor  150 , when the CPU  65  detects that a quantity of sheets stored in the recycle paper feeding cassette  23  is less than the fixed quantity, the CPU  65  does not execute the decolorizing mode. In other words, the CPU  65  prohibits the heating of a fixing and decolorizing device earlier when a quantity of sheets stored in the recycle paper feeding cassette  23  is less than the fixed quantity than when a quantity of sheet stored in the recycle paper feeding cassette is equal to or more than the fixed quantity. 
     When the CPU  65  detects, during the ready mode in five minutes after ending the image forming process (ACT  4 ), that sheets are absent in the recycle paper feeding cassette  23  or a sheet quantity is less than the fixed quantity, after ending the ready mode, the CPU  65  may immediately shift to the sleep mode without entering the energy saving mode. 
     If the temperature of the heat roller  51  reaches 130° C. and the temperature of the pressurizing belt  52  reaches 110° C. (ACT  11 ), the CPU  65  shifts to the automatic decolorizing mode (ACT  12 ). In the automatic decolorizing mode, the CPU  65  starts conveyance of a used sheet from the recycle paper feeding cassette  23  to the fixing and decolorizing device  5  (ACT  13 ). At this point, although the photoconductive drum  12  of the printer section  4  rotates, toner image formation on the photoconductive drum  12  is not performed. 
     The sheet conveyed from the recycle paper feeding cassette  23  via the printer section  4  is heated by the fixing and decolorizing device  5 , whereby a toner on the sheet is decolorized. The sheet bearing the decolorized toner is discharged to the paper discharge section  30  by the discharge roller pair  20 . If the sheet residual quantity sensor  150  detects that sheets are absent in the recycle paper feeding cassette  23  (N in ACT  14 ), the CPU  65  ends the automatic decolorizing mode (ACT  15 ) and enters the sleep mode. 
     Instead of entering the sleep mode, after ending the decolorizing mode, the CPU  65  may return to the ready mode, and may maintain the heat roller  51  at 100° C. and maintain the pressurizing belt  52  at 80° C. to prepare for the next print. 
     A processing flow of processing performed by the CPU  65  when a print operation is received during a decolorizing operation is shown in  FIG. 7 . 
     If the CPU  65  receives a image forming signal or print signal during the decolorizing operation (Y in ACT  21 ), the CPU  65  detects, with a not-shown sheet conveyance sensor, whether all used sheets fed from the recycle paper feeding cassette  23  are discharged to the discharge section  30  of the MFP  1 . If the CPU  65  determines that all the sheets are discharged (Y in ACT  22 ), even if sheets remain in the recycle paper feeding cassette  23 , the CPU  65  ends the automatic decolorizing mode. First, the CPU  65  sets the temperature of the heat roller  51  to 100° C. (ACT  23 ). The CPU  65  sets the temperature of the pressurizing belt  52  to 80° C. Since the temperature of the heat roller  51  is set to 130° C. and the temperature of the pressurizing belt  52  is set to 110° C. during decolorizing, the CPU  65  waits for the temperatures of the heat roller  51  and the pressurizing belt  52  to drop. At this point, in order to quickly lower the temperature of the heat roller  51 , the heat roller  51  and the pressurizing belt  52  may be spaced apart from each other. If the CPU  65  detects that the temperature of the heat roller  51  drops to 100° C. and the temperature of the pressurizing belt  52  drops to 80° C., the CPU  65  shifts to the print mode (ACT  24 ) and starts image formation. After finishing the image formation, as explained with reference to  FIG. 6 , the CPU  65  shifts to the automatic decolorizing mode again when it is detected that the predetermined idle time, for example 30 minutes, elapses. 
     According to this embodiment, it is possible to automatically start decolorizing process according to a state of the MFP  1 . If MFP  1  is not used for predetermined time, the MFP  1  allows an increase in the temperature of the heat roller  51 . Therefore, when print is frequently performed, a temperature rise of the heat roller  51  is suspended. Therefore the operability of the MFP  1  is improved. Since the MFP  1  includes the energy saving mode and performs the shift from the energy saving mode to the decolorizing mode, heating power to heat the heating and decolorizing device  5  can be reduced compared with shifting to the decolorizing mode from a power OFF mode or sleep mode. 
     The automatic decolorizing mode is explained above. However, the interrupt decolorizing mode and the time designated decolorizing mode can also be selected in addition to the automatic decolorizing mode. 
     If the interrupt decolorizing mode is selected, the CPU  65  controls mode shifting to decolorizing mode immediately after a pending job is finished. The temperature of the heat roller  51  rises to 130° C. In this case, when the print is necessary immediately after decolorizing mode, the user has to wait until the temperature of the heat roller  51  drops. 
     In the time designated decolorizing mode, the user designates decolorizing start time and decolorizing end time from the liquid crystal panel  104 . Between the decolorizing start time and the decolorizing end time, decolorizing process is performed. It is possible to prohibit to start the decolorizing process when sheets are absent in the recycle paper feeding cassette  23 . 
     While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.