Abstract:
A custom designed manifold mechanism, to be utilized in conjunction with an ink jet printer, having multiple ink reservoirs, an ink level display mechanism, a ink reservoir removal safety switch, an accurate ink level detection mechanism, ink cut-off valves, ink pressure sensors, and an electronic control system wherein ink reservoirs can be replaced without interrupting a print operation.

Description:
FIELD OF THE INVENTION 
       [0001]    This inventive system relates to ink jet printing. More specifically, the inventive system pertains to a system that uses ink supply cartridges in conjunction with a custom enclosure, and ink delivery control and ink level monitoring systems, for the purpose of delivering ink to an industrial printing apparatus. Control mechanisms incorporating ink level and ink pressure readings are used for the purpose of preventing system failures that often occur using traditional ink level monitoring methods. 
       BACKGROUND OF THE INVENTION 
       [0002]    Ink Jet printing is a common method of non-impact printing. An ink jet printer emits intermittent streams of ink droplets from tiny nozzles in response to received electrical signals. The present inventive system pertains to all types of ink jet printers. 
         [0003]    When used in industrial applications, conventional ink jet printer ink delivery systems suffer from a variety of drawbacks and disadvantages. For example, it is difficult to accurately determine the level of ink in a reservoir modified for use in industrial applications using methods designed for home and office print systems. In addition, in the case of gravity-fed reservoirs, failure in the print system, whether it occurs in the print pressure regulator or in the ink jet print head, often leads to a free flowing ink situation wherein the ink in the reservoir simply runs freely out of the unit through the ink jets contained in the print mechanism. This can cause ink contamination of the print medium, which if unnoticed in an industrial printing operation, can become a costly problem in terms of the cost of the contaminated product, the cost of the lost ink and the cost of lost productivity resulting from an assembly line shut down to remedy a faulty print mechanism. In addition, reservoirs containing microprocessors must be protected so that they are removed in a specific powered state to avoid damage. 
         [0004]    One method of determining the ink level of an reservoir is called “drop counting” When printing, an ink jet printer emits intermittent streams of ink, through a number of ink jet nozzles. Each intermittent pulse from a single nozzle consists of one “drop”. The drop counting technique measures ink usage by measuring how many times each ink jet in an ink jet print mechanism pulses. Knowing the average pulse size, one can roughly calculate how much ink has been drawn from the reservoir. However, over an operational period of time, this system has inherent flaws in that the stated quantity of ink in the reservoir often differs from the actual volume. This is because drop size may vary from pulse to pulse. Individual drop size variations might be seemingly minute, however when examined over several million pulses the accuracy of drop counting becomes subject to a high degree of error. Moreover, industrial printing applications require larger reservoirs than the home or office printers in which the drop counting system was invented for. This further compounds the inaccuracies involved in this type of ink level measurements. 
         [0005]    Inductance measurement is another method of determining the volume of ink in a reservoir, however, this method only works for a percentage of the total volume. A pair of inductance coils are placed such that one coil is at the top of the reservoir and one at the bottom. An alternating current in the primary coil generates a changing magnetic field which in turn generates and alternating current in the secondary coil. A mechanism measures the secondary voltage normalized to the primary current and returns it as an indicator of ink level. The result depends on factors such as distance between the coils, electromagnetic properties of the ink, angle of the coils etc. At high and low ink levels this type of measurement is not very accurate, so it is most commonly used in conjunction with other methods such as drop counting. For example, HP uses both drop counting and inductance measurements to measure the ink level in their industrial ink reservoirs. They do this in three phases depending on the level of ink in the reservoir. They start with drop counting from 100% full to 51% full, then use inductance coil measurement from 50% full to 15% full then use drop counting for the remainder. Inductance measurements accurately work from, 50% of the total volume to 15%, but it yields inconclusive information pertaining to the ink level outside of this bound. The inductance measurement is a closed loop measurement operation designed to bridge the gap between two open loop and inaccurate drop counting operations. 
         [0006]    This is notable for two reasons. First, many of the inks used in the ink jet printing process, especially custom inks and inks designed to have special properties, such as ink designed to be read by ultraviolet light, are reasonably expensive. Inaccurate ink measurements result in discarded ink cartridges containing useful ink or loss of productivity stemming from “dry printing”—print operations that perform without ink because the print controller erroneously believes the reservoir still contains usuable ink. 
         [0007]    Second, in industrial printing applications there are many instances wherein the information needed for drop counting can not be harvested. For instance, some manufacturers do not make public their proprietary information needed to perform drop counting measurements. Additionally, many systems may be modified on site. Drop counting requires a known relationship between printer and corresponding reservoir. On site modifications that change this relationship of a print system, for example re-plumbing, produce useless and thusly inaccurate information. 
         [0008]    Many reservoirs contain embedded microprocessors for the purpose of recording information pertaining to the type of ink, ink level, ink capacity, lot number, as well as custom fields that the end user may specify to his or her requirement, for example, custom reservoir identification numbers. These microprocessors require that the reservoirs be placed in a “stand-by” state prior to being removed from a powered operational state. Removal without placing the unit on stand-by may damage or destroy the microprocessor and thusly the information contained therein. 
         [0009]    Prior art industrial manifold systems without cutoff mechanisms often draw air into their systems upon running out of ink. This requires that the ink delivery system be purged of all air after refilling the reservoir the installation of a new ink cartridge. 
         [0010]    It is an object of the inventive system to solve the drawbacks of the aforementioned methods for measuring the ink level in reservoirs by using inductive current device, a mass flow device and a pressure sensor to accurately determine the volume of ink in a reservoir. 
         [0011]    Another object of the inventive system is to provide a cut-off cut-off valve system to prevent the reservoir ink from freely flowing out of the system in the event of a damaged print component. A related object of this inventive system is to use the cut-off valve system to stop the print operation before air is drawn into the system during a low ink condition. 
         [0012]    It is yet another object of the inventive system to provide a mechanism to restrict reservoirs containing embedded microprocessors from being removed from a manifold system without first being placed in a safe stand-by state. 
         [0013]    Another object of the inventive system is to provide a mechanism to pressurize the reservoir for the purpose of creating a system that is not subject to the restrictions of a standard gravity fed system wherein the reservoir must be placed a specified minimum distance above the print mechanism. 
       SUMMARY OF THE INVENTION 
       [0014]    It is to be understood that both the foregoing and general description and the following detailed description are exemplary, but are not restrictive, of the inventive system. In accordance with the principles and objectives of the inventive system, the inventive system includes a custom enclosure and ink supply control mechanisms for the purpose of delivering regulated ink to a ink jet print system. 
         [0015]      FIG. 9  is an isometric view of industrial manifold  100 , consisting of safety switch  103 , housing  150 , gage  105  and reservoir  101 - 101   c  containing ink  120  is stored in reservoirs  101 . Gage  105  consists of an array of LEDs wherein each vertical column corresponds to a specific reservoir for the purpose of providing a graphical representation of the amount (percentage) of ink  120 . Housing  150  provides a stable mechanical enclosure for the purpose of protecting internal components from environmental contaminants such as dirt and water in addition to providing attachment features, not shown, to mate industrial manifold system to an external support member, also not shown. 
         [0016]    Per  FIG. 5 , Industrial manifold  100  attaches to print system  200  and external controller  400  which consists of hardware and software controls. Print system  200  applies ink to print medium  300 , which may be any medium capable of accepting ink  120  used in the ink-jet printing process. For the purpose of illustration, such mediums may include, but are not restricted to, paper, cardboard, ceramic tile, wood, concrete, plastic, metal, fabric and cloth. 
         [0017]    It is an objective of the inventive system that industrial manifold  100  provides ink  120  to print system  200  such that reservoir  101  may be removed when empty and replaced while print system  200  maintains continuous operation. It is another object of the inventive system to create an accurate method of monitoring the level of ink  120  in reservoir  101  and displaying that information graphically It is yet another object of the inventive system to provide methods to ensure that air can not enter ink passages at any time. It is another object of the inventive system to provide a mechanism to place reservoir  101  in a safe state so that it may be removed from industrial manifold  100  without causing damage to electronics embedded in reservoir  101 . 
         [0018]    Several alternate embodiments of the inventive system propose, and are explained later in full detail, various methods of reaching stated objectives. For the purpose of monitoring the level of ink in reservoir  101 , these methods include the use of mass flow sensor  109  to measure the quantity of ink  120  from reservoir  101  and the use of pressure sensor  104  to measure the weight of ink  120  in reservoir  101 . For the purpose of creating a system which does not rely on gravity for ink transport, air pump  105  is used to pressurize reservoir  101 . 
         [0019]    Additionally, print system  200  consists of chief components: pressure switch  201 , regulator  202  and print head  203 . These components are integral in print system  200 , and are depicted in one physical unit. Although these components are part of print system  200 , they may be separated by distance and placed individual mechanical enclosures. 
     
     
       DESCRIPTION OF FIGURES 
         [0020]      FIG. 1  shows process diagram PL 1  of preferred embodiment  1000  of the inventive system. 
           [0021]      FIG. 2  shows process diagram PL 2  of the inventive system in operation as it pertains to alternative embodiment  1001 . 
           [0022]      FIG. 3  highlights the process of sub-routine S 1 . 
           [0023]      FIG. 4  shows subroutine S 2 . 
           [0024]      FIG. 5  shows a graphical layout of the key components in preferred embodiment  1000  of the present inventive system. 
           [0025]      FIG. 6  shows a graphical layout of the key components in alternate embodiment  1001  of the inventive system. 
           [0026]      FIG. 7  shows a graphical layout of the key components in alternate embodiment  1002  of the inventive system. 
           [0027]      FIG. 8  shows a graphical layout of the key components in alternative embodiment  1003  of the present inventive system. 
           [0028]      FIG. 9  is an isometric view of industrial manifold  100 . 
           [0029]      FIG. 10  is an exploded view of industrial manifold  100 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0030]      FIG. 5  shows preferred embodiment  1000  of the present inventive system, consisting of bulk ink system  100 , print system  200 , controller  400  and power supply  500 . Bulk reservoir  101  contains ink  120 . Industrial manifold  100  supplies ink  120  to print system  200  through ⅛″ ID tube  2 , wherein ink  120  is applied to print medium  300  by print head  203 . Note that ink  120  stream  301  is shown to illustrate the printing process. Ink  120  leaves reservoir  101  through ⅛″ ID tube  1  and passes through cut-off valve  102 . Cut-off valve  102  is connected to controller  400  and is used for the purpose of stopping the flow of ink  120  to print system  200  when reservoir  101  becomes empty or in the event of a damaged print component in print system  200 . It is important to note that this action prevents air from entering ink passages, for example, ⅛″ ID tubes  1  and  2 . Controller  400  is a modified personal computer containing custom software written to govern both industrial manifold  100  and print system  200  for the purpose of printing on print medium  300 . ⅛″ ID tube  2  connects bulk ink supply  100  to print system  200 . Industrial manifold  100  and Print System  200  are not required to be located close together and may be separated by any reasonable distance. However, in preferred embodiment  1000 , industrial manifold  100  delivers ink  120  via gravity and thusly must placed a minimum of 10 inches above print system  200 . Note that this requirement is overcome, in  FIG. 8  alternative embodiment  1003 , by pressurizing reservoir  101 . ⅛″ ID tube  2  delivers ink  120  to pressure switch  201  and regulator  202  by way of a common three port manifold, not shown. Pressure switch  201  connects to controller  400 . When reservoir  101  contains enough ink  120  to allow for the proper operation of print system  200 , and because of the relative difference in elevation between industrial manifold  100  and print system  200 , pressure switch  201  and pressure regulator  202  are supplied ink  120  by ⅛″ ID tube  2  at a pressure greater than or equal to 10 inches of water. When this condition is met, pressure switch  201  is in an open circuit mode. When reservoir  101  no longer contains enough ink to support proper operation, pressure switch  201  is in a closed circuit mode. This information may be used by controller  400  to close cut-off valve  102  for the purpose of stopping the flow of ink  120  to print system  200  such that the print operation is interrupted is such a manner as to prevent air from entering tube  1 , tube  2  or tube  3 . Pressure regulator  202  delivers ink to print head  203  at less than atmospheric pressure for the purpose of preventing ink from freely flowing out of the ink jet mechanisms, not shown. Print head  203  communicates to controller  400  through cable  4 . Regulator  202  works mechanically and does not require electrical input. 
         [0031]    Reservoir  101  communicates with controller  400  via cable  7 . Safety switch  103  consists of an u-shaped handle  103   a  and switch  103  as shown in  FIG. 10 . When u-shaped handle  103   a  is down, the circuit in switch  103  is closed. It is used, via controller  400 , to stop the flow of ink from reservoir  101  in addition to placing reservoir  101  in a “stand-by” mode so that it can be disconnected from industrial manifold  100  without damaging the embedded electronics on reservoir  101 . Safety switch  103  communicates with controller  400  by cable  10 . Software driven actions derived from either the closed or open state of safety switch  103  are communicated to reservoir  101  by cable  7 . Power is supplied to both industrial manifold  100  and print system  200  by power source  500 . 
         [0032]    In preferred embodiment  1000  the level of ink  120  in reservoir  101  is determined by a two methods, drop counting and inductance measurement, in a three phase approach that changes with the volume of ink  120 . Phase one employs drop counting from the initial fill volume of reservoir  101  to approximately 51% of the volume. 
         [0033]    In phase two a pair of inductance coils, not shown, embedded in reservoir  101  accurately measure the level of ink  120  from 50% to 15% of the volume. At this time, there is a correction made to the level of ink  120  level, as the volume information obtained from inductance measurements are more accurate than that of drop counting. As a result, a user looking at gage  105  may see a sudden change in ink level. Inductance measurements proceed until ink  120  volume drops below 15%. 
         [0034]    Phase three uses drop counting for the remaining ink  120  in reservoir  101 . Note that drop counting is a open loop method and has no feedback, whereas inductance measurements consist of a closed loop procedure with feedback, and is therefore inherently more accurate. Phase two is used to bridge the gap between the two inaccurate drop counting measuring phases. Inductance measurements outside of the bound defined by 15% to 50% of the fill volume are not accurate. Ink  120  level information is displayed on gage  105 , which may consist of a LED bar graph display on the inventive system per  FIG. 9 , or a of a software display on a computer screen receiving information from controller  400 . In operation, a newly installed reservoir  101  contains a known volume of ink  120 . Print system  200  applies ink  120  to print medium  300  by a series of ink jet pulses from print head  203 . Each time print head  203  pulses, a known quantity of ink  120  is used and debited, via controller  400  from the known starting quantity of ink  120  in reservoir  101 . When the level of ink  120  reaches approximately 51% of the initial fill volume, fluid volume measurements using the embedded inductance coils, not shown, imbedded in reservoir  120  begin. 
         [0035]      FIG. 9  shows industrial manifold  100 , which consists of housing  150 , safety switch  103 , gage  105  and four reservoirs  101 - 101   c . It is to be understood that the inventive system may contain one to many reservoirs  101 . Mechanical housing  150  shields internal components from environmental contaminants such as dirt, debris and water. Housing  150  mates to external support members, not shown, and is designed to be placed 10 inches above print system  200 . Gage  105  consists of a LED array wherein four vertical columns represent the four reservoirs  101 . The columns in gage  105  are labeled  1  through  4  corresponding to the numbers  150   b  above reservoirs  101 . Individual LEDs in each column are illuminated to provide a visual representation of the amount of ink a corresponding reservoir  101 . The row of LEDs  105   a  represents the bottom of gage  105 &#39;s scale. When the only LED illuminated in a column is that in section  105   a , reservoir  101  is empty. This condition may also be tied into a custom software operation in controller  400  for the purpose of issuing an audible alert, changing the condition on a stack light, changing an external display, or all of the above. Additionally, industrial manifold  100  may utilize a remote display, for example a computer monitor, which has a visual representation of gage  105  or a related visual output showing the amount of ink in individual reservoirs  101 . 
         [0036]      FIG. 10  is an exploded view of industrial manifold  100 , consisting of housing  150 , safety switch  103 , stalls  170 - 170   c , reservoirs  101 - 101   c , tubes  1 , cut-off valves  102 - 102   c , male receptacles  2 - 2   c  and switch port  7 , gage  105 , circuit board  180  and communication port  160 . Housing  150  consists of two sheet metal halves which provide support and protection of the internal components as well as providing a stable platform for external mounting members, not shown. Safety switch  103  is by controller  400  to place reservoirs  101  in a removable state when u-shaped handle  103   a  is lifted. Reservoirs  101 - 101   c  can not physically be removed when u-shaped handle  103   a  is resting in the lowered position as shown. When the u-shaped handle  103   a  is lifted, safety switch  103  is opened triggering a custom software operation in controller  400  to electrically isolate the embedded electronics in reservoirs  101 . Removal of reservoirs without this action may damage or destroy the embedded electronics in reservoirs  101  and via-a-vi any stored information. 
         [0037]    Reservoir  101   c  fit into stalls  170   c  respectively. Stall  170   c  connects an ink tube to reservoir  101   c  for the purpose of drawing ink, and an additional tube, not shown, which may be used to vent reservoir  101  to atmospheric pressure or to an external air pump for the purpose of pressurizing reservoir  101  for applications such as those explained in  FIG. 8 . Stall  170   c  also makes an electrical connection with the embedded electronics in reservoir  101   c . Gage  105  is an LED array consisting of one vertical column of multiple LEDs per each reservoir  101 - 101   c  for the purpose of providing a graphical representation of the amount of ink in each individual reservoir. Circuit board  180  makes an electrical connection between external controller  400  and stalls  170 - 170   c . Communication is made between industrial manifold  100  and controller  400  via a cable, not shown, that connects to communication port  160 . Tube  1  takes ink from an interface in stall  170   c , not shown, and connects it to cut-off valve  102 . Cut-off valve  102  is used by controller  400  to stop the flow of ink in the event of a low fluid condition. This is noteworthy in that cut-off valve  102 , when used with the overall control system, prevents air from entering the ink delivery system. If air were to enter the system, it would have to be stopped and all the air purged fluid delivery lines. Switch port  7  electrically connects safety switch  103  to controller  400 . Male receptacles  2 - 2   c  protrude through housing  150  and mate with female connector(s), now shown, to deliver ink to print system  200 . 
         [0038]      FIG. 1  describes the process flow of preferred embodiment  1000  of the inventive system. A process loop PL 1  begins with step G 1 , wherein controller  400  reads a custom code stored on the embedded electronics in reservoir  101  for the purpose of determining whether the reservoir is compatible with industrial manifold  100 . Reservoir  101  is deemed compatible if it physically fits into stall  170 , shown in  FIG. 10 , if ink  120  is a type that is supported by industrial manifold  100 , if the reservoir is from an approved vendor, and if the reservoir has sufficient ink  120  to support a printing process. It is important to note that a custom read-only code is written to the embedded electronics in reservoir  101  by the manufacturer of industrial manifold  100  (or an authorized supplier). This code is read in step G 1  for the purpose of determining cartridge compatibility. If the code is rejected, an error message is returned per step G 3 . This and other error messages may be used to sound an alarm and warning light, stop industrial manifold  100 , stop print system  200 , perform a custom operation or all of the above. If the cartridge is compatible the process proceeds to step G 4 , where the ink type is read by controller  400  from information stored on the embedded electronics in reservoir  101 . 
         [0039]    Stall  170  is designed to accept one ink type only, therefore the ink type read from reservoir  101  must match the ink type controller  400  designates for stall  170 . An error message is returned per step G 6  if reservoir  101  contains an ink type unsupported by stall  170 . In step G 7 , the ink level is read using by a two step decision process. First, reservoir  101  is checked to ensure that the embedded electronics have not been written “zero”, the command written when controller  400  determines reservoir  101  is out of ink  120 . If a “zero” reading is present, than an error message is returned per step G 9 . If step G 8  does not read “zero”, than an inductance reading is taken per step G 11 . In step G 11 , a decision is made between three possible states: one, the inductance reading is above the bounds of measurement, two, the inductance reading is within the bounds of measurement, or three the inductance reading is below the bounds of measurement. Whether the inductance reading in step G 11  is above or within the bounds of measurement, both conditions proceed to step G 13 , however, an above bounds measurement is used to output one display condition, for example “full”, whereas an in-bounds condition is used to display another, for example, “half-full”. 
         [0040]    When the reading from step G 11  results in less than the bounds of measurement, the process proceeds to step G 12 . Pressure switch  201  is read in step G 12 . If it is above 10 inches of water, step G 15  completes process loop PL 1  and the process proceeds to step G 18 . If step G 12  results in a reading less than 10 inches of water, “zero” is written to the embedded electronics in reservoir  101  and the operation proceeds to a sub routine S 1  per step G 19 . In step G 14 , if pressure switch  201  reads less than 10 inches of water G 21  returns an error message. This situation, where reservoir  101  has ample ink left but pressure switch  201  signals a low ink condition, results from a broken ink feed line in print system  200 . In step G 18 , data read from the previous steps is written to the embedded electronics in reservoir  101  in addition to being recorded in controller  400 , then step G 19  updates the display of the ink level. Lastly, step G 20  returns the process to step G 1 . 
         [0041]      FIG. 6  shows alternate embodiment  1001  of the inventive system. In this embodiment, mass flow sensor  109  has been added as an alternative method of accurately determining the amount of ink  120  in reservoir  101 . This method does not require input from inductance coils or drop counting as stated in  FIG. 5 , however, it may be used in conjunction with those and other methods to enhance the accuracy of the ink  120  level information. Mass flow sensor  109  is capable of monitoring ink  120  flow to a resolution of nanoliters per minute as ink  120  flows from industrial manifold  100  to print system  200 . 
         [0042]    Ink  120  leaves reservoir  101  by tube  1  which terminates in cut-off valve  102 . Ink  120  is taken from cut-off valve  102  by tube  1 A to mass flow sensor  109 . Ink  120  leaves mass flow sensor  109  and industrial manifold  100  by tube  2 , which feeds print system  200 . Mass flow sensor  109  communicates with controller  400  the mass of ink  120 , supplied by tube  1 A, through mass flow sensor  109 . Measurements are taken several times a second. Mass flow information, along with information regarding the initial fill volume of ink  120  in reservoir  101 , is used to determine the level of ink  120  in reservoir  101  at all times during which there is a sufficient quantity of ink  120  in reservoir  101  to support a print operation. As ink  120  flows through mass flow sensor  109  it is debited from the known starting quantity of ink  120  in reservoir  101 . Ink  120  level information is stored in the embedded electronics in reservoir  101  and displayed on gage  105  for the purpose of providing an operator with a visual representation of the level of ink  120  left in reservoir  101  in real time. 
         [0043]      FIG. 2  describes the process flow of the inventive system in operation as it pertains to alternative embodiment  1001  as described in  FIG. 6 , wherein industrial manifold  100  includes mass flow sensor  109  for the purpose of accurately measuring the amount of ink  120  drawn from reservoir  101  at all times during which there is a sufficient quantity of ink  120  in reservoir  101  to support a print operation. 
         [0044]    Process loop PL 2  begins in step MF 1 , wherein controller  400  reads a custom code stored on the embedded electronics in reservoir  101  to verify that the reservoir is compatible with stall  170 . It is important to note that a custom read-only code is written to the embedded electronics in reservoir  101 , by the manufacturer of industrial manifold  100  or an authorized supplier, for the purpose of ensuring that only compatible reservoirs are accepted by industrial manifold  100 . Step MF 2 , the custom code is checked by controller  400  for compatibility with stall  170 . If the code is not approved, step MF 3  returns an error message. Note that error messages may be used to sound an alarm and warning light, stop industrial manifold  100 , stop print system  200 , perform a custom operation or all of the above. If the code is approved, the process proceeds to step MF 4 , where the ink type is verified by matching ink information stored on the embedded electronics in reservoir  101 , with the characteristics of the stall  170  reservoir  101  is inserted into. Bulk ink supply  100  is configured at the time of manufacturer such that individual stalls  170  stored in controller  400 . In step MF 6 , if an unsupported ink type is inserted in stall  170  an error message is returned. If it is determined in step MF 5  that the ink type is acceptable, than the process proceeds to step MF 7  where mass flow sensor  109  flow rate information is recorded. Mass flow information, along with information regarding the initial fill volume of ink  120  in reservoir  101 , that is the volume of a newly installed reservoir  101 , is used to determine the level of ink  120  in reservoir  101  at all times during which there is a sufficient quantity of ink  120  in reservoir  101  to support a print operation. In step MF 8  mass flow information is analyzed to determine the amount of ink being drawn from reservoir  101  and the information is stored. If this information reveals that the level of ink  120  in reservoir  101  is less than zero, step MF 9  returns an error message. If step MF 8  indicates that the level of ink  120  in reservoir  101  is greater than zero, the process proceeds to step MF 11 . Note that line MF 10  indicates a time delay between steps MF 8  and MF 11  for the purpose of minimizing the chance of a faulty reading in step MF 11  by allowing the reading in step MF 11  to occur over a greater time distance than the prior steps. For example, step MF 11  may take several seconds wherein if the reading is mostly positive the output will be yield step MF 14 , and if the output is mostly negative the output will yield step MF 13 . Alternatively, time delay MF 10  may be replaced a sub-routine wherein step MF 12  must return multiple negative answers MF 17  in order to proceed to the sub-routine initiated by step MF 13 . In step MF 11 , controller  400  reads pressure switch  201  for the purpose of determining whether ink  120  in print system  200  is at a pressure greater than 10 inches of water. If it is not, step MF 13  initiates sub-routine S 1  as shown in  FIG. 4 . If ink  120  pressure in print system  200  is greater than 10 inches of water, step MF 14  writes ink  120  level determined from step MF 8 , to the embedded electronics in reservoir  101 . Then, step MF 15  updates display  105 , not shown, and finally, step MF 16  completes Process loop PL 2  and returns the program to the beginning. 
         [0045]      FIG. 7  shows alternate embodiment  1002  of the inventive system, wherein industrial manifold  100  includes pressure sensor  104  for the purpose of accurately measuring the volume of ink  120  in reservoir  101 . The operation of print system  200  is identical to that in  FIGS. 5 &amp; 6 . In this embodiment, the level of ink  120  in reservoir  101  is determined by measuring the weight of the ink in reservoir  101  using pressure switch  104 . To do this it is requited that controller  400  knows the initial full weight of reservoir  101 , the empty weight of reservoir  101  and the pressure on pressure sensor  104  at all times during which there is a sufficient quantity of ink  120  in reservoir  101  to support a print operation. Pressure sensor  104  feedback is used in conjunction with a custom algorithm to determine the weight of ink  120  in reservoir  101 . This information is used to display the corresponding volume information on gate  105  for the purpose of providing an operator with a visual representation of the level of ink  120  left in reservoir  101  in real time. 
         [0046]      FIG. 8  shows alternative embodiment  1003  of the present inventive system, wherein industrial manifold  100  includes air pump  105  for the purpose of pressurizing reservoir  101  such that it may be used without the constraints of a typical gravity fed system. For example, in gravity fed systems FIGS.  5 , 6  &amp;  7 , reservoir  101  in industrial manifold  100  must be located a minimum of 10 inches above print system  200 . By pressurizing the air in reservoir  101  embodiment  1003  allows industrial manifold  100  to be placed below print system  200 , and/or at a much greater distance from print system  200  than a traditional gravity fed system. The level of ink  120  in pressurized reservoir  101  may be measured using either of the aforementioned methods: inductance, mass flow sensor  109  or pressure sensor  104 . 
         [0047]    Air pump  105  receives electrical power from controller  400  for the purpose of regulating the pressure inside of reservoir  101 . Pressure information is obtained from pressure switch  201  in print system  200 . Air pump  105  activates when pressure switch  201  reads below 10 inches of water pressure in order to increase the pressure in reservoir  101 . Air pump  105  continues to operate for a pre-determined period of time after pressure switch  201  indicates more than 10 inches of water pressure, this ensures continual operation of print system  200  as long as there is sufficient ink  120  in reservoir  101 . If after a given period of time, pressure switch  201  does not indicate more than 10 inches of water pressure, the system returns an error message. 
         [0048]    Alternate embodiment  1003  listed in  FIG. 8  follows the process defined by  FIG. 2 , with the exception that step MF 13  initiates the subroutine S 2  shown in  FIG. 4 . Ink  120  level is monitored with mass flow meter  109  or pressure sensor  104 , not shown. Using mass flow measurement, when mass flow meter  109  records a predetermined volume of ink  120  has been drawn out of reservoir  101 , or alternatively, using pressure sensor  104  to indicate when a pre-determined weight of ink  120  is drawn out of reservoir  101 , an error message is initiated by step MF 9  indicating that reservoir  101  is empty. However, until that limit is reached, industrial manifold  100  operates normally until step MF 12  indicates that there is less than 10 inches of water pressure, in which case a sub-routine begins per step MF 13 . 
         [0049]      FIG. 4  shows subroutine S 2 , the process for pressurizing reservoir  101  such that it may supply ink from a location or position not possible by traditional gravity fed systems. For example, in this embodiment industrial manifold  100  may be placed below print system  200 . In step SS 1  air pump  105  activates to pressurize reservoir  101 . Line SS 11  represents a time delay in which air pump  105  operates before a pressure reading in pressure switch  201  is taken. In step SS 3 , controller  400  determines whether the pump operation in step SS 1  supplied adequate pressure to supply the switch with more than 10 inches of water pressure. If the switch is above the 10 inch water pressure requirement, step SS 4  returns the process to the beginning of  FIG. 2 . If it does not, the process proceeds to step SS 5 ,a “de-bounce” element in which multiple readings are taken from reservoir  101 , or, alternatively, a time delay is interjected into the process, to ensure that low pressure readings from pressure switch  201  are accurate and repeatable. This is important to prevent the permanent action in step SS 6  from occurring when there is still useable ink in reservoir  101 . This is especially important in environments where the unit is prone to contact by foreign bodies that could potentially jostle the unit in such a manner as to induce momentary false readings. Step SS 6 , writes “zero” ink remaining to the embedded electronics in reservoir  101 . This command makes the reservoir permanently unusable by industrial manifold  100 . Step SS 6  write “zero” command also sends a signal to controller  400  for the purpose of alerting the operator that reservoir  101  is now empty. 
         [0050]    Step SS 8 , a timer is started for a pre-determined period of time that corresponds to the maximum amount of time a small reservoir in the print cartridge, not shown, in print system  200  could support an ink intensive print operation. This allows an operator several minutes to replace reservoir  101  without stopping the print operation. When an operator replaces reservoir  101 , the operation starts over from either G 1  or MF 1 . If the operator does not do this before step SS 9 , the end of the timer operation, step SS 10  returns an error message that may be used to stop print system  200  or conduct some other user defined operation. 
         [0051]      FIG. 3  describes the process of sub-routine S 1 . Sub-routine S 1 , by design allows a short period of time in which a newly empty reservoir  101  may be replaced without stopping the print operation. In  FIG. 1 , G 19  and  FIG. 2 , MF 13 , reservoir  101  in bulk ink supply  100  is out of ink. However, a print cartridge, not shown, located in part of the ink jet mechanism, also not shown, in print system  200  contains a volume of ink sufficient such that printing can continue for a short period of time without drawing ink from reservoir  101 . This is because the print cartridge, not shown, contains a small reservoir. In sub-routine S 1 , step SR 1  is a “de-bounce” element in which multiple readings are taken from reservoir  101 , or, alternatively, a time delay is interjected into the process, to ensure that low pressure readings from pressure switch  201  are accurate and repeatable. This is important to prevent the permanent action in step SR 2  from occurring when there is still useable ink in reservoir  101 . This is especially important in environments where the unit is prone to contact by foreign bodies that could potentially jostle the unit in such a manner as to induce momentary false readings. In step SR 2 , the command write “zero” writes zero ink remaining to the embedded electronics in reservoir  101 . This command makes the reservoir permanently unusable by industrial manifold  100 . Step SR 2  write “zero” command also sends a signal to controller  400  for the purpose of alerting the operator that reservoir  101  is now empty. 
         [0052]    Step SR 3 , a timer is started for a pre-determined period of time that corresponds to the maximum amount of time a small reservoir in the print cartridge, not shown, in print system  200  could support an ink intensive print operation. This allows an operator several minutes to replace reservoir  101  without stopping the print operation. When an operator replaces reservoir  101 , the operation starts over from either G 1  or MF 1 . If the operator does not do this before step SR 4 , the end of the timer operation, step SR 5  returns an error message that may be used to stop print system  200  or conduct some other user defined operation.