Abstract:
A printing environment is provided, in which the user can obtain prints of special print jobs without stagnation of ordinary print jobs which otherwise might be caused by the loading of a special print job requiring manual sheet feed or sheet change. A controller for managing the print job schedule is operated in such a manner that print jobs J 1  designating ordinary paper are routinely carried out in priority over print jobs J 2  requiring special paper. Upon instruction from an operation input unit, at least one of the previously-loaded print jobs J 2  requiring special paper is carried out in priority over the print jobs J 1  designating ordinary paper.

Description:
BACKGROUND OF THE INVENTION 
     This application is based on Japanese Patent Application No. 308424/1997 filed on Nov. 11, 1997, the contents of which are incorporated herein by reference. 
     1. Field of the Invention 
     The present invention relates to a printing apparatus having a schedule management function accepting a plurality of print jobs from one or more external devices and a control method thereof applicable to a network printer or a print system including a print server and a printer. 
     2. Description of the Prior Art 
     Generally, a printer is capable of storing a plurality of sheets of paper and has an automatic paper feed function in which the paper sheets are taken out from the storage and fed for printing automatically. The printer also has what is called a manual paper feed port by way of which paper are supplied sheet by sheet manually. The manual paper feed port is used mainly for a comparatively small number of printing using a special paper sheet different from the paper sheets stored in the machine. The special paper includes those larger or smaller than the standard size, color printing paper, paper preprinted with a remark column or the like, and an  0 HP sheet. In loading a print job into the printer from an external device typically including a computer, the automatic paper feed or the manual paper feed is designated. 
     A printer such as a network printer adapted to be shared by a plurality of external devices includes a buffer of a predetermined capacity and is capable of accepting a plurality of print jobs. In other words, the printer can accept a print job during the printing work as well as when waiting for a print job. 
     The conventional printing apparatuses are configured so that print jobs are performed in the order in which they are loaded into the machine regardless of automatic or manual paper feed. On the other hand, a system configuration has been suggested in which the printing order of priority can be set, the actual printing order can be changed and the print jobs can be canceled as desired by the user operating an external device or the printing apparatus (JP-A-7-295767). 
     In the prior art, as described above, the print jobs are carried out in the order in which they are loaded into the printer. In the case where a print job of manual paper feed is loaded, therefore, print jobs which may be loaded thereafter, regardless of automatic or manual paper feed, are not carried out until the previously-loaded print job of manual paper feed is complete. Assume, for example, that the user who has designated a print job of manual paper feed on an external device has forgotten to feed paper at the place of installation of the printer, the printer is left in a substantially inoperative state waiting for paper feed at the sacrifice of other users being troubled. 
     Another problem is that the user who has come to the printer at the place of installation thereof to feed paper manually may have to wait for a long time until other print jobs of automatic paper feed are complete and his or her turn comes. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to provide a printing environment in which the user can obtain prints of a special print job requiring manual sheet feed or sheet change at any time without stagnation of ordinary print jobs. 
     According to the present invention, there is provided a printing apparatus comprising a receiving section for receiving and accumulating a plurality of print jobs transmitted from one or more external devices, said print jobs including a first print job with specific attribute information added thereto and a second print job with no specific attribute information added thereto; an operation input unit for inputting an instruction to execute said first print job by operation of a user; and a controller for executing said second print job in the order of accumulation in said receiving section, and for, when the instruction is input through said operation input unit, suspending the execution of said second print job and executing said first print job; wherein said controller executes said first print job only when the instruction is input through said operation input unit. 
     In carrying the present invention in one preferred mode, the controller manages a print job schedule in which print jobs designating ordinary paper rather than special paper are normally executed and upon an appropriate instruction from the operation input unit, at least one of the previously-loaded print jobs requiring special paper is executed in priority over those using ordinary paper. 
     The operation input unit includes a manual button  32 , for example, mounted in an operation panel of the printer or the like. When the user gives an instruction to the printer by way of the manual button  32 , a list of print jobs (manual feed jobs J 2 ) requiring special paper are displayed. The user designates one or more manual feed jobs J 2  from among them. Then, a print job designating ordinary paper (ordinary job J 1 ), which may be proceeding, is suspended and the designated manual feed job J 2  is executed in priority. Upon completion of the printing designated as manual feed job J 2 , the ordinary job J 1  that has thus far been suspended is resumed. 
     According to the preferred mode of the present invention, the ordinary paper means the paper housed in a paper cassette in such a manner as to permit automatic feed, and the special paper means those paper of a size, a color or a quality different from ordinary paper and not normally housed in the paper cassette. Special paper are generally manually fed but may be automatically fed. For automatic feed, the special paper are housed in the paper cassette in place of ordinary paper or are housed in a paper cassette different from that of ordinary paper. Accordingly, the preprinted paper or color paper which can be normally housed to be fed automatically are “ordinary paper.” A print job requiring special paper is the one in which the user is required to make an arrangement to feed the special paper (automatically or manually) after loading the particular print job. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a diagram showing a network configuration according to the present invention. 
     FIG. 2 is a functional block diagram showing a network printer according to the present invention. 
     FIG. 3 is a model diagram showing an example of schedule management. 
     FIG. 4 is a diagram showing a manual feed job select screen. 
     FIG. 5 is a flowchart showing the printing steps on the part of an external device. 
     FIG. 6 is a flowchart showing the process of accepting jobs on the part of the printer. 
     FIG. 7 is a flowchart of the schedule management executed by the CPU. 
     FIG. 8 is a model diagram showing another example of schedule management. 
     FIG. 9 is a flowchart showing a printing procedure on the part of an external device corresponding to FIG.  8 . 
     FIG. 10 is a flowchart for the process of accepting jobs on the part of the printer corresponding to FIG.  8 . 
     FIG. 11 is a flowchart of schedule management corresponding to FIG.  8 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 is a diagram showing a network configuration according to the present invention. 
     In FIG. 1, a computer network system  100  includes a plurality of computers  41  to  44  connected by a network  50  like LAN for sharing a network printer  1 . The network printer  1  has built therein a network interface card (NIC)  16  for connection with the network  50 . With the computer network system  100 , the single computer  41  functions as a print server. It is also possible to employ a system in which the network printer  1  is connected to the computer  41  by use of a parallel port, though not shown, and thus is connected to the network  50  through the computer  41 . 
     FIG. 2 is a functional block diagram showing a network printer according to the present invention. 
     In FIG. 2, the network printer  1  is a page printer configured in such a manner that printing by either automatic or manual paper feed is possible. The network printer  1  includes a controller  11  for control and data processing, a print engine  12  including a paper feed mechanism, an operation panel  13  for giving input instructions, a paper sensor  14  for detecting the presence or absence of the paper manually fed and the network interface card  16 . 
     The operation panel  13  includes a liquid crystal display (LCD)  31  for displaying a guide, and a manual button  32  for designating a print job requiring manual paper feed (manual feed job). The controller  11  includes a CPU  110  mainly constituted by a microprocessor and an image memory  120  for storing print data in various processing stages. The CPU  110  processes data for command analysis and bit map development and controls the printing order of print jobs by a schedule management file  130  arranged in a work area. 
     FIG. 3 is a model diagram showing an example of schedule management. 
     As shown in FIG. 3, the network printer  1  is loaded with two types of print jobs from the computers  41  to  44  constituting external devices. One is ordinary jobs J 1  designating automatic paper feed, and the other is manual feed jobs J 2  designating manual paper feed. 
     The schedule management file  130  includes a print queue  131  and an interrupt list  132 . The CPU  110  identifies the paper feed designation information for a print job received through the NIC  16 . The ordinary jobs J 1  are registered in the order in which they are loaded in the print queue  131 , and the manual feed jobs J 2  are registered in the interrupt list  132 . 
     The printing work is basically performed only for the ordinary jobs J 1  registered in the print queue  131  in the absence of an interrupt instruction by the manual button  32 . Specifically, the ordinary job J 1  at the head of the print queue  131  is determined as an object of printing. Any manual feed job J 2  which may be loaded before the ordinary jobs J 1  is held from the printing work and the ordinary jobs J 1  are performed first. The ordinary jobs J 1  for which the printing work is complete are deleted from the print queue  131 , and the printing order of the registered ordinary jobs J 1  is advanced. In this way, the job stagnation in the prior art (the state waiting for a manual paper feeding) can be avoided by giving priority normally to the ordinary job J 1  over the manual feed job J 2 . 
     Upon operating the manual button  32 , on the other hand, the manual feed job J 2  is given priority over the ordinary job J 1  unlike during the normal time. In this case, the CPU  110  lists up the manual feed jobs J 2  registered in the interrupt list  132  on the LCD  31  and prompts the user to designate an object of printing. Then, the printing of the ordinary job J 1  , if proceeding, is suspended by page, for example, and the print engine  12  is released for performing the manual feed job J 2 . Upon completion of the printing of the designated manual feed job J 2 , the particular manual feed job J 2  is deleted from the interrupt list  132 , and the operation returns to the state in which only the ordinary job J 1  registered in the print queue  131  is performed. 
     FIG. 4 is a diagram showing a manual feed job select screen. 
     As shown in FIG. 4, the manual feed job select screen Q 1  includes a list Z 1  having manual feed jobs arranged in the order of registration (loading) in the interrupt list  132  and a message Z 2  prompting the user to input the number. The user name, the date and time of loading, the number of pages and other job identified information as well as the choice number are displayed in the list Z 1 . The user name may be the number of the external device or the title of the document (file name) to be printed as well as the name of the user himself or herself. The user desiring the printing by manual feed inputs the choice number corresponding to the desired manual feed job J 2  by way of a predetermined button on the operation panel  13 . In the shown case, the choice number “ 3 ” is input. In the presence of a paper sheet in the manual paper feed port, the manual feed job J 2  begins as designated. Consequently,the user can produce the desired prints by setting the paper sheets equal to the number of pages one by one or collectively. 
     FIG. 5 is a flowchart showing the printing steps on the part of an external device. 
     In the flowchart of FIG. 5, when the user designates a printing according to an application program, the print driver is started, and it becomes possible to designate the printing conditions (# 111 ). The user inputs a user name (# 112 ), designates a paper feed mode (# 113 ), and instructs a print job to be loaded (# 114 ). In designating a paper feed mode, the user selects whether the ordinary paper cassette or the manual feed tray is to be used. As an alternative, the printer may be configured to permit the user to select whether the ordinary paper or the special paper is used. In this configuration, “whether or not special paper is used” is determined in step # 122  described later. 
     FIG. 6 is a flowchart showing the process of accepting jobs on the part of the printer. 
     In the flowchart of FIG. 6, the print job received is taken in and the type of job is determined (# 121 , # 122 ). The manual feed job J 2 , if any, is registered in the interrupt list  132  providing a queue dedicated to manual feed job J 2  (# 123 ). An ordinary job J 1 , on the other hand, is registered in the print queue  131  (# 124 ). 
     FIG. 7 is a flowchart of the schedule management executed by the CPU. 
     In the flowchart of FIG. 7, on the other hand, if the manual button  32  is turned on (# 131 ), it is determined whether the manual feed job J 2  is registered in the interrupt list  132  or not (# 132 ). When the manual feed job J 2  is registered, the manual feed job select screen Q 1  is displayed and the selected manual feed job J 2  is designated as an object to print (# 133 , # 134 ). 
     During the normal operation when the manual feed button  32  is off or when the manual button  32  is turned on but the manual feed job J 2  is not registered, it is determined whether the ordinary job J 1  is registered in the print queue  131  or not (# 135 ). When the ordinary job J 1  is registered, the leading (highest-priority) ordinary job J 1  is determined as an object to print (# 136 ). 
     FIG. 8 is a model diagram showing another example of schedule management. 
     In the example shown in FIG. 8, the schedule management file  130   b  includes only a print queue  131   b . Both the ordinary job J 1  and the manual feed job J 2  are registered in the print queue  131   b . Nevertheless, only the ordinary jobs J 1  are considered for determining the order of printing, while the printing of the manual feed job J 2  is held during the normal operation as in the above-mentioned case. Also, the user can designate the ordinary job J 1  for priority printing. The emergency ordinary job J 1  designated for priority printing is printed in priority over the other ordinary jobs J 1 . When the manual feed button  32  is turned on, the manual feed jobs J 2  registered in the print queue  131   b  are displayed in a list, then the selected manual feed job J 2  is printed. 
     FIG. 9 is a flowchart showing a printing procedure on the part of an external device corresponding to FIG.  8 . 
     In the flowchart of FIG. 9, the user designates a printing according to an application program (# 211 ), inputs the user name and attribute (# 212 , # 213 ), and instructs a print job to be loaded (# 214 ). The attributes include the paper feed mode (automatic or manual) and the requirement for priority printing. 
     FIG. 10 is a flowchart for the process of accepting jobs on the part of the printer corresponding to FIG.  8 . 
     In the flowchart of FIG. 10, the CPU  110  fetches the received print job (# 221 ) and registers it in the print queue  131   b  (# 222 ). 
     FIG. 11 is a flowchart of schedule management corresponding to FIG.  8 . 
     In the flowchart of FIG. 11, if the manual feed button  32  is turned on, it is determined whether the manual feed job J 2  is registered in the print queue  131   b  or not (# 232 ). When the manual feed job J 2  is registered, the manual feed job select screen Q 1  is displayed and the selected manual feed job J 2  is determined as an object to print (# 233 , # 234 ). 
     During the normal operation when the manual feed button  32  is off or when the manual feed button  32  is turned on but the manual feed job J 2  is not registered, the contents of the registration in the print queue  131   b  are checked (# 235 , # 236 ). In the case where an emergency ordinary job J 1  is registered, the highest-priority one of the ordinary jobs J 1  is determined as an object to print (# 237 ). In the case where the emergency ordinary job J 1  is not registered but other ordinary jobs J 1  are registered, then, the highest-priority one of them is determined as an object to print (# 238 ). 
     According to the above-mentioned embodiment, the manual feed job J 2  can be designated for printing at any time regardless of the presence or absence of the ordinary job J 1  and therefore there is not trouble of waiting for the end of the ordinary job J 1  . Once the printing of the manual feed job J 2  is over, the ordinary job J 1  suspended or the ordinary job J 1  waiting for printing is started. Therefore, the job stagnation can be minimized. 
     In the embodiment described above, the printing of the ordinary job J 1  is suspended in response to the turning on of the manual feed button  32 . The printing of the ordinary job J 1  , however, can alternatively be suspended in response to the selection of the manual feed job after the manual feed button  32  is turned on. Also, the print engine  12  can be released for the manual feed job J 2  at the end of the ongoing printing of an ordinary job J 1 . It is also possible to designate a plurality of manual feed jobs J 2  collectively with the manual feed job select screen Q 1  on display. 
     The above-mentioned embodiment refers to the case in which the manual feed job select screen Q 1  is displayed and a manual feed job is selected for printing. As an alternative, print jobs can be carried out simply on first-in first-out basis. Also, an arrangement can be made in which “manual feed” and “emergency” can be designated at the same time as a job attribute unlike in the above-mentioned case. In such a case, a manual feed job is carried out in steps # 235 , # 236 , # 237  in that order in the flowchart of FIG.  11 . As a result, the same situation of waiting for paper feed occurs as in the prior art. This situation of waiting for paper feed is allowed, however, in view of the emergency nature of the job. 
     In the above-mentioned embodiment, the control system taking charge of schedule management can be provided separately from the print engine  12 . The manual feed button  32  can be a switch, a keyboard or a touch panel having mechanical or electrical contacts. Also, an input can be made by way of the mouse or the like on the screen. The present invention is applicable to a printer-copier or a composite machine having an image reader and a printer integrated with each other.