Patent Publication Number: US-2004046989-A1

Title: Printing management apparatus and printing management method

Description:
BACKGROUND OF THE INVENTION  
       [0001] 1. Field of the Invention  
       [0002] The present invention relates to a printing management apparatus and a printing management method. More specifically the invention pertains to a printing management apparatus that is connected with multiple printing devices for printing images via a network and manages the multiple printing devices through transmission of information via the network, as well as to a corresponding printing management method.  
       [0003] 2. Description of the Prior Art  
       [0004] A proposed printing management apparatus is connected with multiple printing devices via a network and transmits information, for example, a paper consumption, to and from each of the multiple printing devices via the network, thus attaining management of the individual printing devices. This prior art printing management apparatus obtains use information, such as the paper consumption of each printing device, and contributes the use information to calculation of charges for the respective printing devices.  
       [0005] The prior art printing management apparatus, however, does not take into account the quality of printing by each of the printing devices. This results in only insufficient management of the printing devices.  
       SUMMARY OF THE INVENTION  
       [0006] The object of the present invention is thus to remove the drawbacks of the prior art technique and to provide a printing management apparatus and a corresponding printing management method that attain auto check for quality of printing by each of multiple printing devices and thereby ensure adequate management of the multiple printing devices.  
       [0007] In order to achieve above object, a printing management apparatus and a corresponding printing management method of the present invention are structured as follows.  
       [0008] A first printing management apparatus of the present invention is an apparatus that is connected with multiple printing devices, each of which is used to print an image, via a network and manages the multiple printing devices through transmission of information via the network, the printing management apparatus including: a memory unit that stores identification information on each of the multiple printing devices mapped to timing information on a timing of giving an instruction for printing a predetermined image to each of the multiple printing devices; a printing instruction transmission module that transmits printing instruction information, which represents the instruction for printing the predetermined image, at a timing specified by a specific piece of the timing information stored in the memory unit via the network to an object printing device identified by a piece of the identification information mapped to the specific piece of the timing information; a printing result reception module that receives a printing result, which is printed by the object printing device receiving the printing instruction information and is input by an image input device connecting with the object printing device, as image data via the network from the object printing device; and an abnormality check module that checks for abnormality of printing by the object printing device, based on the received image data.  
       [0009] The first printing management apparatus of the present invention provides the memory unit that maps identification information on each of the multiple printing devices connected with the printing management apparatus via the network to timing information on a timing of giving the instruction for printing the predetermined image to each of the multiple printing devices and stores the mapping. The printing management apparatus transmits the printing instruction information, which represents the instruction for printing the predetermined image, at a timing specified by a specific piece of the timing information stored in the memory unit via the network to an object printing device identified by a piece of the identification information mapped to the specific piece of the timing information. The printing management apparatus receives a printing result, which is printed by the object printing device receiving the printing instruction information and is input by an image input device connecting with the object printing device, as image data via the network from the object printing device, and checks for abnormality of printing by the object printing device, based on the received image data. In this structure of the invention, the instruction for printing the predetermined image is given to the object printing device at the timing specified by the specific piece of the timing information. The printing management apparatus receives the image data representing the printing result printed by the object printing device in response to the given instruction and checks for abnormality of printing by the object printing device. This arrangement attains auto check for abnormality of printing by each of the multiple printing devices and thus ensures adequate management of the multiple printing devices.  
       [0010] In the first printing management apparatus of the present invention, as one aspect, the memory unit may store original data of the predetermined image, and the abnormality check module may check for abnormality of printing, based on the received image data and the original data stored in the memory unit.  
       [0011] The first printing management apparatus of the invention, as another aspect, may further include an output setting information reception module that receives output setting information on an output setting of the object printing device for printing the predetermined image via the network from the object printing device, and in the first printing management apparatus of the invention, the abnormality check module may check for abnormality of printing, based on the image data received by the printing result reception module and the output setting information received by the output setting information reception module. In this case, the first printing management apparatus of the invention may further include a tolerance setting module that specifies a tolerance of deviation from original data of the predetermined image, based on the output setting information received by the output setting information reception module, and in the first printing management apparatus, the memory unit may further store the original data of the predetermined image, and the abnormality check module may determine whether the image data received by the printing result reception module is within the specified tolerance of deviation from the original data. Here, the output setting information may be information on setting of an output resolution.  
       [0012] The first printing management apparatus of the invention, as still another aspect, may include an input setting information reception module that receives input setting information on an input setting of the image input device for inputting the predetermined image printed by the object printing device via the network from the object printing device, and in the first printing management apparatus of the invention, the abnormality check module may check for abnormality of printing, based on the image data received by the printing result reception module and the input setting information received by the input setting information reception module. In this case, the first printing management apparatus may further include a tolerance setting module that specifies a tolerance of deviation from original data of the predetermined image, based on the input setting information received by the input setting information reception module, and in the first printing management apparatus the memory unit may further store the original data of the predetermined image, and the abnormality check module may determine whether the image data received by the printing result reception module is within the specified tolerance of deviation from the original data. Here, the input setting information may be information on setting of an input resolution.  
       [0013] In the first printing management apparatus of the invention, as still another aspect, the memory unit may further store information including a reference time, which is updated at a preset timing, as the timing information, and the printing instruction transmission module may transmit the printing instruction information when a preset time period has elapsed since a latest reference time stored in the memory unit. Here, the memory unit may store information including a latest time, when printing of the predetermined image was executed by the object printing device, as the timing information or a latest time, when general printing was executed by the object printing device, as the timing information.  
       [0014] The first printing management apparatus of the invention, as still another aspect, may further include a use information reception module that receives use information on use of the object printing device, from the object printing device, and in the first printing management apparatus of the invention, the memory unit may store the received use information mapped to identification information of the object printing device, which has sent the use information, and the printing instruction transmission module may transmit the printing instruction information to the object printing device identified by the identification information, which is mapped to the use information and the timing information stored in the memory unit, based on the use information and the timing information. In this case, the memory unit may store information including a latest time, when printing of the predetermined image was executed by the object printing device, as the timing information, and the use information reception module may receive a total printing volume of the object printing device since the stored latest time as the use information. Further, in this case, the printing instruction transmission module may transmit the printing instruction information to the object printing device, when the total printing volume of the object printing device since the latest time stored in the memory unit has reached a preset level.  
       [0015] The first printing management apparatus of the invention, as still another aspect, may include a check result notification module that notifies a result of the check carried out by the abnormality check module.  
       [0016] The first printing management apparatus of the invention, as still another aspect, may further include a maintenance instruction output module that outputs a maintenance instruction on maintenance of the object printing device, according to a result of the check for abnormality of printing by the printing device, which is carried out by the abnormality check module.  
       [0017] The first printing management apparatus of the invention, as still another aspect, may further include a stop instruction output module that outputs a stop instruction on a stop of printing to the object printing device, when the abnormality check module detects abnormality of the object printing device.  
       [0018] A second printing management apparatus of the present invention is an apparatus that is connected with multiple printing devices, each of which is used to print an image, via a network and manages the multiple printing devices through transmission of information via the network, the printing management apparatus including: a printing instruction module that gives an instruction for printing a predetermined image to an object printing device; a printing result acquisition module that acquires a printing result, which is printed by the object printing device receiving the instruction and is input by an image input device connecting with the object printing device, as image data from the object printing device; and an abnormality check module that checks for abnormality of printing by the object printing device, based on the acquired image data.  
       [0019] The second printing management apparatus of the present invention gives the instruction for printing the predetermined image to an object printing device, acquires a printing result, which is printed by the object printing device receiving the instruction and is input by an image input device connecting with the object printing device, as image data from the object printing device, and checks for abnormality of printing by the object printing device, based on the acquired image data. This arrangement attains auto check for quality of printing by the object printing device, based on the image data or the printing result of the predetermined image printed by the object printing device and input by the image input device.  
       [0020] In the second printing management apparatus of the invention, as one aspect, the abnormality check module may check for abnormality of printing, based on the acquired image data and original data of the predetermined image.  
       [0021] The second printing management apparatus of the invention, as another aspect, may further include an output setting information acquisition module that acquires output setting information on an output setting of the object printing device for printing the predetermined image via the network from the object printing device, and in the second printing management apparatus of the invention, the abnormality check module may check for abnormality of printing, based on the image data acquired by the printing result acquisition module and the output setting information acquired by the output setting information acquisition module. In this case, the second printing management apparatus of the invention may further include a tolerance setting module that specifies a tolerance of deviation from original data of the predetermined image, based on the output setting information acquired by the output setting information acquisition module, and in the second printing management apparatus of the invention, the abnormality check module may determine whether the image data acquired by the printing result acquisition module is within the specified tolerance of deviation from the original data. Here, the output setting information may be information on setting of an output resolution.  
       [0022] The second printing management apparatus of the invention, as still another aspect, may further include an input setting information acquisition module that acquires input setting information on an input setting of the image input device for inputting the printing result of the predetermined image printed by the object printing device via the network from the object printing device, and in the second printing management apparatus of the invention, the abnormality check module may check for abnormality of printing, based on the image data acquired by the printing result acquisition module and the input setting information acquired by the input setting information acquisition module. In this case, the second printing management apparatus of the invention may further include a tolerance setting module that specifies a tolerance of deviation from original data of the predetermined image, based on the input setting information acquired by the input setting information acquisition module, and in the second printing management apparatus of the invention, the abnormality check module may determine whether the image data acquired by the printing result acquisition module is within the specified tolerance of deviation from the original data. Here, the input setting information may be information on setting of an input resolution.  
       [0023] The technique of the invention is not restricted to the printing management apparatus discussed above, but is also applicable to a printing management method.  
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0024]FIG. 1 schematically illustrates the structure of a printing management system  20  including a printing management apparatus  30  in one embodiment of the present invention;  
     [0025]FIG. 2 is a flowchart showing an information input routine executed by the printing management apparatus  30  of the embodiment;  
     [0026]FIG. 3 shows one example of the expendable consumption data;  
     [0027]FIG. 4 shows one example of the printing execution data;  
     [0028]FIG. 5 is a flowchart showing a test printing instruction routine executed by the printing management apparatus  30  of the embodiment;  
     [0029]FIG. 6 is a flowchart showing a print diagnosis routine executed by the printing management apparatus  30  of the embodiment;  
     [0030]FIG. 7 is a flowchart showing a printing abnormality check routine;  
     [0031]FIG. 8 shows an example of a nozzle clogging test pattern image; and  
     [0032]FIG. 9 shows one example of a head position deviation test pattern image. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
     [0033] A preferred embodiment of the present invention is discussed below. FIG. 1 schematically illustrates the structure of a printing management system  20  including a printing management apparatus  30  in one embodiment of the invention. As illustrated, the printing management apparatus  30  of the embodiment is constructed as a network server of a single or multiple computers. The printing management apparatus  30  has functions of a, printing management server that acquires data regarding consumption of expendables (hereafter referred to as expendable consumption data) and data regarding execution of printing (hereafter referred to as printing execution data) from multiple printing devices  50   a  and  50   b,  which connect with the printing management apparatus  30  via a network  22 , at regular intervals and transfers the acquired expendable consumption data to a jurisdiction management server  40 , which manages supplies of expendables to the multiple printing devices  50   a  and  50   b  and maintenance of the multiple printing devices  50   a  and  50   b.  The printing management apparatus  30  also functions to give an instruction for printing a preset test pattern image for the purpose of checking the printing quality to each of the printing devices  50   a  and  50   b  based on the printing execution data and to check for abnormality of printing by each printing device based on a printing result of the preset test pattern image by the corresponding printing device in response to the given instruction. The printing management apparatus  30  includes a single or multiple computers to attain such functions. The printing management apparatus  30  has a receiver transmitter module  31   a  that receives and transmits information via the network  22 , an abnormality check module  31   b  that checks for abnormality of printing by each of the multiple printing devices  50   a  and  50   b  connected via the network  22 , an expendable consumption database  32  that stores the expendable consumption data in the form of a database, and a printing execution database  34  that stores the printing execution data in the form of a database.  
     [0034] The jurisdiction management server  40  is installed in each jurisdictional region or block (a block A or a block B in the illustrated example) and functions to manage supplies of expendables to the printing devices  50   a  and  50   b  located at photo studios in each block, as well as maintenance of the printing devices  50   a  and  50   b.  The jurisdiction management server  40  outputs supply instructions and maintenance instructions to a computer  42  of an expendable supply/maintenance organization, so as to keep predetermined stocks of expendables including printing papers and inks at the respective photo studios based on the expendable consumption data transferred from the printing management apparatus  30  and to ensure execution of adequate maintenance of the printing devices  50   a  and  50   b  at the respective photo studios based on maintenance data transferred from the printing management apparatus  30 .  
     [0035] Each of the printing devices  50   a  and  50   b  includes multiple ink jet printers, where each ink jet printer makes inks like pigment inks ejected from a number of nozzles to print an image on printing paper. Scanners  52   a  and  52   b  as image input devices to read and input the image printed on the printing paper as image data are connected respectively to the printing devices  50   a  and  50   b.  Each of the printing devices  50   a  and  50   b  transmits the image data input by the scanner  52   a  or  52   b  to the printing management apparatus  30  via the network  22 . Each of the printing devices  50   a  and  50   b  is capable of printing a preset test pattern image to check for abnormality of printing, for example, clogging of ink or a displacement of the head position, in response to an instruction given by the information management apparatus  30  of the embodiment. Original data used for printing the preset test pattern image is stored in non-illustrated memories of the printing devices  50   a  and  50   b  in the embodiment.  
     [0036] The printing management system  20  thus constructed carries out series of processing discussed below. FIG. 2 is a flowchart showing an information input routine executed by the printing management apparatus  30  of the embodiment. This information input routine is carried out iteratively at preset time intervals (for example, at every 12 hours). When the program enters the information input routine, the printing management apparatus  30  first inputs printing device-related information, which includes the expendable consumption data and the printing execution data described above, from each of the printing devices  50   a  and  50   b  in each block connecting with the printing management apparatus  30  via the network  22  (step S 100 ), and registers the input expendable consumption data into the expendable consumption database  32  while registering the input printing execution data into the printing execution database  34  (step S 102 ).  
     [0037]FIG. 3 shows one example of the expendable consumption data registered in the expendable consumption database  32 , and FIG. 4 shows one example of the printing execution data registered in the printing execution database  34 . As shown in FIG. 3, the expendable consumption data includes a ‘printing device ID’ as information for identifying each of the printing devices  50   a  and  50   b,  a ‘jurisdiction management server ID’ as information for identifying the jurisdiction management server  40  that has jurisdiction over the printing device  50   a  or  50   b,  a ‘data acquisition date’ representing the date when data is acquired from the printing device  50   a  or  50   b,  ‘printer IDs’ as information for identifying respective printers incorporated in the printing device  50   a  or  50   b,  ‘paper consumptions’ representing consumptions of respective printing papers, ‘ink consumptions’ representing consumptions of respective color inks, and ‘ink cartridge stocks’ representing stocks of ink cartridges of respective colors used for printing. The printing execution data, on the other hand, includes a ‘latest printing execution date’ representing a latest date when printing (general printing) is carried out by the corresponding printing device, a ‘latest test printing instruction date’ representing a latest date when an instruction for printing a test pattern image is given to the corresponding printing device, a ‘latest test printing execution date’ representing a latest date when printing of the test pattern image is carried out by the corresponding printing device, a ‘total paper consumption’ representing a total consumption of printing paper by the corresponding printing device after the ‘latest test printing execution date’, a ‘total ink consumption’ representing a total consumption of ink by the corresponding printing device after the ‘latest test printing execution date’, and ‘test pattern image original data’ that is identical with the original data of the test pattern image stored in the memory of the corresponding printing device, in addition to the ‘printing device ID’, the ‘jurisdiction management server ID’, the ‘data acquisition date’, and the ‘printer IDs’ discussed above. Among the printing execution data registered in the printing execution database  34 , the ‘latest test printing instruction date’ is updated every time the printing management apparatus  30  of the embodiment gives an instruction for printing the test pattern image to the corresponding printing device. The ‘total paper consumption’ and the ‘total ink consumption’ are obtained by summing up the ‘paper consumptions’ and the ‘ink consumptions’ received from the corresponding printing device  50   a  or  50   b  after the ‘latest test printing execution date’.  
     [0038] After registration of the expendable consumption data and the printing execution data respectively into the expendable consumption database  32  and into the printing execution database  34 , the expendable consumption data is output to the jurisdiction management server  40  (step S 104 ). The program then exits from this information input routine. The jurisdiction management server  40  instructs the expendable supply/maintenance organization located in the jurisdictional block to supply required expendables to the respective printing devices  50   a  and  50   b,  based on the input expendable consumption data.  
     [0039] The following describes a series of processing executed by the printing management apparatus  30  of the embodiment based on the printing execution data, more specifically a series of processing to give an instruction for printing a preset test pattern image to each of the printing devices  50   a  and  50   b.  FIG. 5 is a flowchart showing a test printing instruction routine executed by the printing management apparatus  30  of the embodiment. This test printing instruction routine is repeatedly carried out at preset time intervals (for example, at every  24  hours). When the program enters this test printing instruction routine, the printing management apparatus  30  first extracts the ‘latest test printing instruction date’, the ‘latest printing execution date’, and the ‘total paper consumption after the latest test printing execution date’ from the printing execution data registered in the printing execution database  34  with regard to each of the printing devices  50   a  and  50   b  (each printing device ID) connected via the network  22  (step S 200 ). It is then determined whether at least a preset time period (for example, at least 1 month) has elapsed since the ‘latest test printing instruction date’, that is, whether non-execution of printing the test pattern image has continued for at least the preset time period (step S 202 ). It is also determined whether at least a specified time period (for example, at least 1 month) has elapsed since the ‘latest printing execution date’, that is, whether non-execution of general printing has continued for at least the specified time period (step S 204 ). It is further determined whether the ‘total paper consumption after the latest test printing execution date’ has reached at least a preset number of sheets (for example, at least 100 sheets) (step S 206 ). When none of the conditions is fulfilled, that is, when it is determined that the preset time period has not yet elapsed since the ‘latest test printing instruction date’, that the specified time period has not yet elapsed since the ‘latest printing execution date’, and that the ‘total paper consumption after the latest test printing execution date’ has not yet reached the preset number of sheets, there is no necessity of printing the test pattern image. The program thus immediately exits from the test printing instruction routine.  
     [0040] When any of the conditions is fulfilled, that is, when it is determined that the preset time period has elapsed since the ‘latest test printing instruction date’, that the specified time period has elapsed since the ‘latest printing execution date’, or that the ‘total paper consumption after the latest test printing execution date’ has reached the preset number of sheets, on the other hand, there is a necessity of printing the test pattern image. The printing management apparatus  30  accordingly transmits printing instruction data representing an instruction for printing the test pattern image to the corresponding printing device (step S 208 ), and updates the ‘latest test printing instruction date’ to the current transmission date of the printing instruction data, while clearing the ‘total paper consumption after the latest test printing execution date’ to zero (step S 210 ). The program then exits from this test printing instruction routine. The printing device receiving the printing instruction data reads the original data of the test pattern image stored in the built-in memory and prints the test pattern image on the printing paper. The printing device then reads the printed test pattern image with the scanner connected thereto and transmits this test pattern image as image data to the printing management apparatus  30  of the embodiment. The printing device also transmits setting data related to printing of the test pattern image (setting data on an output resolution of the printing device in the embodiment) and setting data related to reading of the test pattern image printed on the printing paper as image data (setting data on an input resolution of the scanner in the embodiment) to the printing management apparatus  30  of the embodiment. The printing management apparatus  30  of the embodiment waits for transmission of the image data, the setting data on the output resolution of the printing device, and the setting data on the input resolution of the scanner.  
     [0041] The following describes a series of processing executed by the printing management apparatus  30  of the embodiment, in response to transmission of the image data and the setting data on the input resolution and the output resolution. FIG. 6 is a flowchart showing a print diagnosis routine executed by the printing management apparatus  30  of the embodiment. The printing management apparatus  30  executes this routine, when receiving a signal representing transmission of the image data and the setting data on the input resolution and the output resolution from each printing device. When the program enters this print diagnosis routine, the printing management apparatus  30  of the embodiment first receives the image data obtained by reading the printing result of the test pattern image with the scanner, the setting data on the output resolution of the printing device for printing the test pattern image, and the setting data on the input resolution of the scanner for reading the test pattern image printed on the printing paper (step S 300 ), and carries out a printing abnormality check process, based on the received image data and setting data on the input resolution and the output resolution (step S 302 ). The printing abnormality check process follows the flowchart of FIG. 7.  
     [0042] When the printing abnormality check process starts, the printing management apparatus  30  of the embodiment first specifies a tolerance of deviation of the image data from the original data of the test pattern image, which is used as the standard in check for abnormality of printing, based on the setting data on the output resolution of the printing device and the setting data on the input resolution of the scanner (step S 310 ). The tolerance of deviation is specified to prevent a false detection of abnormal printing, due to a difference between the information volume of the original data of the test pattern image and the information volume of the image data of the test pattern image that is printed according to the original data by the printing device and is read by the scanner.  
     [0043] When the output resolution (effective resolution) of the printing device and the input resolution of the corresponding scanner are set to be not less than a specific resolution level corresponding to a specific information volume equivalent to the information volume of the original data of the test pattern image (specifically, when the settings of both the output resolution of the printing device and the input resolution of the corresponding scanner are not less than the specific resolution level corresponding to the specific information volume equivalent to the information volume of the original data of the test pattern image), the information volume of the image data of the test pattern image printed by the printing device and read by the scanner is practically equal to the information volume of the original data of the test pattern image. In the normal printing state of the printing device, pixels constituting the image data of the test pattern image printed by the printing device and read by the corresponding scanner are substantially identical with pixels constituting the original data of the test pattern image. The normal printing state of the object printing device is thus detectable, based on the image data read by the scanner. On the other hand, when the output resolution of the printing device or the input resolution of the corresponding scanner is set to a certain resolution level corresponding to a certain information volume less than the information volume of the original data of the test pattern image (specifically, when the setting of the output resolution of the printing device is not less than the specific resolution level corresponding to the specific information volume equivalent to the information volume of the original data of the test pattern image but the setting of the input resolution of the corresponding scanner is the certain resolution level corresponding to the certain information volume less than the information volume of the original data of the test pattern image, when the setting of the input resolution of the scanner is not less than the specific resolution level corresponding to the specific information volume equivalent to the information volume of the original data of the test pattern image but the setting of the output resolution of the corresponding printing device is the certain resolution level corresponding to the certain information volume less than the information volume of the original data of the test pattern image, or when the settings of both the output resolution of the printing device and the input resolution of the corresponding scanner are the certain resolution level corresponding to the certain information volume less than the information volume of the original data of the test pattern image), the information volume of the image data of the test pattern image printed by the printing device and read by the corresponding scanner is less than the information volume of the original data of the test pattern image. Even in the normal printing state of the printing device, pixels constituting the image data of the test pattern image input by the corresponding scanner are not identical with pixels constituting the original data of the test pattern image. This may cause a false detection of abnormal printing by the printing device. Specifying the tolerance of deviation from the original data of the test pattern image as the standard according to the output resolution of the printing device and the input resolution of the corresponding scanner absorbs the difference in information volume between the original data of the test pattern image and the image data of the test pattern image printed by the printing device and read by the corresponding scanner. This arrangement thus ensures accurate print diagnosis of the printing device, based on the image data of the test pattern image read by the scanner.  
     [0044] After setting the tolerance of deviation for print diagnosis, it is determined whether the image data of the test pattern image input at step S 300  is within the specified tolerance of deviation (step S 312 ). When it is determined that the image data is within the tolerance of deviation, printing by the object printing device is determined as normal (step S 314 ). When it is determined that the image data is out of the tolerance of deviation, on the other hand, printing by the object printing device is determined as abnormal (step S 316 ). The program then exits from this printing abnormality check routine. The printing abnormality check process id described more with a concrete example of a test for clogging of nozzles in the printing device.  
     [0045]FIG. 8 shows an example of a nozzle clogging test pattern image used to test for clogging of nozzles in the printing device. In this illustrated example, when the test pattern printed by the object printing device has no blot or dropout but forms continuous lines as shown in FIG. 8( a ), it is determined that nozzles have no clogging but are normal. When the printed test pattern has any blot or dropout as shown in FIG. 8( b ), on the other hand, it is determined that nozzles have clogging and are abnormal. The image data are obtained by reading the nozzle clogging test pattern image, which is printed by the printing device, with the corresponding scanner. Pixels corresponding to the blot or the dropout of the printed test pattern image are not recognized as the pixels constituting the image data of the test pattern image read by the scanner. The image data of the test pattern image read by the scanner is thus inconsistent with the original data of the test pattern image. Clogging of the nozzles is thus detected in this case. When a difference of one pixel is specified as the tolerance of deviation from the original data of the test pattern image based on the output resolution of the printing device and the input resolution of the corresponding scanner, a discrepancy of one pixel is allowed. Printing by the object printing device  50   a  or  50   b  is accordingly determined as normal, unless there is a discrepancy of two or more consecutive pixels (that is, unless there are two or more consecutive pixels unrecognized as the test pattern). In the process of testing for clogging of nozzles, it is desirable to specify a greater tolerance of deviation with a decrease in information volume relative to the information volume of the original data of the test pattern image, that is, with a decrease in resolution. The tolerance of deviation may be set equal to 0, when high resolutions are required.  
     [0046] On conclusion of the printing abnormality check routine of FIG. 7, the program goes back to step S 304  in the print diagnosis routine of FIG. 6. The object printing device is notified of the check result obtained by the printing abnormality check routine of FIG. 7 (step S 304 ), and maintenance data (for example, data representing a fixation procedure corresponding to the place of abnormality) according to the check result is output to the jurisdiction management server  40  (step S 306 ). The program then exits from this print diagnosis routine. The jurisdiction management server  40  receives the transmitted maintenance data and manages execution of maintenance by the expendable supply/maintenance organization with regard to the object printing device at the photo studio in the jurisdictional block, based on the received maintenance data.  
     [0047] As discussed above, when at least the preset time period has elapsed since the latest instruction for printing the test pattern image was given to each object printing device  50   a  or  50   b  connecting with the network  22 , when at least the specified time period has elapsed with no execution of general printing by the object printing device  50   a  or  50   b,  or when the total paper consumption has reached at least the preset number of sheets after the latest printing execution date of the test pattern image with the object printing device  50   a  or  50   b,  the printing management apparatus  30  of the embodiment transmits a new instruction for printing the test pattern image to the object printing device  50   a  or  50   b.  The printing management apparatus  30  receives the image data of the test pattern image printed by the object printing device, which has received the instruction, and read by the corresponding scanner via the network  22  and compares the received image data with the original data of the test pattern image registered in the printing execution database  34  to check for abnormality of printing by the object printing device. This arrangement enables the printing management apparatus  30  to transmit the instruction for printing the test pattern image at an adequate timing and ensures auto check for the printing quality by the object printing device  50   a  or  50   b.  The printing management apparatus  30  notifies the object printing device of the check result, while outputting maintenance information corresponding to the check result to the jurisdiction management server  40  having jurisdiction over the object printing device, so as to take action adequate for the check result. The printing management apparatus  30  of the embodiment checks for abnormality of printing by each printing device  50   a  or  50   b  by taking into account the output resolution of the printing device  50   a  or  50   b  in the process of printing the test pattern image and the input resolution of the corresponding scanner  52   a  or  52   b  in the process of inputting the printing result of the test pattern image by the printing device  50   a  or  50   b  as image data. This arrangement effectively prevents a false detection of abnormal printing.  
     [0048] The printing management apparatus  30  of the embodiment performs the nozzle clogging test of each printing device  50   a  or  50   b  as one example of the print diagnosis. The printing management apparatus  30  may be used for other print diagnoses, for example, test for a deviation of the head position. FIG. 9 shows one example of a head position deviation test pattern image used to test for a deviation of the head position in the printing device. In this illustrated example, when each vertical line of the test pattern printed by the object printing device is aligned straight as shown in FIG. 9( a ), it is determined that the head position has no deviation but is normal. When each vertical line of the printed test pattern is misaligned as shown in FIG. 9( b ), on the other hand, it is determined that the head position has a deviation and is abnormal. The image data are obtained by reading the head position deviation test pattern image, which is printed by the printing device, with the corresponding scanner. In the case where pixels constituting the image data read by the scanner include pixels corresponding to the misalignment of each line in the test pattern image, the image data of the test pattern image input by the scanner is inconsistent with the original data of the test pattern image. A deviation of the head position is thus detected in this case. When a deviation of one pixel is specified as a tolerance based on the output resolution of the printing device and the input resolution of the corresponding scanner, a discrepancy of one pixel is allowed. When an adjoining pixel to the deviation is recognized as a constituent pixel of the test pattern image, printing by the object printing device is determined as normal. In the process of testing for a deviation of the head position, it is desirable to specify a greater tolerance with a decrease in information volume relative to the information volume of the original data of the test pattern image, that is, with a decrease in resolution. The tolerance may be set equal to 0, when high resolutions are required.  
     [0049] The printing management apparatus  30  of the embodiment specifies the tolerance based on the output resolution of the printing device and the input resolution of the scanner. When the printing device used is capable of printing the test pattern image with a sufficiently high resolution, the tolerance may be specified based on only the input resolution of the scanner. When the scanner used is capable of reading the test pattern image with a sufficiently high resolution, on the other hand, the tolerance may be specified based on only the output resolution of the printing device. No tolerance may be specified, when the printing device used is capable of printing the test pattern image with a sufficiently high resolution and the scanner used is capable of reading the test pattern image with a sufficiently high resolution.  
     [0050] The printing management apparatus  30  of the embodiment gives the instruction for printing the test pattern image to the corresponding printing device, based on the results of determination of whether at least the preset time period has elapsed since the ‘latest test printing instruction date’, determination of whether at least the specified time period has elapsed since the ‘latest printing execution date’, and determination of whether the ‘total paper consumption after the latest test printing execution date’ has reached at least the preset number of sheets. The instruction for printing the test pattern may alternatively be given, based on only one of such determination results or based on any combination of such determination results. Determination of whether the ‘total ink consumption after the latest test printing execution date’ has reached at least a preset quantity may be used in place of or in combination with the determination relating to the ‘total paper consumption after the latest test printing execution date’. The determination of whether at least the preset time period has elapsed since the ‘latest test printing instruction date’ may be replaced by determination of whether at least a predetermined time period has elapsed since the ‘latest test printing execution date’ or determination of whether at least a preset time period has elapsed since reception of the image data read by the scanner as the printing result of the test pattern image. The instruction for printing the test pattern image may be given, in response to reception of a request from the object printing device or in response to reception of a signal representing replacement of an ink cartridge from the object printing device. In the printing management apparatus  30  of the embodiment, the date is the unit of the criteria like the ‘latest test printing instruction date’, the ‘latest test printing execution date’, and the ‘latest printing execution date’. The unit of the criteria may be the week or the month. Another modified arrangement gives an instruction for cleaning the printing device (for example, cleaning the head), together with the instruction for printing the test pattern image and instructs the printing device to print the test pattern image on completion of the cleaning.  
     [0051] The printing management apparatus  30  of the embodiment notifies each object printing device of the check result for abnormality of printing by the printing device. One modified arrangement may output a print stop instruction to the object printing device according to the seriousness of the abnormality. This arrangement desirably prevents printing from being carried out by the printing device in the abnormal state.  
     [0052] In the structure of the embodiment, the jurisdiction management server  40  is located in each block and manages supplies of expendables to the printing devices  50   a  and  50   b  in the jurisdictional block as well as maintenance of the printing devices  50   a  and  50   b  by the expendable supply/maintenance organization. The printing management apparatus  30 , in place of each jurisdiction management server, may alternatively consolidate the management.  
     [0053] The above description regards the printing management apparatus  30  in one embodiment of the invention. The invention may also be actualized by a printing management method or by a storage medium in which a program for causing a single or multiple computers to attain the functions of the printing management apparatus  30  is stored. In the latter application, the program is installed from the storage medium into a memory device of the computer and is executed appropriately to exert the effects of the printing management apparatus  30  discussed above.  
     [0054] The above embodiment embodiment is to be considered in all aspects as illustrative and not restrictive. There may be many modifications, changes, and alterations without departing from the scope or spirit of the main characteristics of the present invention. All changes within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.