Abstract:
A printing system including a client terminal and a separate printer connected to the client terminal via signal cables. The client terminal includes a print conditions transfer mechanism which transfers print conditions entered by an operator and a document component generating mechanism. The document component generating mechanism divides a document entered by the operator into a document block, converts data in each document block into printable data, and generates document component. A number of the document component is equal to the number of the divided document blocks so that the document components and the divided document block correspond to each other on a one to one basis. The printer includes a print conditions storing mechanism which receives and stores the print conditions, a document component storing mechanism which sequentially stores and transmits the transferred document component, and a composite print processing mechanism. The composite print processing mechanism generates image data according to the print conditions and corresponding to each of the document components and accumulates the generated image data to print the document with the accumulated image data upon receiving a print start instruction.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a system and a method for document printing. More particularly, the present invention relates to a system and a method for preparing print data in an efficient manner in which separate client and printing terminals are connected each other and unnecessarily repetitive operations are avoided during a print data preparation time. 
     2. Discussion of the Background 
     A conventional printing system includes a client terminal for creating and editing a document and a separate printer for printing a document transmitted from the client terminal. The separate printer is connected to the client terminal with a cable. When completing a document on the client terminal, the operator generally (1) inputs desired print conditions to print data generation software (e.g., a printer driver) in order to have the document converted into data written in a selected page description language; (2) sends the converted data to the printer; and (3) starts the printer to print the data. 
     However, the above-described procedure has several drawbacks. Even when changing only a small part of the document, the whole document must be processed through the printer driver and then transferred to the printer. The processing and transferring requires a large amount of time relative to the amount of change. In addition, the fact that the desired print conditions can only be designated after the document data is completed makes it difficult, if not impossible, for the printer driver to perform data generation subsequent to creation and change of the document. 
     Several related techniques are disclosed in Japanese Unexamined Patent Publications JPAP6-243 133, JAPA6-28126, and JPAP8-230249. 
     The printing system disclosed in JPAP6-28126 is capable of selecting pages that include changes and transmitting only the pages that include changes to the printer. However, when the whole document is printed again, the same procedure is repeated. 
     A method for parallel performing a printer command using at least two computing devices is disclosed in JPAP6-28126, and a method for performing data conversion with a page description language at the printer side is disclosed in JPAP8-230249. However, neither JPAP6-28126 nor JPAP8-230249 provide a solution to the above-described drawbacks. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention is to provide a novel printing system that includes a client terminal and a separate printing terminal connected to the client terminal, prepares printable image data in an efficient manner, and avoids repetitive operations. 
     It is yet another object of the present invention to provide a novel method of printing with a printing system that includes a client terminal and a separate printing terminal connected to the client terminal in which printable image data is prepared in an efficient manner and repetitive operations are avoided. 
     These and other objects are achieved according to a novel printing system and method of printing in which a printing system includes a client terminal and a separate printing terminal connected to the client terminal via signal cables. The client terminal includes a print conditions transfer mechanism which transfers print conditions entered by an operator and a document component generating mechanism. The document component generating mechanism divides a document entered by the operator into a document block, converts data in each document block into printable data, and generates a document component corresponding the document block. The printing terminal includes a print conditions storing mechanism which receives, stores, and transmits the transferred print conditions, a document component storing mechanism which receives, stores, and sequentially transmits the transferred document components, and a composite print processing mechanism which generates image data according to the printed conditions and accumulates the generated image data to print the document with the accumulated image data according to the print conditions upon receiving a print start instruction. The image data corresponds to each of the document components. 
     Other objects, features, and advantages of the present invention will become apparent from the following detailed description when read in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A more complete appreciation of the present invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: 
     FIG. 1 is a block diagram of a printing system according to a first embodiment of the present invention; 
     FIG. 2 is an illustration of an exemplary document used in the printing system of FIG. 1; 
     FIG. 3 is a flowchart describing the operation of the client terminal  2  of FIG. 1; 
     FIG. 4 is a flowchart describing the operation of the printer  3  of FIG. 1; 
     FIG. 5 is a block diagram of a printing system according to a second embodiment of the present invention; 
     FIG. 6 is an exemplary list of document components that use the page description language employed in the printers  3  of FIGS. 1,  5 , and  8 ; 
     FIG. 7 is an illustration of an exemplary document used in the printing system of FIGS. 1 and 5; 
     FIG. 8 is a block diagram of a printing system according to a third embodiment of the present invention; 
     FIG. 9 is an exemplary table of the information stored in the memory  16  of FIG. 8; and 
     FIG. 10 is an exemplary list of identification information stored in the document component storing section  23  of FIGS. 1,  5 , and  8 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, and more particularly to FIG. 1 thereof, according to a first embodiment of the present invention, a printing system  1  includes a client terminal  2  for creating and editing a document, a printer  3  for printing a document transferred from the client terminal  2 , and a communications line  4  for transmitting a document from the client terminal  2  to the printer  3 . In addition, the communications line  4  of the printing system  1  may be connected to other equipment and/or network systems, so that the printing system  1  is a part of the whole system. 
     The client terminal  2  includes a print conditions entry section  11 , a print conditions transfer section  12 , a document editing section  13 , a document component generating section  14 , and a communications section  15 . The print conditions entry section  11  serves as a data entry mechanism through which users can arbitrarily input data that represent desired print conditions. The desired print conditions may include a designation of a printer, a print paper size, a number of print copies, a double-sided print, a sorting method, a stapling method, and so forth. These print conditions include parameters necessary for a process of generating the print data and for the data processing by the printer  3 . The print conditions transfer section  12  transfers the entered print conditions to the printer  3 . The document editing section  13  creates and edits a document in accordance with user instructions. The document component generating section  14  creates document components, explained below. The communications section  15  transmits and receives arbitrary data to and from the printer  3 . 
     The printer  3  includes a communications section  21 , a print conditions storing section  22 , a document component storing section  23 , and a composite print processing section  24 . The communications section  21  transmits and receives arbitrary data to and from the client terminal  2 . The print conditions storing section  22  stores print conditions transmitted from the print conditions transfer section  12  via the communications section  15 , the communications line  4 , and the communications section  21 . The document component storing section  23  stores document components transmitted from the document component generating section  14  via the communications section  15 , the communications line  4 , and the communications section  21 . The composite print processing section  24  receives the print conditions from the print conditions storing section  22 , receives the document components from the document component generating section  23 , and generates image data based on the document components and the print conditions. 
     A document component used in the printing system  1  is a predetermined divisible unit of document data. An example of a one page document is conceptually illustrated in FIG. 2. A document  30  is composed of document components  31  through  34  that contain a Japanese text, a table, an image, and an English text, respectively. 
     Next, the operation of the client terminal  2  is explained with reference to the flowchart of FIG.  3 . As described above, users can specify various print conditions (e.g., a designation of a printer, a print paper size, a number of print copies, a double-sided print, a sorting method, a stapling method, and so forth) which include parameters necessary to generate the print data and to process the print data with the printer  3 . 
     In Step S 1  of FIG. 3, an operator designates desired print conditions by inputting the desired print conditions in the print conditions entry section  11 . Then in Step S 2 , the print conditions transfer section  12  transfers the print conditions to the printer  3 . Next in Step S 3 , the operator creates and edits a document through the document editing section  13 . The document which is created and edited in the document editing section  13  is sequentially transferred to the document component generating section  14 . 
     Then, in Step S 4 , the document component generating section  14  determines whether the document data transferred from the document component generating section  14  is sufficient to create a document component, such as one of the document components  31  through  34  of FIG. 2, for example. If the document data is insufficient to create a document component, the process returns to Step S 3 . If the document data is sufficient to create a document component, the process proceeds to Step S 5  and the document component generating section  14  creates a document component by converting the document data into data that conforms to a print data format of the printer  3 . The printer  3  prints documents in accordance with the input print conditions. Further, in Step S 5 , the document component generating section  14  transfers the created document component to the printer  3 . The standard printer commands or one of various page description languages can be used for the print data format of the printer  3 . 
     Next in Step S 6 , the completion of creating and editing the document is checked. The process of generating and sending a document component in Steps S 3  through S 5  is repeated by a NO loop until the process of creating and editing the document is ended. Once the process of creating and editing the document is ended, the process proceeds to Step S 7 . In Step S 7 , an input of a print start instruction is checked. When the print start instruction is input (i.e., the check result of Step S 7  is YES), the client terminal  2  sends the print start instruction to the printer  3  in Step S 8 . Then, the process ends. If the print start instruction is not input (i.e, the check result of Step S 7  is NO), the process skips Step S 8  and ends. 
     Next, the operation of the printer  3  is explained with reference to the flowchart of FIG.  4 . In Step S 11 , a check is performed to determine whether the communications section  21  has received the print conditions sent from the client terminal  2 . When the communications section  21  receives the print conditions (i.e, the check result of Step S 11  is YES), the process proceeds to Step S 12 , and the print conditions are sent to the print conditions storing section  22  so as to be stored therein. Then, the process returns to Step S 11  in order to check for further receipt of the print conditions from the client terminal  2 . This cycle continues until the check result of Step S 11  becomes NO. 
     When the check result of Step S 11  is NO, the process proceeds to Step S 13  and a check is performed to determine whether the communications section  21  receives a document component sent from the client terminal  2 . When the communications section  21  receives a document component (i.e., the check result of Step S 13  is YES), the process proceeds to Step S 14  and the document component is sent to the document component storing section  23  to be stored therein. Then in Step S 15 , the composite print processing section  24  creates image data based on the print conditions and the document component stored in the print conditions storing section  22  and the document component storing section  23 , respectively, and stores the generated image data therein. Then, the process returns to Step S 11  in order to check for further receipt of the print conditions from the client terminal  2 . This cycle continues until the check result of Step S 13  becomes NO. In this manner, an entire document can be accumulated in the form of image data in the composite print processing section  24 . 
     Then, when the check result of Step S 13  is NO, the process proceeds to Step S 16  and a check is performed to determine whether the communications section  21  receives the print start instruction sent from the client terminal  2 . When the communications section  21  receives no print start instruction (i.e., the check result of Step S 16  is NO), the process returns to Step S 11  to check for the receipt of the print conditions from the client terminal  2 . When the communications section  21  receives the print start instruction (i.e., the check result of Step S 16  is YES), the process proceeds to Step S 17  and the composite print processing section  24  starts to print. Then, the process ends. 
     Next, a printing system  51  according to a second exemplary embodiment of the present invention is explained with reference to FIGS. 5 and 6. The printing system  51  of FIG. 5 is similar to the printing system  1  of FIG. 1, except that a page description language converter (PDLC)  14   a  is arranged in the document component generating section  14  of the client terminal  2  of the printing system  51 . In the printing system  51 , the PDLC  14   a  converts the document data into the page description language employed in the printer  3  when the document component generating section  14  generates a document component. Therefore, the generated document component is generated using the page description language employed in the printer  3 . 
     FIG. 6 illustrates an exemplary list of document components using the page description language employed in the printer  3  of FIG.  5 . Numbers, n, in the leftmost column in the list of FIG. 6 represent the nth of lines of a page, for the sake of simplicity. 
     The list of the document components include a portion referred to as a “document header” in lines  1  through  8 . The document header contains document data identifying information such as the document name, the document author, the document data status, the document size, the number of document components, the number of pages, the date of generation, the date of modification, and so forth. 
     The list of the document components of FIG. 6 further include a portion referred to as an “operation” in lines  9  through  11 . The operation indicates the history of document editing with various marks. For example, “DELETED ( 113 )” and “DELETED ( 114 )” marks indicate that document components  113  and  114  are deleted, respectively, and a “NEW ( 145 )” mark indicates that a document component  145  is newly generated. 
     The above-mentioned information is also indicated in a data field for each document component. The list of the document components of FIG. 6 includes three document components in lines,  12  through  20 ,  21  through  28 , and  29  through  37 , respectively. Each document component field includes various information such as a document component number, a document component status, the date of generation, the date of modification, the page number, and print data, for example. 
     In the above-described printing system  51 , the generation of document components by the document component  14  may occur at a time designated by the operator, after a predetermined interval of time, at each time of a saving operation for document data, or at a time corresponding to the progress of document editing in pages, for example. 
     Next, an operation of the printing system when the document is modified is explained with reference to FIG.  7 . When a document is modified on the client terminal  2  of the printing system  1  or  51 , a document component that includes the modified portion is sent to the printer  3 . Then, the document component storing section  23  stores the transferred document component, and the composite print processing section  24  generates image data based on the transferred document component so that a corresponding portion of the image data accumulated therein is changed with the generated image data. Then, upon receiving a print start instruction from the client terminal  2 , the printer  3  starts to print the image data including the modified portion. 
     FIG. 7 shows an original document  100  and a modified document  101  which is a modification of the original document  100 . The original document  100  corresponds to the status of the document components listed in FIG. 6 before it is printed. The modified document  101  corresponds to the status of the document components listed in FIG. 6 after it is printed. That is, in the document component of FIG. 6, the components  113  and  114  are deleted and the component  145  is newly generated, as indicated by the respective component statuses. The components  113  and  114  represent a square and an ellipse, respectively, of the original document  100 . The component  145  represents a different square and an ellipse of the modified document  101 . 
     In this manner, when an operator modifies a document which has been completed, the client terminal  2  transmits only the modified portion of document component to the printer  3 , so that the printing system  1  or  51  can reduce the transmission time for transmitting the document to the printer  3 . 
     Next, a printing system  61  according to a third embodiment of the present invention is explained with reference to FIGS. 8 and 9. The printing system  61  of FIG. 8 is similar to the printing system  1  of FIG. 1, except that a memory  16  is connected to the print conditions transfer section  12  of the client terminal  2  of the printing system  61 . 
     As shown in FIG. 9, the memory  16  stores various information including a user name, a default printer name for each user, various default print conditions for each user (including a paper size), a finishing method (such as a sort and a stapling), a selection of simplex and duplex, a number of copies, and so forth, for example. In the printing system  61 , an operator first designates the user name to designate the default printer and/or print conditions. After the document creating and/or editing process, the document components are transferred to the printer  3  and printed by the printer  3 . In this manner, the time it takes for an operator to designate a printer to print the document is reduced, and the time it takes to account for the various print conditions required by each designated printer is reduced. 
     Next, another operation of the printing system  1 ,  51 , or  61  is explained with reference to FIG.  10 . The document component storing sections  23  of the printer  3  of the printing systems  1 ,  51 , and  61  are configured to store the document component even after the printer  3  completes the printing operation. The document component generating section  14  of the client terminal  2  is configured to search the contents of the document component storing section  23 . By searching the contents of the document component storing section  23 , the client terminal  2  can obtain identification information for the document component and the original document from the document component storing section  23 —even after the document is printed by the printer  3 . 
     An exemplary list of the identification information stored in the document component storing section  23  is shown in FIG.  10 . The identification information includes a cash header in lines  1  through  11  (including various identification information such as the total number of documents, pages, and components), a total data size, and a short list of document names, and corresponding component numbers for each document name. 
     Using the above-described identification information, the client terminal  2  can avoid transmission of the document components when they are already stored in the document component storing section  23 . 
     Next, a still further operation of the printing system  1 ,  51 , and  61  is explained with reference to FIGS. 6 and 10. A document component of the document component storing section  23  is arranged to have various status information including a new generation flag for indicating that the document component is newly generated, an under-rasterization flag for indicating that the document is under conversion from a document component into image data for printing, a rasterization-completed flag for indicating that the document component has been rasterized, a syntax error for indicating that a document component has a syntax error, a process error for indicating that a document component has caused an error during the rasterization process, and a deleted flag for indicating that the document component is deleted. The client terminal  2  can obtain the status information as the identification information for the document component and its original document from the document component storing section  23 —even after the document is printed by the printer  3 . 
     For example, when a document component is newly created, the new generation flag pertinent to the corresponding document component is indicated as “NEW” as shown at line  13  of FIG.  6 . As another example, when a document component is under rasterization, the under-rasterization flag of the corresponding document component is indicated as “RASTERIZING” as shown at line  21 , for example, of FIG.  10 . As yet another example, when a document component is deleted, the delete flag of the corresponding document component is indicated as “DELETED,” as shown at line  33  of FIG.  10 . In a similar manner, the rasterization-completed flag, the syntax error, and the process error will be indicated as “RASTERIZED” (not shown), “SYNTAX ERROR” (not shown), and “PROCESSING ERROR” (not shown), respectively. As for a document component indicated as “DELETED,” such a deleted document component may be brought back using an undo function so that the deleted document component may be used again. 
     In this manner, the client terminal  2  can refer to the identification information to determine whether the document component storing section  23  is storing the same document that the client terminal  2  is going to print. If the client terminal  2  determines that the document component storing section  23  is storing the same document that the client terminal is going to print, the client terminal  2  can avoid transmission of the document. Thus, only the print start instruction has to be transmitted from the client terminal. 
     In describing preferred embodiments of the present invention illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the present invention is not intended to be limited to the specific terminology so selected, and it is to be understood that each specific element includes all technical equivalents which operate in a similar manner. 
     This invention may be conveniently implemented using a conventional general purpose digital computer programmed according to the teaching of the present specification, as will be apparent to those skilled in the computer art. Appropriate software coding can readily be prepared by skilled programmers based on the teachings of the present disclosure, as will be apparent to those skilled in the software art. The present invention may also be implemented by the preparation of application specific integrated circuits or by interconnecting an appropriate network of conventional component circuits, as will be readily apparent to those skilled in the art. 
     Numerous additional modifications and variations of the present invention may be possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described herein. 
     This application is based on Japanese patent application No. JPAP09-202295, filed in the Japanese Patent Office on Jul. 10, 1997, the entire contents of which are hereby incorporated by reference.