1. Field of the Invention
The present invention relates to a printing apparatus such as an ink-jet printer, and ink-jet plotter, and to an ink tank mounted on the printing apparatus, and more particularly to a technique for controlling printing on the basis of information stored in a data storage attached to the ink tank.
2. Description of the Related Art
Color printers for ejecting inks of multiple colors from an ink head are currently used on a wide scale as output apparatus for computers. Dye inks or pigment inks can be cited as examples of the inks of multiple colors used in such color printers. As used herein, the term “dye ink” refers to an ink in which a dye is used as the ink colorant, and the term “pigment ink” refers to an ink in which a pigment is used as the ink colorant. Using a dye ink allows translucent colors to be formed on a print medium, whereas using a pigment ink allows distinct colors (solid colors) to be formed on a print medium. Another advantage of using a pigment ink is that characters or images can be printed with minimal bleeding.
Pigment and dye inks spread differently across a print medium. Specifically, a dye ink tends to spread or bleed across a print medium, whereas a pigment ink resists spreading or bleeding across a print medium. Consequently, different amounts of ink are required for a pigment ink drop and a dye ink drop in order to form dots of the same size on a print medium, and different drive waveforms must be employed for pigment ink and dye ink, respectively.
A conventional printer, however, has internal printer firmware with a single drive waveform. The resulting drawback is that, for example, a printer fabricated for a pigment ink cannot use a dye ink.
Accordingly, an object of the present invention is to provide a technique that allows various types of inks to be used on a single printer.
In order to attain the above and the other objects of the present invention, there is provided a printing apparatus for printing by forming ink dots on a print medium. The printing apparatus comprises: a print head, an ink tank mount, a memory read unit, and a drive signal generator. The print head has a plurality of nozzles for ejecting ink and a plurality of drive elements for actuating the plurality of nozzles. The ink tank mount is capable of supporting an ink tank equipped with a memory. The memory stores drive waveform data to be used in generating a waveform of a drive signal to actuate the plurality of drive elements. The memory read unit is configured to read out the drive waveform data from the memory. The drive signal generator is configured to generate the drive signals based on the drive waveform data.
In the printing apparatus of the present invention, the drive signals are generated based on the drive waveform data stored in the memory of the ink tank, allowing various types of inks to be used by the same printer. In particular, clear printing can be attained using ink tanks developed after the printer has been shipped.
In a preferred embodiment of the invention, the memory is a write-once memory. This will prevent an inadvertent change of the drive waveform data.
In another preferred embodiment of the invention, the memory is a rewritable nonvolatile memory. The memory read unit is configured to further read out an initial amount of each type of ink in each ink tank from the nonvolatile memory at least when the ink tank is mounted on the ink tank mount. The printing apparatus further comprises: a calculating unit, a calculating unit, and a memory write unit. The calculating unit is configured to calculate a remaining amount of each type of ink in each ink tank based on an amount of ejected ink from each ink tank and the initial amount of each type of ink. The memory write unit is configured to write in the nonvolatile memory the remaining amount of each type of ink in each ink tank at an end of printing. The drive signal generator is configured to correct the drive waveform in response to the remaining amount of each type of ink.
Thus, drive waveforms can be corrected in response to the amount of remaining ink when the ink tank has been replaced. This is achieved by adopting an arrangement in which the ink tank is further provided with a nonvolatile memory and the amount of remaining ink is written in the nonvolatile memory of the ink tank in cases in which the memory for storing drive waveform data is a write-once memory.
The present invention can be realized in various forms such as a method and apparatus for printing, a method and apparatus for producing print data for a printing unit, and a computer program product implementing the above scheme.
These and other objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments with the accompanying drawings.
a) is a diagram depicting the structure of a drive circuit for a print head 28 pertaining to a first embodiment of the present invention;
b) is a diagram depicting the specifics of data stored in the memory provided to the ink tank;
a) is a diagram depicting the structure of the drive circuit for the print head 28 pertaining to the first embodiment of the present invention;
b) is a diagram depicting the specifics of data stored in the memory provided to the ink tank;
a) is a diagram depicting appropriate drive waveforms for dye ink;
b) is a diagram depicting appropriate drive waveforms for pigment ink;
a) and 10(b) are diagrams depicting an example of drive waveform data;
a) and 11(b) are diagrams depicting another example of drive waveform data;
a)–12(g) are time charts depicting the operation of the interior components of a head drive circuit pertaining to the first embodiment;
a) is a diagram depicting the structure of a drive circuit for a print head 28 pertaining to a second embodiment of the present invention;
b) is a diagram depicting the specifics of data stored in the memory provided to the ink tank;
a)–14(g) are timing charts depicting the operation of the interior components of a head drive circuit pertaining to the second embodiment;
a)–15(g) are timing charts depicting the operation of the interior components of a head drive circuit pertaining to the second embodiment;
a) is a diagram depicting the structure of a drive circuit for a print head 28 pertaining to a third embodiment of the present invention;
b) is a diagram depicting the specifics of data stored in the memory provided to the ink tank;
a) and 18(b) are diagrams depicting a method for correcting drive signals;
Embodiments of the present invention will now be described through embodiments in the following sequence.
In the computer 90, an application program 95 is executed under a specific operating system. The operating system contains a video driver 91 and a printer driver 96, and the application program 95 outputs the print data PD to be transmitted to the color printer 20 via the se drivers. The application program 95 processes images and displays the images on a CRT 21 with the aid of the video driver 91.
When the application program 95 issues a print command, the printer driver 96 receives image data from the application program 95 and converts the se data to the print data PD to be supplied to the color printer 20. In the example shown in
The role of the resolution conversion module 97 is to convert the resolution of the color image data handled by the application program 95 (that is, the number of pixels per unit length) into a resolution that can be handled by the printer driver 96. The image data converted in terms of resolution in this manner are still in the form of image information composed of RGB color components. The color correction module 98 converts the RGB data in individual pixels into multilevel data suitable for a plurality of ink colors and usable by the color printer 20 while referring to the color correction table LUT.
The color-corrected multilevel data may, for example, have 256 gradations. The halftone module 99 executes a halftone routine to allow the color printer 20 to represent the multilevel gradations as dispersed ink dots. The halftoned image data are rearranged by the print data generator 100 according to a sequence in which the data are sent to the color printer 20, and are outputted as final print data PD. The print data PD comprise raster data for specifying a dot formation state at each pixel during main scanning, and data for specifying sub-scan feeds.
The printer driver 96 is a program for performing functions to generate print data PD. The program of the printer driver 96 can be supplied to users in the form of a computer-readable storage medium storing the same. Examples of such storage media include floppy disks, CD-ROMs, magnetooptical disks, IC cards, ROM cartridges, punch cards, printed matter with bar codes and other printed symbols, internal computer storage devices (RAM, ROM, and other types of memory), external storage devices, and various other computer-readable media.
The sub-scanning mechanism for transporting the printing paper P is provided with a gear train (not shown) for transmitting the rotation of the paper feed motor 22 to the platen 26 and a paper feed roller (not shown). The main scanning mechanism for reciprocating the carriage 30 comprises a sliding shaft 34 mounted parallel to the axis of the platen 26 and designed to slidably support the carriage 30, a pulley 38 for extending an endless drive belt 36 from the carriage motor 24, and a position sensor 39 for sensing the original position of the carriage 30.
The print head unit 60 has a print head 28 and is designed for mounting ink tanks. The print head unit 60 can be mounted on the color printer 20 and removed there from as a single component. In other words, the print head unit 60 is replaced when the print head 28 needs to be replaced.
The first capital letter in the symbol designating each nozzle array refers to the ink color, with the suffix “D” designating a comparatively dense ink, and the suffix “L” designating a comparatively light ink.
The nozzles of each nozzle array are disposed in the direction of sub-scanning SS at a constant nozzle pitch k·D, where k is an integer and D is a pitch (also referred to as a “dot pitch”) that corresponds to the print resolution in the direction of sub-scanning. The phrase “the nozzle pitch is equal to k dots” will also be used in this specification. The corresponding dot unit refers to the dot pitch of print resolution. The dot unit will be used in the same manner with respect to the sub-scan feed amounts.
Each nozzle is provided with a piezoelectric element (not shown) as a drive element designed to actuate the nozzle and to eject ink drops. During printing, ink drops are ejected from each nozzle while the print head 28 is moving in the direction of main scanning MS.
The nozzle of each nozzle array may, for example, be arranged in a staggered configuration rather than being aligned in a straight line in the direction of sub-scanning. When the nozzles are arranged in a staggered configuration, the nozzle pitch k·D in the direction of sub-scanning can still be defined in the same manner as in
The color printer 20 whose hardware is configured in the above-described manner operates such that the carriage 30 is reciprocated by the carriage motor 24, and the piezoelectric element of the print head 28 are actuated to eject ink drops at the same time. The ink drops of each color are ejected to form ink dots and to form multicolored gray-scale images on the paper P.
The print head unit 60 has a driver IC 51 for feeding drive signals to piezoelectric element PE. The driver IC 51 has a switching circuit (not shown; also referred to as a “mask circuit”) for on/off controlling the original drive signals ORGDRV from the drive waveform generation circuits 46 in accordance with serial print signals PRT from the drive waveform generation control circuit 66. The serial print signals PRT are formed in accordance with the levels of the raster data contained in the print data PD from the computer 90 (
Memories 180k and 180F are provided on a black ink cartridge 107k and a color ink cartridge 107F, respectively. The memories 180k and 180F store information on the types of inks contained in the ink cartridges 107k and 107F, the drive waveform data used in the generation of drive waveforms, and information on the residual amount of ink in the tanks. Nonvolatile memories are used for the memories 180k and 180F in order to store information on the remaining ink.
The color ink cartridge 107F is a combination of five ink tanks designed for five types of ink. The ink cartridge 107F can be replaced with a print head unit 60 configured to allow ink tanks used separately for each type of ink to be mounted on the print head unit 60. In this arrangement, each ink tank has a memory. It follows from this description that the term “ink tank” used herein refers to a container designed to store a single type of ink. In addition, the term “ink cartridge” refers to a monolithically formed container having at least one ink tank.
As can be seen in
B. Embodiments
a) is a diagram depicting the structure of a drive circuit for a print head 28 pertaining to a first embodiment of the present invention. According to the first embodiment, a single drive waveform generation circuit 46 is provided as a common unit to all the nozzle arrays. An original drive signal ORGDRV generated by each drive waveform generation circuit 46 is turned on and off by a mask circuit 222 in the driver IC 51 in accordance with a print signal PRT, thereby generating a drive signal DRV for each nozzle. The mask circuit 222 presents the drive signal DRV to the piezoelectric element PE of each nozzle. The piezoelectric elements PE are thus actuated, ink is ejected from the nozzles, and ink dots are formed on the print medium.
b) is a diagram illustrating the contents of data stored in the memories 180k and 180F provided to the ink cartridge. According to the first embodiment, at least one of the memories 180k and 180F contains ink type data, drive waveform data, and mask data. As used herein, the term “ink type data” refers to data that represent an ink type, for example, whether the ink stored in each ink tank is a dye ink or a pigment ink. The term “drive waveform data” refers to the data that defines the shape of the drive waveform generated by the drive waveform generation circuit 46. The term “mask data” refers to data that represent various patterns of the serial print signal PRT (
According to the first embodiment, all the ink tanks thus mounted contain dye inks, so each nozzle ejects a dye ink, as shown in
The memory 180k and/or the memory 180F contain drive waveform data and mask data for pigments when all six inks are pigments.
a) and 7(b) depict a case in which the light cyan ink CL and the light magenta ink ML are pigments, and the other four inks are dyes. In this case, a set of drive waveform data for dye/pigment combinations capable of allowing both dye and pigment inks to be adequately ejected are stored as drive waveform data in the memories 180k and 180F. The same applies to mask data.
It follows from the above examples that it is possible to operate a printing apparatus by employing ink tanks containing various types of ink if a procedure is adopted in which the memories of the ink tanks are provided with drive waveform data suitable for ejecting the inks contained therein. When, for example, a new type of ink is developed after the printer has been shipped, and a drive signal must be generated using an optimal drive waveform for ink ejection, this drive waveform can still be used for printing. Even in this case, the mask data may be common data applicable to any ink type.
a) and (b) are diagrams depicting the relation between ink types and the drive waveforms suitable there for.
a) and 10(b) are diagrams depicting an example of drive waveform data. According to the first embodiment, the memory 180 stores drive waveforms (which are inherently analog data) as sets of sample values for each 50-ns sample cycle, as shown in
a) and 11(b) are diagrams depicting another example of drive waveform data and a method for correcting the same. Drive waveforms can be generated as drive waveform data on the basis of ΔV1–ΔVn (where n is a natural number), which show the change in potential for each specific clock signal, and on the basis of the timing data for their switching, as shown in
a)–12(g) are time charts depicting a method for reshaping an original drive signal ORGDRV by a serial print signal PRT(i) to generate a drive signal DRV in accordance with the first embodiment of the present invention. The original drive signal ORGDRV of the present embodiment contains three types of pulses W1–W3 with different waveforms for the three sub-segments of a single pixel segment, as shown in
b)–12(d) depict the serial print signals PRT(i) for small, medium, and large dots, respectively. A serial print signal PRT(i), which assumes an “H” or “L” state in each sub-segment of a pixel segment, is generated based on the mask data that are read from the memory 180. According to the first embodiment, the serial print signal for small dots (
e)–12(g) depict the resulting drive signals DRV(i). As described above, a drive signal DRV(i) has the same waveform as the original drive signal ORGDRV only when the serial print signal PRT(i) is in the “H” state. Consequently, a drive signal for small dots (
Drive signals DRV suitable for a dye ink can be generated on the basis of the ink type data, drive waveform data for dye inks, and mask data for dye inks obtained from the memory provided to the ink tank, as described above. The same applies to cases in which all the inks are pigments.
a) is a diagram depicting the structure of a drive circuit for a print head 28 pertaining to a second embodiment of the present invention. The structure of the drive circuit and the ink types are the same as those described above with reference to
a)–14(g) and 15(a)–15(g) are timing charts depicting the operation of the interior components of the head drive circuit according to the second embodiment.
The difference between ejecting of a dye ink and that of a pigment ink lies in the serial print signal PRT(i) for large dots (
e)–14(g) and 15(e)–15(g) depict the resulting drive signals DRV(i). As described with reference to the first embodiment, a drive signal DRV(i) has the same waveform as the original drive signal ORGDRV only when the serial print signal PRT(i) is in the “H” state. Consequently, a drive signal for large dots of dye ink (
Although the present embodiment was described with reference to the use of an original drive signal ORGDRV containing three types of pulses (W1–W3) within a single pixel segment, it is also possible to use an original drive signal containing four types of pulses (obtained by adding an even bigger, fourth pulse) within a single pixel segment. Adopting this arrangement makes it possible to generate a drive signal for large dots in the case of pigment ink by making use of the fourth pulse alone.
It is also possible to form dye and pigment inks into three types of dots (small, medium, and large) by employing an original drive signal ORGDRV containing four identical pulses W1–W4 within a pixel segment. For example, it is possible to form a small dot by means of a single pulse, a middle dot by means of two pulses, and a large dot by means of three pulses in the case of a dye ink, and a small dot by means of a single pulse, a middle dot by means of two pulses, and a large dot by means of four pulses in the case of a pigment ink.
a) is a diagram depicting the structure of the drive circuit for a print head 28 pertaining to a third embodiment of the present invention. The third embodiment differs from the first and second embodiments in that the head drive circuit 52 has three drive waveform generation circuits 46a, 46b, and 46c and that the drive waveform generation circuits 46a, 46b, and 46c can generate mutually different drive waveforms.
According to the third embodiment, ink tanks are provided such that dye inks can be used for cyan CD, magenta MD and yellow YD inks, and pigment inks can be used for light cyan CL and light magenta ML inks.
b) is a diagram depicting the contents of data stored in the memories 180k and 180F provided to the ink cartridge. The third embodiment is similar to the first and the second embodiments in that the memory 180k and/or the memory 180F stores ink type data, drive waveform data, and mask data. The head drive circuit 52 has three drive waveform generation circuits 46a–46c, making it possible to read drive waveform data that correspond to each ink when two or three types of ink are used.
The drive waveform generation control circuit 66 specifies the drive waveform to be fed to each nozzle array on the basis of ink type data obtained from the memory of each ink tank. For example, the head drive circuit 52 establishes a connection for the drive waveform generation circuits 46 such that a drive signal for dye ink is fed to the nozzle array for ejecting black ink (which is a dye ink) and that a drive signal for pigment ink is fed to the nozzle array for ejecting light cyan ink (which is a pigment ink). Adopting this approach makes it possible to eject dye and pigment inks such that appropriate dots are formed on a print medium by means of signals based on drive waveforms suitable for dye inks and pigment inks, respectively.
C. Correction of Drive Waveforms
According to the embodiments described above, original drive signals ORGDRV are generated based on the information obtained from a memory provided to the ink tank, and these original drive signals ORGDRV can be further corrected. For example, a drive waveform can be corrected and image quality improved depending on the amount of ink remaining in the ink tank, the humidity, the temperature of the print head 28, or an actuator rank AR. As used herein, the term “actuator rank AR” refers to the rating or grade that expresses the characteristics of an ink-ejecting actuator and is preset by analyzing the actual characteristics of the actuator including actuator circuit (not shown) and piezoelectric element PE. In other words, it corresponds to an ejection characteristic rank used to for express the ink ejection characteristics of a print head. Adopting this approach makes it possible to prevent the actuator characteristics or the operating environment maintained during printing from having an adverse effect on dot formation.
a) and 18(b) are diagrams depicting a method for correcting drive signals.
Correction specifics (for example, the width L1a of the high-voltage level) may be read from the memory provided to the ink tank. An appropriate correction customized for the desired ink type can thereby be made.
b) is a diagram depicting a method for correcting a drive waveform on the basis of humidity, the temperature of the print head 28, or the amount of ink remaining in the ink tank. W1M is an uncorrected drive waveform, W1H is a drive waveform with an increased amplitude, and W1L is a drive waveform with a reduced amplitude. In other words, a correction might entail increasing or reducing the amplitude of the drive waveform. The amount of ink ejection tends to decrease with the amount of remaining ink in the tank, so the amplitude of the drive waveform is increased to compensate for reduction in the amount of ink ejection. Similarly, variations in temperature or humidity can be offset by varying the amplitude of the drive waveform to achieve a more stable print quality irrespective of temperature and other operating environment parameters. Corrections specifics (such as the extend of an increase) may be read from the memory provided to the ink tank. The method for measuring the amount of remaining ink will be described below.
(a) Reading of Cumulative Amount of Ejected Ink (step S300)
A routine for monitoring the amount of remaining ink is immediately initiated once the printer 20 is turned on, and an ink remainder measurement unit 68 (
The remaining amount of ink in the cartridge is measured by comparing the ink capacity of the ink cartridge, or the initial ink amount, and the cumulative amount of ejected ink.
(b) Determining Ink Supply Conditions (step S302)
The ink remainder measurement unit 68 determines the ink supply conditions (step S302) after the cumulative amount of ejected ink has been read. The ink supply conditions include ink temperature, ink type, and the remaining amount of ink in the ink cartridge.
(c) Ink Drop Count Within Specific Period (step S304)
After determining the ink supply conditions, the ink remainder measurement unit 68 counts the number of ink drops which are ejected within a specific period for each ink color (step S304). For example, the ink remainder measurement unit 68 differentiates among ink dots of different sizes when the color printer 20 forms three types of ink dots: large, medium, and small. In other words, the unit 68 counts the number of ink drops separately for each of the large, medium, and small dots.
(d) Calculation of Amount of Ejected Ink (step S306)
After counting the numbers of ink dots within a specific period, the ink remainder measurement unit 68 multiplies the counts by the respective weights of ink drops for three drop sizes, and add the results to obtain the amount of ejected ink (step S306). The weight of ink drops varies under varying ink supply conditions (which are related to the supply of ink), so the accuracy of the calculated amount of ejected ink in step S306 is increased by taking into account the ink supply conditions determined in advance in step S302. The volume of ejected ink may also be calculated by adopting a procedure in which volume data are stored instead of the weight per ink drop, and the number of ejected ink drops is multiplied by the ink volume.
(e) Displaying Amount of Remaining Ink and Cumulative Value of Ejected Ink, and Other Operations (steps S308–S312)
Once the weight of the ink ejected during a specific period has been calculated, the ink remainder measurement unit 68 adds the resulting value to the previously calculated weight of ejected ink.
When the above procedure is completed, it is determined whether printing is completed (step S310), and if the answer is negative, the operation returns to step S304, and the next series of operations is an repeated. If the answer is positive, the cumulative value of the amount of ejected ink is stored in the memory 180 (step S312) for the next printing operation. Adopting this arrangement allows the amount of ejected ink to be accumulated and the amount of ink remaining in the ink cartridge to be monitored even when the printing apparatus is turned off.
D. Selection of Cleaning Method
Nozzles are sometimes clogged due to increased ink viscosity, bubbling, or other factors. In particular, pigment inks are more prone to clogging than dye inks, and tend to be less amenable to dissolve it. An appropriate cleaning method should therefore be established in accordance with the type of ink stored in the ink tank.
E. Specifics of Data Stored in Memory Provided to Ink Tank or Ink Cartridge
(1) Ink Type Data ITD: Ink type data stored in the color ink cartridge 107F.
(2) First Drive Waveform Data DW1: Data on optimum drive waveforms for the types of ink stored in the color ink cartridge 107F. In the example shown in
(3) First Mask Data MD1: Mask data suitable for first drive waveform data DW1.
(4) Second Drive Waveform Data DW2: Data on the drive waveforms to be used when the ink stored in the color ink cartridge 107F is a combination with other types of ink. The second drive waveform data DW2 are common drive waveform data for dye/pigment combinations.
(5) Second Mask Data MD2: Mask data suitable for second drive waveform data DW2.
(6) Correction Data CD: Data for correcting drive waveforms on the basis of humidity, print head temperature, and actuator rank.
(7) Ink Remainder IR: Indicates the remaining amount of each ink in the color ink cartridge 107F.
Seven types of data should preferably be stored in the memory 180k of the black ink cartridge 107k in the same manner as above.
Adequate drive waveforms can be generated when various cartridges are combined in the printer 20 by adopting an approach in which mask data or third drive waveform data used together with other ink cartridges are stored in the memories of the ink cartridges in addition tot eh first and second drive waveform data DW1 and DW2 or the mask data MD1 and MD2, which are suitable for the types of inks stored in the ink cartridges, as shown in
F. Modified Examples
The present invention is not limited to the above-described embodiments or embodiments and can be implemented in a variety of ways as long as the essence thereof is not compromised. The following modifications are possible, for example.
F-1.
Although the above embodiments are described with reference to a case in which each ink tank is provided with a single memory, a plurality of memories may also be provided. In such cases, the preferred option is to equip the ink tank with a rewritable memory (such as EEPROM) and write-once memory, to use the rewritable memory for storing information that varies as the ink cartridge is used up (such as the amount of remaining ink), and to use the write-once memory for storing information that remains unchanged as the ink cartridge is used up (such as ink type or cleaning sequence information).
As used herein, the term “cleaning sequence information” refers to information about the operations needed to clean the ink conduit extending from an ink cartridge to a nozzle, and the term “cleaning sequence” refers to the specifics (for example, ink suction procedures) of the cleaning operation performed when a nozzle is clogged or an ink cartridge mounted.
F-2.
Although the above embodiments are described with reference to cases in which the drive waveform data represent a plurality of drive waveform levels that varied as a chronological series, it is also possible, for example, to use data capable of reproducing drive waveforms by interpolation of some element data. The drive waveform data used in the present invention should commonly be capable of reproducing the waveforms of drive signals for driving a plurality of drive elements. The interpolation processing can be performed on the printer side, or it can be performed on the computer side after drive waveform data have been transmitted to the computer.
F-3.
The present invention can be used not only for color printing but also for monochromatic printing. It can also be adapted to a printing process in which a multilevel gradation is reproduced by representing a single pixel as a plurality of dots. The invention can also be adapted to a drum type printer. In a drum type printer, the direction of drum rotation is the direction of main scanning, and the direction of carriage travel is the direction of sub-scanning. In addition, the present invention can be adapted not only to an ink-jet printer but also to any other dot-recording devices in which images are recorded on the surface of a print medium with the aid of a recording head having a plurality of nozzle arrays.
F-4.
When some or all of the functions of the present invention are performed by software, this software (computer programs) can be provided in the form in which it is stored on a computer-readable recording medium. As used in connection with the present invention, the term “computer-readable recording medium” is not limited to a portable recording media such as a floppy disk or CD-ROM and includes internal computer storage devices (various types of memory) and external storage devices mounted in computers (e.g. hard disk).
Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the append claims.
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