Patent Publication Number: US-2018046137-A1

Title: Image forming apparatus and image forming control method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2016-158135, filed Aug. 10, 2016 and Japanese Patent Application No. 2017-46811, filed Mar. 10, 2017, entire contents of which are incorporated herein by reference. 
     FIELD 
     Embodiments described herein relate generally to an image forming apparatus and an image forming control method. 
     BACKGROUND 
     Conventionally, an information recording medium such as an IC chip or a RFID tag is loaded in a recording agent cartridge that is used in an image forming apparatus in most cases. Information unique to the recording agent cartridge and information of use history of the recording agent cartridge are recorded in the information recording medium. In some image forming apparatus, a recording agent cartridge installed in the image forming apparatus is authenticated, and various kinds of information required for image formation are read out from the authenticated recording agent cartridge to carry out the image formation. In a case in which the authentication of the recording agent cartridge fails, the recording agent cartridge is treated as an unknown cartridge. In this case, a value unique to a recording agent included in the recording agent cartridge is not acquired. Thus, an image forming processing is executed with a general parameter stored in the image forming apparatus regardless of the type of the recording agent accommodated in the recording agent cartridge. 
     In recent years, a recording agent cartridge with no information recording medium is packaged with the image forming apparatus to be provided for a user at time of shipment from the point of view of cost reduction. Even if there is no information recording medium in the packaged recording agent cartridge, the image forming apparatus allows execution of formation of a predetermined number of images only if the recording agent cartridge is recognized the packaged one. However, since the packaged recording agent cartridge does not have the information recording medium, data for authentication does not have the information required for the image formation either. Thus, if the packaged cartridge is used in the image forming apparatus for reading out various kinds of information required for the image formation on the basis of an authentication result to carry out image formation control, the image formation can only be carried out with the general parameter stored at the main body side. Since the image forming processing corresponding to the type of the recording agent in such a recording agent cartridge is not carried out, there is a case in which inconvenience such as deterioration of image quality is caused. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view illustrating an image forming apparatus according to an embodiment; 
         FIG. 2  is a diagram illustrating a constitution of main portion of the image forming apparatus according to the embodiment; 
         FIG. 3  is a block diagram illustrating a constitution of a control system of an image forming operation according to the embodiment; 
         FIG. 4  is a diagram illustrating table structures of a first memory and a second memory according to the embodiment; 
         FIG. 5  is a flowchart illustrating the image forming operation according to the embodiment; and 
         FIG. 6  is a flowchart illustrating the image forming operation according to the embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     In accordance with an embodiment, the image forming apparatus has an authentication section configured to authenticate an installed recording agent cartridge, a first image forming process parameter storage section configured to store a first image forming process parameter for controlling an image forming operation using the recording agent cartridge which is authenticated, a second image forming process parameter storage section configured to store a second image forming process parameter for controlling an image forming operation using the recording agent cartridge which is not authenticated, a determination section configured to determine whether or not the unauthenticated recording agent cartridge is equivalent to the authenticated recording agent cartridge; and an image forming control section configured to carry out control of an image forming operation by using the first image forming process parameter stored in the first image forming process parameter storage section in a case in which the recording agent cartridge is not authenticated by the authentication section and is determined to be equivalent to the authenticated recording agent cartridge by the determination section and to carry out control of an image forming operation by using the second image forming process parameter stored in the second image forming process parameter storage section in a case in which the recording agent cartridge is not authenticated by the authentication section and is determined not to be equivalent to the authenticated recording agent cartridge by the determination section 
     Hereinafter, an image forming apparatus and an image forming control method are described with reference to the accompanying drawings. “Decoloring” in the present embodiment refers to a processing of making an image formed with a color (containing not only chromatic colors but also achromatic colors such as white, black and the like) different from a base color of a sheet invisible visually. 
       FIG. 1  is an external view illustrating an example of an entire constitution of an image forming apparatus  100  according to the embodiment. The image forming apparatus  100  is, for example, an MFP (Multi-Functional Peripheral). The image forming apparatus  100  is equipped with a display  110 , a control panel  120 , a printer section  130 , a sheet housing section  140  and an image reading section  200 . The printer section  130  of the image processing apparatus  100  maybe a device for fixing a toner image or an inkjet type device. Cartridges of toner and ink are collectively called a recording agent cartridge. Further, the recording agent cartridge also includes a recording agent cartridge in which either decoloring toner which can decolor a color later or toner which cannot decolor a color later is filled. 
     The image forming apparatus  100  forms an image on a sheet with a recording agent such as the toner. The sheet is, for example, a paper or a label paper. The sheet may be an optional sheet as long as the image forming apparatus  100  can form an image on the surface of the sheet. 
     The display  110  is an image display device such as a liquid crystal display, an organic EL (Electro Luminescence) display and the like. The display  110  displays various kinds of information relating to the image forming apparatus  100 . 
     The control panel  120  includes a plurality of buttons. The control panel  120  receives an operation of a user. The control panel  120  outputs a signal corresponding to an operation carried out by the user to a control section of the image forming apparatus  100 . Furthermore, the display  110  and the control panel  120  can be separate or both may be integrated into a single touch panel. 
     The printer section  130  forms an image on a sheet on the basis of image information generated by the image reading section  200  or image information received via a communication path. The printer section  130  forms the image with, for example, the following processing. The image forming section of the printer section  130  forms an electrostatic latent image on a photoconductive drum on the basis of the image information. The image forming section of the printer section  130  enables a recording agent to adhere to the electrostatic latent image to form a visible image. As a concrete example of the recording agent, toner is exemplified. The transfer section of the printer section  130  transfers the visible image on the sheet. The fixing section of the printer section  130  heats and pressures the sheet to enable the visible image to be fixed on the sheet. 
     The sheet on which the image is formed may be a sheet housed in the sheet housing section  140  or a manually fed sheet. The sheet housing section  140  houses a sheet used for the image formation by the printer section  130 . 
     The image reading section  200  reads the image information of a read object as intensity of light. The image reading section  200  records the read image information. The recorded image information may be sent to another information processing apparatus via a network. The recorded image information may be used for the image formation on the sheet through the printer section  130 . 
     Next, a constitution of main portion of the image forming apparatus  100  shown in  FIG. 1  is described with reference to  FIG. 2 .  FIG. 2  is a diagram illustrating the constitution of main portion of the image forming apparatus  100 . The main portion of the image forming apparatus  100  is equipped with a control section  11 , a first memory  12 , a sensor  17 , a recording agent cartridge (hereinafter, referred to as a “cartridge”)  2 , a second memory  21 , a recording agent replenishment motor  31 , a cleaning unit  32 , a charging charger  33 , a photoconductor  34  and a developing device  35 . 
     The control section  11  collectively controls operations of the image forming apparatus  100 . The first memory  12  is constituted as a nonvolatile memory, and stores information required for control of an image forming operation. The sensor  17  detects a density of a recording agent left in the developing device  35  of the image forming apparatus  100 . The cartridge  2  is detachably constituted with respect to the image forming apparatus  100 , and is filled with the recording agent. The second memory  21  is constituted as a nonvolatile memory, is arranged in the cartridge  2  and stores information required for control of an image forming operation suitable to the cartridge  2 . The recording agent replenishment motor  31  is a motor for replenishing the recording agent accommodated in the cartridge  2 . The cleaning unit  32  removes the recording agent adhering to the surface of the photoconductor  34 . The charging charger  33  charges the surface of the photoconductor  34 . The photoconductor  34  has a surface on which an image is formed with the recording agent. The developing device  35  is capable of storing the recording agent and supplies the recording agent to the photoconductor  34  through a developing roller. 
     Next, a device constitution of a control system for controlling the image forming operation of the image forming apparatus  100  shown in  FIG. 1  is described with reference to  FIG. 3 .  FIG. 3  is a block diagram illustrating the device constitution of the control system for controlling the image forming operation of the image forming apparatus  100  shown in  FIG. 1 . The control section  11  collectively controls the operations of the image forming apparatus  100 . The first memory  12  is constituted as the nonvolatile memory, and stores the information required for the control of the image forming operation. An input section  13  is equivalent to the control panel  120  shown in  FIG. 1  and receives the operation of the user. The display section  14  is equivalent to the display  110  shown in  FIG. 1  and displays various kinds of information relating to the image forming apparatus  100 . 
     The first communication section  15  carries out information communication with the recording agent cartridge  2 . A recording agent replenishment counter  16  counts the operations of the recording agent replenishment motor for rotating a screw arranged in the cartridge  2  to count a replenishment amount of the recording agent (toner or ink). The replenishment amount can be assumed to represent the number of times of the execution of the image formation or image forming execution amount. The sensor  17  detects the density of the recording agent left in the developing device  35  of the image forming apparatus  100 . The control section  11  determines that the toner is empty on the basis of the detected density in a case in which the toner density does not rise no matter how many times the toner replenishment is carried out from the toner cartridge  2 . An image forming control section  18  carries out the control of the image forming operation in the printer section  130  shown in  FIG. 1 . 
     The cartridge  2  is originally equipped with the second memory  21  that is nonvolatile and a second communication section  22 . The cartridge  2  is detachably constituted with respect to the image forming apparatus  100 . The second memory  21  stores the information required for the control of the image forming operation suitable to the cartridge  2 . The second communication section  22  carries out information communication with the image forming apparatus  100 . The communication carried out between the first communication section  15  and the second communication section  22  may be wired communication or wireless communication. However, in a case in which the communication is the wireless communication, the communication can be carried out only in a case in which the cartridge  2  is installed in the image forming apparatus  100 . 
     Herein, the cartridge  2  is described. There are a plurality of types of cartridges  2  that can be used as the cartridges  2 . One type of the cartridge  2  is equipped with the second memory  21 , and another type of the cartridge  2  is not equipped with the second memory  21 . The second memory  21  stores identification data for identifying the cartridge  2  and a process parameter data for an image formation which is readout by the image forming apparatus  100  at the time the cartridge  2  is used by the image forming apparatus  100 . 
     The cartridge  2  having no second memory  21  is so-called non-recommended product. A recommended product is a product which is recommended to use with image forming apparatus  100  by the manufacture of the image forming apparatus  100 . 
     However, there is a case in which the cartridge  2  with no second memory  21  is used as the recommended product, only if it is packaged with the image forming apparatus  100  for a shipment (Such a cartridge is called the packaged cartridge hereafter). This packaged cartridge  2  is not equipped with the second memory  21  from the point of view of cost reduction although it is the recommended cartridge. 
     Mutual authentication is carried out with the information of the identification data that are held in the memory  12  of the image forming apparatus  100  and in the memory  21  of the cartridge  2  side, and exchange of the data between the image forming apparatus  100  and the cartridge  2  is carried out. 
     Further, all the cartridge  2  having no second memory  21  should fail in the authentication. However, since the packaged cartridge  2  is the recommended cartridge, the packaged cartridge needs to pass the authentication to assure the most suitable image forming control. Therefore some measures are necessary to distinguish the packaged cartridge among all the cartridges  2  with no second memories  21 . 
     The image forming apparatus  100  described herein carries out the control of the image forming operation by using a image forming process parameter fitting for recommended cartridge even if the packaged cartridge having no second memory is used. 
     Next, information stored in the first memory  12  and the second memory  21  shown in  FIG. 4  is explained. 
     The first memory  12  stores ( 1 ) an identification data for identifying the cartridge  2 . Any specific data can be used as the identification data. The first memory  12  also has an area in which a toner residual amount threshold value is stored. This threshold value is set to allow the image forming apparatus  100  the predetermined amount of printing when the packaged cartridge is used in the image forming apparatus  100  the first memory  12  has also an area for storing a counted value A and counted value B which are the values counted by a recording agent replenishment motor counter shown in  FIG. 3 . The counted value A is counted when the recommended cartridge  2  is installed in the image forming apparatus  100 . The counted value B is counted when the non-recommended cartridge  2  is installed in the image forming apparatus. The counted value A and counted value B are respectively stored in separate area in the first memory  12  based on the identification result based on the identification data. The control section  11  compares the counted value A with the toner residual amount threshold value stored in the first memory  12 . The control section  11  compares the counted value B with the residual amount threshold value stored in the first memory  12 . 
     The memory  12  is configured to be written history information A which shows if supplied toner amount form the recommended cartridge  2  had passed the threshold value stored in memory  12  or not based on the comparison result of the control section  11 . The memory  12  is configured to be written history information B which shows if supplied toner amount form the non-recommended cartridge  2  had excessed the threshold value stored in memory  12  or not based on the comparison result of the control section  11 . The history information A and the history information B are recorded as a flag comprising one or a few bit data to show if the supplied toner amount from the cartridge  2  surpassed the threshold value or not alternatively. A recording method of the history information A, B is not limited. Any method is available as long as it can show if the counted value A, B has surpassed the threshold value or not. 
     The first memory  12  has also stores process parameter data A and process parameter data B, which are respectively used for image forming in accordance with the property of the toner accommodated in the toner cartridge  2 . Example of the process parameter data are charging bias voltage for an image photosensitive drum, light emitting power, or developing bias voltage and so on. These process parameter data can be set in accordance with print volume, the counted value of the rotational number of the motor  31  and environmental condition of the image forming apparatus  100  including environmental temperature or humidity. 
     The process parameter data A is used when the packaged cartridge  2  is used in the image forming apparatus  100 . The process parameter data A is set according to lot number, manufacturing condition or characteristics of toner accommodated in the packaged cartridge  2 . 
     The first memory  12  also stores another process parameter data B which is used for image forming with the toner accommodated in the non-recommended toner cartridge  2 . In other words, another parameter data B is used when the identification fails. 
     The process parameter data B for the non-recommended toner cartridge  2  is different from the process parameter data A. 
     Next, the information stored in the second memory  21  is explained. 
     The second memory  21  stores an identification data for identifying the cartridge  2 . The identification data stored in the second memory  21  is same as that stored in the first memory  12 . The second memory  21  has an area for storing same value as the counted value A counted by the recording agent replenishment motor counter  16 . 
     The second memory  21  also has an area for storing history information to show if the toner amount supplied from the recommended toner cartridge  2  has surpassed or not. 
     The second memory  21  stores a process parameter data C for the image forming. The process parameter data C is set according to lot number, manufacturing condition or characteristics of toner accommodated in the cartridge  2  with the second memory  21 . 
     The process parameter data A, B, and C are respectively set to perform the image forming suitable to the toner accommodated in the respective toner cartridge  2 . Therefore, the process parameter A and the process parameter C is set to be same when the property of the toner stored in the packaged cartridge  2  and toner that is stored in the cartridge  2  with the second memory  21  other than the packaged cartridge  2  is regarded as same. Further, a plurality of process parameter data C can be prepared according to the property of the toner and the selected process parameter data C can be stored in the second memory  21 . 
     The counted value A and the history information A in the first memory  12  are reset each time a new cartridge  2  is installed in the image forming apparatus  100 . The reset said herein means to delete information that shows the counted value A has surpassed the threshold value. As a result of the reset, the cartridge  2  installed in the image forming apparatus  100  is treated as the new cartridge. 
     On the other hand, the counted value B and history information B is never reset if the new cartridge  2  is installed in the image forming apparatus  100 . 
     Next, control method of the first memory  12  and the second memory  21  is described. The identification data stored in the second memory  21  is compared with the identification data stored in the first memory  12  to carry out authentication when the cartridge  2  is installed in the image forming apparatus. The value the counter  16  counts up during a toner supply time is written in the first memory  12 . However, the area for storing the value counter  16  counts up is different depending if the recommended cartridge or non-recommended cartridge is used in the image forming apparatus  100 . 
     The stored data as same as counted value A in the second memory  21  is read out during a warming up operation after the power-ON or door opening/closing which implies a possibility that the toner is exchanged. The read data as the counted value A from the second memory  21  is written into first the memory  12 . 
     On the other hand, when the cartridge  2  has finished the printing while the cartridge  2  is used in the image forming apparatus  100 , the counted value A stored in the first memory  12  is read out and written in the memory  21  in the end of the printing job. 
     Further, when the counted value A stored in the first memory  12  has surpassed the residual amount threshold value stored in the first memory  12 , the history information A is written into the first memory  12 . The history information A is also read out and written into the second memory in the end of the printing job. 
     When the cartridge  2  that failed the authentication is used in the image forming apparatus  100 , the counted value B is written in the first memory  12 . If the counted value B has surpassed the residual amount threshold value stored in the first memory  12 , the history information B is written into the first memory  12 . 
     As to the process parameter data, when the authentication of the cartridge  2  has succeeded, the control section  11  of image forming apparatus  100  reads out the process parameter data C stored in the second memory  21  and uses it for the image forming. When the authentication of the cartridge  2  fails, the image forming apparatus  100  judges if the cartridge  2  is the packaged cartridge  2  or not. When the cartridge  2  satisfies the following both conditions, the cartridge  2  is judged as the packaged cartridge  2 .
         1. It failed the authentication.   2. The counted number B stored in the first memory  12  is less than the residual amount threshold value.       

     In other word, if the cartridge has no second memory  21  and the counted number B stored in the first memory  12  is more than the residual amount threshold value, that cartridge  2  in the image forming apparatus  100  is judged as the non-recommended cartridge  2 . To the contrary, the cartridge  2  is not judged as the non-recommended cartridge even if the counted number B is less than the residual amount threshold value while the cartridge  2  has no second memory  21 . In this case, the control section  11  judges the cartridge  2  in the image forming apparatus  100  as the packaged cartridge  2 . 
     With this judgment by the control section  11 , the packaged cartridge  2  is treated to be equivalent to the authenticated cartridge  2 . Being equivalent to the authenticated cartridge  2  means that the cartridge  2  is allowed to be regarded as the authenticated cartridge  2  although the packaged cartridge  2  is not identical to the cartridge  2  with the second memory  21  in reality. When the cartridge  2  is judged to be the packaged cartridge  2 , a procedure comprising reading the image forming process parameters and using them for the toner accommodated in the packaged cartridge  2  is determined by the control section  11 . As a result, the control section  11  read out the process parameter data A stored in the first memory  12  when the cartridge  2  installed in the image forming apparatus  100  is judged is the packaged cartridge  2 . The control section  11  read out the process parameter data B stored in the first memory  12  when the cartridge  2  installed in the image forming apparatus  100  is judged is the non-recommended cartridge  2 . Which area in the first memory  12  the control section  11  accesses to is changed in accordance with the result of judging the type of the toner cartridge  2 . 
     The controlling explained above means where to access to read out the image forming process parameter should be changed in accordance with the result of judging the type of the toner cartridge  2 . 
     Next, with reference to  FIG. 5 , operations for controlling the image forming operation in the image forming apparatus  100  are described.  FIG. 5  is a flowchart illustrating the operations for controlling the image forming operation in the image forming apparatus  100 . At first, the control section  11  detects the power-ON of the image forming apparatus  100  or the opening and closing of the front door that is opened and closed at the time of the exchange of the toner (ACT  1 ). The control section  11  determines whether or not the authentication of the cartridge  2  can be carried out by carrying out the communication between the first communication section  15  and the second communication section  22  if the power-ON or the opening and closing of the door is detected (ACT  2 ). This authentication is carried out according to whether the identification data stored in the first memory  12  and in the second memory  21  are coincident. 
     Next, if the authentication can be carried out (YES in ACT  2 ), the control section  11  reads the process parameter data C stored in the second memory  21  (ACT  3 ). Further, the control section  11  writes the counted value A stored in the second memory  21  to the first memory  12 . If the toner cartridge  2  is anew (unused) one, the counted value equals zero. The history information stored in the second memory  21  is also read out and the read out information is written into the first memory  12 . The control section  11  finishes the warming up operation which is associated with possibility of an exchange of the cartridge  2 . 
     On the other hand, if the authentication of the cartridge  2  fails (NO in ACT  2 ), the control section  11  determines whether or not the installed cartridge  2  is the packaged cartridge (ACT  4 ). This determination is carried out by the control section  11  according to whether the counted value B stored in the first memory  21  is more than the residual amount threshold value. When counted value B has not surpassed the residual amount threshold yet, the cartridge  2  installed in the image forming apparatus  100  is judged as the packaged cartridge (YES in ACT  4 ). 
     Subsequently, the control section  11  determines to use the process parameter data A stored in the first memory  12  to control the image forming operation (ACT  5 ). Then, the control section  11  ends the warming up operation carried out at the time of the opening and closing of the front cover which has a possibility that the toner is exchanged. 
     Next, in a case the cartridge  2  is considered not to be the packaged cartridge (NO in ACT  4 ), the control section  11  selects to use the image forming process data set B stored in the first memory  12  (ACT  6 ). Then, the control section  11  ends the warming up operation. 
     Next, with reference to  FIG. 6 , the operations of the image forming operation by the image forming apparatus  100  are described.  FIG. 6  is a flowchart illustrating the operations in the image forming apparatus  100 . 
     At first, if a print JOB occurs, the control section  11  issues the print JOB for the image forming control section  18  to instruct the execution of the print JOB (ACT  11 ). 
     In response to the instruction described above, the image forming control section  18  outputs an instruction for carrying out a replenishment operation of toner when the sensor  17  detects reduced concentration of the toner in the developing device (ACT  12 ). 
     At this time, the recording agent replenishment counter  16  counts recording agent replenishment amount based on the rotation number of the recording agent replenishment motor  31 . The control section  11  writes the counted value A or the counted value B the counter  16  counts up into the first memory  12  (ACT  13 ). 
     Next, the control section  11  determines whether or not the counted value A or counted value B exceeds the residual amount threshold value on the basis of the number of counts of the recording agent replenishment counter  16  (ACT  14 ). As a result of this determination, if the count value exceeds the residual amount threshold value (YES in ACT  14 ), the control section  11  record the history information a or history information B in the first memory  12 . 
     Next, the counted value A or the counted value B does not exceed the residual amount threshold value (NO in ACT  14 ), the control section  11  determines whether or not the image forming control section  18  carries out the image forming operation until the print JOB is ended, and notifies the control section  11  of the end of the print JOB at a point in time at which the image forming operation is ended. The control section  11  determines whether or not the print JOB is ended according to whether to receive the notification indicating the end of the print JOB from the image forming control section  18  (ACT  20 ). As a result of this determination, if the print JOB is not ended (NO in ACT  20 ), the control section  11  repeats the processing in ACT  12 -ACT  16 . On the other hand, if the print JOB is ended, the control section  11  writes counted number A stored in the first memory  12  into the second memory  21  if the authenticated cartridge is used, and ends the image forming operation (ACT  17 ). 
     In the above explanation, whether the cartridge  2  is the packaged cartridge  2  or not is determined based on the counted value A or the value B compared with the threshold. If it can be detected the cartridge  2  is empty, it is also acceptable to determine the type of the cartridge  2  based on the information that shows the cartridge  2  is already reached empty. 
     Further, the identification data stored in the first memory  12  and identification data stored in the second memory  21  is set to be identical so that the identification is carried out by confirming matching of these data in the above explanation. However, the identification method is not limited to this method. Any method is available as long as the identification is carried out by communicating between the first memory  12  provided in the image forming apparatus  100  and the second memory  21  provided on the cartridge  2 . Mutual authentication system using encryption system such as public key encryption system or a private key encryption system is available. 
     Further to make the recording agent residual amount threshold reflected data that reflect the property of the recording agent accommodated in the cartridge  2  more correctly, the recording agent residual amount threshold can be stored in the second memory  21 . In this case the recording agent residual amount stored in the second memory  21  is read out and read out data is written into the first memory  12  at the timing of power-on or opening/closing the door. By adding this step, same control as the image forming control explained above forming can be performed. 
     Part of functions of the image forming apparatus  100  of the embodiment described above may be realized by a computer. In this case, a program for realizing the function is recorded in a computer-readable information recording medium. Then, the program recorded in the information recording medium for recording the foregoing program is read into a computer system and may be realized by being executed. Furthermore, the “computer system” described herein includes hardware such as an operating system and a peripheral device. Further, the “computer-readable information recording medium” is referred to as a portable medium or a storage device. The portable medium is a flexible disk, a magneto-optical disk, a ROM, a CD-ROM and the like. The storage device is a hard disk built in the computer system. 
     Furthermore, the “computer-readable information recording medium” dynamically holds a program for a short time, such as a communication wire in a case of transmitting the program via a communication line. The communication line is a network such as the Internet, a telephone line and the like. Further, the “computer-readable information recording medium” may be a volatile memory inside the computer system serving as a server or a client. The volatile memory holds the program for a certain time. Further, the above-mentioned program may be a program for realizing part of the foregoing functions. Further, the above-mentioned program may be realized by combining with a program that is already recorded in the computer system. 
     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 invention. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the invention. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the invention.