Patent Publication Number: US-2007103726-A1

Title: Control of distributed printing with multiple printers

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
      This application is a continuation of U.S. patent application Ser. No. 09/980,111, filed Nov. 30, 2001, the disclosure of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD  
      The present invention relates to a technique of outputting print data of interest, which are to be printed, to multiple printers in a distributive manner.  
     BACKGROUND ART  
      Recent advancement of the computer network enables a plurality of printers to be readily connected to one information processing apparatus like a personal computer. In the structure where one information processing apparatus connects with multiple printers, print data generated by the information processing apparatus may be output to the respective printers in a distributive manner. When there is a large mass of print data, it takes an undesirably long time to complete printing with only one printer. Output of the print data to multiple printers in a distributive manner desirably shortens the total time required for printing.  
      The prior art technique has a variety of operatability-related problems discussed below.  
      Problems Regarding Operatability of Printing  
      The prior art technique requires the operator to adequately divide a document to be printed and individually output a print command to the multiple printers. This makes the series of operations significantly complicated and leads to poor operatability and insufficiently shortened printing time.  
      It is thus highly demanded to attain the good operatability and the high-speed distributed printing.  
      Problems Regarding Acquisition of Favorable Resulting prints  
      In the prior art technique, it is required to set various pieces of information in an information processing apparatus for distributed printing. The various pieces of information to be set include information on the printer names for identifying printers specified as destinations of distribution and paper-related information like the paper size and the paper type. A data input window is open on a display, and the operator inputs data on the window through operations of a keyboard and a mouse, so as to set the required pieces of information.  
      The information processing apparatus notifies each printer specified by the printer name of information regarding the printing performance of the printer, such as the paper-related information, prior to actual distributive output of the print data to the respective printers. Each printer prepares for printing to satisfy the paper-related information, based on such notification. The information processing apparatus then outputs the print data to each printer that has been ready for printing.  
      In this prior art arrangement, the setting with regard to the paper-related information may be out of the range of the printing performance possessed by a certain printer specified as the destination of distribution. For example, A3 may be set to the paper size, while the certain printer specified as the destination of distribution is capable of printing up to the size A4. The printing requirement with the A3 paper to the printer having the printing performance of up to the size A4 does not ensure the favorable resulting print from the printer.  
      It is accordingly demanded to adequately set various pieces of information, such as the paper-related information, and thereby ensure preferable resulting prints.  
      Problems Regarding Coincidence of Printing Area  
      In the prior art technique, when the multiple printers specified as destinations of distribution are of different types, printing on sheets of an identical size with different printers does not ensure an identical printing area on the sheets. This causes some irregularity in resulting prints. Each printer has an unprintable area on the paper area, and the size of the unprintable area depends upon the type of the printer. This leads to a variation in printable area among different types of printers. Here the unprintable area represents any area that does not allow printing, due to the relation of the sheet feed mechanism to paper, for example, a lower end or a right end of the paper.  
      It is accordingly demanded to enable resulting prints having a perfectly identical size and position of the printing area to be obtained from the multiple printers specified as the destinations of distribution.  
     DISCLOSURE OF THE INVENTION  
      The object of the present invention is thus to solve at least part of the above problems and to ensure favorable resulting prints with good operatability.  
      The present invention is directed to a first distributed printing control apparatus, which includes: a data allocation module that divides print data, which is an object to be printed, by page and specifies information representing pages allocated to multiple printers; and a data output control module that outputs the print data in a distributive manner to the multiple printers according to the information specified by the data allocation module. The first distributed printing control apparatus is capable of printing multiple copies of the print data according to a requirement. The data allocation module arranges pages included in each copy in a sequence of the pages, divides all the pages of the multiple copies into the number of the multiple printers specified as destinations of distribution, and allocates respective divisions to the multiple printers. The data output control module carries out the distributive output of the print data to the multiple printers in a substantially parallel manner, the data output control module converting the print data of each page, sequentially from a head page of each division, to a format suitable for each printer specified as the destination of distribution and then performing each distributive output.  
      In the first distributed printing control apparatus of the above construction, the data allocation module specifies allocation of the respective pages of the print data to the multiple printers. The operator is thus not required to individually output the print command to each of the printers specified as the destinations of distribution. This arrangement thus ensures favorable operatability. In this first distributed printing control apparatus the distributive output of the print data to the respective printers is performed in a substantially parallel manner. The data output control module converts the print data of each page, sequentially from a head page of each division, to a format suitable for each printer specified as the destination of distribution and then performing each distributive output.  
      The technique of the present invention carries out the series of processing to obtain the print data of the head page adequate for the respective printers sequentially: that is, the head page allocated to the first printer, the head page allocated to the second printer, and the head page allocated to the third printer. While the series of processing is executed for the head page allocated to the second printer, the print data obtained as the result of the processing for the head page allocated to the first printer is output to the first printer. The process of generating the print data adequate for a certain printer is thus carried out in parallel with the process of outputting the previously obtained data to another printer. Compared with the prior art technique, this technique effectively shortens the total time required for printing.  
      In accordance with one preferable application, the first distributed printing control apparatus further includes: a virtual printer driver storage module that stores a virtual printer driver for specifying information on a virtual printer corresponding to the multiple printers; and an intermediate print data generation module that executes the virtual printer driver and thereby obtains intermediate print data, which is adequate for the virtual printer, from an application program that generates source data of the print data. The intermediate print data thus obtained is specified as the print data used in the data allocation module and the data output control module.  
      In the first distributed printing control apparatus with the virtual printer driver, the intermediate print data is obtained by outputting only one print command from the application program to the virtual printer driver. The distributed printing of the intermediate print data to the respective printers is carried out automatically. The operator is thus required to carry out only one series of printing operation on the application program. This arrangement effectively ensures excellent operatability.  
      The present invention is also directed to a second distributed printing control apparatus, which includes: a data allocation module that divides print data, which is an object to be printed, by page and specifies information representing pages allocated to multiple printers; a data output control module that outputs the print data in a distributive manner to the multiple printers according to the information specified by the data allocation module; and a printer speed performance detection module that detects a performance on a printing speed of each of the multiple printers. The data allocation module specifies the pages allocated to the multiple printers according to the performance on the printing speed of each printer detected by the printer speed performance detection module.  
      In the second distributed printing control apparatus of the above construction, the data allocation module specifies allocation of the respective pages of the print data to the multiple printers. The operator is thus not required to individually output the print command to each of the printers specified as the destinations of distribution. This arrangement thus ensures favorable operatability. In this second distributed printing control apparatus, the number of pages to be allocated to each of the multiple printers is specified according to the performance information on the printing speed of each printer. This arrangement enables the printer with the high printing speed performance to print a large number of pages, while causing the printer with the low printing speed performance to print a small number of pages. This makes the respective printers conclude the printing operations almost simultaneously, thus effectively shortening the total time required for printing.  
      In accordance with one preferable application, the second distributed printing control apparatus further includes a distribution information setting module that causes an input window to be displayed on a display device and sets various pieces of information regarding distribution of the print data based on input data from an input device. The data allocation module specifies the pages allocated to the multiple printers, based on the various pieces of information set by the distribution information setting module. The distribution information setting module has a display control module that generates an illustrated image, which includes an arrangement of printing media and corresponds to the information specified by the data allocation module, based on the various pieces of information and causes the illustrated image to be displayed on the display device.  
      The operator sees the illustrated image displayed by the display control module and is thereby informed of the form of distributed printing in the process of setting the various pieces of distribution-related information in the input window. This visually informs the operator of the distributed form prior to actual execution of the distributed printing, thus further enhancing the operatability.  
      The present invention is further directed to a third distributed printing control apparatus, which includes: a data allocation module that divides print data, which is an object to be printed, by page and specifies information representing pages allocated to multiple printers; and a data output control module that outputs the print data in a distributive manner to the multiple printers according to the information specified by the data allocation module. The data allocation module specifies number of pages to be allocated to each of the multiple printers, such that each specified set of pages are printed with an identical printer.  
      In the third distributed printing control apparatus of the above construction, the data allocation module specifies allocation of the respective pages of the print data to the multiple printers. The operator is thus not required to individually output the print command to each of the printers specified as the destinations of distribution. This arrangement thus ensures favorable operatability. In this third distributed printing control apparatus, the number of pages to be allocated to each of the multiple printers is specified, such that each specified set of pages are printed with an identical printer. The resulting print obtained from each printer that has concluded the printing operation is the specified set of pages. This arrangement thus ensures excellent operatability in collection of resulting prints.  
      In accordance with one preferable application, the third distributed printing control apparatus further includes a printer speed performance detection module that detects a performance on a printing speed of each of the multiple printers. The data allocation module specifies the number of pages to be allocated to each printer, such that each specified set of pages are printed with an identical printer, in response to an externally input predetermined first command. Otherwise the data allocation module specifies the number of pages to be allocated to each printer according to the performance on the printing speed of each printer detected by the printer speed performance detection module.  
      This arrangement ensures excellent operatability in collection of resulting prints in the case of input of the first command. In the case of no input of the first command, on the other hand, as discussed previously, the arrangement enables the respectively printers to conclude the printing operations almost simultaneously, thus desirably shortening the total time required for printing. Input or non-input of the first command readily changes over the mode between the speed preference mode and the print collection convenience preference mode (handling preference mode). This also ensures the excellent operatability.  
      In the third distributed printing control apparatus that enables the mode to be readily changed over between the speed preference mode and the handling preference mode, the data allocation module specifies the number of pages to be allocated to each printer, based on the condition that each specified set of pages are printed with an identical printer and according to the performance on the printing speed of each printer detected by the printer speed performance detection module, in response to both an externally input predetermined second command and the externally input predetermined first command.  
      This arrangement attains both the handling preference and the speed preference in the case of input of both the first command and the second command.  
      In accordance with another preferable application of the third distributed printing control apparatus, the data allocation module has a unit setting module that changes over the specified set of pages between a unit of each copy and a unit of each set of identical pages, in response to an externally input predetermined third command.  
      In response to the externally input third command, the specified set of pages is changed over between the unit of each copy and the unit of each set of identical pages.  
      In accordance with still another preferable application, the third distributed printing control apparatus further includes a distribution information setting module that causes an input window to be displayed on a display device and sets various pieces of information regarding distribution of the print data based on input data from an input device. The data allocation module specifies the pages allocated to the multiple printers, based on the various pieces of information set by the distribution information setting module. The distribution information setting module has a display control module that generates an illustrated image, which includes an array of printing media and corresponds to the information specified by the data allocation module based on the various pieces of information and causes the illustrated image to be displayed on the display device.  
      The operator sees the illustrated image displayed by the display control module and is thereby informed of the form of distributed printing in the process of setting the various pieces of distribution-related information in the input window. This visually informs the operator of the distributed form prior to actual execution of the distributed printing, thus further enhancing the operatability.  
      The present invention is also directed to a fourth distributed printing control apparatus that controls distributed printing and includes: a printer specification module that specifies multiple printers as destinations of distribution; and a distributive output module that outputs print data, which is an object to be printed, to the multiple printers specified by the printer specification module in a distributive manner. The fourth distributed printing control apparatus further includes: a condition setting module that causes a data input box for setting a predetermined condition relating to a printing performance of each printer to be displayed on a display device, receives input data into the data input box from an input device, and sets the predetermined condition based on the input data; a printer performance information collection module that collects performance information with regard to the predetermined condition from each of the multiple printers specified by the printer specification module; and a data input restriction module that restricts the input data in the data input box according to the performance information of each printer collected by the printer performance information collection module.  
      In the fourth distributed printing control apparatus of the above construction, the printer specification module specifies multiple printers as destinations of distribution, whereas the condition setting module sets a predetermined condition relating to the printing performance of each printer. The printer performance information collection module collects the performance information with regard to the predetermined condition from each of the multiple printers specified by the printer specification module. The data input restriction module restricts the input data in the data input box according to the collected performance information of each printer.  
      The predetermined condition set in the data input box accordingly reflects the performance information of each printer. The adequate setting of the predetermined condition ensures distributed printing according to the performance of the printer, thus effectively giving favorable resulting prints.  
      In accordance with one preferable application of the fourth distributed printing control apparatus, the data input restriction module specifies a set of performance information, which includes all the performance information of the respective printers collected by the printer performance information collection module, and restricts the input data in the data input box within a range of the specified set of performance information.  
      The input data in the data input box is restricted within the range of the specified set of performance information, which includes all the performance information of the respective printers with regard to the predetermined condition. This arrangement enables printing to be carried out with the performance possessed by at least one of the multiple printers specified as the destinations of distribution, thus ensuring the high-performance printing operation.  
      In accordance with another preferable application of the fourth distributed printing control apparatus, the data input restriction module specifies a set of common performance information, which is common to all the performance information of the respective printers collected by the printer performance information collection module, and restricts the input data in the data input box within a range of the specified set of common performance information.  
      The input data in the data input box is restricted within the range of the specified set of common performance information, which is common to all the performance information of the respective printers with regard to the predetermined condition. This arrangement enables printing to be carried out with the performance possessed by any of the multiple printers specified as the destinations of distribution, thus ensuring the printing operation with any of the multiple printers.  
      In accordance with still another preferable application of the fourth distributed printing control apparatus, the data input restriction module has a mode changeover module that selectively changes over a working mode between a first mode and a second mode, the first mode specifying a set of performance information, which includes all the performance information of the respective printers collected by the printer performance information collection module, and restricting the input data in the data input box within a range of the specified set of performance information, the second mode specifying a set of common performance information, which is common to all the performance information of the respective printers collected by the printer performance information collection module, and restricting the input data in the data input box within a range of the specified set of common performance information.  
      This arrangement enables the input data in the data input box to be restricted within the range of the specified set of performance information, which includes all the performance information of the respective printers with regard to the predetermined condition or within the range of the specified set of common performance information.  
      The fourth distributed printing control apparatus that is capable of changing over the working mode between the first mode and the second mode, the mode changeover module has a module that displays a switch for the mode changeover on the display device, receives input data for operating the switch from the input device, and gives an instruction to change over the working mode based on the input data.  
      The operator implements the changeover of the working mode through an operation of the input device. This arrangement thus ensures the excellent operatability.  
      In one preferable embodiment of the fourth distributed printing control apparatus, the condition setting module displays an option display box showing options possibly input in the data input box, together with the data input box, and sets one option selected among the options and specified from the input device as the predetermined condition, and the data input restriction module prohibits at least part of the options included in the option display box from being specified from the input device, so as to restrict the input data in the data input box.  
      This arrangement enables the operator to select one of the options satisfying the predetermined condition according to the performance information of the printer in the option display box, while not allowing the operator to select any of the options not satisfying the predetermined condition according to the performance information of the printer. This enhances the operatability of data input in the data input box.  
      In accordance with another preferable application, the fourth distributed printing control apparatus further includes a group mapping module that maps a plurality of printers to each group, wherein the printer specification module specifies the multiple printers by a unit of group mapped by the group mapping module.  
      This arrangement enables the multiple printers to be specified by the unit of a group as the destinations of distribution, thus ensuring favorable operatability.  
      In another preferable embodiment of the fourth distributed printing control apparatus, the printer specification module has a name display control module that displays names assigned to the specified multiple printers on the display device.  
      The display on the display device informs the operator of the multiple printers specified as the destinations of distribution.  
      In the fourth distributed printing control apparatus with the name display control module, the printer specification module has an input control module that displays switches, which correspond to the respective printer names displayed by the name display control module and are operated to exclude the corresponding printers from the destinations of distribution, and receives operation data of the switches from the input device. The distributive output module has an output resource exclusion module that excludes a printer, which is determined that the corresponding switch has been operated based on the operation data received by the input control module, from an output resource of the print data.  
      Any of the multiple printers once specified as the destinations of distribution may be excluded from the destinations of distribution through a simple operation of the corresponding switch. This arrangement ensures excellent operatability.  
      In still another preferable embodiment of the fourth distributed printing control apparatus, the printer specification module has a priority order specification module that specifies an order of priority allocated to the specified multiple printers, and the distributive output module carries out the distributive output by taking into account the order of priority specified by the priority order specification module.  
      Allocation of the order of priority to the multiple printers specified as the destinations of distribution desirably enhances convenience in collection of the resulting prints.  
      The fourth distributed printing control apparatus, which restricts the input data within the range of the specified set of performance information including all the performance information of the respective printers, further includes a performance decision module that determines whether or not each of the multiple printers specified by the printer specification module has a printing performance represented by the predetermined condition set by the condition setting module. The distributive output module has an output resource exclusion module that excludes a printer, which has been determined by the performance decision module not to have the printing performance, from an output resource of the print data.  
      The printing operation is carried out with the performance possessed by at least one of the multiple printers specified as the destinations of distribution. Some printers may thus not have the printing performance represented by the predetermined condition set by the condition setting module. Such printers are excluded from the output resources of the print data. This arrangement effectively prevents the print data from being mistakenly output to the printers without the printing performance represented by the predetermined condition.  
      In the fourth distributed printing control apparatus having the output resource exclusion module, the printer specification module has a name display control module that displays names of the specified multiple printers on the display device, and the name display control module has a module that prohibits distinctive display of the name of the printer, which is excluded by the output resource exclusion module.  
      The display on the display device informs the operator of the printer, which does not have the printing performance with regard to the predetermined condition and is thereby excluded from the destinations of distribution. This arrangement ensures excellent operatability.  
      In accordance with still another preferable application of the fourth distributed printing control apparatus, the printer performance information collection module receives information regarding performances of the multiple printers from printer drivers provided for respective types of the multiple printers and collects the performance information with regard to the predetermined condition from the received information.  
      This arrangement enables the performance information of the respective printers to be received from the printer drivers provided for the respective types of the multiple printers.  
      The present invention is further directed to a fifth distributed printing control apparatus, which includes: a first setting module that specifies multiple printers as destinations of distribution; a second setting module that sets paper information with regard to paper used for printing; and a distribution control module that processes externally input print data based on the specification by the first setting module and the setting by the second setting module and outputs plural divisions of the print data, which satisfy the paper information, to the multiple printers specified as the destinations of distribution. The fifth distributed printing control apparatus supplies the plural divisions of the print data output from the distribution control module to the multiple printers via printer drivers provided for the respective printers. The fifth distributed printing control apparatus further includes: an information input module that receives information with regard to an unprintable area included in a paper area in each of the multiple printers specified by the first setting module; and a printable area computation module that computes a printable area in the paper area, which is printable with any of the multiple printers, from the information of the respective printers received by the information input module. The distribution control module has an area fitting module that causes the plural divisions of the print data to be fit to the printable area computed by the printable area computation module.  
      The fifth distributed printing control apparatus thus constructed receives information with regard to an unprintable area included in a paper area, on which printing is performed, in each of the multiple printers specified as destinations of distribution, and computes a printable area in the paper area, which is printable with any of the multiple printers, from the received information of the respective printers. Externally input print data is distributed and output to be fit to the printable area. Each division of the print data accordingly occupies an identical printing area in any of the multiple printers specified as the destinations of distribution. This arrangement thus effectively enables resulting prints having a perfectly identical size and position of the printing area to be obtained from the multiple printers specified as the destinations of distribution.  
      In accordance with one preferable application of the fifth distributed printing control apparatus, the area fitting module has a margin correction module that corrects margins on each sheet of paper defined by the print data, based on the printable area computed by the printable area computation module. This arrangement makes the print data fit for the printable area by simply correcting the margins on the sheet of paper defined by the print data based on the printable area. This desirably simplifies the configuration.  
      In accordance with another preferable application of the fifth distributed printing control apparatus, the information input module receives the information from the printer drivers provided for the respective printers. This arrangement facilitates input of the information with regard to the unprintable area included in a certain size of paper area used in each printer.  
      In accordance with still another preferable application of the fifth distributed printing control apparatus, the multiple printers are connected via a computer network. The use of the computer network facilitates connection with a large number of printers.  
      The present invention is not restricted to the applications of the first through fifth distributed printing control apparatuses discussed above, but may be directed to corresponding distributed printing control methods. Other applications of the present invention include computer programs for attaining the functions of these apparatuses and methods and computer readable recording media in which such computer programs are recorded. Typical examples of the recording media include flexible disks, CD-ROMs, magneto-optic discs, IC cards, ROM cartridges, punched cards, prints with barcodes or other codes printed thereon, internal storage devices (memories like a RAM and a ROM) and external storage devices of the computer, and a variety of other computer readable media.  
      Still other applications of the present invention include data signals that include the computer programs and are embodied in carrier waves, as well as a program supply unit that supplies the computer programs via a communication path. In the application of the program supply unit, the computer programs are stored, for example, in a server on the computer network, and a required program is downloaded to a computer via the communication path and executed to attain the apparatuses discussed above and the corresponding methods. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a block diagram schematically illustrating the hardware structure of a computer system in a first embodiment of the present invention;  
       FIG. 2  is a block diagram schematically illustrating the general flow of a distributed printing process;  
       FIG. 3  is a block diagram showing the functions of a virtual printer driver  110  in the distributed printing process;  
       FIG. 4  is a block diagram showing the functions of a distributed printing utility  120 , which actualizes part of the distributed printing process;  
       FIG. 5  illustrates a ‘Printer’ window WN 1 ;  
       FIG. 6  illustrates a ‘Distribution Settings’ card CD 1  displayed on a ‘Distributed Printing Properties’ dialog box WN 2 ;  
       FIG. 7  shows a change of an illustrated image in a distributed form display box by the combination of the settings in data input boxes id 1  to id 3 ;  
       FIG. 8  shows an exemplified allocation of distributed printing in a speed preference mode;  
       FIG. 9  shows an exemplified allocation of distributed printing in a handling preference mode;  
       FIG. 10  shows a change of the illustrated image in the distributed form display box by the combination of the settings in data input boxes id 4  and id 5 ;  
       FIG. 11  illustrates a ‘Printer’ card CD 2  displayed on the ‘Distributed Printing Properties’ dialog box WN 2 ;  
       FIG. 12  is a flowchart showing a series of processing described in an application program  100  and a series of processing described in a virtual printer driver  110 ;  
       FIG. 13  illustrates a ‘Print’ dialog box WN 3  open on a CRT display  12  in response to execution of a ‘Print’ command on the application program  100 ;  
       FIG. 14  is a flowchart showing a distribution information setting routine executed by a CPU  30 ;  
       FIG. 15  is a flowchart showing a first half of a processing routine described in a distributed printing utility  120 ;  
       FIG. 16  is a flowchart showing a latter half of the processing routine described in the distributed printing utility  120 ;  
       FIG. 17  is a flowchart showing details of the allocation specification process executed at step S 430 ;  
       FIG. 18  shows an example of output resource list data in the speed preference mode;  
       FIG. 19  shows an example of output resource list data in the handling preference ode;  
       FIG. 20  is a timing chart showing the procedure of the embodiment for distributed printing, compared with a prior art procedure;  
       FIG. 21  illustrates a ‘Printer’ card CD 12  displayed on a ‘Distributed Printing Properties’ dialog box WN 12  in a second embodiment of the present invention;  
       FIG. 22  shows a ‘Group List’ dialog box WN 13 ;  
       FIG. 23  shows a ‘Group Settings’ dialog box WN 14 ;  
       FIG. 24  shows addition to a ‘Printers Belonging to’ display box id 33 ;  
       FIG. 25  shows an example of group registration list data PD;  
       FIG. 26  is a flowchart showing a series of processing described in the application program  100  and a series of processing described in the virtual printer driver  110  in the second embodiment;  
       5   FIG. 27  illustrates a ‘Print’ dialog box WN 16  open on the CRT display  12  in response to execution of a ‘Print’ command on the application program  100 ;  
       FIG. 28  is a flowchart showing a distribution information setting routine executed by the CPU  30 ;  
       FIG. 29  is a flowchart showing a first half of a data input processing routine executed by the CPU  30 ;  
       FIG. 30  is a flowchart showing a latter half of the data input processing routine;  
       FIG. 31  shows a pull-down menu MN 1  used for inputting a group name;  
       FIG. 32  shows a pull-down menu MN 2  used for inputting paper size in a ‘Functionality Preference’ mode;  
       FIG. 33  shows the pull-down menu MN 2  used for inputting paper size in a ‘Speed Preference’ mode;  
       FIG. 34  shows mapping of a ‘Paper Size’ data input box id 141  to a ‘Printers’ display box id 113 ;  
       FIG. 35  illustrates a ‘Printer’ card CD 12  in one modified example of the present invention;  
       FIG. 36  shows a pull-down menu MN 2  used for inputting paper size in the modified example of the present invention;  
       FIG. 37  is a block diagram showing the functions of a distributed printing utility  120 C in a third embodiment of the present invention;  
       FIG. 38  is a flowchart showing a first half of a processing routine described in the distributed printing utility  120 ;  
       FIG. 39  shows a process of computing a common printable area in a whole paper area P; and  
       FIG. 40  shows an example of output resource list data. 
    
    
     BEST MODES OF CARRYING OUT THE INVENTION  
      Some modes of carrying out the present invention are discussed below as preferred embodiments in the following sequence:  
     A. First Embodiment  
      A1. General Hardware Structure  
      A2. Distributed Printing Process  
      A3. Virtual Printer Driver  
      A4. User Interface  
      A5. Computer Programs  
      A6. Effects of Embodiment  
     B. Second Embodiment  
      B1. User Interface  
      B2. Computer Programs  
      B3.Effects of Embodiment  
     C. Third Embodiment  
      C1. Distributed Printing Process  
      C2. Computer Programs  
      C3. Effects of Embodiment  
      A1. General Hardware Structure  
       FIG. 1  is a block diagram schematically illustrating the hardware structure of a computer system in a first embodiment of the present invention. As illustrated, the computer system of the first embodiment includes a computer  10 , which is connected with a plurality of printers  70 ,  80 , . . . having substantial computer functions via a computer network  90  constructed as a Local Area Network (LAN). The computer network  90  is, however, not restricted to the LAN but may be any of diverse networks like the Internet, an Intranet, and a Wide Area Network (WAN).  
      The computer  10  is further connected with a CRT display  12  as a peripheral device and is locally connected with another printer  60 . The computer  10  has a computer main body  16 , a keyboard  18 , and a mouse  20 . The computer main body  16  has a floppy disk drive  24  to read the contents of a floppy disk  22 .  
      The computer main body  16  includes a central processing unit or CPU  30 , a ROM  31 , a RAM  32 , a display video memory  33 , a mouse interface  34 , a keyboard interface  35 , an FDC  36 , an HDC  37 , a CRTC  38 , a printer interface  39 , and a network control circuit  40 , which are mutually connected via a bus.  
      The ROM  31  is a built-in read only memory that stores therein diverse programs. The RAM  32  is a readable and writable memory that stores various data therein. The display video memory  33  stores video data representing images to be displayed on the CRT display  12 . The mouse interface  34  takes charge of transmission of data to and from the mouse  20 . The keyboard interface  35  takes charge of key inputs from the keyboard  18 . The FDC  36  is a floppy disk controller for controlling the floppy disk drive (FDD)  24 . The HDC  37  is a hard disk controller for controlling a hard disk drive (HDD)  41 . The CRTC  38  is a CRT controller for controlling display of images on the CRT display  12  based on the display video data stored in the display video memory  33 . The printer interface  39  controls data output to the locally connected printer  14 . The network control circuit  40  includes a network card and is connected to the computer network  90 .  
      In this computer system, an operating system is stored in the HDD  41 . In response to power supply to the computer main body  16 , the operating system is loaded into a predetermined area in the RAM  32  according to a loader written in a boot block of the HDD  41 . A real printer driver provided for each of the types of the printers  60 ,  70 , and  80  is stored in advance in the floppy disk  22  and is installed from the floppy disk drive  24  into the computer  10  according to an activated preset installation program. The installed real printer driver is stored in the HDD  41 , and is incorporated in the operating system and loaded into a predetermined area of the RAM  32  in response to power supply to the computer  10 .  
      The computer system further includes a virtual printer driver  110  for specifying information on a virtual printer. Like the real printer driver, the virtual printer driver  110  is stored in advance in the floppy disk and is installed from the floppy disk drive  24  into the computer  10  according to an activated preset installation program. The installed virtual printer driver  110  is stored in the HDD  41 , and is incorporated in the operating system and loaded into a predetermined area of the RAM  32  in response to power supply to the computer  10 . The computer program of the virtual printer driver  110  may be stored in another portable recording medium (carriable recording medium), such as a CD-ROM, a magneto-optic disc, or an IC card, in place of the floppy disk  22 . This computer program may be program data, which are downloaded from a specific server connecting with an external computer network (for example, the Internet) via the computer network and transferred to either the RAM  32  or the HDD  41 .  
      The printers  60 ,  70 , and  80  are laser printers that paint a photosensitive drum with a laser beam to form a latent image, which is developed by a toner and transferred onto a sheet. Diverse printers like ink jet printers and thermal transfer printers may alternatively be applied for the printers  60 ,  70 , and  80 . Here the printers  60 ,  70 , and  80  are of respectively different types.  
      A2. Distributed Printing Process  
      In the computer system of the above configuration, the computer main body  16  generates print data to be printed and carries out a distributed printing process to distribute the generated print data into the printers  60 ,  70 , and  80  connecting with the computer main body  16  for printing. The details of the distributed printing process are discussed below.  
       FIG. 2  is a block diagram schematically illustrating the general flow of the distributed printing process.  FIG. 3  is a block diagram showing the functions of the virtual printer driver  110  in the distributed printing process.  FIG. 4  is a block diagram showing the functions of a distributed printing utility program (hereinafter simply referred to as the ‘distributed printing utility)  120 , which actualizes part of the distributed printing process.  
      Referring to  FIG. 2 , an application program  100  working inside the computer main body  16  carries out image processing to generate video data and issues a print command to make the video data printed. In response to output of the print command from the application program  100 , the virtual printer driver  110  receives the print command and returns performance information, which regards the performances of the virtual printer assumed by the virtual printer driver  110 , to the application program  100 . More specifically, as shown in  FIG. 3 , a print command receiving module  111  of the virtual printer driver  110  receives the print command output from the application program  100 , and a performance information return module  112  returns the performance information regarding the performances of the virtual printer in response to receipt of the print command by the print command receiving module  111 .  
      The performances of the virtual printer represent the performances of the highest-performance printer among all the available printers as destinations of distribution. In general, the high-performance printer applies a high-quality program language for drawing. For example, the high-quality program language uses complicated drawing commands based on mathematical expressions to express figures, whereas a lower-quality program language uses simple drawing commands based on bitmaps to express figures. In this embodiment, the performances of the highest-performance printer among all the available printers as the destinations of distribution are set to the performances of the virtual printer. This arrangement enables the virtual printer driver  110  to carry out a data conversion process (rendering process) in the high-quality program language. Since the high-quality program language uses the complicated drawing command as mentioned above, the virtual printer driver  110  is capable of actualizing the efficient rendering process for the highest-performance printer.  
      The available printers as the destinations of distribution are printers belonging to a specific printer group set by a properties setting module  113  among all the printers connected to the computer main body  16  locally or via the network. Here the printers  60 ,  70 , and  80  are the available printers.  
      More specifically, a performance information input module  114  receives the performance information of the respective printers  60 ,  70 , and  80 , which has been transmitted from printer drivers  130 ,  140 , and  150  (hereinafter referred to as real printer drivers) provided for the respective types of the printers  60 ,  70 , and  80  to the distributed printing utility  120 . A virtual printer performance specification module  115  selects the highest performance from the performance information of the respective printers  60 ,  70 , and  80  and specifies the extracted performance as performance information of the virtual printer. The performance information return module  112  returns the performance information of the virtual printer to the application program  100 .  
      The performance information specified by the virtual printer driver  110  may be arbitrarily selected among the performance information of the respective printers  60 ,  70 , and  80 , instead of the performance of the highest-performance printer adopted in this embodiment. The performance information of the virtual printer may otherwise be preset performance information that does not depend upon the performance information of the respective printers  60 ,  70 , and  80 .  
      In the virtual printer driver  110 , the properties setting module  113  activates a user interface  116  to set and store various pieces of information required for printing. Some of he various pieces of information required for printing are returned, together with the performance information, to the application program  100  via the performance information return module  112 . The various pieces of information required for printing include, for example, information with regard to the basic settings of printing like the printing quality, the color correction, and the type of halftoning, information with regard to the settings of paper like the paper size and the printing orientation, information with regard to the printer group specifying available printers as destinations of distribution, and information with regard to the distributed form in the distributed printing process. Among these pieces of information, the information excluding those with regard to the printer group and the distributed form is sent to the application program  100 .  
      The application program  100  receives the performance information and other pieces of information mentioned above, converts the generated video data into print data adequate for the printer (the virtual printer) based on the input performance information and the other pieces of information, and transmits the converted print data to the virtual printer driver  110 . The conversion of the print data carried out here follows the efficient rendering process as described previously, while neither color conversion nor halftoning process carried out by the real printer driver is performed here.  
      Referring to  FIG. 2 , the virtual printer driver  110  sets the print data transmitted from the application program  100  as intermediate print data and temporarily stores a data set or a collection of the intermediate print data in the HDD  41  as an intermediate print file MF. More specifically, as shown in  FIG. 3 , a print data receiving module  117  receives the print data transmitted from the application program  100 , and an intermediate print data output module  118  specifies the input print data as intermediate print data and outputs a set of the intermediate print data to the HDD  41 . The intermediate print data in the intermediate print file MF is then read by the distributed printing utility  120 . The intermediate print file MF may be stored in the RAM  32 , in the floppy disk  22 , or even in another external storage device, instead of the HDD  41 . The virtual printer driver  110  also transmits the various pieces of information set by the properties setting module  113  as printer property data to the distributed printing utility  120  via a property data output module  119 .  
      Referring back to  FIG. 2 , the distributed printing utility  120  receives the intermediate print data constituting the intermediate print file MF and the printer property data and allocates the intermediate print data to the respective printers  60 ,  70 , and  80  according to the information with regard to the printer group and the distributed form included in the printer property data, and transmits the allocation to the real printer drivers  130 ,  140 , and  150  provided corresponding to the respective printers  60 ,  70 , and  80 . This series of processing carried out by the distributed printing utility  120  is discussed in detail.  
      In the distributed printing utility  120 , as shown in  FIG. 4 , an intermediate print data input module  121  first inputs the intermediate print data constituting the intermediate print file MF, whereas a property data input module  122  receives the printer property data transmitted from the virtual printer driver  110 . An allocation specification module  123  specifies allocation of the intermediate print data, based on the information with regard to the printer group and the distributed form included in the printer property data. Here the allocation means to group the intermediate print data by the unit of each page and specify pages to be printed with the printers  60 ,  70 , and  80  belonging to the specific printer group.  
      The allocation information thus specified is transmitted to an output data control module  124 . The output data control module  124  actually allocates and outputs the intermediate print data, which has been input into the intermediate print data input module  121 , to the real printer drivers  130 ,  140 , and  150  of the respective printers  60 ,  70 , and  80 , based on the transmitted allocation information. The data output to the real printer drivers  130 ,  140 , and  150  follows the series of processing discussed below.  
      A printer setting module  125  first gives an instruction to change the settings via the printer drivers to the printers specified as the destinations of allocation. An output command output module  126  issues an output command. A performance information input module  127  receives the performance information regarding the performances of the respective printers  60 ,  70 , and  80  returned from the real printer drivers  130 ,  140 , and  150  in response to the output command. The output data conversion module  124  converts the allocating pages of the intermediate print data into data suitable for the printers  60 ,  70 , and  80  specified as the destinations of allocation, based on the performance information transmitted from the performance information input module  127  as well as the information with regard to the basic settings of printing and the information with regard to the paper settings included in the printer property data (excluding the information with regard to the printer group and the distributed form) transmitted from the property data input module  122  (hereinafter this process of data conversion is referred to as the rendering process).  
      The output data control module  124  sends the converted print data as final print data to the real printer drivers  130 ,  140 , and  150  via a final print data output module  128 . The real printer drivers  130 ,  140 , and  150  cause the final print data to undergo a required series of processing, such as color conversion or halftoning, suitable for each printer, which is not carried out by the virtual printer driver, and transmit the processed final print data to the corresponding printers  60 ,  70 , and  80 .  
      The distributed printing utility  120  has a printer monitoring module  129 , which monitors the conditions of the respective printers  60 ,  70 , and  80 , based on signals output from the real printer drivers  130 ,  140 , and  150 . The printer monitoring module  129  monitors the length of a waiting queue and occurrence of any error (for example, failure, paper jam, or out-of-paper) in each of the printers. The output data control module  124  receives signals output from the printer monitoring module  129  and changes the output resource of the allocated print data or stops the output with regard to the printer having a long waiting queue or being in any error state.  
      The performance information of the respective printers  60 ,  70 , and  80  transmitted from the real printer drivers  130 ,  140 , and  150  is utilized by the distributed printing utility  120  as described above, while being transmitted to the virtual printer driver  110  via a performance information output module  12   a.    
      A3. Virtual Printer Driver  
      The following describes a change in state of the operating system when the virtual printer driver  110  is installed in the computer  10 . The description regards an example wherein Windows95 (trade mark by Microsoft Inc.) is adopted as the operating system, on which the virtual printer driver  110  works.  
      The user (operator) operates the computer  10  in the following sequence to open a dialog box for setting various pieces of information required for printing on the screen of the CRT display  12 . The sequence of operations ‘Start’→‘Settings’→‘Printer’ opens a ‘Printer’ window.  FIG. 5  shows this ‘Printer’ window. In the case where the virtual printer driver  110  is installed in the computer  10 , an icon IC 4  that corresponds to the virtual printer driver  110  and is expressed as, for example, ‘Distributed Printing’ is displayed in the illustrated ‘Printer’ window WN 1 , in addition to icons IC 1 , IC 2 , and IC 3  representing the real printer drivers  130 ,  140 , and  150  individually provided for the respective types of the printers  60 ,  70 , and  80 . Like the real printer driver, installation of the virtual printer driver  110  causes the icon IC 4  corresponding to the virtual printer driver  110  to be displayed in the ‘Printer’ window WN 1 .  
      The operator double clicks the icon IC 4  ‘Distributed Printing’ corresponding to the virtual printer driver  110  on the ‘Printer’ window WN 1  to open a window of the virtual printer driver  110  and clicks ‘Printer’ and ‘Properties’ in the window. This series of operations opens a dialog box ‘Distributed Printing Properties’ for setting various pieces of information with regard to the virtual printer. The operator can input the settings of the various pieces of information in the dialog box ‘Distributed Printing Properties’ through the operations of the mouse  20  and the keyboard  18 . This dialog box ‘Distributed Printing Properties’ corresponds to the user interface  116  mentioned previously.  
      A4. User Interface  
       FIG. 6  illustrates the dialog box WN 2  ‘Distributed Printing Properties’. Two cards CD 1  ‘Distribution Settings’ and CD 2  ‘Printer’ are provided in the dialog box WN 2  ‘Distributed Printing Properties’. The ‘Distribution Settings’ card CD 1  is used to set the information with regard to the distributed form in the distributed printing process. The ‘Printer’ card CD 2  is used to set the information with regard to the printer group as the potential destinations of distribution, the basic settings of printing, and the paper settings. The operator selects either of the two cards CD 1  and CD 2  to be displayed in the dialog box WN 2  through operations of the mouse  20 . In the state of  FIG. 6 , the ‘Distribution Settings’ card CD 1  is selected. The division of the information into the cards CD 1  and CD 2  is not restricted to the above example, but the information may all be included in one card or may be divided into three or more cards.  
      As illustrated, the ‘Distribution Settings’ card CD 1  includes three fields ‘Document’, ‘Recovery’, and ‘Time’ fd 1 , f 2 , and fd 3 . The ‘Document’ field fd 1  is used to set the specification of printing a document, and has a data input box id 1  ‘Copies’, a check box id 2  ‘Collate’, a check box id 3  ‘Bundle by Page or Copy’, a data input box id 4  ‘Job Grouping’, and a data input box id 5  ‘Marked Page’. The respective data input boxes (including check boxes in the following description) id 1  to id 5  are designed in the following specification:  
      1) ‘Copies’ Data Input Box id 1 :  
      The number of copies to be printed is input in this data input box. The default is the setting by the application program  100 .  
      2) ‘Collate’ Check Box id 2 :  
      Gathering print is selected by checking this check box id 2 , and otherwise stack print is selected. The gathering print carries out printing by the unit of copy and in the order of pages in each copy. The stack print, on the other hand, carries out printing by the unit of page and by the number of copies in each page. Namely printing is carried out by the unit of copy when the check box id 2  is checked, while being carried out by the unit of page when the check box id 2  is not checked.  
      3) ‘Bundle by Copy or Page’ Check Box id 3 :  
      A check in this check box id 3  prohibits one copy or one set of identical pages from being printed with multiple printers. No check in the check box id 3 , on the other hand, allows the copy or the set of identical pages to be printed with multiple printers. In the off state of this check box id 3 , that is, in the case of not ‘Bundle by Copy or Page’, the number of pages allocated to each printer is varied according to the performance of the printing speed (hereinafter referred to as the printing speed performance) of the printer, so as to conclude the printing operation substantially simultaneously in all the printers specified as the destinations of distribution. Hereinafter this working state in which the number of pages allocated to each printer is varied according to the printing speed performance is referred to as the ‘speed preference’ mode, which will be discussed later in detail.  
      4) ‘Job Grouping’ Data Input Box id 4 :  
      When one radio button ‘By Printer’ is selected in this data input box id 4 , all the pages output from one printer are handled as one group. The selection of this radio button prevents the results of a user&#39;s specified print job from being mixed with the results of printing required by another user in the share computer  70  or  80  connecting with the network. When the other radio button ‘By Copy or Page’ is selected, one copy or one set of identical pages is handled as one group. The latter is utilized in the case where a user&#39;s specified print job is distributed to the local printer  60  or in the case where no problem arises even if the results of the print job are mixed with the results of printing required by another user.  
      5) ‘Marked Page’ Data Input Box id 5 :  
      The marked page represents a head page or an end page of each group to allow discrimination in the case where resulting prints of a specified group are mixed with resulting prints required by another user. In response to a check in a ‘Head’ check box, the marked page is printed at the head position of each group. In response to a check in an ‘End’ check box, on the other hand, the marked page is printed at the end position of each group. The name of the document to be printed, the number of copies, the total number of pages, and the name of the user are printed on the marked page.  
      The ‘Document’ field fd 1  includes a distributed form display box dd representing the distributed form specified by the settings in the data input boxes id 1  to id  5 , in addition to the data input boxes id 1  to id 5  discussed above. An illustrated image in the distributed form display box dd shows the distributed form specified by the settings in the data input boxes id 1  to id 5 .  
      The check box id 2  ‘Collate’ corresponds to the module of inputting the ‘third command’ specified in the claims; the check box id 3  ‘Bundle by Copy or Page’ corresponds to the module of inputting the ‘first command’ specified in the claims; and the check box id 4  ‘Job Grouping’ corresponds to the module of inputting the ‘second command’ specified in the claims.  
      The following describes a change of the illustrated image in the distributed form display box dd by the combination of the settings in the data input boxes id 1  to id 5  with reference to  FIGS. 7 through 10 . The description first regards a change of the illustrated image by the combination of the settings in the ‘Copies’ data input box id 1 , the ‘Collate’ check box id 2 , and the ‘Bundle by Copy or Page’ check box id 3 .  
       FIG. 7  shows a change of the illustrated image in the distributed form display box dd by the combination of the settings in the data input box id 1  and the two check boxes id 2  and id 3 . In the illustration of the table, the columns show whether or not the print job is to be collated, that is, the on-off settings in the ‘Collate’ check box id 2 . The rows show whether or not the print job is to be bundled by copy or page, that is, the on-off settings in the ‘Bundle by Copy or Page’ check box id 3 . In the example of the table, it is assumed that the number of copies set in the ‘Copies’ data input box id 1  is four copies.  
      In the combination of ‘Collate’ and not ‘Bundle by Copy or Page’, the gathering print is selected. As shown in a cell C 11  of the first row and the first column in the table, the illustrated image shows that the 1 st  and the 2 nd  pages of the 1 st  copy and the 1 st  page of the 2 nd  copy are printed with the first printer  60 , that the 2 nd  page of the 2 nd  copy and the 1 st  and the 2 nd  pages of the 3 rd  copy are printed with the second printer  70 , and that the 1 st  and the 2 nd  pages of the 4 th  copy are printed with the third printer  80 .  
      In the combination of not ‘Collate’ and not ‘Bundle by Copy or Page’, the stack print is selected. As shown in a cell C 12  of the first row and the second column in the table, the illustrated image shows that three copies of the 1 st  page are printed with the first printer  60 , that the remaining copy of the 1 st  page and two copies of the 2 nd  page are printed with the second printer  70 , and that the remaining copies of the 2 nd  page are printed with the third printer  80 .  
      In the combination of ‘Collate’ and ‘Bundle by Copy or Page’, printing each specified group with multiple printers is prohibited. As shown in a cell C 21  of the second row and the first column in the table, the illustrated image shows that the 1 st  page of the 1 st  copy to the 2 nd  page of the 2 nd  copy are printed with the first printer  60 , that the 1 st  and the 2 nd  pages of the 3 rd  copy are printed with the second printer  70 , and that the 1 st  and the 2 nd  pages of the 4 th  copy are printed with the third printer  80 .  
      In the combination of not ‘Collate’ and ‘Bundle by Copy or Page’, as shown in a cell C 22  of the second row and the second column in the table, the illustrated image shows that the required number of copies of the 1 st  page are printed with the first computer  60  and that the required number of copies of the 2 nd  page are printed with the second computer  70 .  
      The example shown in the cells C 11  and C 12  of the first row in the table of  FIG. 7  is on the assumption that the printers  60 ,  70 , and  80  specified as the destinations of distribution have substantially equal printing speed performances. When the printers  60 ,  70 , and  80  have substantially equal printing speed performances, practically similar numbers of pages are allocated to the respective printers. When the printers  60 ,  70 , and  80  specified as the destinations of distribution have different printing speed performances, on the other hand, different numbers of pages are allocated to the different types of printers. This is allocation of distributed printing in the ‘speed preference’ mode. For example, the printing speed performance of the first printer  60  is 20 ppm (pages per minute), the printing speed performance of the second printer  70  is 40 ppm, and the printing speed performance of the third printer  80  is 40 ppm. In this example, the ratio of the printing speed performance of the respective printers  60 ,  70 , and  80  is 1:2:2. In the case of allocation of distributed printing in the ‘speed preference’ mode (that is, in the case of not ‘Bundle by Copy or Page’ corresponding to the first row in the table), the numbers of pages allocated to the respective printers are determined to follow this ratio of the printing speed performance. The printers  60 ,  70 , and  80  can thus conclude the printing operations almost simultaneously.  
       FIG. 8  shows an exemplified allocation of distributed printing in the &#39;speed preference’ mode. In this example, the job of printing four copies of a document including 5 pages is distributed into the three printers  60 ,  70 , and  80 . The printing speed performances of the printers  60 ,  70 , and  80  are respectively 20 ppm, 40 ppm, and 40 ppm as mentioned above. In this case, the total number of pages to be printed is 20. The allocation to the first printer  60 , to the second printer  70 , and to the third printer  80  are respectively 4 pages, 8 pages, and 8 pages according to the ratio of the printing speed performance (1:2:2) of the respective printers  60 ,  70 , and  80 . In the case of ‘Collate’, gathering print is selected as shown in  FIG. 8 . The 1 st  to the 4 th  pages of the 1 st  copy are printed with the first printer  60 . The 5 th  page of the 1 st  copy, the 1 st  to the 5 th  pages of the 2 nd  copy, and the 1 st  and the 2 nd  pages of the 3 rd  copy are printed with the second printer  70 . The 3 rd  to the 5 th  pages of the 3 rd  copy and the 1 st  to the 5 th  pages of the 4 th  copy are printed with the third printer  80 . In the case of not ‘Collate’, stack printing is selected, and the numbers of pages allocated to the respective printers  60 ,  70 , and  80  are similarly determined according to the ratio of the printing speed performance (1:2:2) of the respective printers  60 ,  70 , and  80 .  
      In the arrangement of this embodiment, in the case of not ‘Bundle by Copy or Page’ on the first row in the table of  FIG. 7 , allocation of distributed printing is specified in the ‘speed preference’ mode as discussed above. In the case of ‘Bundle by Copy or Page’ on the second row in the table of  FIG. 7 , on the other hand, allocation of distributed printing is specified with preference given to handling (hereinafter this is referred to as the ‘handling preference’ mode).  FIG. 9  shows an exemplified allocation of distributed printing in the ‘handling preference’ mode. In the ‘handling preference’ mode, ‘Bundle by Copy or Page’, that is, allocation of distributed printing to prohibit one copy or one set of identical pages from being printed with multiple printers, facilitates collection of resulting prints from the respective printers. Like the example shown in  FIG. 8 , in the example of  FIG. 9 , the job of printing four copies of a document including 5 pages is distributed into the three printers  60 ,  70 , and  80 . In the gathering print, the 1 st  to the 5 th  pages of the 1 st  copy are printed with the first printer  60 . The 1 st  to the 5 th  pages of the 2 nd  copy and the 1 st  to the 5 th  pages of the 3 rd  copy are printed with the second printer  70 . The 1 st  to the 5 th  pages of the 4 th  copy are printed with the third printer  80 . In the example of  FIG. 35 , the second printer  70  prints two copies. This satisfies both the speed preference mode and the handling preference mode. In the speed preference mode, according to the ratio of the printing speed performance 1:2:2, it is expected that the first printer  60  prints one copy, the second printer  70  prints two copies, and the third printer  80  prints two copies. Since only five copies are required, however, the third printer  80  prints the residual one copy.  
      In the case of ‘Bundle by Copy or Page’ on the second row in the table of  FIG. 7 , allocation of distributed printing may be specified to satisfy not the speed preference mode but the handling preference mode. In this case, in the handling preference mode that prohibits one copy or one set of identical pages from being printed with multiple printers, the pages are equally allocated to the respective printers irrespective of the printing speed performances of the printers. In the case where the number of copies can not be equally divided by the number of printers specified as the destinations of distribution as in the examples of  FIGS. 8 and 9 , the greater number of copies is allocated to the printer having the smaller ordinal number. For example, in the job of printing four copies of a 5-page document with the three printers, the first printer  60  prints two copies, while the second printer  70  and the third printer  80  respectively print one copy.  
      As described above, in the case of ‘Bundle by Copy or Page’ on the second row in the table of  FIG. 7 , allocation of distributed printing may be specified to satisfy both the handling preference mode and the speed preference mode or to satisfy not the speed preference mode but the handling preference mode. The changeover between these two states is based on the settings in the ‘Job Grouping’ data input box id 4 . When the radio button ‘By Printer’ is selected in the data input box id 4 , all the pages output from one printer are handled as one group. The speed preference mode is thus active to take into account the printing speed performances of the respective printers. When the other radio button ‘By Copy or Page’ is selected in the data input box id 4 , one copy or one set of identical pages is handled as one group, so that the speed preference mode is inactive. In the case of selection of the radio button ‘By Copy or Page’ in the data input box id 4 , irrespective of the printing speed performances of the respective printers, one copy is allocated to each of available printers and the residual copies are sequentially allocated to the available printers.  
      The description then regards a further change of the illustrated image specified by the settings in the data input boxes id 1  to id 3  by the combination of the settings in the ‘Job Grouping’ data input box id 4  and the ‘Marked Page’ data input box id 5 .  FIG. 10  shows a change of the illustrated image in the distributed form display box dd by the combination of the data input boxes id 4  and id 5 . The example of  FIG. 10  shows a further change of the illustrated image, which is specified by the settings in the data input boxes id 1  to id 3  in the cell C 11  of  FIG. 7 , by the combination of the settings in the data input boxes id 4  and id 5 .  
      In the table of  FIG. 10 , the columns show the settings in the ‘Job Grouping’ data input box id 4 , that is, selection of either ‘By Printer’ or ‘By Copy or Page’. The rows show the settings in the ‘Marked Page’ data input box id 5 , that is, checks in the two check boxes ‘Head’ and ‘End’.  
      In the case of a click of the radio button ‘By Printer’ in the ‘Job Grouping’ data input box id 4 , as shown by a cell CE 11  of the first row and the first column in the table, the illustrated image in the cell C 11  of  FIG. 7  is not changed and all the pages printed with one printer are handled as one group. In the case of a click of the other radio button ‘By Copy or Page’, on the other hand, as shown by a cell CE 12  of the first row and the second column, each copy or each page is handled as one group and distinguished from a subsequent group. In the actual services, since no marked page is selected, the same printing results are obtained both in the case of the click of the radio button ‘By Printer’ and in the case of the click of the other radio button ‘By Copy or Page’.  
      When the marked page is specified in the ‘Marked Page’ data input box id 5 , on the other hand, as shown by the second, the third, and the fourth rows in the table, the illustrated image is changed to make the marked pages (closed figures in the table) are inserted at the head, at the end or at both the head and the end of the respective groups specified in the first row. The illustrated image specified by this table is displayed in the distributed form display box dd.  
      Referring back to  FIG. 6 , the ‘Recovery’ field fd 2  specifies another printer as a recovery resource in the case of occurrence of any error in the printer specified for distributed printing. The ‘Recovery’ field fd 2  has three radio buttons ‘No Recovery’, ‘Output to’, and ‘Automatically Select Recovery Resource’. In the case of selection of the ‘No Recovery’ radio button, no recovery is performed even when an error occurs in the printer specified for distributed printing. In the case of selection of the ‘Output to’ radio button, the output resource input in a ‘Printer’ data input box is set to the recovery resource. In the case of selection of the ‘Automatically Select Recovery Resource’ radio button, the same type of a printer as the printer with the error is set to the recovery resource. When there is no same type of printer, an available printer is set to the recovery resource.  
      The ‘Time’ field fd 3  specifies the time of printing. When a check box ‘Specify Time’ is checked, the printing operation starts at the time specified in the ‘Time’ field fd 3 .  
      The following describes the ‘Printer’ card CD 2  on the ‘Distributed Printing Properties’ dialog box WN 2  with reference to  FIG. 9 . As illustrated in  FIG. 11 , the ‘Printer’ card CD 2  includes a ‘Printer Group’ field fd 4 , and ‘Paper Settings’ field fd 5 , and a settings display box fd 6 .  
      The ‘Printer Group’ field fd 4  specifies a group of printers, which are used for distributed printing of a document and has a ‘Group Name’ data input box id 11 , a ‘Printers’ display box id 12 , and a ‘Group Setting’ button id 13 . The ‘Group Name’ data input box id 11  sets the name of the printer group and preset group names are provided as possible options. The ‘Printers’ display box id 12  displays the names of the printers belonging to the printer group set in the ‘Group Name’ data input box id 11 . A click of the ‘Group Setting’ button id 13  opens a non-illustrated new window and accepts user&#39;s data input, so as to allow addition and deletion of an option to and from the options provided in the ‘Group Name’ data input box id 11 . The computer  10  gives an instruction of distributed printing to all the printers belonging to the printer group specified in the ‘Printer Group’ field fd 4 , that is, the respective printers displayed in the ‘Printers’ display box id 12 . Among all the printers connected to the computer main body  16  locally or via the computer network  90 , the printers included in the printer group specified in the ‘Printer Group’ field fd 4  are thus set as the destinations of distributed printing.  
      The ‘Paper Settings’ field fd 5  sets the paper and the printing quality and has data input boxes ‘Paper Size’ ‘Orientation’, ‘Paper Type’, ‘Color’, and ‘Resolution’ id 14 , id 15 , id 16 , id 17 , and id 18 .  
      The ‘Paper Size’ data input box id 14  sets the paper size, and examples of possible options include ‘A4 210×297 mm’, ‘A4 Lateral 210×297 mm’, ‘Envelop 120×235 mm’, and ‘Postcard 100×147 mm’. The ‘Orientation’ data input box id 15  represents the orientation of paper set in the printer and has two options ‘Portrait’ and ‘Landscape’. The ‘Paper Type’ data input box id 16  specifies the type of paper, and ‘Plain’, ‘Superfine’, and ‘Glossy’ are provided as possible options. The ‘Color’ data input box id 17  specifies the type of ink used in the printer  14 , and ‘Color’ and ‘Black’ are provided as possible options. The ‘Resolution’ data input box id 18  sets the printing resolution, and ‘Fast’ and ‘Fine’ are provided as possible options. Here ‘Fast’ and ‘Fine’ respectively represent the resolutions of 360×360 (dots) and 720×720 (dots).  
      The settings display box fd 6  displays desired data among the settings in the ‘Printer Group’ field fd 1  and the ‘Paper Settings’ field fd 5 .  
      Various pieces of information regarding the settings in the ‘Distributed Printing Properties’ dialog box WN 2  are input into the computer main body  16  through the user&#39;s operations of the mouse  20  and the keyboard  18 . The acceptance of the input data is restricted according to the performance information of the respective printers  60 ,  70 , and  80 . For example, when the performance information of the respective printers  60 ,  70 , and  80  specifies the printable size up to A4 in all the printers  60 ,  70 , and  80 , paper sizes of greater than A4 are excluded from the options in the ‘Paper Size’ data input box id 14  in the ‘Distributed Printing Properties’ dialog box WN 2 . Namely the input data regarding paper sizes of greater than A4 is not acceptable.  
      A5. Computer Programs  
      The respective modules  111  through  119  in the virtual printer driver  110  shown in  FIG. 3  are actualized by the virtual printer driver  110  as the computer program and series of processing executed by the CPU  30  according to the virtual printer driver  110 . The respective modules  121  through  129  in the distributed printing utility  120  shown in  FIG. 4  are actualized by the distributed printing utility  120  as the computer program and series of processing executed by the CPU  30  according to the distributed printing utility  120 .  
      Like the virtual printer driver  110 , the distributed printing utility  120  is stored in advance in the floppy disk  22  and is installed from the floppy disk drive  24  into the computer  10  according to an activated preset installation program. The installed distributed printing utility  120  is stored in the HDD  41 , and is incorporated in the operating system and loaded into a predetermined area of the RAM  32  in response to power supply to the computer  10 . Like the virtual printer driver  110 , the distributed printing utility  120  may be stored in another portable recording medium (carriable recording medium), such as a CD-ROM, a magneto-optic disc, or an IC card, in place of the floppy disk  22 . The distributed printing utility  120  may be program data, which are downloaded from a specific server connecting with an external computer network (for example, the Internet) via the computer network and transferred to either the RAM  32  or the HDD  41 .  
       FIG. 12  is a flowchart showing a processing routine described in the virtual printer driver  110  as well as a processing routine described in the application program  100 . The CPU  30  in the computer main body  16  starts the processing in the application program  100  and carries out a series of image processing to generate video data (step S 210 ). The application program  100  may be a general purpose application program used to create documents and pictures, and video data is generated by the functions characteristic of each application program.  
      The CPU  30  executes a ‘Print’ command provided in the application program and thereby outputs a print command for distributed printing (step S 220 ).  FIG. 13  illustrates a ‘Print’ dialog box WN 3  open on the CRT display  12  in response to execution of the ‘Print’ command on the application program  100 . As illustrated, the ‘Print’ dialog box WN 3  has a ‘Printer Name’ data input box id 21 . The print command for distributed printing is output from the application program  100  to the virtual printer driver  110  in response to a click of an ‘OK’ button id 22  with the mouse  20 , while a series of letters ‘Distributed Printing’, which corresponds to the ‘Distributed Printing’ icon IC 4  discussed previously with  FIG. 5 , is selectively input in the ‘Printer Name’ data input box id 21 . A click of a ‘Properties’ button id 23  in the ‘Print’ dialog box WN 3  shifts the processing to a distribution information setting routine executed in the virtual printer driver  110 . The process opens the ‘Distributed Printing Properties’ dialog box WN 2  on the CRT display  12  and reads input data from the keyboard  18  and the mouse  20 , so as to set various pieces of information regarding the distributed printing. The print command may be output from the application program via the operating system.  
       FIG. 14  is a flowchart showing a distribution information setting routine executed by the CPU  30 . When the program enters this routine, the CPU  30  first opens the ‘Distributed Printing Properties’ dialog box WN 2  shown in  FIG. 6  on the CRT display  12  (step S 301 ). The CPU  30  subsequently inputs various pieces of data through data input operations of the keyboard  18  and the mouse  20  by the operator who checks the display on the CRT display  12  (step S 302 ). The various pieces of data can be input in the ‘Distributed Printing Properties’ dialog box WN 2  shown in  FIGS. 6 and 11  and include information regarding the form of distributed printing, information regarding the printer group, information regarding the basic settings of printing, and information regarding the paper settings. An illustrated image generated from the various pieces of input data is shown in the distributed form display box dd in the ‘Distributed Printing Properties’ dialog box WN 2 . The illustrated image may be any of the images shown in FIGS.  7  to  10 . The CPU  30  then stores the various pieces of data input at step S 302  as printer property data into the RAM  32  (step S 303 ). The program then goes to RETURN and exits from this routine.  
      After completion of the processing according to this distribution information setting routine, the print command is output in response to a click of the ‘OK’ button id 22  in the ‘Print’ dialog box WN 3  with the mouse  20 . In the case where the ‘Properties’ button id 23  is not clicked but the ‘OK’ button id 22  is clicked immediately with the mouse  20 , the printer property data stored in the RAM  32  in the previous cycle of the distribution information setting routine (in the first cycle, preset initial printer property data) are maintained without any modification.  
      In response to the output of the print command at step S 220 , the CPU  30  shifts the processing to the virtual printer driver  110  and determines whether or not the print command is input from the application program  100  (step S 310 ). In the case of no input of the print command, the CPU  30  iteratively carries out the decision at step S 310  and waits for input of the print command from the application program  100 . In the case of input of the print command at step S 310 , on the other hand, the CPU  30  carries out the series of processing discussed below.  
      The CPU  30  first reads from the distributed printing utility  120  the performance information of the respective printers  60 ,  70 , and  80 , which has been transmitted from the real printer drivers  130 ,  140 , and  150  provided for the respective types of the printers  60 ,  70 , and  80  to the distributed printing utility  120  (step S 320 ). The CPU  30  then extracts the highest performance out of the performance information of the respective printers  60 ,  70 , and  80  and specifies the extracted highest performance as the performance information of the virtual printer (step S 330 ). The CPU  30  then transmits the performance information of the virtual printer to the application program  100  (step S 340 ).  
      When the performance information of the virtual printer is transmitted from the virtual printer driver  110 , the CPU  30  shifts the processing to the application program  100  and receives the transmitted performance information of the virtual printer (step S 240 ). The CPU  30  subsequently converts the video data generated at step S 210  into print data adequate for the virtual printer, based on the performance information as well as the information regarding the basic settings of printing and the information regarding the paper settings, which are included in the printer property data stored in the RAM  32  in the distribution information setting routine discussed above (excluding the information regarding the printer group and the distributed form) (step S 250 ). After the data conversion, the CPU  30  transmits the converted print data to the virtual printer driver  110  (step S 260 ). On completion of the processing at step S 260 , the CPU  30  exits from the processing routine in the application program  100 .  
      When the print data adequate for the virtual printer is transmitted from the application program  100 , the CPU  30  shifts the processing to the virtual printer driver  110  and receives the transmitted print data (step S 350 ). The CPU  30  subsequently outputs the input print data as intermediate print data to the HDD  41  (step S 360 ). A data set or a set of the intermediate print data is then stored as an intermediate print file MF into the HDD  41 . On completion of the processing at step S 360 , the CPU  30  exits from the processing routine in the virtual printer driver  110 .  
       FIGS. 15 and 16  are flowcharts showing a processing routine described in the distributed printing utility  120 . This processing routine is activated after conclusion of the processing routine in the virtual printer driver  110 . When the program enters this processing routine, as shown in  FIG. 15 , the CPU  30  first reads the intermediate print data in the intermediate print file MF from the HDD  41  (step S 410 ). The CPU  30  subsequently reads the printer property data, which include the various pieces of information set in the distribution information setting routine (step S 420 ).  
      The CPU  30  then carries out an allocation specification routine (step S 430 ), which specifies allocation of the intermediate print data input at step S 410 , based on the information with regard to the printer group and the distributed form included in the printer property data input at step S 420 . The allocation specification routine specifies allocation of the respective pages included in the intermediate print data to the respective printers  60 ,  70 , and  80  belonging to the specified printer group. The respective pages of the intermediate print data are allocated to the printers  60 ,  70 , and  80 , in order to attain the distributed form set in the ‘Distributed Printing Properties’ dialog box WN 2  (that is, the distributed form displayed in the distributed form display box dd of the ‘Distribution Settings’ card CD 1  shown in  FIG. 10 ).  
       FIG. 17  is a flowchart showing the details of the allocation specification routine executed at step S 430 . When the program enters this routine, the CPU  30  first specifies the total number of pages to be printed according to the intermediate print data input at step S 410  (step S 431 ). The CPU  30  then specifies printers as destinations of distribution, based on the information with regard to the printer group included in the printer property data read at step S 420  (step S 432 ). The CPU  30  collects the performance information of the respective printers  60 ,  70 , and  80  from the real printer drivers  130 ,  140 , and  150 , which are respectively prepared for the printers  60 ,  70 , and  80  specified as the destinations of distribution (step S 433 ). The CPU  30  then reads the printing speed performances of the respective printers  60 ,  70 , and  80  from the collected information and calculates the performance ratio of the printers  60 ,  70 , and  80  with regard to the printing speed from the printing speed performances (step S 434 ).  
      The CPU  30  subsequently determines whether or not the speed preference mode is set (step S 435 ). The concrete procedure reads the information with regard to the distributed form included in the printer property data read at step S 420  and carries out the determination based on activation or inactivation of the ‘Bundle by Copy or Page’ command, that is, the on-off state of the check box id 3 . In the speed preference mode, that is, in the off state of the check box id 3 , the CPU  30  specifies allocation of the intermediate print data input at step S 410  by taking into account the performance ratio calculated at step S 434  (step S 436 ). The concrete procedure first specifies the ratio of pages allocated to the respective printers corresponding to the performance ratio calculated at step S 434 . For example, when the performance ratio of the printers  60 ,  70 , and  80  is 1:2:2, the ratio of pages allocated to the respective printers  60 ,  70 , and  80  is also set equal to 1:2:2. The concrete procedure then divides the intermediate print data input at step S 410  by page and allocates the preset pages to the respective printers  60 ,  70 , and  80  belonging to the specified printer group, in order to attain the distributed form set in the ‘Distributed Printing Properties’ dialog box WN 2 . The division of the pages should satisfy the specified ratio of the pages allocated to the respective printers. Information regarding the preset pages allocated to the respective printers is stored as output resource list data into the RAM  32 .  
       FIG. 18  shows an example of the output resource list data. The illustrated example follows the allocation of  FIG. 8 . In the illustrated example, pages 1, 2, 3, and 4 are allocated to the first printer  60  (the printer having the first ordinal number) in this sequence as page numbers to be printed. Pages 5, 1, 2, 3, 4, 5, 1, and 2 are allocated to the second printer  70 , and pages 3, 4, 5, 1, 2, 3, 4, and 5 are allocated to the third printer  80  (the printer having the last ordinal number) in the respective sequences.  
      When it is determined at step S 435  that the speed preference mode is not set, that is, in the on state of the check box id 3 , on the other hand, the CPU  30  specifies allocation of the intermediate print data input at step S 410 , in order to prevent one copy or one set of identical pages from being printed with multiple printers, that is, to attain the handling preference mode (step S 437 ). The concrete procedure divides the intermediate print data input at step S 410  by page and allocates the preset pages to the respective printers  60 ,  70 , and  80  belonging to the specified printer group, in order to prevent each copy or a set of identical pages (this depends upon the state of the check box id 2 ) from being printed with multiple printers and attain the distributed form set in the ‘Distributed Printing Properties’ dialog box WN 2 . Information regarding the preset pages allocated to the respective printers is stored as output resource list data into the RAM  32 .  
       FIG. 19  shows an example of the output resource list data. The illustrated example follows the allocation of  FIG. 9 . In the illustrated example, pages 1, 2, 3, 4, and 5 are allocated to the first printer  60  in this sequence as page numbers to be printed. Pages 1, 2, 3, 4, 5, 1, 2, 3, 4, and 5 are allocated to the second printer  70 , and pages 1, 2, 3, 4, and 5 are allocated to the third printer  80  in the respective sequences.  
      After conclusion of either step S 436  or step S 437 , the program goes to END and exits from this processing routine.  
      The following series of processing is carried out to actualize the printing operation according to the allocation of the pages to the output resources specified at either step S 436  or step S 437 . Referring to the flowchart of  FIG. 16 , the CPU  30  first sets a value ‘1’ to a printer counter C 1  representing a target printer used for printing (step S 440 ). The printer counter C 1  shows each available printer as the destination of distribution; the value ‘1’ represents the first printer  60 , the value ‘2’ represents the second printer  70 , and the value ‘3’ represents the third printer  70 .  
      The CPU  30  subsequently gives an instruction to change the settings to the printer specified by the value of the printer counter C 1  (step S 450 ). This processing makes the target printer ready for printing via the printer driver by transmitting the required information on the settings among the information with regard to the basic settings of printing and the information with regard to the paper settings included in the printer property data input at step S 420  to the printer driver. For example, the procedure informs the printer driver of the paper type ‘Glossy’ to make the printer ready for printing suitable for the glossy paper.  
      The CPU  30  sets a value ‘1’ to a page counter C 2  representing the page number to be printed (step S 460 ). The CPU  30  then determines whether or not the output resource list data obtained at step S 430  includes the page specified by the values of the printer counter C 1  and the page counter C 2  (step S 470 ). When the result of the determination shows that the output resource list data includes the specified page, the following series of processing is carried out. The CPU  30  gives an output command to the real printer driver  130  ( 140  or  150 ) of the printer specified by the value of the printer counter C 1  to make the specified printer carry out printing (step S 480 ). The real printer driver  130  ( 140  or  150 ) receiving the output command returns the performance information of the corresponding printer  60  ( 70  or  80 ), and the CPU  30  inputs the transmitted performance information (step S 490 ).  
      The CPU  30  subsequently generates final print data with regard to the page specified by the values of the page counter C 2  and the printer counter C 1 , based on the input performance information as well as the information with regard to the basic settings of printing and the paper settings included in the printer property data input at step S 420  (excluding the information with regard to the printer group and the distributed form) (step S 500 ). The concrete procedure of step S 500  extracts page data regarding the page corresponding to the value of the page counter C 2  from the intermediate print data input at step S 410  and carries out the rendering process to convert the extracted page data into data suitable for the printer  60  ( 70  or  80 ) corresponding to the value of the printer counter C 1  based on the performance information, the information regarding the basic settings of printing, and the information regarding the page settings, so as to generate the final print data.  
      The CPU  30  then outputs the generated final print data to the real printer driver  130  ( 140  or  150 ) of the printer  60  ( 70  or  80 ) corresponding to the value of the printer counter C 1  (step S 510 ). Prior to execution of printing at steps S 480  to S 510 , one modified procedure may monitor the status of each printer  60 ,  70 , or  80  based on the signal output from the corresponding real printer driver  130 ,  140 , or  150 . When the result of monitoring shows that there is a long queue of print jobs in the printer specified as the output resource or the specified printer is in an error state, the modified procedure may change the output resource to another printer or temporarily stop the output of the print job.  
      The CPU  30  subsequently increments the value of the page counter C 2  by one (step S 520 ). In the case of the negative answer at step S 470 , the program skips the processing of steps S 480  to S 510  and directly proceeds to step S 520 . The CPU  30  then determines whether or not the current value of the page counter C 2  exceeds a value LC 2  representing the last page (step S 530 ). When it is determined that the current value of the page counter C 2  does not exceed the value LC 2  representing the last page, the program returns to step S 470  and generates and outputs the final print data on the new page specified by the incremented value. When it is determined at step S 530  that the current value of the page counter C 2  exceeds the value LC 2  representing the last page, on the other hand, the CPU  30  increments the value of the printer counter C 1  by one (step S 540 ) and determines whether or not the current value of the printer counter C 1  exceeds a value LC 1  representing the last printer (step S 550 ). When it is determined that the current value of the printer counter C 1  does not exceed the value LC 1  representing the last printer, the program returns to step S 450  and generates and outputs the final print data on each page of the print job with the next printer  70  ( 80  or  60 ) specified by the incremented value of the printer counter C1. When it is determined at step S 550  that the current value of the printer counter C 1  exceeds the value LC 1  representing the last printer, on the other hand, the program determines that generation and output of the final print data has been concluded for all the pages of the print job required for printing with all the printers and goes to END to exit from the processing routine in the distributed printing utility.  
      The processing routine in the distributed printing utility is described to generate and output the final print data regarding the first page to the last page sequentially by the printer unit, that is, from the first printer to the last printer. Such description is, however, for convenience of illustration in the flowchart. The actual procedure carries out generation and output of the final print data regarding the first page to the last page by the respective printers in parallel by time sharing. The series of processing is executed in parallel in the respective printers in the structure of the embodiment. A computer main body including multiple microprocessors may alternatively be used to attain completely parallel processing.  
      A6. Effects of Embodiment  
       FIG. 20  is a timing chart showing a procedure of distributed printing with the computer system constructed as discussed above, compared with a prior art procedure. In the illustrated example, the print job is given to make each of the three printers  60 ,  70 , and  80  print one copy of a document including  3  pages. The procedure of this embodiment first generates the intermediate print data ([ 1 ]) and carries out the parallel rendering process to sequentially convert the page data on the first page of the intermediate print data into data adequate for the printer  60 , the printer  70 , and the printer  80  ([ 2 ], [ 3 ], [ 4 ]). Transmission of the data converted for the printer  60  (that is, the final print data) to the printer  60  is carried out in parallel with the rendering process for the next printer  70 . In a similar manner, transmission of the converted data to the printer  70  and to the printer  80  is carried out in parallel with the rendering process for the next printer. The procedure then carries out the parallel rendering process to sequentially convert the page data on the second page of the intermediate print data into data adequate for the printer  60 , the printer  70 , and the printer  80  ([ 5 ], [ 6 ], [ 7 ]). The procedure subsequently carries out the parallel rendering process to sequentially convert the page data on the third page of the intermediate print data into data adequate for the printer  60 , the printer  70 , and the printer  80  ([ 8 ], [ 9 ], [ 10 ]). The printing operation of the whole print job is thus concluded.  
      The prior art procedure first carries out the rendering process to convert the page data on the first page into data adequate for a first printer A and transmits the converted data by the rendering process to the printer A. The prior art procedure then carries out the rendering process to convert the page data on the second page into data adequate for the first printer A and transmits the converted data to the printer A. The prior art procedure subsequently carries out the rendering process to convert the page data on the third page into data adequate for the first printer A and transmits the converted data to the printer A. In the same manner as for the first printer A, the procedure sequentially carries out the rendering process for the first page, the second page, and the third page and transmission of the converted data to a second printer B. Similarly, the procedure sequentially carries out the rendering process for the first page, the second page, and the third page and transmission of the converted data to a third printer C.  
      The procedure of the embodiment carries out the rendering process in parallel with transmission of the processed data to the printer. Compared with the prior art procedure, the procedure of this embodiment thus effectively shortens the total time required for printing.  
      In the procedure of this embodiment, the intermediate print data is obtained by simple output of a print command from the application program  100  to the virtual printer driver  110 , and the distributed printing of the intermediate print data with the printers  60 ,  70 , and  80  is automatically carried out. The operator is thus only required to execute the ‘Print’ command once on the application program. This arrangement effectively ensures the excellent operatability.  
      In the structure of this embodiment, the distributed printing utility  120  automatically specifies allocation of the respective pages of print data to printers, and the operator is not required to individually output a print command to each printer specified as the destination of distribution. This ensures excellent operatability. In the speed preference mode, the procedure of the embodiment calculates the performance ratio of the respective printers  60 ,  70 , and  80  with regard to the printing speed from the information on the printing speed performances of the printers  60 ,  70 , and  80 , and specifies allocation of the pages to the respective printers  60 ,  70 , and  80  corresponding to the performance ratio. The printer having the high printing speed performance prints a large number of pages, while the printer having the low printing speed performance prints a little number of pages. This makes the respective printers conclude the printing operations almost simultaneously. This arrangement effectively shortens the total time required for printing.  
      In the handling preference mode, the procedure of the embodiment prevents each copy or a set of identical pages from being printed with multiple printers. Each copy or a set of identical pages is thus not parted in the resulting prints obtained from the respective printers. This effectively ensures the operatability in collection of the resulting prints.  
      In the structure of this embodiment, the mode is readily changed over between the speed preference mode and the handling preference mode by checking or non-checking of the check box id 3  ‘Bundle by Copy or Page’ in the ‘Distributed Printing Properties’ dialog box WN 2 . This ensures excellent operatability.  
      In this embodiment, inputting ‘By Printer’ in the ‘Job Grouping’ data input box id 4  effects the speed preference even in the handling preference mode, which is set by checking the check box id 3  ‘Bundle by Copy or Page’.  
      In the structure of this embodiment, the printing method is readily changed over between gathering print and stack print by checking or non-checking the check box id 2  ‘Collate’.  
      The structure of this embodiment allows the operator to readily input the information with regard to the form of distributed printing and the information with regard to the printer group in the ‘Distributed Printing Properties’ dialog box WN 2  open on the CRT display  12 . Especially the illustrated image in the distributed form display box dd in the ‘Distributed Printing Properties’ dialog box WN 2  informs the operator of the specified distributed form. The visual information of the distributed form prior to execution of actual distributed printing further enhances the operatability. In the example of  FIG. 6 , the printer names specified as the destinations of distribution are not added to the illustrated image in the distributed form display box dd. The printer names specified as the destinations of distribution may alternatively be added to the illustrated image. Namely the printer name specified as the destination of distribution is given to each set of pages. This distinctly informs the operator of the printer specified as the destination of distribution.  
      In the distributed printing control apparatus of the above embodiment according to the present invention, print data is directly output from one computer  10  to the multiple printers  60 ,  70 , and  80 . Another possible application is a client-server system, in which a server may be provided on the computer network  90  to manage distributed printing with multiple printers. In this application, the virtual printer driver is incorporated in each client, and the distributed printing utility is incorporated in the server.  
     B. Second Embodiment  
      B1. User Interface  
      The following describes a second embodiment of the present invention. The details of ‘A1. General Hardware Structure’, ‘A2. Distributed Printing Process’, and ‘A3. Virtual Printer Driver’ discussed in the first embodiment are adopted in the second embodiment of the present invention. The same parts as those of the first embodiment are expressed by the same numerals. The differences between the first embodiment and the second embodiment are part of the details of the user interface and part of the computer programs. The details of the user interface are discussed first.  
      Like the first embodiment, in the structure of the second embodiment, a dialog box ‘Distributed Printing Properties’ is provided as the user interface.  FIG. 21  illustrates a dialog box WN 12  ‘Distributed Printing Properties’. Like the first embodiment, two cards CD 11  ‘Distribution Settings’ and CD 12  ‘Printer’ are provided in the dialog box WN 12  ‘Distributed Printing Properties’. The ‘Distributed Settings’ card CD 11  is identical with the ‘Distributed Settings’ card CD 1  of the first embodiment (see  FIG. 6 ).  
      The ‘Printer’ card CD 12  is used to set the information with regard to the printer group as the potential destinations of distribution, the basic settings of printing, and the paper settings. This corresponds to the card CD 2  of the first embodiment. The operator selects either of the two cards CD 11  and CD 12  to be displayed in the dialog box WN 12  through operations of the mouse  20 . In the state of  FIG. 21 , the ‘Printer’ card CD 12  is selected. The division of the information into the cards CD 11  and CD 12  is not restricted to the above example, but the information may all be included in one card or may be divided into three or more cards.  
      The contents of the ‘Printer’ card CD 12  are discussed in detail. As illustrated, the ‘Printer’ card CD 12  includes a ‘Printer Group’ field fd 14 , a ‘Select Option’ field fd 15 , a ‘Paper Settings’ field fd 16 , and a settings display box fd 17 .  
      The ‘Printer Group’ field fd 14  specifies a group of printers, which are used for distributed printing of a document. The ‘Printer Group’ field fd 14  includes a ‘Group Name’ data input box id 111 , a ‘Comment’ display box id 112 , a ‘Printers’ display box id 113 , a ‘Number of Printers’ display box id 114 , and a ‘Group Settings’ button id 115 . In the following discussion, the group of printers or the printer group may simply be referred to as the group.  
      The ‘Group Name’ data input box id 111  sets the name of the group. A click of a button id 111   a  with an inverse triangle on the right end opens a pull-down menu (see  FIG. 31 ). A plurality of group names are preset as possible options in this pull-down menu. The operator clicks one of the options included in the pull-down menu with the mouse  20 , so as to set a desired group name in the data input box id 111 .  
      The ‘Comment’ display box id 112  shows any comment given to the currently selected group in the ‘Group Name’ data input box id 111 . The ‘Printers’ display box id 113  shows the names of the printers belonging to the currently selected group in the ‘Group Name’ data input box id 111 . The ‘Number of Printers’ display box id 114  shows the number of printers used for distribution printing.  
      The ‘Group Settings’ button id 115  is a switch to start various operations, such as addition of a new group or change of settings in an existing group. The following describes the operation of adding a new group. When the operator clicks the ‘Group Settings’ button id 115  with the mouse  20 , a ‘Group List’ dialog box is open on the CRT display  12 .  
       FIG. 22  shows a ‘Group List’ dialog box WN 13 . As illustrated, the ‘Group List’ dialog box WN 13  includes a ‘List’ display box id 121 , an ‘Add’ button id 122 , an ‘Edit’ button id 123 , and a ‘Delete’ button id 124 . The ‘List’ display box id 121  shows a list of existing groups. The ‘Add’ button id 122  is used to add a new group to the list. In response to a click of the ‘Add’ button id 122  with the mouse  20 , a ‘Group Settings’ dialog box is open on the CRT display  12 .  
       FIG. 23  shows a ‘Group Settings’ dialog box WN 14 . As illustrated, the ‘Group Settings’ dialog box WN 14  includes a ‘Group Name’ data input box id 131 , a ‘Comment’ data input box id 132 , a ‘Printers Belonging to’ display box id 133 , and a ‘Printers Not Belonging to’ display box id 134 .  
      The ‘Group Name’ data input box id 131  is used to input the name of the selected group of printers. The ‘Comment’ data input box id 132  is used to input any description of the selected group. The ‘Printers Belonging to’ display box id 133  shows printers belonging to the selected group. The ‘Printers Not Belonging to’ display box id 134  shows printers that are not included in the selected group among a large number of preset printer names.  
      The operator selects a desired one out of the printer names shown in the ‘Printers Not Belonging to’ display box id 134  and clicks an ‘Add’ button id 135 . The selected printer name is then transferred to the ‘Printers Belonging to’ display box id 133 . In the example of  FIG. 23 , there are the names of eight printers in the ‘Printers Not Belonging to’ display box id 134 . When the operator selects three printers ‘LP-100’, ‘LP-200’, and ‘LP-300’ and clicks the ‘Add’ button id 135 , the names of the three selected printers are transferred to the ‘Printers Belonging to’ display box id 133  as shown in  FIG. 24 .  
      The printers displayed in the ‘Printers Belonging to’ display box id 133  have the order of priority specified by the sequence of display. The printer displayed on the top has the highest priority, and the lower positioned printer has the lower priority. The displayed sequence of the printers is coincident with the sequence of the shift to the ‘Printers Belonging to’ display box id 133 . Selection of each printer out of the printer names in the ‘Printers Not Belonging to’ display box id 134  and a subsequent click of the ‘Add’ button id 135  sequentially shifts the selected printer to the ‘Printers Belonging to’ display box id 133 . This specifies the sequence of printers displayed in the ‘Printers Belonging to’ display box id 133 , that is, the order of priority allocated to the respective printers. The order of priority allocated to the respective printers is utilized for allocation in the distributed printing.  
      A ‘Delete’ button id 136  is used to delete a selected printer from the names of the printers included in the ‘Printers Belonging to’ display box id 133 .  
      One or a plurality of printers are allocated to each group through a series of operations on the ‘Group Settings’ dialog box WN 14 . The results of allocation are stored as group registration list data in the RAM  32 .  FIG. 25  shows an example of group registration list data PD. The group registration list data PD includes one or multiple group names, wherein one or multiple printer names and any related comment are mapped to each group name.  
      The group names displayed in the ‘List’ display box id 121  on the ‘Group List’ dialog box WN 13  are based on the group name data included in the group registration list data PD. Referring back to  FIG. 21 , the contents of the ‘Group Name’ data input box id 111 , the ‘Comment’ display box id 112 , and the ‘Printers’ display box id 113  in the ‘Printer Group’ field fd 14  are updated with the group registration list data PD, that is, the new registration in the ‘Group List’ dialog box WN 13  and the ‘Groups Settings’ dialog box WN 14 . The pull-down menu open from the ‘Group Name’ data input box id 111  accordingly includes the group names registered in the ‘Group List’ dialog box WN 13 . The registration in the ‘Group Settings’ dialog box WN 14  is reflected on the contents of the ‘Comment’ display box id 112  and the ‘Printers’ display box id 113 .  
      The ‘Select Option’ field fd 15  is used to restrict the data input in the ‘Paper Settings’ field fd 16  in two different modes ‘Functionality Preference’ and ‘Speed Preference’. The field fd 15  has a radio button BT 1  corresponding to the ‘Functionality Preference’ mode and a radio button BT 2  corresponding to the ‘Speed Preference’ mode. A click of the radio button BT 1  or BT 2  respectively activates the ‘Functionality Preference ‘mode or the ‘Speed Preference’ mode and restricts the data input. Restriction of the data input in the ‘Paper Settings’ field fd 16  in each mode will be discussed later in detail.  
      The ‘Paper Settings’ field fd 16  sets the paper and the printing quality and has data input boxes ‘Paper Size’ ‘Orientation’, ‘Double-faced Print’, ‘Paper Type’, ‘Color’, and ‘Resolution’ id 141 , id 142 , id 143 , id 144 , id 145 , and id 146 .  
      The ‘Paper Size’ data input box id 141  sets the paper size as well as the paper type. A pull-down menu (see  FIG. 32 ) is open in response to a click of a button id 141   a  with an inverse triangle on the right end. A plurality of paper sizes are preset as possible options in this pull-down menu. Examples of the possible options include ‘A4 210×297 mm’, ‘A4 Lateral 210×297 mm’, ‘Envelop 120×235 mm’, and ‘Postcard 100×147 mm’.  
      The ‘Orientation’ data input box id 142  represents the orientation of paper set in the printer and has two options ‘Portrait’ and ‘Landscape’. The ‘Double-faced Print’ data input box id 143  has a check box to specify double-faced printing. When this check box is clicked, only the printers having the double-faced printing function are used for distributed printing.  
      The ‘Paper Type’ data input box id 144  specifies the type of paper, and ‘Plain’, ‘Superfine’, and ‘Glossy’ are provided as possible options. The ‘Color’ data input box id 145  specifies the type of ink used in the printer  14 , and ‘Color’ and ‘Black’ are provided as possible options. The ‘Resolution’ data input box id 146  sets the printing resolution, and ‘Fast’ and ‘Fine’ are provided as possible options. For example, ‘Fast’ and ‘Fine’ respectively represent the resolutions of 360×360 (dots) and 720×720 (dots).  
      A settings display box fd 17  displays desired data among the settings in the ‘Printer Group’ field fd 14  and the ‘Paper Settings’ field fd 16 .  
      Various pieces of information with regard to the settings in the ‘Distributed Printing Properties’ dialog box WN 12 , for example, information on the form of distributed printing, information on the printer group as the destination of distribution, information on the paper settings, and information on the basic settings of printing, are input into the computer main body  16  through the user&#39;s operations of the mouse  20  and the keyboard  18 .  
      B2. Computer Programs  
      Like the first embodiment, the computer programs are executed in the virtual printer driver  110  and the distributed printing utility  120  in the second embodiment. The distributed printing utility  120  of the second embodiment is identical with that of the first embodiment and is thus not specifically described here. The following describes the virtual printer driver  110 .  
      Like the first embodiment, the virtual printer driver  110  is stored in advance in the floppy disk  22  and is installed from the floppy disk drive  24  into the computer  10  according to an activated preset installation program. The virtual printer driver  110  may be stored in another portable recording medium (carriable recording medium), such as a CD-ROM, a magneto-optic disc, or an IC card, in place of the floppy disk  22 . The virtual printer driver  110  may be program data, which are downloaded from a specific server connecting with an external computer network (for example, the Internet) via the computer network and transferred to either the RAM  32  or the HDD  41 .  
       FIG. 26  is a flowchart showing a processing routine described in the virtual printer driver  110  as well as a processing routine described in the application program  100 . The CPU  30  in the computer main body  16  starts the processing in the application program  100  and carries out a series of image processing to generate video data (step S 910 ). The application program  100  may be a general purpose application program used to create documents and pictures, and video data is generated by the functions characteristic of each application program.  
      The CPU  30  executes a ‘Print’ command provided in the application program and thereby outputs a print command for distributed printing (step S 920 ).  FIG. 27  illustrates a ‘Print’ dialog box WN 16  open on the CRT display  12  in response to execution of the ‘Print’ command on the application program  100 . As illustrated, the ‘Print’ dialog box WN 16  has a ‘Printer Name’ data input box id 151 . The print command for distributed printing is output from the application program  100  via the operating system to the virtual printer driver  110  in response to a click of an ‘OK’ button id 152  with the mouse  20 , while a series of letters ‘Distributed Printing’, which corresponds to the ‘Distributed Printing’ icon IC 4  discussed previously with  FIG. 5 , is selectively input in the ‘Printer Name’ data input box id 151 . A click of a ‘Properties’ button id 153  in the ‘Print’ dialog box WN 16  shifts the processing to a distribution information setting routine executed in the virtual printer driver  110 . The process opens the ‘Distributed Printing Properties’ dialog box WN 12  on the CRT display  12  and reads input data from the keyboard  18  and the mouse  20 , so as to set various pieces of information regarding the distributed printing.  
      The following describes a series of processing to set various pieces of information relating to the distributed printing in the ‘Distributed Printing Properties’ dialog box WN 12 .  FIG. 28  is a flowchart showing a distribution information setting routine executed by the CPU  30 . When the program enters this routine, the CPU  30  first opens the ‘Distributed Printing Properties’ dialog box WN 12  shown in  FIG. 21  on the CRT display  12  (step S 610 ). The CPU  30  then determines which of the ‘Distribution Settings’ card CD 11  and the ‘Printer’ card CD 12  is active in this dialog box WN 12  (step S 620 ). When it is determined that the ‘Distribution Settings’ card CD 11  is active, the program goes to step S 630 .  
      At step S 630 , the CPU  30  inputs diverse data through the operator&#39;s data input operations with the keyboard  18  and the mouse  20  while the operator checks the display on the CRT display  12 . The diverse data input here represent the settings in the ‘Distribution Settings’ card CD 11  in the ‘Distributed Printing Properties’ dialog box WN 12 , and includes information with regard to the form of distributed printing. The CPU  30  subsequently stores the diverse data input at step S 630  as part of the printer property data into the RAM  32  (step S 640 ). The program then goes to RETURN and exits from this processing routine.  
      When it is determined at step S 620  that the ‘Printer’ card CD 12  is active, on the other hand, the program goes to step S 650  to execute a data input routine on the ‘Printer’ card CD 12 . The details of the data input routine will be discussed later. Information with regard to the printer group, information with regard to the paper settings, and information with regard to the basic settings of printing are input in the ‘Printer’ card CD 12  by execution of the data input routine. The CPU  30  subsequently stores the diverse data input at step S 650  as part of the printer property data into the RAM  32  (step S 660 ). The program then goes to RETURN and exits from this processing routine.  
      The following describes the details of the data input routine executed at step S 650 .  FIGS. 29 and 30  are flowcharts showing the details of the data input routine. When the program goes to step S 650  in the distribution information setting routine and starts the data input routine, the CPU  30  first reads input data through the operator&#39;s input operations with the keyboard  18  and the mouse  20  (step S 710 ) as shown in  FIG. 29 . The CPU  30  then determines whether or not a button id 111   a  attached to the data input box id 111  ‘Group Name’ is clicked with the mouse  20 , based on the input data (step S 720 ). The following series of processing is carried out in response to the click.  
      The CPU  30  first opens a pull-down menu MN 1  for input of the group name on the CRT display  12  (step S 730 ).  FIG. 31  shows an example of the pull-down menu MN 1  for input of the group name open on the CRT display  12 . As illustrated, the pull-down menu MN 1  is open immediately below the ‘Group Name’ data input box id 111 . The pull-down menu MN 1  includes multiple group names as possible options. The concrete procedure of step S 730  specifies the options to be included in the pull-down menu MN 1  based on the group registration list data PD stored in the RAM  32  and opens the pull-down menu MN 1  on the CRT display  12 .  
      The CPU  30  then selects one group name in the pull-down menu MN 1  in response to an operator&#39;s click with the mouse  20  (step S 740 ). The names of the printers belonging to the group expressed by the selected group name are read from the group registration list data PD stored in the RAM  32 , is registered into a temporary area in the RAM  32 , and is displayed in the ‘Printers’ display box id 113  on the ‘Printer’ card CD 12  (step S 750 ). As a result, the names of the printers belonging to the group expressed by the group name set in the ‘Group Name’ data input box id 111  are enumerated in the ‘Printers’ display box id 113  as illustrated in  FIG. 32 .  
      The CPU  30  subsequently reads the performance information with regard to the printers expressed by the printer names stored in the RAM  32  at step S 750  (step S 760 ). Here the performance information includes information with regard to the printable paper sizes, the printable paper types, and permission to double-faced print, and is received from the real printer drivers provided for the respective types of the printers and loaded in advance in the RAM  32 . After execution of step S 760 , the program goes to RETURN and exits from this data input routine.  
      In a negative answer at step S 720 , on the other hand, the CPU  30  goes to step S 770  in the flowchart of  FIG. 30 . At step S 770 , it is determined whether or not a button id 141   a  attached to the ‘Paper Size’ data input box id 141  on the ‘Printer’ card CD 12  is clicked with the mouse  20 , based on the input data read at step S 710 . The following series of processing is carried out in response to the click.  
      The CPU  30  first detects the printable paper sizes in each printer, based on the performance information of each printer read at step S 760  (step S 780 ). The CPU  30  then determines whether or not the ‘Functionality Preference’ mode is selected in the ‘Select Option’ field fd 15  on the ‘Printer’ card CD 12  (step S 790 ). The determination depends upon selection of either the radio button BT 1  corresponding to the ‘Functionality Preference’ mode or the radio button BT 2  corresponding to the ‘Speed Preference’ mode.  
      When it is determined at step S 790  that the ‘Functionality Preference’ mode is selected, the CPU  30  selects all the printable paper sizes with any of the printers detected at step S 780  (this corresponds to execution of the OR operation) (step S 800 ). For example, when the printable paper sizes with the printers  60  and  70  are ‘B5’ and ‘A4’ and the printable paper sizes with the printer  80  are ‘B5’, ‘A4’, and ‘A3’, the procedure of step S 800  selects all the paper sizes ‘B5’, ‘A4’, and ‘A3’ as the possible options.  
      When it is determined at step S 790  that not the ‘Functionality Preference’ mode but the ‘Speed Preference’ mode is selected, the CPU  30  selects common paper sizes to al the printers among the printable paper sizes in the respective printers detected at step S 780  (this corresponds to the AND operation) (step S 810 ). For example, when the printable paper sizes with the printers  60  and  70  are ‘B5’ and ‘A4’ and the printable paper sizes with the printer  80  are ‘B5’, ‘A4’, and ‘A3’, the procedure of step S 810  selects the paper sizes ‘B5’ and ‘A4’ as the possible options.  
      After execution of either step S 800  or step S 810 , the CPU  30  goes to step S 820  to open a pull down menu MN 2  for input of the paper size on the CRT display  12 .  FIG. 32  shows an example of the pull-down menu MN 2  for input of the paper size open on the CRT display  12 . As illustrated, this pull-down menu MN 2  is open immediately below the ‘Paper Size’ data input box id 141 . The pull-down menu MN 2  includes the paper sizes selected at either step S 800  or step S 810  as possible options.  
      As shown in  FIG. 32 , in the case where the ‘Functionality Preference’ mode is selected in the ‘Select Option’ field fd 15 , the pull-down menu MN 2  for input of the paper size includes all the printable paper sizes with any of the printers belonging to the currently selected group (that is, the printers displayed in the ‘Printers’ display box id 113 ). For example, the paper sizes ‘B5’, ‘A4’, and ‘A3’ are shown as possible options.  
      As shown in  FIG. 33 , in the case where the ‘Speed Preference’ mode is selected in the ‘Select Option’ field fd 15 , on the other hand, the pull-down menu MN 2  for input of the paper size includes the paper sizes common to all the printers among the printable paper sizes in the respective printers belonging to the currently selected group (that is, the printers displayed in the ‘Printers’ display box id 113 ). For example, the paper sizes ‘B5’ and ‘A4’ are shown as possible options.  
      Comparison between the display in the ‘Speed Preference’ mode shown in  FIG. 33  and the display in the ‘Functionality Preference’ mode shown in  FIG. 32  shows exclusion of the ‘A3’ paper size from the possible options. One modified procedure of this embodiment may gray down the display of the option to be excluded. The gray-down display means to lower the density of letters in the display and forbids selection with the mouse  20 , although the letters are distinguishable. This modified arrangement informs the operator of the non-settable conditions by lack of the functions in some printers.  
      Referring back to  FIG. 30 , after execution of step S 820 , the CPU  30  selects one paper size in the pull-down menu MN 2  in response to an operator&#39;s click with the mouse  20  (step S 830 ). The selected paper size is set in the ‘Paper Size’ data input box id 141 . The setting of the paper size is then registered into the temporary area in the RAM  32  (step S 840 ).  
      The CPU  30  subsequently compares the paper size registered at step S 840  with the paper sizes of the respective printers detected at step S 780 , selects the printer that is incapable of printing the selected paper size among the printers belonging to the currently selected group, and grays down the display of the selected printer in the ‘Printers’ display box id 113  (step S 850 ).  
      For example, when the ‘A3’ paper size is set in the ‘Paper Size’ data input box id 141  as shown in  FIG. 34 , the display of the names of the printers that are incapable of printing the ‘A3’ paper size, for example, ‘LP-100’ and ‘LP-200’, is grayed down among the printer names displayed in the ‘Printers’ display box id 113 . The processing of step S 840  is carried out only in the ‘Functionality Preference’ mode. Since only the paper sizes common to all the printers are selected in the ‘Speed Preference’ mode, the processing of step S 840  is not required. This arrangement distinctly informs the operator of the printers that can not be used for distributed printing. After execution of step S 850 , the program goes to RETURN and exits from this data input routine.  
      In the case of a negative answer at step S 770 , on the other hand, the CPU  30  goes to step S 860  to input data in another data input box on the ‘Printer’ card CD 12  (step S 860 ). The input data is registered into the temporary area in the RAM  32 . The program then goes to RETURN and exits from this data input routine.  
      The data input routine starts when the processing shifts to step S 650  in the distribution information setting routine, and is iteratively carried out in response to each data input in any of the various data input boxes on the ‘Printer’ card CD 12 . The data input routine is concluded in response to a click of an ‘OK’ button BTOK provided at the lower-most position of the ‘Distributed Printing Properties’ dialog box WN 12 . After conclusion of the data input routine, the CPU  30  goes to step S 660  in the flowchart of  FIG. 28  to store the various input data, which have been registered in the temporary area in the RAM  32  according to the data input routine, into the RAM  32  as part of the printer property data. Information regarding the printer group, information regarding the paper settings, and information regarding the basic settings of printing set in the ‘Printer’ card CD 12  are then input into the computer main body  16 .  
      In the structure of the embodiment, the options settable in the ‘Paper Size’ data input box id 141  as one printing condition are restricted according to the performances of the respective printers belonging to the currently selected group. The input in the ‘Double-faced Print’ data input box id 143  is also restricted by a non-illustrated flowchart according to the performances of the respective printers belonging to the currently selected group. In the case where at least one among the printers included in the currently selected group has the function of double-faced printing, data input in the ‘Double-faced Print’ data input box id 143  is permitted (that is, input of either of the two conditions, double-faced print and no double-faced print, as the result of the OR operation of the performance information of the respective printers is allowed) in the ‘Functionality Preference’ mode. In the ‘Speed Preference’ mode, on the other hand, data input in the ‘Double-faced Print’ data input box id 143  is prohibited (that is, input of only one condition, no double-faced print, as the result of the AND operation of the performance information of the respective printers is allowed). The concrete procedure activates the ‘Double-faced Print’ data input box id 143  in the ‘Functionality Preference’ mode, while graying down and inactivating the data input box id 143  in the ‘Speed Preference’ mode.  
      After setting the various pieces of information relating to the distributed printing in the ‘Distributed Printing Properties’ dialog box WN 12 , a print command is output at step S 920  in the flowchart of  FIG. 26  in response to a click of the ‘OK’ button id 152  in the ‘Print’ dialog box WN 16  as discussed previously. In the case where the ‘Properties’ button id 153  is not clicked but the ‘OK’ button id 152  is clicked immediately with the mouse  20 , the printer property data stored in the RAM  32  in the previous cycle of the distribution information setting routine (in the first cycle, preset initial printer property data) are maintained without any modification.  
      In response to the output of the print command at step S 920 , the CPU  30  shifts the processing to the virtual printer driver  110  and determines whether or not the print command is input from the application program  100  (step S 1010 ). In the case of no input of the print command, the CPU  30  iteratively carries out the decision at step S 1010  and waits for input of the print command from the application program  100 . In the case of input of the print command at step S 1010 , on the other hand, the CPU  30  carries out the series of processing discussed below.  
      The CPU  30  first reads from the distributed printing utility  120  the performance information of the respective printers  60 ,  70 , and  80 , which has been transmitted from the real printer drivers  130 ,  140 , and  150  provided for the respective types of the printers  60 ,  70 , and  80  to the distributed printing utility  120  (step S 1020 ). The CPU  30  then extracts the highest performance out of the performance information of the respective printers  60 ,  70 , and  80  and specifies the extracted highest performance as the performance information of the virtual printer (step S 1030 ). The CPU  30  then transmits the performance information of the virtual printer to the application program  100  (step S 1040 ).  
      When the performance information of the virtual printer is transmitted from the virtual printer driver  110 , the CPU  30  shifts the processing to the application program  100  and receives the transmitted performance information of the virtual printer (step S 940 ). The CPU  30  subsequently converts the video data generated at step S 910  into print data adequate for the virtual printer, based on the performance information as well as the information regarding the basic settings of printing and the information regarding the paper settings, which are included in the printer property data stored in the RAM  32  in the distribution information setting routine discussed above (excluding the information regarding the printer group and the distributed form) (step S 950 ). After the data conversion, the CPU  30  transmits the converted print data to the virtual printer driver  110  (step S 960 ). On completion of the processing at step S 960 , the CPU  30  exits from the processing routine in the application program  100 .  
      When the print data adequate for the virtual printer is transmitted from the application program  100 , the CPU  30  shifts the processing to the virtual printer driver  110  and receives the transmitted print data (step S 1010 ). The CPU  30  subsequently outputs the input print data as intermediate print data to the HDD  41  (step S 1060 ). A data set or a set of the intermediate print data is then stored as an intermediate print file MF into the HDD  41 . On completion of the processing at step S 1060 , the CPU  30  exits from the processing routine in the virtual printer driver  110 .  
      After conclusion of the processing routine in the virtual printer driver, the distributed printing utility is activated, which is identical with that of the first embodiment (see  FIGS. 15 and 16 ) as mentioned above. The series of distributed printing process executed in the distributed printing utility is identical with that of the first embodiment shown in  FIG. 20 .  
      B3. Effects of Embodiment  
      In the second embodiment constructed as discussed above, the paper size condition set in the data input box id 141  ‘Paper Size’ in the ‘Printer’ card CD 12  is restricted by the performances of the respective printers belonging to the currently selected group. Namely the paper size condition set in the data input box id 141  follows the performance information of the respective printers. This ensures the adequate paper size condition and enables the distributed printing to be performed according to the performances of the printers, thus effectively assuring favorable resulting prints.  
      In the structure of the embodiment, in the case of selection of the ‘Functionality Preference’ mode, a set of all the printable paper sizes with any of the printers belonging to the currently selected group is displayed as options in the pull-down menu MN 2  for input of the paper size. In the case of selection of the ‘Speed Preference’ mode, on the other hand, a set of common paper sizes to all the printers among the printable paper sizes in the respective printers belonging to the currently selected group is displayed as options in the pull-down menu MN 2  for input of the paper size. In the ‘Functionality Preference’ mode, the printing operation utilizes the performance of any of the multiple printers specified as the destinations of distribution. This ensures the high-performance printing. In the ‘Speed Preference’ mode, the printing operation utilizes the performance common to all the multiple printers specified as the destinations of distribution. This allows the printing operation to be performed with any of the multiple printers, thus desirably shortening the total time required for printing.  
      In the structure of this embodiment, the mode is changed over between the ‘Functionality Preference’ mode and the ‘Speed Preference’ mode by selecting either of the radio buttons BT 1  and BT 2  on the ‘Printer’ card CD 12  displayed on the CRT display  12 . The operator can thus freely select the priority of functionality or the priority of speed. This arrangement effectively ensures the excellent operatability.  
      In this embodiment, the radio buttons BT 1  and BT 2  are specifically provided for changing over the mode. One possible modification may change over the mode between the ‘Functionality Preference’ mode and the ‘Speed Preference’ mode according to the input data in an existing data input box. For example, the process sets the ‘Functionality Preference’ mode in response to selection of ‘Fast’ in the ‘Resolution’ data input box id 146 , while setting the ‘Speed Preference’ mode in response to selection of ‘Fine’.  
      In this embodiment, a plurality of printers as destinations of distribution are specified by the unit of a group in the ‘Group Name’ data input box id 111 . This arrangement does not require individual specification of each printer as a destination of distribution, thus enhancing the user&#39;s operatability. Allocation of the order of priority to the printers belonging to the selected group enhances the convenience of collection of the resulting prints.  
      Some examples of possible modification are given below.  
      (1) In the structure of the above embodiment, the ‘Printers’ display box id 113  only shows the names of the printers belonging to the currently selected group in the ‘Group Name’ data input box id 111 . One possible modification provides check boxes cbx before the respective printer names as shown in  FIG. 35 . In response to setting a selected group name in the ‘Group Name’ data input box id 111 , the names of all the printers belonging to the selected group are shown in the ‘Printers’ display box id 113 . In the initial state, the check boxes cbx provided before the respective printer names are all checked. When the operator desires to prohibit output of the print data to a certain printer because of out-of-paper, failure, or any other reason, the operator releases the check in the corresponding check box cbx to exclude the printer from the output resource of the print data. This arrangement effectively ensures the excellent operatability.  
      In this modified structure, the options included in the pull-down menu MN 2  for input of the paper size, which is open in the ‘Paper Size’ data input box id 141 , depend upon the printers having checks in the corresponding check boxes cbx. For example, when the check box cbx ‘LP-300’ is inactivated to exclude the printer that is capable of printing the ‘A3’ paper size from the output resources of the print data as shown in  FIG. 36 , in the ‘Functionality Preference’ mode, the option ‘A3’ is grayed down to be not selectable in the pull-down menu MN 2  for input of the paper size.  
      (2) In the above embodiment, the paper size is discussed as the predetermined condition relating to the printing performance of the printer. The predetermined condition is, however, not restricted to the paper size, but may be any other suitable conditions relating to the printing performance, for example, data input in the respective data input boxes id 143 , id 144 , id 145 , and id 146  ‘Double-faced Print’, ‘Paper Type’, ‘Color’, and ‘Resolution’.  
      (3) In the distributed printing control apparatus of the above embodiment according to the present invention, print data is directly output from one computer  10  to the multiple printers  60 ,  70 , and  80 . Another possible application is a client-server system, in which a server may be provided on the computer network  90  to manage distributed printing with multiple printers. In this application, the virtual printer driver is incorporated in each client, and the distributed printing utility is incorporated in the server.  
     C. Third Embodiment  
      C1. Distributed Printing Process  
      The following describes a third embodiment of the present invention. The details of ‘A1. General Hardware Structure’, ‘A2. Distributed Printing Process’, ‘A3. Virtual Printer Driver’, and ‘A4. User Interface’ discussed in the first embodiment are adopted in the third embodiment of the present invention. The same parts as those of the first embodiment are expressed by the same numerals. The third embodiment has unique characteristics in the ‘Distributed Printing Process’.  
       FIG. 37  is a block diagram showing the functions of a distributed printing utility  120 C in the third embodiment. As illustrated, the distributed printing utility  120 C includes an intermediate print data input module  121 , a property data input module  122 , an allocation specification module  123 , an output data control module  124 , a printer setting module  125 , an output command output module  126 , a performance information input module  127 , a final print data output module  128 , a printer monitoring module  129 , and a performance information output module  12   a , which exert the same functions as those of the corresponding elements in the distributed printing utility  120  of the first embodiment. The output data control module  124  of this embodiment exerts the same functions as those of the output data control module  124  of the first embodiment, as well as the functions of a printable area computation module  124   a  and an area fitting module  124   b .  
      Prior to description of the modules  124   a  and  124   b , the performance information transmitted from the real printer drivers  130 ,  140 , and  150  is discussed. The performance information represents the performances of the printers  60 ,  70 , and  80  corresponding to the real printer drivers  130 ,  140 , and  150  as discussed above, and includes information on the printable paper sizes, the unprintable area size representing an unprintable area in the whole paper area, and permission to double-faced print. The unprintable area size is set for four directions, top, bottom, left, and right sides of paper. In general, each printer has an unprintable area, where printing is not allowable because of various reasons, for example, a sheet feed roller slips out of the end of paper. The size of the unprintable area depends upon the type of the respective printers  60 ,  70 , and  80 . The performance information input module  127  receives such various pieces of information from the real printer drivers  130 ,  140 , and  150 .  
      The printable area computation module  124   a  specifies a printable area with any of the printers  60 ,  70 , and  80  specified as the destinations of allocation (hereinafter referred to as the common printable area), based on the value of the unprintable area size out of the performance information input into the performance information input module  127 . The area fitting module  124   b  restricts the printing area of the intermediate print data into the common printable area, in the case where the printing area defined by the intermediate print data is partly out of the common printable area computed by the printable area computation module  124   a  in the process of data conversion of the intermediate print data to data suitable for each of the printers  60 ,  70 , and  80 . The converted print data output from the output data control module  124  having the above functions is transmitted as final print data to the real printer drivers  130 ,  140 , and  150  via the final print data output module  128 .  
      C2. Computer Programs  
      Like the first embodiment, the computer programs are executed in the virtual printer driver  110  and the distributed printing utility  120 C in the third embodiment. The virtual printer driver  110  of the third embodiment is identical with that of the first embodiment and is thus not specifically described here. The following describes the distributed printing utility  120 C.  
      Like the virtual printer driver  110 , the distributed printing utility  120 C is stored in advance in the floppy disk  22  and is installed from the floppy disk drive  24  into the computer  10  according to an activated preset installation program. The installed distributed printing utility  120  is stored in the HDD  41 , is incorporated into the operating system in response to power supply to the computer  10 , and is loaded to a predetermined area in the RAM  32 . Like the virtual printer driver  110 , the distributed printing utility  120  may be stored in another portable recording medium (carriable recording medium), such as a CD-ROM, a magneto-optic disc, or an IC card, in place of the floppy disk  22 . The distributed printing utility  120  may be program data, which are downloaded from a specific server connecting with an external computer network (for example, the Internet) via the computer network and transferred to either the RAM  32  or the HDD  41 .  
       FIG. 38  is a flowchart showing a first half of a processing routine described in the distributed printing utility  120 . This processing routine is activated after conclusion of the processing routine executed in the virtual printer driver  110 . When the program enters the processing routine, as shown in  FIG. 38 , the CPU  30  first inputs the intermediate print data in the intermediate print file MF from the HDD  41  (step S 410 ). The CPU  30  then inputs the printer property data as the various pieces of information set in the virtual printer driver  110  (step S 420 ). The processes of steps S 410  and S 420  are identical with those of the first embodiment and are thus expressed by the same step numbers.  
      The CPU  30  subsequently sends a control signal to the real printer drivers  130 ,  140 , and  150  of the respective printers  60 ,  70 , and  80  and receives the performance information regarding the performances of the printers  60 ,  70 , and  80  from the respective real printer drivers  130 ,  140 , and  150  that have received the control signal (step S 422 ). The CPU  30  then extracts data on the unprintable area size on the top, bottom, left, and right sides of the whole paper area in the respective printers from the performance information and computes a common printable area with any of the printers  60 ,  70 , and  80  specified as the destinations of distribution from the data on the unprintable area size (step S 424 ).  
      The computation carries out comparison among the unprintable area sizes on the top, bottom, left, and right sides of the whole paper area in the respective printers  60 ,  70 , and  80 , defines a common unprintable area by the respective largest values, and specifies an area in the whole paper area excluding this common unprintable area as the common printable area.  FIG. 39  shows a process of such computation. For example, when the unprintable area size of the printer  60  is left=4 mm, right=5 mm, top=3 mm, and bottom=3 mm and the unprintable are size of the printers  70  and  80  is left=3 mm, right=8 mm, top=3 mm, and bottom=8 mm, the size of the common unprintable area is left=4 mm, right=8 mm, top=3 mm, and bottom=8 mm. The area in the paper area P excluding this common unprintable area (that is, the hatched area in the illustration) is specified as the common printable area. This step S 424  corresponds to the printable area computation module  124   a  discussed above.  
      The CPU  30  then corrects the margins defined by the intermediate print data based on the common printable area computed at step S 424  (step S 426 ). Here the margins represent the sizes of the top, bottom, left, and right spaces specified by the operator in the ‘Page Settings’ dialog box in the process of generating the print data by the application program  100 . When any of the margins is out of the common printable area, the procedure of step S 426  restricts the margins to values coincident with the common printable area. For example, when the common printable area has the size shown in  FIG. 14  and the top, bottom, left, and right margins set by the application program are all equal to 5 mm, the top, bottom, left, and right margins are corrected to 5 mm, 8 mm, 5 mm, and 8 mm. This step S 426  corresponds to the area fitting module  124   b  discussed above.  
      The CPU  30  subsequently specifies allocation of the intermediate print data, which has been subjected to the margin correction at step S 426 , based on the information with regard to the printer group and the information with regard to the distributed form included in the printer property data input at step S 420  (step S 430 ). This process specifies allocation of the respective pages included in the intermediate print data to the printers  60 ,  70 , and  80  belonging to the selected printer group. The concrete procedure of step S 430  specifies allocation of the respective pages of the intermediate print data to the printers  60 ,  70 , and  80 , in order to attain the distributed form set in the ‘Distributed Printing Properties’ dialog box WN 2  (that is, the distributed form displayed in the distributed form display box dd of the ‘Distribution Settings’ card CD 1  shown in  FIG. 10 ). Information regarding the preset pages allocated to the respective printers is stored as output resource list data into the RAM  32 .  
       FIG. 40  shows an example of the output resource list data. In the illustrated example, the print job is given to make each of the three printers  60 ,  70 , and  80  print one copy of a document including  3  pages. The 1 st  to the 3 rd  pages are set as the page numbers to be printed with each of the three printers  60 ,  70 , and  80 . The process of step S 430  is identical with that of the first embodiment and is thus expressed by the same step number.  
      When allocation of the respective pages to the output resources is specified at step S 430 , the program goes to a latter half of the processing routine to implement the actual printing operation according to the specified allocation. The latter half follows the processing of steps S 440  to S 550  of the first embodiment shown in  FIG. 16 .  
      In the third embodiment, the process of step S 500  shown in  FIG. 16  extracts page data representing the page specified by the value of the page counter C 2  from the intermediate print data, which has been input at step S 410  and subjected to the margin correction at step S 426 , and converts the extracted page data into data suitable for the printer  60  ( 70  or  80 ) specified by the value of the printer counter C 1 , based on the performance information as well as the information regarding the basic settings of printing and the information regarding the paper settings, so as to generate the final print data. The margin correction of the intermediate print data at step S 426  effectively restricts the printing area in each page of the final print data generated at step S 500  into the common printable area to all the printers  60 ,  70 , and  80 .  
      The series of distributed printing process executed in the distributed printing utility  120 C follows the process of the first embodiment shown in  FIG. 20 .  
      C3. Effects of Embodiment  
      The procedure of the third embodiment receives information on the unprintable area size, which represents an unprintable area in the whole paper area, in each of the multiple printers  60 ,  70 , and  80  specified as the destinations of distribution, and computes a common printable area in the whole paper area with any of the printers  60 ,  70 , and  80  from the information on the unprintable area size. The print data from the application program is then distributed and output to satisfy the condition of the common printable area. The print data accordingly occupies an identical printing area in any of the multiple printers  60 ,  70 , and  80  specified as the destinations of distribution. The user can thus obtain resulting prints having the perfectly coincident size and position of the printing area from the multiple printers  60 ,  70 , and  80  specified as the destinations of distribution.  
      The procedure of this embodiment makes the print data fit for the common printable area by simply correcting margins specified in the application program based on the common printable area. This effectively simplifies the configuration of the computer programs.  
      In the structure of the embodiment, the information on the unprintable area size is input from the printer drivers provided for the respective printers  60 ,  70 , and  80 . This facilitates input of the information without requiring any specific input means.  
      In the structure of this embodiment, when any error arises in one of the printers specified for distributed printing, another printer is used for recovery. The common printable area is also allocated to the printer specified as the recovery resource. Namely the user can obtain resulting prints having the perfectly coincident size and position of the printing area from all the printers including the printer specified as the recovery resource.  
      Some examples of possible modification are discussed below.  
      (1) The procedure of the above embodiment receives the information on the unprintable area size in the whole paper area from the multiple printers specified as the destinations of distribution and computes the common printable area to all the printers from the input information. One possible modification may receive information on the printable area and compute the common printable area from the input information. This arrangement is allowed since the printable area is complement of the unprintable area.  
      (2) The procedure of this embodiment makes the print data fit for the common printable area by simply correcting margins specified in the application program based on the common printable area. One possible application may carry out data conversion to restrict the printing area of each page in the final print data into the common printable area in the processing of step S 500 , that is, in the rendering process that generates final print data with the real printer drivers  130 ,  140 , and  150 .  
      (3) In the distributed printing control apparatus of the above embodiment according to the present invention, print data is directly output from one computer  10  to the multiple printers  60 ,  70 , and  80 . Another possible application is a client-server system, in which a server may be provided on the computer network  90  to manage distributed printing with multiple printers. In this application, the virtual printer driver is incorporated in each client, and the distributed printing utility is incorporated in the server.  
      The above embodiments are 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.  
     INDUSTRIAL APPLICABILITY  
      The technique of the present invention is applicable to diverse information processing apparatuses like various computers connectable with a plurality of printers.