JPH09212314A - Network printer - Google Patents

Abstract

(57) An object of the present invention is to solve the problem that the operating rate of printer resources in the entire network is low and it is not possible to satisfy the request from the user for the print end time. According to the present invention, in a network printer connected to a network 114 and having a printer engine unit 2 and a printer controller 1, the printer controller 1 prints unprocessed print data in a file when a trouble occurs in the printer engine unit 2. Is transferred to another network printer connected to the network 114.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network printer used in a distributed processing environment in which terminal devices including a plurality of personal computers or workstations are connected to a network.

[0002]

2. Description of the Related Art Conventionally, in a distributed processing environment in which a terminal device including a plurality of personal computers or workstations is connected to a network, one of a plurality of network printers connected to the network is used.
When a user makes a print data output request to one network printer and accepts the request, the one network printer prints the print data on paper.

Further, Japanese Patent Laid-Open No. 5-108582 discloses that an output request is directed to a self-computer or another computer for the purpose of efficiently distributing print output and effectively using print output resources in a network environment. To determine whether or not the print output unit or the transmission / reception data processing unit is activated, and whether or not the number of output waiting entries of the print output device is a certain value or more when an output request is made to another computer. And a print processing unit including means for transferring data to another computer if a predetermined value or more is determined.

[0004]

In the above distributed processing environment, even if the user makes a print data output request to a certain network printer, and the output request is accepted, the unprocessed print at that time is accepted. It is not known whether the print result will be obtained by the required time according to the request, and if the network printer runs out of paper or a paper jam occurs, the print data will not be output forever. Also,
Even if there is another network printer in the network and it is available, that network printer could not be used effectively.

In the above computer system, once a print data print request is accepted, even if a failure occurs in the middle of printing the print data, the print processing of the print data cannot be sent to another network printer. . In addition, the print processing order of each print data is dynamically scheduled based on the print end request time, and the print processing time and the remaining amount of paper in the paper feeding device that feeds the paper of the network printer are estimated / counted to determine the network. There was no function that supports efficient use that increases the operating rate of the printer.

The present invention solves the above problems and can dynamically grasp the print processing time and the trouble occurrence state to increase the operating rate of the printer resources of the entire network and improve the serviceability to the user. It is an object of the present invention to provide a network printer that is capable of satisfying a request for a print end time from a user.

[0007]

In order to achieve the above object, the invention according to claim 1 is connected to a network constituting a distributed environment, a printer engine section for printing print data on paper, the network and print. In a network printer having a printer controller that communicates a request and print data, stores the received print request and print data in a file, and causes the printer engine unit to print the print data in response to the print request, the printer controller includes: It has a function to transfer the unprocessed print data in the file to another network printer connected to the network when a trouble occurs in the printer engine unit, and dynamically grasps the trouble occurrence state. Whole network It is possible to increase the operating rate of the printer resource can increase the serviceability for the user.

According to a second aspect of the present invention, a printer engine unit which is connected to a network forming a distributed environment and prints print data on a sheet, and a print request received by communicating the print request and the print data with the network, In a network printer having a printer controller for temporarily storing print data in a file and causing the print engine unit to print the print data in response to a print request, the printer controller determines whether or not a trouble occurs in the printer engine unit. It is equipped with a function to transfer the unprocessed print data in the file to another network printer connected to the network when the problem cannot be resolved even after the lapse of the specified time. To Grip and it is possible to increase the operating rate of the printer resource of the entire network, it is possible to increase the serviceability for the user.

According to a third aspect of the present invention, a printer engine unit which is connected to a network forming a distributed environment and prints print data on a sheet, and a print request received by communicating the print request and print data with the network, In a network printer having a printer controller for temporarily storing print data in a file and causing the printer engine unit to print the print data in response to a print request, the printer controller includes a print request requested by a user when receiving a print request and a print job. It has a function of accepting the end request time and scheduling the printing of the print data stored in the file based on the print end request time. It can meet the demand for printing end time from The.

According to a fourth aspect of the present invention, a printer engine unit which is connected to a network forming a distributed environment and prints print data on a sheet, and a print request received by communicating the print request and the print data with the network, In a network printer having a printer controller that temporarily stores print data in a file and causes the printer engine unit to print the print data in response to a print request, the printer controller determines the time required to print each print job on one sheet of paper. It is equipped with a function that predicts from the amount of print data per print and the number of prints of each print job, and it is possible to dynamically grasp the print processing time and satisfy the request from the user regarding the print end time. Become.

According to a fifth aspect of the present invention, in the network printer according to the fourth aspect, the printer controller is connected to the network when it is predicted that printing of the print job will not be completed by the received print end request time. Transfers the print data with the user identification code and print end request time to the network printer that communicates with other network printers that are in use and finishes printing the print job by the print end request time requested by the user. This is provided with a function of notifying the user or the print manager of the fact, and the print processing time can be dynamically grasped to satisfy the request from the user regarding the print end time.

According to a sixth aspect of the present invention, a printer engine unit which is connected to a network forming a distributed environment and prints print data on a sheet, and a print request received by communicating the print request and print data with the network, In a network printer having a printer controller for temporarily storing print data in a file and printing the print data in the printer engine section in response to a print request, the printer engine section is set in a sheet feeding device for feeding the sheet. The printer controller has a means for managing the number of sheets of paper stored in the sheet feeding device, and whether a paper out occurs during printing of each print job before the start of printing of each print job. Out of paper by judging whether or not There are those having a function allowed to inform the user or the print manager when generated, dynamically grasp the paper out can increase the efficiency of the entire network printer.

According to a seventh aspect of the present invention, in the network printer according to the sixth aspect, when the number of sheets of paper set in the paper feeding device reaches a preset number, the printer controller causes a paper out. It has a function of notifying the user or the print manager of that fact when a certain time has passed before the occurrence, and it is possible to improve the efficiency of the printers in the entire network by dynamically grasping the paper shortage.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the invention according to claims 1 to 7. This embodiment is an embodiment of a color laser network printer including a color laser printer used by being connected to a network in a distributed processing environment in which a plurality of personal computers or workstations or the like are connected to the network. It comprises a printer controller 1 and a printer engine unit 2 for printing print data on paper.

The printer engine unit 2 includes a timing / laser control unit 120 for controlling the writing timing of image data and modulation of the laser 121, a laser 121, an image carrier 122 composed of a photosensitive drum, a transfer belt 123,
In addition to the sequence control and process control of the printer engine unit 2, the engine control / state detection unit 124 detects the state of the printer engine unit 2 such as running out of paper, running out of toner, and jamming, and a paper feeding device 125.

In the printer engine unit 2, the photosensitive drum 122 is driven to rotate by a motor so that it moves in the sub-scanning direction and is uniformly charged by the charging means. Then, the photosensitive drum 122 is exposed to light from the laser 121 to be electrostatically charged. A latent image is formed. Here, the timing / laser control unit 120 controls the modulation of the laser 121 by the print data composed of image data of a plurality of colors from the high-speed video I / F 104 of the printer controller 1, and the light from the laser 121 is mainly scanned by the polarizer. By repeatedly scanning in the direction and irradiating the photosensitive drum 122, print data is written on the photosensitive drum 122, and electrostatic latent images for a plurality of colors are sequentially formed.

The electrostatic latent images of a plurality of colors on the photosensitive drum 122 are developed by a developing device to form a visible image (toner image) of a plurality of colors, which are transferred onto the transfer belt 123 by the transfer means. By doing so, a full-color image is obtained. The full-color image on the transfer belt 123 is transferred to the paper fed from the paper feeding device 125 by the transfer means and fixed on the paper by the fixing means.
Also, the transfer belt 123 is cleaned by the cleaning means and can be reused. The developing device is replenished with toner from the toner replenishing section.

The engine control / state detection unit 124 has troubles such as the paper set in the paper feeding device 125 has run out (runs out), the toner in the toner supply unit has run out, and the paper has jammed. (The state of the printer engine unit 2) is detected, and the detection result is transferred to the control I / F 111 of the printer controller 1.

The printer controller 1 includes a microprocessor 101, a memory 102, and compression / compression of image data.
A compression / decompression circuit 103 for decompression, a high-speed video interface (I / F) 104 having a direct memory access (DMA) function for transferring image data to be printed out to the printer engine unit 2, and a timer 10.
5, a local area network (LAN) controller 107 for connecting to a network 114 such as Ethernet, a SCSI controller 108 for connecting a hard disk device 109, and a memory 102 via these controllers 107, 108 DMA
DMA controller 106 for transferring, image processing / CMS circuit 110 for performing image processing and color matching processing,
A control I / F 111 for exchanging signals with the engine control / state detector 124, a system bus 112 for connecting the above, and an image bus 113 for bypassing image data from the memory 102 and reading it at high speed.
Having.

Further, the printer controller 1 is functionally connected to the network controller 20 as shown in FIG.
1, network management data file 202, print data communication unit 203, file control unit 204, print request acceptance / print processing unit 205, print processing time prediction processing unit 206, print control data file 207,
A print output unit 208, a PS expansion processing unit 209, a printer state detection processing unit 210, a time control unit 211, and a print data file (spool file) 212 are provided. The network controller 201 shown in FIG. 2 includes the LAN controller 107 shown in FIG. 1 from a program controlling the LAN controller 107 to protocol control such as TCP / IP.

The print request and print data sent via the network 114 are interpreted by the print request acceptance / print processing unit 205 via the network control 201 and the print data communication processing unit 203, and the print data and print data are interpreted. Is stored in the print data file 212 via the file control unit 204. At the same time, the print request is stored in the print control data file 207, and the print queue (spool queue) in the print control data file 207 is updated.

Further, the print request acceptance / print processing unit 205 sends the print data to the file control unit 204 according to the print queue in the print control data file 207 (sequentially from the print data corresponding to the first print request in the print queue). The print data is read from the print data file 212 via the and the print output unit 208 prints. The print output unit 208 outputs the print data to the PS expansion processing unit 209 if the print data is Postscript.
After the image is developed in the memory 102 by means of the image processing / CMS circuit 110 and the control I / F 111, the engine control / state detection unit 124 of the printer engine unit 2 is executed.
While controlling the printer engine unit 2, the high-speed video I / F 104 transfers image data from the memory 102 to the timing / laser control unit 12 of the printer engine unit 2.
Transfer to 0. Further, the compression / expansion circuit 103 compresses / expands the image data as needed.

During the printing operation of the printer engine unit 2, the engine control / state detection unit 124 controls the control I / F 11
When troubles such as running out of paper, running out of toner, and jamming of the printer engine unit 2 are notified via 1, the printer state detection processing unit 210 delivers unprocessed print data to the print data communication unit 203 by the notification of the trouble. Make a request.

The print data communication unit 203 reads the print data from the print data file 212 via the file control unit 204 in response to the delivery request of the unprocessed print data, and transfers this print data to the network control 201 and the network 114. Transfer to another connected network printer.

Information regarding other network printers connected to the network 114 is held in the network management data file 202, and user information and print administrator information of each print job are stored in the print control data file 207 and the network management data file 202.
Respectively held in. When a print job ends or a trouble occurs in the printer engine unit 2, the printer state detection processing unit 210 requests the print data communication unit 203 to deliver user information and print manager information.

In response to the delivery request, the print data communication unit 203 transfers the user information and the print manager information in the print control data file 207 and the network management data file 202 by the network control 201 to a personal computer or a work connected to the network 114. It is sent to the station to notify the user or print manager of the end of the print job or the occurrence of trouble in the printer engine unit 2.

During the printing operation of the printer engine unit 2, the engine control / state detection unit 124 controls the control I / O.
When troubles such as running out of paper, running out of toner, and jamming of the printer engine unit 2 are notified via F111, the time control unit 211 measures a predetermined time by using the timer 105 by the notification of the trouble, When the trouble of the printer engine unit 2 is not solved even after the measurement of the predetermined time is completed, the print data communication unit 203 is requested to deliver the unprocessed print data.

In response to the unprocessed print data delivery request, the print data communication unit 203 reads the print data from the print data file 212 via the file control unit 204, and the print data is sent to the network 114 by the network control 201. Transfer to another connected network printer.

Further, when the print request and the print job are accepted, the print end request time requested by the user is accepted, and the print request and print data and the print end request time sent via the network 114 are the network controller 201. The print request reception / print processing unit 205 interprets the print request via the print data communication processing unit 203, the print request reception / print processing unit 205 stores the print request in the print control data file 207, and each print request is transmitted. The print queue (spool queue) in the print control data file 207 is updated so that the print end request time is arranged in ascending order, and
The print data is stored in the print data file 212 via the file control unit 204. Therefore, each print data is scheduled so that each print data is printed in the ascending order of the print end request time requested by the user.

Further, the print processing time prediction processing unit 206
Predicts the print processing time required for printing each print job in the printer engine unit 2 from the print data amount per sheet and the number of prints (the number of pages and the number of copies) of each print job. When it is predicted that the print processing of the print job will not be completed by the print end request time required by the print data communication unit 203 and the network controller 20.
1 to communicate with another network printer connected to the network 114 to satisfy a user's request (a request to end the print processing of print data by the print end request time) (or meet the user's request most). ) Transfer the print data, which is predicted not to be completed, to the other network printer through the print data communication unit 203 and the network controller 201 together with the user identification code, and if the print data is not satisfied because the user's request cannot be satisfied. The fact that the data has been transferred to another network printer is transmitted to the personal computer or workstation connected to the network 114 via the print data communication unit 203 and the network controller 201, and the user or the print manager is notified.

The paper feeding device 125 of the printer engine unit 2 has a paper amount detecting means for detecting the amount of set paper, and a paper amount detecting signal from the paper amount detecting means is used for the control I of the printer controller 1. / F111 is sent to the print request acceptance / print processing unit 205. The print request acceptance / print processing unit 205, before passing the print data corresponding to the print request at the head of the spool queue in the print control data file 207 to the print processing time prediction processing unit 206, the number of prints of the print job and the above If the paper amount detection signal from the paper amount detection means determines whether the paper will run out during printing, and if it is determined that the paper will run out during printing, print data indicating that the paper will run out during printing. Communication department 20
3 to the terminal device connected to the network 114 via the network controller 201 and cause the terminal device to notify the user or the print manager.

Further, the print output unit 208 counts the remaining amount of paper in the paper feeding device 125 every time the printer engine unit 2 prints the print data on one sheet, and the remaining amount of paper in the paper feeding device 125 is counted. When the number of sheets reaches a predetermined number, the print data communication process 203 and the network control 2 indicate that the remaining number of sheets reaches the predetermined number.
01 is sent to a personal computer or workstation connected to the network 114 to notify the user or print manager.

The print output unit 208 holds the print processing time of each print job predicted by the print processing time prediction processing unit 206 together with print data when the print request is received, and the print processing of each predicted print job. Paper feeder 12 that counts time and above
It is judged whether the paper will run out after a certain amount of time from the remaining amount of paper in 5, and when the paper runs out after a certain amount of time, the number of papers to be printed by that time will be calculated, and the paper will run out after printing that number. An out-of-paper prediction indicating that is to be transmitted to a terminal device connected to the network 114 via the print data communication unit 203 and the network controller 201 to notify the user or the print manager.

As described above, this embodiment is an embodiment of the invention according to claim 1, and is connected to the network 114 constituting the distributed environment, and the printer engine unit 2 for printing the print data on the paper. Network 11
The print request and print data received by communicating with the print request and the print data are temporarily stored in the file 2
In the network printer having the printer controller 1 that stores the print data in the printers 07 and 212 and causes the printer engine unit 2 to print the print data in response to the print request, the printer controller 1 includes the printer engine unit 2
When a trouble occurs, the unprocessed print data in the file 212 is transferred to another network printer connected to the network 114, so that the trouble occurrence state of the printer engine can be dynamically grasped and the entire network can be grasped. It is possible to increase the operating rate of the printer resource of the above and to improve the serviceability to the user.

Further, this embodiment is an embodiment of the invention according to claim 2, and is connected to the network 114 constituting the distributed environment and the printer engine unit 2 for printing the print data on the paper, and the network 114. The print request and print data that are received by communicating with the print request and print data once,
In a network printer having a printer controller 1 which stores the print data in 212 and causes the printer engine unit 2 to print the print data in response to a print request, when the printer controller 1 has a trouble, the trouble occurs at a predetermined time. Since it has a function to transfer the unprocessed print data in the file 212 to another network printer connected to the network 114 when the problem is not solved even after
By dynamically grasping the trouble occurrence state of the printer engine unit, it is possible to improve the operating rate of the printer resources of the entire network and also improve the serviceability to the user.

Further, this embodiment is an embodiment of the invention according to claim 3, and is connected to the network 114 constituting the distributed environment and the printer engine unit 2 for printing the print data on paper and the network 114. The print request and print data that are received by communicating with the print request and print data once,
In a network printer having a printer controller 1 stored in 212 and causing the printer engine unit 2 to print the print data in response to the print request, the printer controller 1 uses the print end request time requested by the user when receiving the print request and the print job. The print data stored in the file 212 is scheduled based on the print end request time, so that the print processing time is dynamically grasped and the user's request for the print end time is satisfied. be able to. Further, since the print request is scheduled according to the urgency, even when the print processing of the print data has to be performed urgently, the user does not need to consider the vacant network printer, but simply the user's printer. It is possible to provide not only resource sharing but also a printing environment that makes use of the network environment.

Further, this embodiment is an embodiment of the invention according to claim 4, and is connected to the network 114 constituting the distributed environment and the printer engine unit 2 for printing print data on a sheet and the network 114. The print request and print data that are received by communicating with the print request and print data once,
In a network printer having a printer controller 1 that stores the print data in 212 and causes the printer engine unit 2 to print the print data in response to a print request, the printer controller 1 determines the time required to print each print job by the print data per sheet. Since it has a function of predicting the amount and the number of prints of each print job, it is possible to dynamically grasp the print processing time and satisfy the request for the print end time from the user.

Further, this embodiment is an embodiment of the invention according to claim 5, and in the network printer according to claim 4, the printer controller 1 prints the print job by the accepted print end request time. Network 114 if it is predicted that the
Transfers print data with a user identification code and print end request time to the network printer that communicates with other network printers connected to the network printer and finishes printing the print job by the print end request time requested by the user. Since a function for notifying the user or the print manager of that fact is provided, it is possible to dynamically grasp the print processing time and satisfy the request for the print end time from the user. Also, because print requests are scheduled according to the urgency,
Even when the print processing of the print data is urgently needed, the user does not need to consider the vacant network printer, and it is possible to provide a print environment that utilizes the network environment rather than merely sharing the user's printer resources. It will be possible.

Further, this embodiment is an embodiment of the invention according to claim 6, and is connected to a network 114 which constitutes a distributed environment, and a printer engine unit 2 for printing print data on a sheet and a network 114. The print request and print data that are received by communicating with the print request and print data once,
In a network printer having a printer controller 1 for storing print data in 212 and causing the printer engine unit 2 to print print data in response to a print request, a paper feeding device 125 for feeding paper in the printer engine unit 2
Has a means to manage the number of sheets set in
The printer controller 1 determines whether a paper out occurs during printing of each print job based on the number of sheets set in the paper feeding device before starting the print of each print job, and when the paper out occurs. Since a function (print request reception / print processing unit 205) for notifying the user or the print manager of that fact is provided, the printer engine unit dynamically grasps the paper exhaustion and increases the operating rate of the printer resources of the entire network. It is possible to improve the serviceability to the user.

The invention according to claim 7 is the network printer according to claim 6, wherein the printer controller 1
Is a function to notify the user or print manager when the number of sheets set in the paper feeder reaches a preset number or when a certain amount of time elapses before the paper runs out (print output). Since the unit 208) is provided, it is possible to dynamically grasp the paper exhaustion of the printer engine unit and increase the operating rate of the printer resources of the entire network, and it is possible to improve the serviceability to the user.

[0041]

As described above, according to the first aspect of the present invention, a printer engine unit which is connected to a network forming a distributed environment and prints print data on a sheet,
A network printer having a printer controller which stores the print request and the print data received by communicating with the network with the print request and the print data, and causes the printer engine unit to print the print data according to the print request, The printer controller has a function of transferring the unprocessed print data in the file to another network printer connected to the network when a trouble occurs in the printer engine unit. It is possible to increase the utilization rate of printer resources of the entire network by dynamically ascertaining, and improve the serviceability to the user.

According to the second aspect of the present invention, a printer engine unit which is connected to a network that constitutes a distributed environment and prints print data on a sheet, and a print request and print data that are received by communicating with the network. In a network printer having a printer controller for temporarily storing a request and print data in a file and causing the print engine unit to print the print data in response to a print request, the printer controller is configured to prevent the trouble when the trouble occurs in the printer engine unit. The printer engine has a function to transfer the unprocessed print data in the file to another network printer connected to the network when the problem cannot be solved even after a predetermined time elapses. Dynamically grasp the Le occurrence it is possible to increase the operating rate of the printer resource of the entire network, it is possible to increase the serviceability for the user.

According to the third aspect of the present invention, a printer engine unit which is connected to a network forming a distributed environment and prints print data on a sheet, and a print request and print data which are received by communicating with the network. In a network printer having a printer controller for temporarily storing a request and print data in a file and causing the printer engine unit to print the print data in response to the print request, the printer controller is configured such that the printer controller requests a print request and a user's request when receiving a print job. Since it has a function of accepting the print end request time and performing the scheduling of the print of the print data stored in the file based on the print end request time, it dynamically grasps the print processing time and It can meet the demand for printing end time from The. Further, even when the print processing of the print data has to be performed urgently, the user does not have to consider the vacant network printer, and the print environment utilizing the network environment is not limited to the user's printer resource sharing. It becomes possible to provide.

According to the fourth aspect of the present invention, a printer engine unit which is connected to a network forming a distributed environment and prints print data on a sheet, and a print request made by communicating with the network and the print request are received. In a network printer having a printer controller for temporarily storing a request and print data in a file and causing the printer engine unit to print the print data in response to the print request, the printer controller determines the time required for printing each print job to the paper sheet. Since it has a function to predict from the print data amount per sheet and the number of prints of each print data, it is possible to dynamically grasp the print processing time and satisfy the request from the user for the print end time. Become.

According to the fifth aspect of the present invention, in the network printer according to the fourth aspect, the network is used when the printer controller predicts that printing of the print job will not be completed by the received print termination request time. Transfers print data with a user identification code and print end request time to the network printer that communicates with other network printers connected to the network printer and finishes printing the print job by the print end request time requested by the user. Since a function for notifying the user or the print manager of that fact is provided, it is possible to dynamically grasp the print processing time and satisfy the request for the print end time from the user. Further, even when the print processing of the print data has to be performed urgently, the user does not have to consider the vacant network printer, and the print environment utilizing the network environment is not limited to the user's printer resource sharing. It becomes possible to provide.

According to the sixth aspect of the present invention, a printer engine unit that is connected to a network that constitutes a distributed environment and prints print data on a sheet, and a print request that has been received by communicating the network with the print request and print data. In a network printer having a printer controller for temporarily storing a request and print data in a file and causing the print engine unit to print the print data in response to the print request, a paper feeding device for feeding the paper by the printer engine unit The printer controller has means for managing the number of sheets set, and the printer controller runs out of sheets during the printing of each print job based on the number of sheets set in the sheet feeding device before starting the printing of each print job. Decide whether to do A function is provided to notify the user or print administrator of a paper shortage in the event of a paper shortage, so that the printer engine section can be dynamically grasped to increase the utilization rate of printer resources in the entire network. The serviceability to the user can be improved.

According to a seventh aspect of the present invention, in the network printer according to the sixth aspect, the printer controller controls the paper when the number of sheets set in the sheet feeding device reaches a preset number. A function has been provided to notify the user or print administrator of the fact that a certain amount of time has passed before the paper runs out. It is possible to improve the serviceability to the user as well.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the invention according to claims 1 to 7.

FIG. 2 is a block diagram showing a functional configuration of a printer controller in the embodiment.

[Explanation of symbols]

 1 Printer Controller 2 Printer Engine Unit 124 Engine Control / Status Detection Unit 125 Paper Feeding Device 114 Network 201 Network Controller 202 Network Management Data File 203 Print Data Communication Unit 204 File Control Unit 205 Print Request Reception / Print Processing Unit 206 Print Processing Time Prediction Processing unit 207 Print control data file 208 Print output unit 209 PS expansion processing unit 210 Printer status detection processing unit 211 Time control unit 212 Print data file

Claims (7)

[Claims] 1. A printer engine unit which is connected to a network constituting a distributed environment and prints print data on a sheet, and a print request and print data received by communicating with the network and print request and print data are once stored in a file. In a network printer having a printer controller that stores print data in the printer engine unit in response to a print request and stores the unprocessed print data in the file when a trouble occurs in the printer engine unit. A network printer having a function of transferring to another network printer connected to the network. 2. A printer engine unit which is connected to a network forming a distributed environment and prints print data on a sheet, and a print request and print data received by communicating with the network and print request and print data are once stored in a file. In a network printer having a printer controller that stores print data in the printer engine unit in response to a print request and the printer controller causes a trouble to occur in the printer engine unit when a predetermined time elapses. A network printer having a function of transferring the unprocessed print data in the file to another network printer connected to the network if the problem is not solved. 3. A printer engine unit which is connected to a network constituting a distributed environment and prints print data on a sheet, and a print request and print data which are received by communicating with the network and print request and print data are once stored in a file. In a network printer having a printer controller for storing print data in the printer engine unit according to a print request, the printer controller receives a print request and a print end request time requested by a user when receiving a print job, A network printer having a function of scheduling printing of print data stored in the file based on the print end request time. 4. A printer engine unit which is connected to a network constituting a distributed environment and prints print data on a sheet, and a print request and print data received by communicating with the network and print request and print data are once stored in a file. In a network printer having a printer controller that stores print data in the printer engine unit in response to a print request, the printer controller determines the time required to print each print job as the print data amount per sheet. A network printer having a function of predicting the number of prints of each print job. 5. The network printer according to claim 4, wherein the printer controller is connected to the other network when it is predicted that printing of the print job will not end by the received print end request time. Communicates with the printer and finishes printing the print job by the print end request time requested by the user. Transfers the print data with the user identification code and the print end request time to the network printer, and notifies the user or print management to that effect. A network printer that is equipped with a function for informing the person. 6. A printer engine unit which is connected to a network constituting a distributed environment and prints print data on a sheet, and a print request and print data received by communicating with the network and print request and print data are once stored in a file. In a network printer having a printer controller that stores print data in the printer engine unit in response to a print request and stores the number of sheets set in a sheet feeding device that feeds the sheet in the printer engine unit. The printer controller has a means for managing, and judges from the number of paper sheets set in the paper feeding device whether or not a paper out occurs during printing of each print job before the start of printing of each print job. If you run out of paper Network printers that comprising the functions allowed to notify users or print manager. 7. The network printer according to claim 6, wherein the printer controller, when the number of sheets set in the sheet feeding device reaches a preset number, a predetermined time before the occurrence of the sheet exhaustion. A network printer that is equipped with a function to notify the user or print administrator of such a situation.