Abstract:
A method for controlling an imaging apparatus based on an intelligent usage tracking system is provided. The method monitors use of the imaging apparatus over a period of time and uses the collected data to predict future use. The collected data is used to control the imaging apparatus to minimize warm-up delays and to maximize time in one or more standby modes.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not applicable. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     FIELD OF INVENTION 
     This invention relates generally to a method for controlling an imaging apparatus and, more specifically, to a method for collecting and analyzing data regarding use of the imaging apparatus and controlling the operation and various functions of the imaging apparatus based on the collected usage data. 
     BACKGROUND OF THE INVENTION 
     Many imaging apparatus, such as electrophotographic printers and copiers, ink jet printers and the like, utilize various operating modes and perform different functions that require a “warm-up” time when the imaging apparatus is not in a fully operational state. For example, an imaging apparatus may utilize a ready or operating mode and a standby mode. The operating mode corresponds to the imaging apparatus being in a fully operational status and ready to generate output. The standby mode corresponds to a reduced status in which the imaging apparatus remains powered up, but one or more of its imaging components is not ready to operate. For example, the temperatures of the apparatus&#39; thermal components, such as a fuser or a heated ink jet print head, may be lowered. In an electrophotographic printer or copier, the laser mirrors may require “spinning up” before the imaging process may proceed. These situations are also encountered when the imaging apparatus is turned on from the off status. 
     Placing an imaging apparatus in a standby mode has the advantages of reducing power consumption and reducing thermal wear on the thermally sensitive components of the apparatus. For example, in a solid ink jet color printer, the temperature of the print head during printing and in the operating mode between print jobs may be in the range of about 140° C. In a standby mode, the temperature of the print head maybe lowered to a range of between about 95° C. and about 105° C., thereby reducing thermal wear and power consumption. 
     When an imaging apparatus is in a standby made, the imaging apparatus must return to the operating mode before imaging can begin. This imposes an undesirable delay on the imaging process. For example, in the Phaser® 360 solid ink color printer manufactured by Tektronix, Inc., the assignee of the present application, the printer can require approximately five minutes to raise the temperatures of the print head and associated ink reservoirs from the standby mode to the operating mode. 
     It is desirable to avoid warm up delays whenever possible. It is also desirable to maximize the time in a standby mode between imaging commands to minimize thermal wear and power consumption. One attempt to address these needs has involved the use of a timer to track the elapsed time between print commands. For example, the Phaser® 360 printer remains in the operating mode for a fixed period of time (four hours) after a print command is received, and thereafter enters the standby mode. When the next print command is received, the printer must warm-up from the standby mode before printing can begin. 
     Using a timer to control whether the printer is in an operating or a standby mode inevitably creates situations in which a print command is received while the imaging apparatus is in the standby mode. A timer also maintains the imaging apparatus in the operating mode for a fixed period of time regardless of whether imaging commands are typically received during this period. In this regard, the timer may keep the imaging apparatus in the operating mode even though print commands are rarely received during this period. 
     What is needed is an intelligent usage tracking system that is capable of monitoring actual use over a period of time and controlling the imaging apparatus based on prior use to minimize warm-up delays and maximize time in a standby mode. 
     SUMMARY OF THE INVENTION 
     It is an aspect of the present invention to provide a method for controlling an imaging apparatus. 
     It is another aspect of the present invention to provide a method for collecting data regarding use of the imaging apparatus during a period of time. 
     It is yet another aspect of the present invention to provide a method for utilizing the collected data to place the imaging apparatus in one of at least two modes. 
     It is a feature of the present invention that the method intelligently tracks user activity to customize the operation of the imaging apparatus according to usage patterns. 
     It is another feature of the present invention that the method periodically updates user activity information to reflect current usage. 
     It is an advantage of the present invention that the method minimizes undesirable warm-up delays by predicting typical usage periods and controlling the imaging apparatus to be in the operating mode for those periods. 
     It is another advantage of the present invention that the method reduces thermal wear on the imaging apparatus by maximizing time in one or more standby modes. 
     It is another advantage of the present invention that the method reduces power consumption by maximizing time in one or more standby modes. 
     It is still another advantage of the present invention that the method minimizes time in the operating mode when the imaging apparatus is not executing an imaging command. 
     To achieve the foregoing and other aspects, features and advantages, and in accordance with the purposes of the present invention as described herein, a method for controlling an imaging apparatus based on an intelligent usage tracking system is provided. The method monitors use of the imaging apparatus over a period of time and uses the collected data to predict future use. The collected data is used to control the imaging apparatus to minimize warm-up delays and to maximize time in one or more standby modes. 
     Still other aspects of the present invention will become apparent to those to skilled in this art from the following description wherein there is shown and described a preferred embodiment of this invention, simply by way of illustration of one of the modes best suited to carry out the invention. As it will be realized, the invention is capable of other different embodiments and its several details are capable of modifications in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive. And now for a brief description of the drawings. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     FIG. 1 is an overall perspective view of an ink jet printer that uses the method of the present invention. 
     FIG. 2 is a schematic diagram showing the printer controller receiving print data from a data source and communicating with the printer driver and an NVRAM memory source. 
     FIG. 3 shows a 24×7 array of elements and their associated values, with each element corresponding to one hour in a one week period. 
     FIGS. 4-6 are functional block diagrams showing the steps of the method of the present invention. 
     FIG. 7 is a schematic illustration of the operation of the method and its control of the printer over an exemplary nine hour period. 
    
    
     Reference will now be made in detail to the present preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 is an overall perspective view of a phase change ink jet printer, generally indicated by the reference numeral  10 , that utilizes the method of the present invention. It will be appreciated that the present invention may be practiced with and embodied in various other imaging apparatus, such as aqueous ink jet printers, electrophotographic printers and copiers and any other imaging apparatus that utilize a warm up period. Accordingly, the following description is merely illustrative of one embodiment of the present invention. 
     The ink jet printing apparatus  10  is preferably designed to operate with phase change ink. Conventional phase change ink is initially solid at room temperature and is changed to a molten state by the application of heat energy to raise its temperature to between about 85° C. and about 150° C. For optimal jetting through an ink jet print head, the ink is maintained at a temperature of between about 120° C. and about 150° C. in the print head and in the ink reservoir that supplies liquid ink to the print head. 
     When the ink jet printer  10  is in an operating or ready mode, the print head and reservoir are maintained at or near the optimal jetting temperature for the phase change ink being used. The printer  10  may also enter other status conditions in which the print head and/or reservoir are maintained at a temperature lower than the optimal jetting temperature. For example, the printer may enter a printer standby mode. In one embodiment of the printer standby mode, the print head is maintained at a print head standby temperature of between about 94° C. and about 110° C., and preferably about 104° C. The reservoir is maintained at a reservoir standby temperature of between about 92° C. and about 112° C., and more preferably about 102° C. 
     The printer  10  may also utilize other standby modes that maintain the print head and/or reservoir at a temperature closer to but still lower than the required jetting temperature. For example, in one embodiment the print head is cooled to a jetstack standby temperature of between about 104° C. and about 124° C., and preferably about 114° C., while the reservoir is maintained at the reservoir operating temperature. 
     Advantageously, utilizing one or more standby modes reduces the thermal stress and wear in the print head and associated thermal components of the imaging apparatus. Changing the imaging apparatus from an operating mode to a standby mode also reduces power consumption. However, the time required to heat the print head and/or reservoir from a standby temperature to an operating temperature imposes an undesirable delay on the printing process. It would therefore be desirable to minimize these warm-up delays while also maximizing the time the imaging apparatus spends in one or more standby modes. 
     These competing interests are addressed in the present invention by providing a method for intelligently tracking and forecasting use of an imaging apparatus. The method tracks usage of the imaging apparatus and places the imaging apparatus in one of at least two modes according to the usage pattern. The method may place the imaging apparatus in an operating mode or one or more standby modes, may turn on or turn off the imaging apparatus, or may control other components of the imaging apparatus to optimize throughput based on prior use. 
     As shown in FIG. 2, the printer  10  includes a controller  12  that receives imaging data from a data source  14 . The controller  12  utilizes a printer driver  16  to process the imaging data and control the operation of the print head  18  and other imaging components (not shown) of the printer  10 . The method of the present invention may be implemented in the controller&#39;s firmware. The controller  12  utilizes the method of the present invention to control the printer  10  according to prior usage patterns. A non-volatile memory source  20  (NVRAM) stores the usage pattern data generated by the present method, as described in more detail below. 
     With reference now to FIGS. 3-7, a preferred embodiment of the present invention will now be described. In its broadest aspects, the method of the present invention controls the printer  10  by collecting data regarding use of the printer during a period of time. The method uses the collected data to control the printer to minimize warm-up delays and to place the printer in the appropriate operating mode or standby mode based on the usage pattern. 
     In a preferred embodiment, the method maps a usage pattern based on collected data for a recurring period of time. The usage data is collected and continuously updated over a one week period. Each day is preferably divided into a plurality of periods of about one hour each. The data is then organized into a 24×7 array of elements corresponding to each hour of the one week period. A usage pattern is mapped for each of the elements in the array by assigning a value to each element based on whether the printer has received a print command during that hour over a previous number of weeks. FIG. 3 shows an example of a 24×7 array of elements and their associated values. It will be appreciated that other methods may be utilized for tracking and quantifying a frequency of use of the imaging apparatus. For example, a histogram of a frequency distribution of use of the imaging apparatus may be developed. The method may then control the imaging apparatus as described above based on data from the histogram 
     FIGS. 4-6 illustrate a preferred embodiment of the method of the present invention. FIG. 7 illustrates an example of the operation of the method and its control of the printer over an exemplary nine hour period. With reference now to FIG. 4, when the printer  10  is powered on from an off state (step  100 ), the controller  12  places the printer in the operating mode. The controller  12  then utilizes a real-time clock to set a timer for signaling the transition between a first period and a second period (step  102 ). The periods may be synchronized with the hours of the day, such that a transition between periods occurs on each hour change. Alternatively, the periods may not be correlated to the hours of the day. In step  102 , the controller may also clear a “try again” flag, the function of which is explained in more detail below. Further, when a printer is powered on for the first time, step  102  may include the step of initializing all of the elements in the 24×7 array to an initial value. 
     After setting the timer and performing any of the other steps in step  102 , the method enters an idle state (step  104 ) in which the controller waits for either a print message or an hour message from the timer (step  106 ). 
     FIG. 7 graphically illustrates the operation of the method of the present invention and its control of the printer  10  over a representative nine hour period of a day. The horizontal axis D indicates the time of day. The area immediately above axis D shows the value assigned to each one hour element or period. The value may be, but is not restricted to, an integer value and any number of different values may be used. In the preferred embodiment, the value of each element is an integer value of zero, one, two or three. Using a maximum element value of three corresponds to analyzing and collecting data for that period over a three week time frame. It will be appreciated that many other maximum element values may be utilized in practicing the method of the present invention. 
     In the column above each of the element values is the corresponding printer mode for that period. The printer mode is indicated by the letters T, J and S. Mode T corresponds to an operating mode in which the printer is ready to process and carry out a print command. Mode J represents a first standby mode and mode S represents a second standby mode. 
     A preferred embodiment of the present method will now be explained with reference to the exemplary nine hour time period shown in FIG.  7 . Entering the 7:00 hour, the value for the 7:00 period (defined here as the time period between 7:00 and 8:00) is zero ( 200 ) and the printer is in the second standby mode S ( 202 ). During the 7:00 period the controller  12  waits for either a print message or an hour message (FIG. 4, step  106 ). At the transition from the 7:00 period to the 8:00 period, the controller  12  receives an hour message from the timer at the end of the 7:00 period (step  111 , FIGS.  4  and  6 ). With reference now to FIG. 6, when the hour message is received the method determines whether the value of the element from the previous hour (7:00) is zero and the value of the element from the next hour (8:00) is non-zero (step  113 ). Because the value of the next hour&#39;s element ( 203 ) is not non-zero, the method proceeds to step  115  to determine whether the previous hour&#39;s element is non-zero or the “try again” flag is set (the “try again” flag is explained in more detail below). Because the previous hour&#39;s element is zero ( 200 ) and the “try again” flag is not set, the method proceeds to step  116  to determine if a print command was received in the previous hour. Because there was no print command in the previous hour, the method then determines if the previous hour&#39;s element ( 200 ) is zero (step  140 ). As the value of the 7:00 period element ( 203 ) is zero, the method then sets the timer for the next hour (step  118 ) and returns to the idle state  104  (step  120 ). Therefore, the printer mode is not changed at the transition from the 7:00 period to the 8:00 period and remains in the operating mode S ( 204 ) at the beginning of the 8:00 period. 
     With continued reference to FIG. 7, at approximately 8:30 a print command  206  is received by the controller  12 . Just prior to the print command being received, the value of the element for the 8:00 period is zero ( 208 ) and the printer is in the second standby mode S ( 211 ). Upon receipt of the print command, the controller  12  immediately places the printer in the operating mode T ( 212 ) (this action of the controller occurs independently of the present method). As a general rule, any time that a print command is received the controller  12  will place the printer in the operating mode T regardless of the value of the element for that period. 
     With reference now to FIGS. 4 and 5, when the print command  206  is received in step  108 , the controller determines whether there have been other prints made during this particular period (step  110 ). If the answer to this query were yes, the method would return to the idle state  104  (step  112 ). This insures that when a plurality of print commands are received during a current period, the value of the element for the current period is incremented only once when the first print command is received for that period. Because no other prints were made during this period, the method then determines whether the current period&#39;s element value is equal to either two or three (step  114 ). If the answer to this query were yes, the method would set the value of the current hour&#39;s element to three (step  117 ). But because the current hour&#39;s element ( 208 ) is equal to zero, the method increments the current hour&#39;s element to a value of two (step  119 ), as indicated by element  210  in FIG.  7 . The controller then returns to the idle state  104  (step  112 ). 
     At the next transition between the 8:00 period and the 9:00 period, the value of the 8:00 period element is now two ( 210 ) and the printer is in operating mode T ( 212 ). The value of the element for the next period (9:00) is one ( 214 ). At the end of the 8:00 period an hour message is received at step  106  (FIG. 4) and the controller executes steps  111 ,  113  and  115  of FIG.  6 . With reference to step  115 , because the value of the element of the previous hour ( 210 ) is non-zero, the method proceeds to steps  121  and  122 . In step  122  the method determines whether the values of each of the next three hours&#39; elements are zero. Because the value of the element of the next hour ( 214 ) is non-zero, the method proceeds to step  116  to determine if there was a print in the last hour (8:00). Because there was a print in the last hour, the method advances to step  118  to set the timer for the next hour and then returns to the idle state  104 . Therefore, no change is made at this point to the mode of the printer, which remains in the operating mode T ( 216 ) for the 9:00 period. 
     At approximately 9:50 a print command  219  is received. Turning to step  108  in FIGS. 4 and 5, the method proceeds through steps  108 ,  110 ,  114 ,  119  and  112  to set the current hour&#39;s element value to two ( 218 ) and return to the idle state  104 . At the next transition between the 9:00 period and the 10:00 period, the value of the 9:00 (previous) period element is now two ( 218 ) and the printer remains in operating mode T ( 216 ), while the value of the 10:00 (next) period is zero ( 220 ). At the end of the 9:00 period an hour message is received at step  106  (FIG. 4) and the controller executes steps  111 ,  113  and  115  of FIG.  6 . 
     With reference to step  115 , because the value of the element of the previous hour ( 218 ) is non-zero, the method proceeds to steps  121  and  122  and determines whether the next three hours&#39; elements are zero. In this case, the values of the elements  220 ,  230 ,  232  of each of the next three hours (10:00, 11:00 and 12:00) are zero, and the method proceeds to step  124  to determine if a print has been made in a specified amount of time immediately preceding the period transition. The amount of time may be between about five minutes and about 30 minutes, and is more preferably about 15 minutes. If the answer to this query were No, the method would send a standby command to the printer (step  128 ) to place the printer in the first standby mode (J) or the second standby mode (S). However, because a print was made at 9:50, 10 minutes before the transition, the method sets the “try again” flag ( 222 ) (step  126 ) and proceeds through steps  116 ,  118  and  120  to return to the idle state  104  (the function of the “try again” flag will be explained with reference to the next transition). Thus, the printer remains in the operating mode T ( 224 ) for the next period (10:00). Advantageously, by maintaining the printer in the operating mode T for the next period, step  124  assures that the printer does not “shut down” in the middle of a print job that was received near the end of a period. 
     At the next transition between the 10:00 period and the 11:00 period, the value of the 10:00 (previous) period element has remained at zero ( 220 ) and the printer remains in operating mode T ( 226 ), while the value of the 11:00 (next) period is zero ( 230 ). At the end of the 10:00 period an hour message is received at step  106  (FIG. 4) and the controller proceeds to step  113  of FIG.  6 . Because the value of the element for the next hour is zero (not non-zero), the method proceeds to step  115 . Because the “try again” flag  222  is set, the method proceeds to clear the “try again” flag (step  121 ) and determine whether the next three hours&#39; elements are zero (step  122 ). Because the value of the elements  230 ,  232 ,  234  of each of the next three hours (11:00, 12:00 and 1:00) are zero, the method proceeds to step  124  to determine if a print has been made in the last 15 minutes. Because no print has been made in the last 15 minutes, the method proceeds to step  128  and sends a standby command to the printer. In the preferred embodiment, the standby command of step  128  places the printer in the first standby mode J ( 233 ). 
     The method then proceeds to step  116  to determine if a print was made in the last hour. Because no print was made, the method proceeds to step  140  to determine if the value of the last hour&#39;s element ( 220 ) is zero. Because the value of element  220  is zero, the method proceeds to steps  118  and  120  and returns to the idle state  104 . Thus, the printer enters the 11:00 period in the first standby mode J. 
     At the next two transitions (11:00-12:00 and 12:00-1:00), the method advances through steps  111 ,  113 , 115 ,  116 , 118  and  120 . The values ( 232 ) and ( 234 ) for each of the next two periods remain at zero, and the printer remains in the first standby mode J during these periods. In one embodiment, a timer may be used to change the printer from the first standby mode J to the second standby mode S after a predetermined amount of time in the first standby mode J. For example, where the printer remains in the first standby mode J for one hour, the timer may then signal the printer to enter the second standby mode S. 
     At the transition from 1:00 to 2:00, the value of the 1:00 (previous) period element has remained at zero ( 234 ), while the value of the 2:00 (next) period is two ( 236 ). At the end of the 1:00 period an hour message is received at step  106  (FIG. 4) and the controller proceeds to step  113  of FIG.  6 . Because the value of the element for the previous hour is zero and the value of the next hour&#39;s element is non-zero, the method proceeds to step  150  and sends a wake-up command that changes the printer from the first standby mode J ( 241 ) to the operating mode T ( 243 ). The method then proceeds through steps  116 ,  140 ,  118  and  120  to return to the idle state  104 . Thus, the printer enters the 2:00 period in the operating mode T. 
     At the transition from 2:00 to 3:00, the value of the 2:00 (previous) period element has remained at two ( 238 ), while the value of the 3:00 (next) period is three ( 240 ). At the end of the 2:00 period an hour message is received at step  106  (FIG. 4) and the controller proceeds to step  113  of FIG.  6 . Because the value of the previous hours&#39; element ( 238 ) is non-zero, the method proceeds through steps  113 ,  115  and  121  to step  122 . Because the value of the next hours&#39; element is non-zero, the method proceeds to step  116 . Because a print was not made in the last hour, the method proceeds to step  140 . Because the value of the last hour&#39;s element is not zero but two ( 238 ), the method proceeds to step  142  and the value of the last hour&#39;s element  238  is decremented by one to a value of one ( 242 ). The method then proceeds through steps  118  and  120  to return to the idle state  104 , and the printer remains in the operating mode T ( 250 ) for the next period. Thus, at the end of the 2:00 period the valve of the element for that period ( 242 ) is one. 
     The foregoing description of a preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation. The use of such terms and expressions is not intended to exclude equivalents of the features shown and described or portions thereof. For example, the term “controller” as used herein is intended to include microprocessors, microcomputers, ASICs and dedicated discrete hardware devices serving the function of a controller. Many changes, modifications, and variations in the materials and arrangement of parts can be made, and the invention may be utilized with various different imaging apparatus, all without departing from the inventive concepts disclosed herein. 
     The preferred embodiment was chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as is suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when the claims are interpreted in accordance with breadth to which they are fairly, legally, and equitably entitled.