JPH09272243A - Device and system for forming image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously receive a plurality of commands for a job becoming an object of image formation in particular from a host device in relation to an image formation device which receives image data from the host device and expands them to a printable image to perform printing treatment. SOLUTION: In the image formation device 10, a command sent from a workstation 20 being a host device is simultaneously received by a plurality of receiving parts 112-1-112-n. When the number of a print demand command (image formation command) during reception is equal to the simultaneous print demand maximum number Ipr-max decided in a decision part 113, an interrupt part 114 interrupts reception of a new print demand command and receives both an inquiry command of a normal image formation state and an image formation cancel command even when a print demand command is received.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus that receives image data from a host apparatus, develops the image data into a printable image, and prints the image data. The present invention relates to an image forming apparatus capable of simultaneously receiving commands from a host apparatus and an image forming system using the image forming apparatus.

[0002]

2. Description of the Related Art An image forming apparatus is an apparatus that receives image data from a host apparatus, develops the image data into a printable bitmap image, and prints the output sheet. Generally, the image forming apparatus receives a plurality of commands from the host device,
Various processes are performed based on the received command. For example, when the command from the higher-level device is an image formation command requesting image formation, image data transmitted after the command is received, image formation processing is performed, and the state of the image formation device is inquired. In the case of the device status inquiry command, the various statuses (in the image forming process, offline, paper jam, etc.) inside the device are notified to the host device, and in the case of the image forming cancel command for canceling the requested image forming process, Delete the image data being processed or the image data already received in the device.

When performing image data receiving processing and image forming processing from the host apparatus, the image forming processing is performed in parallel with the image data receiving processing from the host apparatus and the received image data is processed. In some cases, the image forming process is performed after the image is once stored in the storage device.
Hereinafter, the former will be referred to as non-spool processing, and the latter will be referred to as spool processing. Further, when a command can be received simultaneously from two or more host devices and image data can be received at the same time, and only a command from one host device can be received, that is, a command and image data can be received from one host device. In some cases, it may not be possible to receive commands from other higher-level devices. Hereinafter, the former will be referred to as a plurality of sessions, and the latter will be referred to as a single session. In particular, a session that can receive commands and image data from two higher-level devices at the same time is called two sessions.

As this type of image forming apparatus, there is a network printer connected to a network so that it can be shared and used by a plurality of host apparatuses. For example, as disclosed in Japanese Patent Application Laid-Open No. 7-164683, one-to-one image data is received from a host device via a network and print processing is performed. In this network printer, the end of the reception of the image data is detected as soon as possible by acquiring the data size of the image data existing in the host device in advance in order to determine the end of the reception of the image data. It is configured to release the connection (session) for the host device.

Further, in the case of the Lpd printing protocol of a general SUN workstation, image data from a plurality of host devices can be processed at the same time, and printing processing after spooling is performed. Here, the Lpd printing protocol is a communication method between the higher-level device and the image forming apparatus, in particular, a printing method, and here, Rpd printing protocol is used.
FC1179 Line Printer Daemo
n Protocol. Less than,
In particular, the printing process of the SUN workstation according to the Lpd printing protocol will be described.

As shown in FIG. 8, a client (corresponding to a host device here) and a server (image forming device or network printer here) are connected by a network, and the client is a port 101 (TCP) of the server.
In the case of / IP, 515 is reserved), and the command is transmitted (,,). For example, when the server receives a command from the client 1, another server 102
To establish a session with client 1 ('). Similarly, client 2 establishes a session at port 103 ('), client 3 at port 1
A session is established at 04 ('). In the case of the example in FIG. 8, the server can simultaneously receive three commands from the client through the ports 102 to 104 (three sessions).

In the Lpd printing protocol, when the session is established, the client then sends the first command as shown in FIG. In the figure, (1) and (2)
Corresponds to the image forming command, (3) and (4) are image forming apparatus status inquiry commands,
(5) is an image formation cancel command. In the first command, if the image formation command (2) in FIG.
Then, the second command as shown in FIG. 10 is transmitted. In the figure, (1) is cancellation of the first command, (2) is control file transmission, and (3) is data file transmission. Here, the control file is various parameters necessary for image formation and is generated by the client. A data file is the substance of image data.

FIG. 11 shows a sequence between the client and the server in the image forming command. When the client issues the first command (image forming command) (1), the server receives the command and notifies the corresponding response (2). Here, the response is ACK or NACK, ACK means permission for the received request, and NACK means rejection. The client subsequently transmits the second command (data file transmission command) (3), and the server notifies the response (4). In response to this, the client transmits the data file (5), and when the transmission is completed, transmits a response to that effect (6), and the server notifies the response (7). Subsequently, the client similarly transmits the control file (8 to 12). Finally, the session is disconnected and the communication ends.

Next, the sequence of the client and server in the image forming apparatus status inquiry command is shown in FIG.
It is shown in FIG. First, the client issues a first command (image forming apparatus status inquiry command) (1), and when the server receives the command, notifies the corresponding response (2) and notifies the client of the status inside the apparatus ( 3). Thereafter, the session is disconnected and the communication is terminated.

Next, FIG. 13 shows a sequence between the client and the server in the image formation cancel command.
First, the client is the first command (cancel command)
(1) and the server receives the command,
The corresponding response is notified (2), and after the corresponding processing is completed, the processing result is notified to the client (3). Thereafter, the session is disconnected and the communication is terminated.

[0011]

However, in the network printer disclosed in Japanese Patent Laid-Open No. 7-164683, that is, a network printer connected to a network so that it can be shared by a plurality of host devices, When a session is established, other host devices or other commands cannot be received. Therefore, when receiving an image formation command that takes longer to receive (communicate) than other commands, the network printer There was a problem that the command was monopolized.

Further, in the case of the Lpd printing protocol of a general SUN workstation, since spool processing is performed, after the image data of the first page is once stored in the storage device, there is a delay until it is output from this storage device. There is a problem that the larger the amount of image data, the longer it takes and the higher the cost required for the storage device for spooling.

The present invention has been made in view of the above problems, and an object of the present invention is to allow a plurality of commands to be simultaneously received from a higher-level device, and also to receive other commands even when an image forming command is received. To provide an image forming apparatus that can always receive the command and an image forming system using the same.

[0014]

In order to solve the above-mentioned problems, an image forming apparatus according to the present invention comprises a plurality of receiving means capable of simultaneously receiving a plurality of commands for a job to be image-formed from a host device. If the determining means for determining the maximum number of image forming commands simultaneously received by the plurality of receiving means is equal to the maximum number determined by the determining means, the number of image forming commands being received by the plurality of receiving means is new. And an interrupting means for interrupting the reception of the image forming command received by.

In the image forming apparatus having the above structure, the commands from the host device are simultaneously received by the plurality of receiving means.
At this time, if the number of image forming commands being received becomes equal to the maximum number determined by the determining unit, the interrupting unit rejects the newly received image forming command. As a result, it is possible to prevent the image forming command from monopolizing all the receiving means.

Another image forming apparatus according to the present invention uses a plurality of receiving means capable of simultaneously receiving a plurality of commands for a job to be subjected to image formation from a host device, and an image forming command received by the plurality of receiving means. When the image forming process is being executed, it is configured to include an interrupting unit that interrupts reception of a newly received image forming command.

In another image forming apparatus having the above structure, a plurality of receiving means simultaneously receive commands from the host device. At this time, if the image forming process is in progress, the interrupting means rejects the newly received image forming command. As a result, it is possible to prevent the image forming command from monopolizing all the receiving means.

The image forming system according to the present invention transmits the image forming apparatus having the above-mentioned structure and an image forming apparatus status inquiry command prior to transmitting the image forming command to the image forming apparatus, and the image forming apparatus forms an image. It is configured to include a host device that transmits an image formation command when processing is possible.

In the above-described image forming system, the host device transmits the image forming device status inquiry command once before transmitting the image forming command to the image forming device, and when the image forming device can perform the image forming process, the image forming process is performed. Send a command. As a result, it is possible to avoid the situation in which the image forming command transmitted from the host device is rejected.

[0020]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic block diagram showing an embodiment of the present invention. In the present embodiment, the image forming apparatus 10 and a workstation (WS) 20 which is an upper apparatus are connected by a network 30 to form an image forming system.

In FIG. 1, an image forming apparatus (hereinafter referred to as the present image forming apparatus) 10 according to this embodiment includes a CPU 11 that controls the entire apparatus and an image output unit that forms and outputs an image on a print sheet. 12, a decomposer 13 for expanding image data, a memory 14, a user interface (U / I) 15, and an interface (I / F) 16
And is connected to the workstation 20 by the network 30.

The CPU 11 has a main function as a block, and a control unit 111 and a plurality of receiving units 112-1 to 112-1.
12-n, a determination unit 113, and an interruption unit 114. In the CPU 11, the control unit 111 has a CPU
11 to perform the respective functions of 11
112-n, the determining unit 113, and the interrupting unit 114 are controlled, and the image output unit 12, the decomposer 13,
It controls each of the memory 14, the user interface 15, and the interface 16. Various processes of the image forming apparatus 10 are performed under the control of the control unit 111.

The receiving units 112-1 to 112-n receive image data including various request commands and image forming commands from the workstation 20 via the network 30 and the interface 16. Since the image forming apparatus 10 has the plurality of receiving units 112-1 to 112-n, it is possible to receive commands and image data in parallel from another workstation (not shown).

The determination unit 113 includes a plurality of reception units 112-1 to 112-1.
112-n determines the maximum number of image forming commands to be simultaneously received, and is usually set in advance.
Here, the image forming command is a command for transmitting image data and requesting an image forming process. Interruption 1
14 compares the maximum number of image formation commands that are simultaneously received, which is determined by the determination unit 113, with the number of image formation commands that are being received, and when both are the same, the newly received image formation command is received. It interrupts.

On the other hand, the image output unit 12 includes the decomposer 1
The image-formable data expanded by No. 3 is image-formed on a print sheet and discharged. Since image formation is a known technique, description thereof will be omitted. Decomposer 13
Is for expanding the image data received by the plurality of receiving units 112-1 to 112-n into image-formable data. In general, the image data received from the workstation 20 is not image-formable data but code data described in a page description language such as PostScript (PostScript), so it is converted into image-formable data. And stores it in the memory 14.

The memory 14 is expanded by a ROM (read-only memory) in which programs and prescribed values required for controlling the image forming apparatus 10 are stored, and temporary variables and a decomposer 13 for program processing and processing. And a RAM (readable / writable memory) that stores image-formable data. User interface 15
Is composed of an input unit such as a keyboard or a button for receiving a request from the user of the image forming apparatus 10 and a display unit such as a display or a liquid crystal panel for notifying the user of the state of the image forming apparatus 10. To be done. Interface 16
Is a network interface that transmits and receives data to and from the network 30.

The work station (WS) 20 is a higher-level device for the image forming apparatus 10, creates image data, and performs image forming, status inquiry, and requested image forming processing for the image forming apparatus 10. Make various requests (commands) such as cancellation. Various commands are transmitted to the image forming apparatus 10 via the network 30. In the present embodiment, the workstation is illustrated as the higher-level device, but a device such as a personal computer or a word processor may be used as long as it sends an image forming command together with the image data.

The network 30 includes the image forming apparatus 10
And a workstation 20 for exchanging data with each other. The network 30 is generally Ethernet, token ring, or the like, but is not limited to this as long as a plurality of workstations can be connected to the image forming apparatus 10.

Next, the operation of the image forming apparatus 10 according to the above embodiment will be described. In the following description of the operation, the number of receiving units is 5, and the maximum number of image forming commands simultaneously received from the host device (hereinafter referred to as the maximum simultaneous print request number) is 3, for convenience sake. FIG.
3 and 4 are flowcharts for explaining the basic operation of the image forming apparatus 10. In the following, description will be made step by step according to this flowchart.

First, when the image forming apparatus 10 is activated,
Each means performs an initialization process. That is, the current number of simultaneous image formation command receptions (hereinafter referred to as the number of print requests) n is initialized to 0 (step S1), and the determination unit 1
The maximum simultaneous print request number lpr_max is determined in step 13 (step S2). In the case of this example, lpr_
max = 3. In this example, for the sake of simplicity, the maximum number of simultaneous print requests lpr_max is set to a fixed value in the initialization process, but it is not always necessary to set it in the initialization process, and it may be changed appropriately after startup. .

When the initialization process is completed, the image forming apparatus 10 waits for reception of various commands from the workstation 20 (step S3). When various commands are received from the workstation 20 (step S4), the connection with the workstation 20 is established (step S5). Subsequently, the command is received (step S6), and it is determined whether the command is a print request command (image forming command) (step S6).
7) If it is a print request command, the simultaneous print request number n is incremented (step S8).

Then, it is judged whether or not the counted-up simultaneous print request number n has reached the maximum simultaneous print request number lpr_max set in step S2 (step S9).
NACK (a value other than 0) indicating rejection of the print request is notified to 0 (step S10). If the number of simultaneous print requests n has not reached the maximum number lpr_max, print processing is performed (step S11).
The printing process, that is, the image forming process is well known and will not be described here.

In step S10, the workstation 20
To the print request rejection or after performing the print processing in step S11, the number n of simultaneous print requests is counted down (step S12),
Then, the connection with the workstation 20 is disconnected (step S13), and this processing is ended.

On the other hand, when it is determined in step S7 that the received command is not the print request command, it is determined whether the command is an image forming apparatus status inquiry command (step S14). If it is an image forming apparatus status inquiry command, the workstation 20 is notified of information on the job currently being processed and information on the status of the image forming apparatus 10 (step S15). If the received command is not the image forming apparatus status inquiry command, it is further determined whether or not the command is an image formation cancel command (step S16). Then, in the case of the image formation cancellation command, if there is a job whose cancellation request matches the requested job, the cancellation process is performed (step S17).

If it is determined in step 16 that the received command is not the image formation cancel command, the command cannot be processed by the image forming apparatus 10, and therefore ACK (value 0) or N is sent to the workstation 20.
Only ACK is notified (step S18). When the processing of step S15, step S17, or step S18 is completed, the process proceeds to step S13, the connection with the workstation 20 is disconnected, and this processing is completed.

In the description of the operation of this embodiment, the number of receiving units is 5, and the maximum number of simultaneous print requests lpr_max is 3.
However, it is possible to receive three print requests from a plurality of workstations and two other requests at the same time. In general, the time required for processing other requests is shorter than that for print requests, so it is more effective to set the maximum number of simultaneous print requests lpr_max as large as possible.

As described above, a plurality of receiving units 112-1 receives commands from the workstation 20, which is a higher-level device.
If the number of print request commands (image forming commands) being received is equal to the maximum simultaneous print request number lpr_max determined by the determining unit 113 in the image forming apparatus 10 capable of receiving simultaneously with 112 to n. By stopping the reception of various print request commands,
According to the print request command, all the receiving units 112-1 ...
112-n will no longer be monopolized.

As a result, even when the print request command is received, it is possible to always receive the image forming apparatus status inquiry command and the image formation cancel command. In particular, when the image forming process is performed together with the process of receiving the image data from the host device, the image forming process is far better than the process for the image forming device status inquiry or the process for canceling the requested image forming process. Since it takes time, the effect is extremely large.

In the above embodiment, the number of receiving units is 5.
However, the number is not limited to five. Further, when the number of receiving units is set to 2, one of them receives only the print request command and the other receives a command other than the print request command,
That is, it may be configured to receive the image forming apparatus status inquiry command and the image formation cancel command. Even in this case, even when one receiving unit receives the print request command, the other receiving unit does not receive the print request command, so that the image forming apparatus status inquiry command and the image forming cancel command are always received. It becomes possible.

FIG. 4 is a schematic block diagram showing another embodiment of the present invention. In the figure, the same parts as those in FIG. 1 are designated by the same reference numerals. In this embodiment, the image forming apparatus 4
In the image forming system in which 0 and the workstation 20, which is a higher-level device, are connected via the network 30, the number of receiving units of the image forming apparatus 40 is limited to two.

In FIG. 4, the image forming apparatus 40 includes a CPU 41 that controls the entire apparatus, an image output unit 12 that forms and outputs an image on printing paper, a decomposer 13 that expands image data, and a memory 14. And a user interface (U / I) 15 and an interface (I / F)
16 and are connected to the workstation 20 by the network 30.

The main function of the CPU 41 is shown by blocks, and the control unit 411 and the two receiving units 412-1 and 412-1 and 4-4.
12-2, an identification unit 413, and a host device information storage unit 414
And the interruption part 415. In the CPU 41, the control unit 411 has two receiving units 412-1 and 412-2 and an identifying unit 41 in order to execute each function of the CPU 41.
3. Controls the processes of the higher-level device information storage unit 414 and the interruption unit 415, and also controls the image output unit 12, decomposer 13, memory 14, user interface 15, and interface 16. The image forming apparatus 40
Various types of processing are performed under the control of the control unit 411.

The two receiving sections 412-1 and 412-2 receive image data including various request commands and image forming commands from the workstation 20 via the network 30 and the interface 16. This image forming apparatus 4
Since 0 has two receiving units 412-1 and 412-1,
Commands and image data can be received in parallel from another workstation (not shown).

The identification unit 413 identifies the workstation that transmits various commands or image data, and acquires the IP address or MAC address (Ethernet address) of the workstation of the transmission source. The higher-level device information storage unit 414 stores the IP address or MAC address identified by the identification unit 413 in association with the job to be processed in the image forming apparatus 40. From the higher-level device information storage unit 414, when the image forming apparatus 40 is processing, it is possible to obtain from which workstation the job being processed is the job by the IP address or the MAC address.

The interruption section 414 is in the process of forming an image by the image forming apparatus 40, and the upper apparatus information storage section 414.
And the IP address or MAC address of the workstation of the transmission source of the job being processed acquired by the identification unit 413 and the IP address or the MAC address of the workstation of the transmission source of the newly received print request command (image forming command) acquired by the identification unit 413. When is different from, the print request is rejected.

On the other hand, the image output unit 12 includes the decomposer 1
The image-formable data expanded by No. 3 is image-formed on a print sheet and discharged. Since image formation is a known technique, description thereof will be omitted. Decomposer 13
Is to expand the image data received by the two receiving units 412-1 and 412-2 into image formable data. In general, the image data received from the workstation 20 is not image-formable data but code data described in a page description language such as PostScript (PostScript), so it is converted into image-formable data. And stores it in the memory 14.

The memory 14 is a ROM in which programs and prescribed values required for controlling the image forming apparatus 40 are stored, and temporary variables for program processing and processing and image formation developed by the decomposer 13 are possible. It is composed of a RAM in which data is stored. User interface 1
Reference numeral 5 denotes an input unit such as a keyboard and buttons for receiving a request from the user of the image forming apparatus 40, and a display unit such as a display or a liquid crystal panel for notifying the user of the state of the image forming apparatus 40. Composed. Interface 16
Is a network interface that transmits and receives data to and from the network 30.

The workstation (WS) 20 is a higher-level device for the main image forming apparatus 40, creates image data, and performs image forming, status inquiry, and requested image forming processing for the main image forming apparatus 40. Make various requests (commands) such as cancellation. Various commands are transmitted to the image forming apparatus 40 via the network 30. In the present embodiment, the workstation is illustrated as the higher-level device, but a device such as a personal computer or a word processor may be used as long as it sends an image forming command together with the image data.

The network 30 includes the image forming apparatus 40.
And a workstation 20 for exchanging data with each other. The network 30 generally includes Ethernet and token ring, but is not limited to this as long as a plurality of workstations and the image forming apparatus 40 can be connected.

Next, the operation of the image forming apparatus 40 according to the above embodiment will be described. In this embodiment, as described above, the number of receiving units is set to two. 5 and 6 show the image forming apparatus 4
6 is a flowchart for explaining a basic operation of 0. In the following, description will be made step by step according to this flowchart.

First, when the image forming apparatus 40 is activated,
Each means performs an initialization process. That is, the flag indicating whether or not the print processing is currently being performed is cleared (step S21), and the higher-level device information storage table (not shown) of the higher-level device information storage unit 414 is initialized (step S2).
2). Here, the higher-level device information storage table is a table that stores the IP address or MAC address indicating the source workstation of a job that is being printed by the image forming apparatus 40.

Upon completion of the initialization process, the image forming apparatus 40 waits for reception of various commands from the workstation 20 (step S23). When various commands are received from the workstation 20 (step S24), the connection with the workstation 20 is established (step S25). Subsequently, the command is received (step S26), and the identification unit 413 causes the IP address or MAC of the workstation that transmitted the command.
An address is acquired (step S27).

In this embodiment, the IP address is acquired when the communication protocol in the network 30 is TCP / IP, and the MAC address is acquired when the communication protocol is SPX or DLC. After obtaining the address, it is determined whether the command is a print request command (image forming command) (step S
28) If the command is a print request command, it is determined whether the image forming apparatus 40 is in the process of printing (step S).
29). If it is determined that the printing process is in progress, the host device information storage table of the host device information storage unit 414 is referenced to obtain the address of the transmission source workstation of the job being processed (step S30).

Next, the address of the transmission source workstation of the print request command acquired in step S27 is compared with the address of the request source workstation of the job being processed acquired in step S30 (step S3).
1) If they are the same, it is judged again whether or not the print processing is in progress (step S32), and if the print processing is in progress,
It waits until the printing process is completed.

When it is determined in step S29 or step S32 that print processing is not in progress, or step S3
When the print processing is completed through the standby loop of 2, the print processing flag is newly set (step S33), and the address of the print request source workstation is set in the upper apparatus information storage table of the upper apparatus information storage unit 414. Register (step S34). Then, the print process is performed (step S35), and when the print process is completed, the in-process flag is cleared (step S3).
6). The printing process, that is, the image forming process is well known and will not be described here. After that, the connection with the workstation 40 is disconnected (step S37), and this processing ends.

In step S31, the address of the print request command transmission source WS acquired in step S27 is compared with the address of the request source workstation of the job being processed acquired in step S30. Request command NACK meaning rejection of print request to requesting workstation
(A value other than 0) is notified (step S38), and then the process proceeds to step S37 to disconnect the connection with the workstation 40 and end this processing.

On the other hand, when it is determined in step S28 that the received command is not the print request command, it is determined whether the command is the image forming apparatus status inquiry command (step S39). If it is an image forming apparatus status inquiry command, the workstation 20 is notified of information on the job currently being processed and information on the status of the image forming apparatus 40 (step S40). If the received command is not the image forming apparatus status inquiry command, it is further determined whether the command is an image formation cancel command (step S41). Then, in the case of the image formation cancellation command, if there is a job for which the cancellation request matches the requested job, the cancellation process is performed (step S42).

If it is determined in step 41 that the received command is not the image formation cancel command, the command cannot be processed by the image forming apparatus 40, and therefore ACK (value 0) or N is sent to the workstation 20.
Only ACK is notified (step S43). When the processing of step S40, step S42, or step S43 is completed, the process proceeds to step S37, the connection with the workstation 20 is disconnected, and this processing is completed.

In the present embodiment, the case in which the number of receiving units is limited to two has been described. However, from the viewpoint of cost, only two are usually effective, and therefore more may be used. Further, although the IP address or the MAC address is used for the workstation identification, the present invention is not particularly limited to this, and for example, the identification information such as the identification ID or the workstation name determined independently may be used. .

As described above, the command from the workstation 20, which is the higher-level device, is received by, for example, the two receiving units 4.
Image forming apparatus 40 capable of receiving simultaneously by 12-1 to 412-2
In the case where the print request command (image forming command) is received from the workstation 20, if the print request command is being received, the reception of the newly received print request command is interrupted. As a result, the two receiving units 412-1 to 412-2 are not monopolized together.

As a result, even when the print request command is received, it is possible to always receive the image forming apparatus status inquiry command and the image formation cancel command. In particular, when the image forming process is performed together with the process of receiving the image data from the host device, the image forming process is far better than the process for the image forming device status inquiry or the process for canceling the requested image forming process. Since it takes time, the effect is extremely large.

When the print request command is received from the workstation 20 and the print processing is in process, whether or not the source workstation of the print request command is the same as the request source workstation of the job being processed. By waiting for the print processing to end when the same, and rejecting the print request command when different, priority processing is given to continuous image forming requests from the same workstation. You can

Next, the operation of the workstation 20 side in the image forming system shown in FIG. 1 or 4 will be described. FIG. 7 is a flowchart explaining the basic operation of the workstation 20. In the following, description will be made step by step according to this flowchart.

First, when the workstation 20 is activated, initialization processing such as setting of various drivers is performed (step S51). The user of the workstation 20 creates the image data by an application for creating / printing the image data, or reads the image data from a file server, a local hard disk or the like (step S52). When the print process is executed, the print request is not issued immediately and the image forming apparatus 10 (4
0), a status inquiry request is made (step S53). Based on the response to the request, the request destination image forming apparatus determines whether the job can be processed (step S).
54).

If it is determined that the job can be processed, a print request is made (step S55), and the process ends. On the other hand, when it is determined that the job cannot be processed, it is determined whether or not the request-destination image forming apparatus is performing print processing (step S56). If not, whether or not the request-destination image forming apparatus is in an error state. Is determined (step S57). If it is determined in step S56 that the printing process is in progress, if it is determined in step S57 that there is no error, or if it is determined in step S57 that there is an error,
Wait for 3 seconds, 5 seconds, and 10 seconds respectively (step S
58, S59, S60), the process again returns to step S53 to make a status inquiry request to the image forming apparatus 10 (40).

Here, steps S58, S59, S60
In this example, it is predicted that the job waiting time in the case of the request destination image forming apparatus is likely to be in the job processable state earlier than in the error state, for example. The value is set to, and should not be fixed to the numerical value, and may be changed according to the characteristics of the image forming apparatus 10 (40).

As described above, the image forming apparatus 10 (4
0) and the workstation 20, which is a higher-level device, are connected to each other via the network 30, the workstation 20 includes the image forming apparatus 10 (4).
0) to a print request command (image forming command), an image forming apparatus status inquiry command is sent, and when the image forming apparatus 10 (40) is capable of image forming processing, a print request command is sent. By doing so, it is possible to eliminate the trouble of retransmission when the user of the workstation 20 is rejected.

When the image forming apparatus 10 (40) cannot perform the image forming process, the image forming apparatus 10 (40)
The image forming apparatus 10 (40) is waited for a time corresponding to the state, and after that time, the processing of transmitting the image forming apparatus state inquiry command to the image forming apparatus 10 (40) is repeated. When the image forming process becomes possible, the user of the workstation 20 can perform the print process without performing the retransmit process.

[0069]

As described above, according to the present invention,
When multiple commands are received from the host device at the same time and the number of image formation commands being received reaches a predetermined number, or when image formation processing is in progress, new image formation commands are rejected. It becomes possible to receive a device status inquiry command and an image formation cancellation command. In particular, when the image forming process is performed while receiving the image data from the host device, the image forming process requires much time compared with the process for the image forming device state inquiry and the process for canceling the image forming process. The effect is extremely large. Further, since the image data from the host device is not stored once, the time required to output the image data of the first page can be shortened and the cost can be reduced.

Further, the upper-level device temporarily transmits the image forming device status inquiry command before transmitting the image forming command to the image forming device, and transmits the image forming command when the image forming device can perform the image forming process. By doing so, it becomes possible to eliminate the trouble of re-transmission when the user of the host device is rejected.

[Brief description of drawings]

FIG. 1 is a schematic block diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart (No. 1) for explaining a basic operation according to the embodiment.

FIG. 3 is a flowchart (part 2) for explaining the basic operation according to the embodiment.

FIG. 4 is a schematic block diagram showing another embodiment of the present invention.

FIG. 5 is a flowchart (No. 1) for explaining a basic operation according to another embodiment.

FIG. 6 is a flowchart (part 2) for explaining a basic operation according to another embodiment.

FIG. 7 is a flowchart for explaining a basic operation on the workstation side.

FIG. 8 is an explanatory diagram of general network communication.

FIG. 9 is a diagram showing a first command in the Lpd printing protocol.

FIG. 10 is a diagram showing a second command in the Lpd printing protocol.

FIG. 11 is a sequence diagram of Lpr in the Lpd printing protocol.

FIG. 12 is a sequence diagram of Lpq in the Lpd printing protocol.

FIG. 13 is a sequence diagram of Lprm in the Lpd printing protocol.

[Explanation of symbols]

 10, 40 Image forming apparatus 11, 41 CPU 12 Image output unit 13 Decomposer 20 Workstation 30 Network 112-1, 112-n, 412-1, 412-2 Receiving unit 113 Determining unit 114, 415 Interrupting unit 413 Identifying unit 414 Host device information storage

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G06F 13/00 354 G06F 13/00 354A

Claims (6)

[Claims] 1. A plurality of receiving means capable of receiving a plurality of commands for an image forming job from a host device at the same time, and a determining means for determining the maximum number of image forming commands received simultaneously by the plurality of receiving means. And an interruption means for interrupting the reception of a newly received image formation command when the number of image formation commands being received by the plurality of reception means is equal to the maximum number determined by the determination means. An image forming apparatus characterized by the above. 2. The image according to claim 1, wherein the plurality of receiving units are two, one of which receives only an image forming command and the other receives a command other than the image forming command. Forming equipment. 3. A plurality of receiving units capable of simultaneously receiving a plurality of commands for a job to be subjected to image formation from a host device, and an image forming process being executed by the image forming commands received by the plurality of receiving units. An image forming apparatus comprising: an interrupting unit that interrupts reception of a newly received image forming command. 4. The image forming apparatus according to claim 3, further comprising: identification means for identifying the higher-order apparatus, and higher-order apparatus information storage for storing the higher-order apparatus information identified by the identification means in association with a job. The interrupting means is executing the image forming processing by the image forming command received by the plurality of receiving means, and is the transmission source host of the running job stored by the host device information storing means. An image forming apparatus, characterized in that reception of the command is interrupted when the apparatus and a transmission source upper apparatus of the newly received image forming command are different. 5. The image forming apparatus according to claim 1, wherein a status inquiry command of the image forming apparatus is transmitted before the image forming command is transmitted to the image forming apparatus. An image forming system comprising: a host device that transmits an image forming command when an image forming process is possible in the forming device. 6. When the image forming apparatus cannot perform an image forming process, the upper apparatus inquires again about the state of the image forming apparatus after a predetermined time has elapsed according to the state of the image forming apparatus. The image forming system according to claim 5, wherein a command is transmitted.