Image forming apparatus

Abstract

To provide an image forming device that can suppress an image from being formed in a condition that is different from an intended intention by a user, more effectively than before, when time-out occurs, after image data are interrupted during reception of the image data relating to a printing command.SOLUTION: An image forming device is provided with a communication part that receives a printing instruction for image data from a user terminal through a network, an image forming part that forms an image on the basis of the image data, and a control part that controls the communication part and the image forming part. After receiving the printing instruction from the user terminal, the control part determines whether or not the image data relating to the printing instruction are complete or not, on the basis of prescribed determination steps, when a predetermined time-out time elapses without receiving a notification of completion of transmission of the printing instruction from the user terminal; when determining that the image data are complete, makes the image forming part execute image formation on the basis of the image data; and when determining that the image data are not complete, suspends execution of the printing instruction.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] This disclosure relates to an image forming apparatus.

Background Art

[0002] Conventionally, in an image forming apparatus such as an MFP (Multifunction Peripheral), only a part of print data is transmitted from a user terminal such as a personal computer (PC) to the image forming apparatus, and printing in a plurality of copies may be performed on a per-part basis.

[0003] For example, in the ROPM (RIP Once Print Multi) method, after a part of the print data received from the user terminal is RIP (analyzed), the RIP-processed data is stored in a storage area such as the HDD of the image forming apparatus, and this is repeatedly input to the print engine to achieve printing in a plurality of copies.

[0004] In such an image forming apparatus, if the print data is interrupted during reception of the print data from the user terminal, the image forming apparatus may not receive a session close (notification of completion of transmitted data) from the user terminal, and a preset timeout period may elapse. As a result, if it is determined that the interrupted print data is incomplete based on the analysis result of the image forming apparatus, a timeout error occurs.

[0005] Conventionally, in response to such a problem, when an error occurs during processing of data input from a host machine in a multiple-copy printing mode, only the first sheet is printed, and a display is provided for the operator to select whether to continue printing the remaining number of copies, and printing of the remaining number of copies is performed only when continuation is selected. A multiple-copy printing method has been disclosed (see, for example, Patent Document 1).

[0006] Furthermore, a printing apparatus is disclosed that includes a job continuation inquiry means for inquiring with a data source whether or not it is permissible to discard a job in progress when a timeout error occurs, and a job discard determination means for determining whether or not to discard the job in progress using a job discard means based on status information from the data source in response to the inquiry by the job continuation inquiry means (see, for example, Patent Document 2).

[0007] Furthermore, an image forming apparatus is disclosed that includes a setting reception means for receiving setting commands via the communication means and input operations on the operation panel, which set a limit time for waiting for reception to resume from when the image forming apparatus starts receiving data from an external device via a communication means until the reception of data is interrupted and the image forming apparatus starts receiving data again, and a limit time for the printing process from when the image forming apparatus starts printing until it finishes printing, respectively, and a control means for controlling the printing operation according to the limit time received by the setting reception means (see, for example, Patent Document 3). [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 08-310083 [Patent Document 2] Japanese Patent Application Publication No. 08-016331 [Patent Document 3] Japanese Patent Publication No. 2009-291983 [Overview of the project] [Problems that the invention aims to solve]

[0009] Incidentally, based on the analysis results of the image forming apparatus, even if the printed result differs from the complete printed data, such as some images being missing, the interrupted printed data may not be judged as incomplete. In this case, since the image forming apparatus is a ROPM (Return-to-Print Programmable) system, the print data is saved directly to the HDD.

[0010] Therefore, even if the print data saved by ROPM is incomplete, the image forming apparatus will print the specified number of copies.

[0011] Furthermore, if a timeout error occurs, the user's terminal may attempt to resend the print data, assuming that it was unable to successfully complete the transmission of the print data. In this case, if a timeout occurs again in the resent print data, the above problem will be repeated.

[0012] On the other hand, even if a timeout error occurs, the print data may still be complete. For example, this could occur if the user terminal times out after sending all the print data to the image forming machine but fails to send a session close message.

[0013] However, in this case, users may not be able to make an appropriate decision because they have no information to determine whether or not to continue printing when a timeout occurs. Therefore, if a user cancels printing, the printing is canceled even though the user's terminal has sent complete data to the image forming machine.

[0014] This disclosure was made in consideration of the circumstances described above, and provides an image forming apparatus that more effectively suppresses the formation of an image in a state different from the user's intention when a timeout occurs after the reception of image data related to a print command is interrupted. [Means for solving the problem]

[0015] The image forming apparatus according to this invention includes a communication unit that receives a print command of image data from a user terminal via a network, an image forming unit that forms an image based on the image data, and a control unit that controls the communication unit and the image forming unit. After receiving the print command from the user terminal, when a predetermined timeout time elapses without receiving a transmission completion notification of the print command from the user terminal, the control unit determines whether the image data related to the print command is complete based on a predetermined determination procedure. When it is determined that the image data is complete, the control unit causes the image forming unit to execute formation of an image based on the image data. When it is determined that the image data is not complete, the control unit suspends execution of the print command.

Advantages of the Invention

[0016] According to this disclosure, when a timeout occurs after the image data related to the print command is interrupted during reception of the print command, an image forming apparatus is realized that more effectively suppresses the formation of an image in a state different from the user's intention than in the past.

Brief Description of the Drawings

[0017] [Figure 1] It is an explanatory diagram showing an example of the configuration of an image forming system including the digital multifunction device of this disclosure. [Figure 2] It is a block diagram showing the schematic configuration of the digital multifunction device of FIG. 1. [Figure 3] It is a block diagram showing the schematic configuration of the user terminal of FIG. 1. [Figure 4] It is an explanatory diagram showing an example of print data of a plurality of units of the digital multifunction device of FIG. 1. [Figure 5] It is a flowchart showing the processing of print data of the digital multifunction device of FIG. 1. [Figure 6] It is a flowchart showing the processing of print data of the digital multifunction device of FIG. 1. [Figure 7] It is a table showing an example of recording the reception rate of print data received by the digital multifunction device of FIG. 1. [Figure 8] A table showing another example of recording the reception rate of print data received by the digital multifunction machine of FIG. 1. [Figure 9] A table showing yet another example of recording the reception rate of print data received by the digital multifunction machine of FIG. 1. [Figure 10] A flowchart showing the processing of print data of the digital multifunction machine according to Embodiment 2 of this disclosure. [Figure 11] A flowchart showing the processing of print data of the digital multifunction machine according to Embodiment 2 of this disclosure. [Figure 12] A flowchart showing the processing of print data of the digital multifunction machine according to Embodiment 2 of this disclosure. [Figure 13] A flowchart showing the processing of print data of the digital multifunction machine according to Embodiment 3 of this disclosure. [Figure 14] A flowchart showing the processing of print data of the digital multifunction machine according to Embodiment 3 of this disclosure.

Mode for Carrying Out the Invention

[0018] In this disclosure, an "image forming apparatus" is an apparatus that forms and outputs an image, such as a copying machine (copying function) having a copying function using an electrophotographic method for image formation by toner, a multifunction machine, or an MFP including functions other than copying. The "user terminal" is not limited to a personal computer (PC), and may be a portable information terminal such as a smartphone or a tablet terminal, an electronic blackboard, an information display, or the like.

[0019] Furthermore, preferred embodiments of this disclosure will be described.

[0020] In the image forming apparatus of this disclosure, the control unit may determine whether the image data is complete based on whether the image data related to the print command includes a predetermined unique header and a unique footer.

[0021] In this way, if a timeout occurs after the image data related to a print command is interrupted during reception of the image data, the image forming apparatus can be made more effectively than before by determining whether the image data is complete based on whether or not it contains a predetermined unique header and footer, thereby preventing the image from being formed in a state different from the user's intention.

[0022] In the image forming apparatus disclosed herein, the control unit may determine that the image data is complete if it includes the unique header and the unique footer, and determine that the image data is incomplete if it does not include the unique footer.

[0023] In this way, if a timeout occurs after the image data related to a print command is interrupted during reception of the image data, the image data is determined to be complete if it includes a predetermined unique header and footer, and to be incomplete if it does not include the unique footer. This makes it possible to realize an image forming apparatus that more effectively suppresses the formation of images in a state different from the user's intention than in conventional methods.

[0024] In the image forming apparatus disclosed herein, the apparatus further comprises a storage unit for storing various data related to image formation, and the control unit calculates the reception rate of the image data related to the print command and stores it in the storage unit. If the image data does not include the unique header, the control unit refers to the history of the reception rate stored in the storage unit for a predetermined time from the start of the measurement of the timeout period, and determines that the image data is complete if the reception rate has remained above a predetermined tolerance value during the predetermined time, and determines that the image data is incomplete otherwise.

[0025] In this way, if a timeout occurs after the image data related to a print command is interrupted during reception of the image data, and the image data does not include a predetermined unique header, it is possible to determine whether the image data is complete or not based on the reception rate history for a predetermined period of time. This makes it possible to realize an image forming apparatus that more effectively suppresses the formation of images in a state different from the user's intention than in conventional methods.

[0026] In the image forming apparatus disclosed herein, the control unit may determine whether the print command received from the user terminal specifies the printing of multiple copies, and if the print command specifies the printing of multiple copies and the timeout period has elapsed without receiving notification of completion of transmission of the print command from the user terminal, it may determine whether the image data is complete based on the determination procedure.

[0027] In this way, if a timeout occurs after the image data related to a print command is interrupted during reception of the image data, the image forming apparatus can be designed to determine whether the image data is complete or not only when the print command specifies printing multiple copies, thereby more effectively suppressing the formation of images in a state different from the user's intention than in conventional designs.

[0028] In the image forming apparatus disclosed herein, the control unit may, after suspending the execution of the print command, cancel the execution of the print command and discard the image data related to the print command once a predetermined suspension period has elapsed.

[0029] In this way, an image forming apparatus can be realized that more effectively suppresses the formation of images in a manner different from the user's intention by suspending the execution of the print command if the image data is incomplete, and then canceling the execution of the print command after a predetermined suspension period has elapsed.

[0030] In the image forming apparatus disclosed herein, if the communication unit receives subsequent image data after suspending the execution of the print command and before the suspension time has elapsed, the control unit may compare the subsequent image data with the image data related to the suspended print command and determine that they are the same, then treat the subsequent image data as if the image data related to the suspended print command had been retransmitted, discard the image data related to the suspended print command, and determine whether the subsequent image data is complete or not.

[0031] In this way, if the execution of the print command is suspended because the image data is incomplete, and then subsequent image data is received before a predetermined suspension time has elapsed, it is possible to determine whether the image data is a retransmission of the image data related to the suspended print command, thereby realizing an image forming apparatus that more effectively suppresses the formation of images in a state different from the user's intention than in conventional methods.

[0032] The image forming apparatus disclosed herein further comprises a display unit that displays various information to the user and an operation unit that receives commands from the user. The control unit may, if it determines that the image data related to the print command is incomplete, cause a predetermined message to be displayed on the display unit, and the operation unit may receive a command from the user indicating whether or not to cancel the execution of the print command.

[0033] In this way, if the image data related to the print command is determined to be incomplete, a message to that effect is displayed on the display unit, and the user is asked whether or not to cancel the print command. This makes it possible to realize an image forming apparatus that more effectively prevents images from being formed in a state different from the user's intention than in conventional models.

[0034] The following details of this disclosure will be illustrated with drawings. The following description is illustrative in all respects and should not be construed as limiting the scope of this disclosure.

[0035] [Embodiment 1] <Outline configuration of the image forming system 100> Based on Figures 1 to 3, a digital multifunction device 1, which is one embodiment of the image forming apparatus disclosed herein, will be described.

[0036] Figure 1 is an explanatory diagram showing an example of the configuration of an image forming system 100 including the digital multifunction printer 1 of this disclosure. Figure 2 is a block diagram showing the schematic configuration of the digital multifunction printer 1 shown in Figure 1. Figure 3 is a block diagram showing the schematic configuration of user terminal 2 in Figure 1.

[0037] As shown in Figure 1, in the image forming system 100 disclosed herein, the digital multifunction printer 1 is connected to the user terminal 2 via a wired or wireless network 3.

[0038] Digital multifunction device 1 is a device such as a multifunction printer or MFP (Multifunction Peripheral) that digitally processes image data and has copy, printer, scanner, and facsimile functions.

[0039] User terminal 2 includes personal computers (PCs), tablets, and mobile devices such as smartphones. User terminal 2 sends and receives image data to and from the digital multifunction printer 1 via network 3.

[0040] <Outline configuration of digital multifunction printer 1> Next, the general configuration of the digital multifunction printer 1 will be explained based on Figure 2. Figure 2 is a block diagram showing the schematic configuration of the digital multifunction printer 1 shown in Figure 1.

[0041] As shown in Figure 2, the digital multifunction printer 1 comprises a control unit 10, an image data acquisition unit 11, an image forming unit 12, a storage unit 13, an image processing unit 14, a communication unit 15, a timer 16, and an operation panel 17.

[0042] The following describes each component of the digital multifunction printer 1.

[0043] The control unit 10 comprehensively controls the digital multifunction printer 1 and consists of a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read-only memory), various interface circuits, and the like.

[0044] The control unit 10 monitors and controls all loads, including detection by each sensor, motor, clutch, and control panel 17, in order to control the operation of the entire digital multifunction printer 1.

[0045] The image data acquisition unit 11 is the part that detects and reads documents placed on the document glass or documents transported from the document tray, and generates image data.

[0046] The image forming unit 12 is the part that prints the image data acquired by the image data acquisition unit 11 and processed by the image processing unit 14 onto paper.

[0047] The memory unit 13 is an element or storage medium that stores information and control programs necessary to realize the various functions of the digital multifunction device 1. For example, semiconductor elements such as RAM and ROM, storage media such as hard disks, flash memory units, and SSDs (Solid State Drives) are used.

[0048] The memory unit 13 stores intermediate data such as information related to print job instructions (print jobs) and internal data (work memory) necessary for executing jobs, such as image data. Furthermore, the storage unit 103 has a spool area for temporarily storing print / fax data.

[0049] Furthermore, the data may be stored in different devices, such as a hard disk drive for the data storage area and a flash memory unit for the program storage area.

[0050] The image processing unit 14 is the part that processes the image data input from the image data acquisition unit 11 into appropriate electrical signals based on the analysis results of print job commands acquired from the user terminal 2 etc. via the communication unit 15 and print job commands input from the operation unit 162, so that it is suitable for output such as enlargement and reduction.

[0051] The communication unit 15 is the part that communicates with external devices such as user terminals 2 via the network 3 and sends and receives data to and from these external devices.

[0052] Timer 16 is the part that measures and counts time, and obtains the time, for example, from an internal clock or through network 3.

[0053] The operation panel 17 consists of a display panel made of a liquid crystal panel or the like, and a touch panel, such as a capacitive type, which is placed on top of the display panel and detects the position where a finger is touched, and includes a display unit 171 and an operation unit 172.

[0054] The display unit 171 is the part that displays various types of information. The display unit 171 is composed of, for example, a CRT display, a liquid crystal display, or an EL display, and is a display device such as a monitor or line display for displaying electronic data such as processing status by the operating system or application software.

[0055] The control unit 10 displays the operation and status of the digital multifunction printer 1 through the display unit 171.

[0056] The control unit 172 is an interface for operating the digital multifunction printer 1 and is the part that receives commands from the user.

[0057] <Outline configuration of user terminal 2> Next, the general configuration of user terminal 2 will be explained based on Figure 3.

[0058] As shown in Figure 3, the user terminal 2 comprises a control unit 20, a storage unit 21, an image processing unit 22, a communication unit 23, a display unit 24, and an operation unit 25.

[0059] The following describes each component of user terminal 2.

[0060] The control unit 20 is the part that comprehensively controls the user terminal 2 and consists of a CPU, RAM, ROM, various interface circuits, etc.

[0061] The memory unit 21 is an element or storage medium that stores information and control programs necessary to realize various functions of the user terminal 2. For example, semiconductor elements such as RAM and ROM, or storage media such as hard disks, flash memory units, and SSDs are used.

[0062] The image processing unit 22 is the part that, based on operation instructions from the operation unit 25, converts image data to be displayed on the display unit 24 into appropriate electrical signals and processes them to make them suitable for output such as enlargement and reduction.

[0063] The communication unit 23 communicates with the digital multifunction printer 1 via the network 3 and sends and receives data such as setting information necessary for printing.

[0064] The display unit 24 is the part that displays various information from the user terminal 2.

[0065] The operation unit 25 is an interface for operating the user terminal 2 and is the part that receives commands from the user.

[0066] The display unit 24 and the operation unit 25 may be implemented by a display panel made of a liquid crystal panel or the like, and a touch panel such as a capacitive touch panel that is placed on top of the display panel and detects the position where a finger is touched.

[0067] <An example of print data processing by the digital multifunction printer 1 of Embodiment 1 of this invention> Next, an example of the processing of print data by the digital multifunction printer 1 of Embodiment 1 of this invention will be described based on Figures 4 to 9.

[0068] Figure 4 is an explanatory diagram showing an example of print data for multiple copies from the digital multifunction printer 1 shown in Figure 1.

[0069] Printing from the digital multifunction printer 1 is typically done by generating print data through software (printer driver) pre-installed on the user terminal 2 for printing from the digital multifunction printer 1, and then sending that data to the digital multifunction printer 1.

[0070] Print data generated by a printer driver generally includes a header and footer called PJL (Printer Job Language), which are involved in controlling the entire job. Furthermore, this PJL contains PDL (Print Description Language) data that describes the print content for each page.

[0071] A PJL header is typically structured by being flanked by PJL commands that indicate the beginning and end of the PJL header. In the example in Figure 4, "%-12345X@PJL JOB NAME="test page"" is the PJL command that represents the beginning of the PJL header.

[0072] The PJL footer is typically composed of PJL commands that indicate the end of the PJL footer. In the example in Figure 4, "%-12345X" is the PJL command that represents the trailing end of the PJL footer.

[0073] While specifying multiple copies can sometimes be done within the PDL data itself, it is more common to specify them in the form of PJL commands within the PJL header. In the example in Figure 4, "@PJL SET QTY=999" is the PJL command used to specify the number of copies.

[0074] PJL headers and footers can contain vendor-specific PJL commands generated by the printer driver.

[0075] In the example in Figure 4, "@PJL SET DRIVERNAME" in the PJL header and "@PJL SET ORIGINALCOUNTINFO" in the PJL footer are vendor-specific PJL commands.

[0076] PDL data consists of specific command sequences, such as PostScript or PCLXL.

[0077] While the print data generated by the printer driver is as described above, the print data sent to the printing device may not follow the above format, such as when directly printing PDF or TIFF files.

[0078] Figures 5 and 6 are flowcharts illustrating the processing of print data by the digital multifunction printer 1 shown in Figure 1.

[0079] In Embodiment 1, we assume a case where print data is sent from the user terminal 2 to the digital multifunction printer 1 to print an image.

[0080] In step S1 of Figure 5, the control unit 10 of the digital multifunction printer 1 determines whether or not the communication unit 15 has received print data from the external user terminal 2 (step S1).

[0081] If the communication unit 15 receives print data from an external user terminal 2 (if the determination in step S1 is Yes), in step S2, the control unit 10 determines whether or not the received print data contains a command specifying multiple copies (step S2).

[0082] Specifically, as shown in Figure 4, the control unit 10 analyzes the PJL header of the print data and searches for the presence or absence of the PJL command "@PJL SET QTY=999" for specifying the number of copies.

[0083] If the received print data does not contain a command to specify multiple copies, or if it contains a command to specify multiple copies but only specifies one copy (if the determination in step S2 is No), in step S8, the received print data is analyzed and the image processing unit 14 is instructed to process the image data related to the print, and the image forming unit 12 is instructed to start printing (step S8).

[0084] In the following step S9, the control unit 10 determines whether or not all of the specified number of copies have been printed (step S9).

[0085] If all the specified number of copies have been printed (if the determination in step S9 is Yes), the control unit 10 terminates the process.

[0086] On the other hand, in step S2, if the received print data contains a command specifying multiple copies (two or more copies) (if the determination in step S2 is Yes), in step S3, the control unit 10 starts saving the received print data to the spool area of ​​the storage unit 13 (step S3).

[0087] In the following step S4, the control unit 10 performs the print data reception process (step S4).

[0088] In step S5, the control unit 10 calculates the reception rate and stores it in the storage unit 13 (step S5).

[0089] Figure 7 is a table showing an example of a record of the reception rate of print data received by the digital multifunction printer 1 in Figure 1. Specifically, this is an example of recording the reception rate for a print job with multiple copies, from the start of reception to the completion of receiving all data and the notification of session closure.

[0090] Here, the communication unit 15 polls for print data reception every 10ms (0.01sec), and is assumed to be able to receive data at a maximum performance of 1024KB / sec.

[0091] In this case, the control unit 10 calculates the cumulative received size every 10ms (0.01sec) from the start of reception and records it in the storage unit 13.

[0092] In the example in Figure 7, the elapsed time (sec) is 0, 0.01, 0.02, ..., 1, ..., 10, and the acquired data size (cumulative (KBytes)) is 0, 10.24, 20.48, ..., 1024, ..., 10240, respectively.

[0093] Furthermore, the control unit 10 calculates the reception rate (every 10ms) and the average reception rate (over the entire period) using the cumulative reception size and records them in the storage unit 13. The average reception rate may also be calculated as a moving average over a certain period.

[0094] In the example in Figure 7, the reception rate (KBytes / sec) is 1024, and the average reception rate (KBytes / sec) is also 1024.

[0095] Next, in step S6 of Figure 5, the control unit 10 determines whether or not there is print data received by the communication unit 15 (step S6).

[0096] If the communication unit 15 has received any print data (if the determination in step S6 is Yes), in step S7, the control unit 10 determines whether or not it has received a session close (step S7).

[0097] If a session close has not been received (i.e., the determination in step S7 is No), the control unit 10 returns the process to step S4.

[0098] On the other hand, if a session close is received (if the determination in step S7 is Yes), in step S8, the control unit 10 analyzes the received print data, causes the image processing unit 14 to process the image data related to the print, and causes the image forming unit 12 to start printing (step S8).

[0099] In the example shown in Figure 7, print data is received continuously at a rate of 1024 KB / sec from the start of data reception, and the session close is received after an elapsed time (10.01 sec), so printing is completed successfully.

[0100] On the other hand, if the communication unit 15 has not received any print data in step S6 (the determination in step S6 is No), then in step S10 of Figure 6, the control unit 10 determines whether or not a timeout has occurred (step S10).

[0101] If no timeout has occurred (the determination in step S10 is No), the control unit 10 returns to step S4 in Figure 5.

[0102] On the other hand, if a timeout occurs (if the determination in step S10 is Yes), in step S11, the control unit 10 determines whether or not the spool data of the print data has a unique header (step S11).

[0103] If the print data spool data has a unique header (if the determination in step S11 is Yes), in step S12, the control unit 10 determines whether or not the print data spool data has a unique footer (step S12).

[0104] If the spool data of the print data has a unique footer (if the determination in step S12 is Yes), in step S13, the control unit 10 determines that the print data is complete (step S13).

[0105] Subsequently, in step S8 of Figure 5, the control unit 10 analyzes the received print data, causes the image processing unit 14 to process the image data related to the print, and instructs the image forming unit 12 to start printing (step S8).

[0106] On the other hand, if the spool data of the print data does not have a unique footer (if the determination in step S12 is No), in step S16, the control unit 10 determines that the print data is incomplete (step S16).

[0107] Furthermore, if the spool data of the print data does not have a unique header (if the determination in step S11 is No), in step S14, the control unit 10 reads the reception rate history for a certain period of time prior to the start of the timeout measurement (step S14).

[0108] In the following step S15, the control unit 10 determines whether the reception rate history has been exceeding a predetermined allowable value (step S15).

[0109] If the reception rate history does not remain above a predetermined tolerance value (i.e., the determination in step S15 is No), in step S13, the control unit 10 determines that the print data is complete.

[0110] Figure 8 is a table showing another example of a record of the reception rate of print data received by the digital multifunction printer 1 in Figure 1.

[0111] In the example in Figure 8, for a print job with multiple copies, data was received at a rate of 1024 KB / sec from the start of reception. However, the size of the print data acquired at time T(0) became 0, and thereafter, the size of the acquired print data remained 0 until the pre-set timeout period elapsed (time T(0) + Timeout), without receiving a session close notification.

[0112] In this case, prior to time T(0), print data was being received at a rate of 1024KB / sec. If user terminal 2 sends all print data to digital multifunction printer 1 but fails to send a session close message for some reason, the history of received data may progress in this manner.

[0113] In this case, if a timeout occurs at time T(0) + Timeout, the control unit 10 checks the reception rate by going back a predetermined amount of time from time T(0) when the measurement of the elapsed time Timeout began.

[0114] In other words, it checks whether the reception rate remained above or below a predetermined acceptable level.

[0115] For example, the reception rate for the section 60 seconds prior to T(0) is determined to be an acceptable value of 100KB / sec, which is approximately 10% of the maximum capacity.

[0116] In this case, as shown in the example in Figure 8, the reception rate remains constant at 1024 KB / sec throughout the interval from time T(0)-60.0 sec to time T(0). Therefore, the control unit 10 considers the reception to have been normal and determines that the received data is complete (if the determination in step S15 is Yes).

[0117] On the other hand, if the reception rate history is below a predetermined tolerance value (if the determination in step S15 is No), in step S16, the control unit 10 determines that the print data is incomplete.

[0118] Figure 9 is a table showing yet another example of a record of the reception rate of print data received by the digital multifunction printer 1 in Figure 1.

[0119] In the example in Figure 9, for a print job with multiple copies, data was received at a rate of 1024 KB / sec from the start of reception, but the size of the received print data decreased from around time T(0)-60s.

[0120] Then, the size of the print data acquired at time T(0) becomes 0, and from then until the pre-set timeout period has elapsed (time T(0)+Timeout), the size of the acquired print data remains 0 without receiving a session close.

[0121] In the example shown in Figure 9, the reception rate remains below 100KB / sec throughout the interval from time T(0)-60.0sec to time T(0). Therefore, the control unit 10 assumes that an abnormality has occurred in reception and that data reception has stopped, and determines that the received data is incomplete.

[0122] The above determination method is merely an example, and the control unit 10 may use not only whether the reception rate in the set section is above or below the allowable value, but also the trend of the reception rate, such as the average reception rate or the moving average of the reception rate, as criteria for determination.

[0123] Next, if it is determined in step S16 that the print data is incomplete, in step S17 the control unit 10 cancels the received print job (step S17).

[0124] The control unit 10 may also display a message on the display unit 171 indicating that the print job was canceled because the print data was incomplete.

[0125] In this way, a digital multifunction printer 1 can be realized that more effectively than before prevents the print data from being printed in multiple copies in a manner unintended by the user when a timeout occurs after the print data is interrupted while receiving multiple copies of print data.

[0126] [Embodiment 2] Next, an example of the processing of print data by the digital multifunction printer 1 of Embodiment 2 of this disclosure will be described based on Figures 10 to 12.

[0127] The general configuration of the image forming system 100 according to Embodiment 2 is the same as that of Embodiment 1 (Figures 1 to 3), so a description will be omitted.

[0128] Figures 10 to 12 are flowcharts illustrating the processing of print data by the digital multifunction printer 1 according to Embodiment 2 of this disclosure.

[0129] The processes in steps S21-S29 in Figure 10 and steps S30-S36 in Figure 11 correspond to the processes in steps S1-S9 in Figure 5 and steps S10-S16 in Figure 6, respectively, so their explanation is omitted. Here, we will describe the processes from step S37 onwards in Figure 11, which are not described in Embodiment 1.

[0130] In step S36 of Figure 11, if it is determined that the print data is incomplete, in step S37, the control unit 10 suspends the analysis and printing of the received print data (step S37).

[0131] In the following step S38, the control unit 10 determines whether the communication unit 15 has received subsequent print data (step S38).

[0132] If the communication unit 15 has not received subsequent print data (the determination in step S38 is No), in step S39, the control unit 10 determines whether a predetermined holding time has elapsed (step S39).

[0133] If the predetermined holding time has not elapsed (i.e., the determination in step S39 is No), the control unit 10 returns to step S37.

[0134] On the other hand, if a predetermined holding time has elapsed (if the determination in step S39 is Yes), in step S40, the control unit 10 discards the held print data, cancels the print job related to the said print data (step S40), and terminates the process.

[0135] On the other hand, if the communication unit 15 receives a subsequent print job in step S38 (if the determination in step S38 is Yes), then in step S41 of Figure 12, the control unit 10 starts analyzing the said subsequent print job (step S41).

[0136] Next, in step S42, the control unit 10 determines whether or not the subsequent print data contains a command specifying multiple copies (step S42).

[0137] If the subsequent print data does not contain a command specifying multiple copies (i.e., the determination in step S42 is No), the control unit 10 returns to step S37 in Figure 11.

[0138] On the other hand, if the subsequent print data contains a command specifying multiple copies (if the determination in step S42 is Yes), in step S43, the control unit 10 compares the pending print data with the subsequent print data (step S43).

[0139] In the following step S44, the control unit 10 determines whether the pending print data matches the subsequent print data (step S44).

[0140] If the pending print data and the subsequent print data do not match (if the determination in step S44 is No), the control unit 10 returns to step S37 in Figure 11.

[0141] If the pending print data matches the subsequent print data (if the determination in step S44 is Yes), the control unit 10 determines that the subsequent print data is a retransmission of the pending print data and returns to step S40 in Figure 11.

[0142] Furthermore, the control unit 10 will perform the processing from step S23 onwards in Figure 10 for the subsequent print data.

[0143] In this way, if a timeout occurs after the print data is interrupted while receiving multiple copies of print data, the incomplete print data is held, and if the print data is resent, the incomplete print data is discarded and the complete data is printed. This makes it possible to realize a digital multifunction printer 1 that more effectively suppresses the printing of multiple copies of print data in a manner different from the user's intention.

[0144] [Embodiment 3] Next, an example of the processing of print data by the digital multifunction printer 1 of Embodiment 3 of this disclosure will be described based on Figures 13 and 14.

[0145] The general configuration of the image forming system 100 according to Embodiment 3 is the same as that of Embodiment 1 (Figures 1 to 3), so a description will be omitted.

[0146] Figures 13 and 14 are flowcharts illustrating the processing of print data by the digital multifunction printer 1 according to Embodiment 3 of this disclosure.

[0147] The processes in steps S51-S59 in Figure 13 and steps S60-S66 in Figure 14 correspond to the processes in steps S1-S9 in Figure 5 and steps S10-S16 in Figure 6, respectively, so their explanation is omitted. Here, we will describe the processes from step S67 onwards in Figure 14, which are not described in Embodiment 1.

[0148] In step S66 of Figure 14, if it is determined that the print data is incomplete, in step S67, the control unit 10 suspends the analysis and printing of the received print data and displays a message to that effect on the display unit 171 (step S67).

[0149] In the following step S68, the control unit 10 determines whether or not the operation unit 172 has received a user instruction (step S68).

[0150] The control unit 172 determines whether or not it has received the user's instruction (step S68).

[0151] If the operation unit 172 has not received any user instructions (the determination in step S68 is No), in step S70 the control unit 10 determines whether a predetermined holding time has elapsed (step S70).

[0152] If the predetermined holding time has not elapsed (i.e., the determination in step S70 is No), the control unit 10 returns to step S67.

[0153] On the other hand, if a predetermined holding time has elapsed (if the determination in step S70 is Yes), in step S71, the control unit 10 discards the held print data, cancels the print job related to the said print data (step S71), and terminates the process.

[0154] Furthermore, if the operation unit 172 receives instructions from the user in step S68 (if the determination in step S68 is Yes), in step S69, the control unit 10 determines whether or not to print the reserved print data based on the user's instructions (step S69).

[0155] If the pending print data should be printed (if the determination in step S69 is Yes), the control unit 10 returns to step S58.

[0156] On the other hand, if the pending print data should not be printed (if the determination in step S69 is No), in step S71, the control unit 10 discards the pending print data, cancels the print job related to the print data (step S71), and terminates the process.

[0157] In this way, if a timeout occurs after the print data is interrupted while receiving multiple copies of print data, the incomplete print data is held, and based on the user's instructions, it is decided whether to print or discard the held print data. This makes it possible to realize a digital multifunction printer 1 that more effectively prevents the print data from being printed in multiple copies in a manner contrary to the user's intention.

[0158] Preferred embodiments of this invention include combinations of any of the embodiments described above.

[0159] In addition to the embodiments described above, various modifications of this invention are possible. These modifications should not be considered outside the scope of this invention. This invention should include the meaning of equivalence to the claims and all variations within that scope. [Explanation of symbols]

[0160] 1: Digital multifunction printer, 2: User terminal, 3: Network, 10,20: Control unit, 11: Image data acquisition unit, 12: Image forming unit, 13,21: Storage unit, 14,22: Image processing unit, 15,23: Communication unit, 16: Timer, 17: Operation panel, 24,171: Display unit, 25,172: Operation unit, 100: Image forming system

Claims

1. A communication unit that receives print data including image data from a user terminal via a network, An image forming unit that forms an image based on the aforementioned image data, The system comprises a communication unit and a control unit that controls the image forming unit, The image forming apparatus is characterized in that, after the control unit receives the print data from the user terminal, if a predetermined timeout period has elapsed without receiving a session close from the user terminal, it determines, based on a predetermined determination procedure, whether or not the image data relating to the print data is complete; if it determines that the image data is complete, it causes the image forming unit to perform image formation based on the image data; and if it determines that the image data is incomplete, it suspends the execution of the printing process for the print data.

2. The image forming apparatus according to claim 1, wherein the control unit determines whether the image data relating to the print data is complete based on whether or not it includes a predetermined unique header and a unique footer.

3. The control unit determines that the image data is complete if the image data includes the unique header and the unique footer. The image forming apparatus according to claim 2, wherein if the image data does not include the unique footer, the image data is determined to be incomplete.

4. It further includes a storage unit that holds various data related to image formation, The control unit calculates the reception rate of the image data relating to the print data and stores it in the storage unit. If the image data does not include the unique header, the image forming apparatus according to claim 3, which refers to the history of the reception rate held in the storage unit for a predetermined time from the start of the measurement of the timeout period, and determines that the image data is complete if the reception rate has remained above a predetermined allowable value during the predetermined time, and determines that the image data is incomplete otherwise.

5. The control unit determines whether the print data received from the user terminal relates to the specification of printing multiple copies, and if the print data specifies the specification of printing multiple copies and the timeout period has elapsed without receiving the session close from the user terminal, the control unit determines whether the image data is complete based on the determination procedure, as described in claim 1.

6. The image forming apparatus according to claim 1, wherein the control unit, after suspending the execution of the printing process for the print data, cancels the execution of the printing process for the print data and discards the image data related to the print data after a predetermined suspension time has elapsed.

7. The image forming apparatus according to claim 6, wherein the control unit, after suspending the execution of the printing process for the print data, if the communication unit receives subsequent image data before the suspension time has elapsed, compares the subsequent image data with the image data for the suspended print data, and if it determines that they are the same, it discards the image data for the suspended print data, treating the subsequent image data as if the image data for the suspended print data had been retransmitted, and determines whether the subsequent image data is complete or not.

8. A display unit that shows various information to the user, The system further comprises an operating unit that receives commands from the user, If the control unit determines that the image data relating to the print data is incomplete, it will cause a predetermined message to be displayed on the display unit. The image forming apparatus according to claim 1, wherein the operation unit receives a command from the user indicating whether or not to cancel the execution of the print data.

Images