Image forming system having an image checking apparatus and non-transitory computer-readable medium

An image forming apparatus including an image forming apparatus and an image checking apparatus. The image forming apparatus includes a transport control unit which transports a recording medium at a transport speed, and forms an image on the recording medium. The image checking apparatus includes a transport-speed acquisition unit, a detector, a reading unit, and an operation-state notification unit. The transport-speed acquisition unit acquires transport-speed information from the image forming apparatus. The detector detects a mark shown on the recording medium. The reading unit reads a checking-target image formed by the image forming apparatus at a position distant from the mark, on the basis of the transport-speed information and information concerning a positional relationship between the mark and the checking-target image. The operation-state notification unit notifies the image forming apparatus of an operation state of the image checking apparatus.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2012-063384 filed Mar. 21, 2012.

BACKGROUND

Technical Field

The present invention relates to an image forming system and a non-transitory computer-readable medium.

SUMMARY

According to an aspect of the invention, there is provided an image forming apparatus including an image forming apparatus and an image checking apparatus. The image forming apparatus includes a transport control unit which transports a recording medium at a set transport speed, and forms an image on the recording medium. The image checking apparatus includes a transport-speed acquisition unit, a detector, a reading unit, and an operation-state notification unit. The transport-speed acquisition unit acquires transport-speed information concerning a transport speed from the image forming apparatus. The transport-speed information is used as control information of the image forming apparatus. The detector detects a mark shown on the recording medium which is being transported. The reading unit reads a checking-target image on the basis of the transport-speed information and information concerning a positional relationship between the mark and the checking-target image. The checking-target image is formed by the image forming apparatus at a position distant from the mark detected by the detector. The operation-state notification unit notifies the image forming apparatus of an operation state of the image checking apparatus. In a case where the image forming apparatus has received, from the operation-state notification unit, a notification indicating that the image checking apparatus is in a state of performing checking, the image forming apparatus prohibits the set transport speed from being changed. In a case where the image forming apparatus has received, from the operation-state notification unit, a notification indicating that the image checking apparatus is in a state of having finished checking, the image forming apparatus cancels the prohibition of changing the set transport speed and stops transport of the recording medium.

DETAILED DESCRIPTION

Next, an exemplary embodiment of the present invention will be described with reference to the drawings. Note that, although an exemplary embodiment of the present invention is described below using continuous paper as an example of a recording medium, the recording medium is not limited to continuous paper, and an exemplary embodiment of the present invention may be described using cut paper as an example of the recording medium.

FIG. 1is a schematic diagram illustrating an example of a configuration of an image forming system2according to an exemplary embodiment of the present invention. The image forming system2includes an image forming apparatus4and an image checking apparatus6.

As illustrated inFIG. 1, the image forming apparatus4includes, for example, a paper feeding device8, a stack (storage) device10, a printing device12, and a control device14. The image checking apparatus6includes an image-checking-apparatus body16, a detection sensor18, and an image capture camera20.

First, the image forming apparatus4will be described.

The paper feeding device8supplies continuous paper22, such as roll paper, as a recording medium to the printing device12. The stack device10, for example, rolls up the continuous paper22that has been printed by the printing device12, thereby storing the continuous paper22.

The printing device12includes photoconductor drums24to30and a fixing unit32. The photoconductor drums24to30hold toner images of individual colors, e.g., Y (yellow), M (magenta), C (cyan), and K (black). The printing device12performs printing on the continuous paper22, which is a recording medium, under control performed by the control device14described below.

For example, when the control device14accepts, from an external apparatus (for example, a computer) that is not illustrated, via a network or the like, a print job for forming images on multiple pages, the printing device12irradiates the individual photoconductor drums24to30with laser light under control performed by the control device14, thereby forming individual electrostatic latent images on the photoconductor drums24to30. Then, the electrostatic latent images formed on the photoconductor drums24to30are developed by developing devices (not illustrated) using toners of the individual colors to obtain four types of toner images, and the four types of toner images are transferred onto the continuous paper22so as to be superimposed on each other. Then, the toner images transferred onto multiple pages of the continuous paper22are fixed on the continuous paper22by the fixing unit32.

The control device14has, for example, similarly to the image checking apparatus6described below, a configuration of a computer that is configured by connecting a central processing unit (CPU), a memory, a storage device such as a hard disk drive (HDD), and a communication interface (IF), which performs transmission/reception of data, with each other via a control bus. Furthermore, a user interface (UI) device is also connected to the control bus.

In the control device14, the CPU performs processes based on a program that is stored in the memory or the storage device, thereby controlling the individual units constituting the image forming apparatus4. Note that, instead of being supplied from the memory or the storage device, the program may be stored on a recording medium such as a compact disc read-only memory (CD-ROM), and supplied. This recording medium may be a magnetic disk, a semiconductor memory, or another recording medium. Moreover, the program may be supplied via the above-mentioned communication I/F.

The control device14transmits/receives data to/from an external apparatus that transmits a print job and that is not illustrated, the image checking apparatus described below, and so forth via the above-mentioned communication I/F. For example, the control device14receives a print job that has been transmitted by an external apparatus and that is written in page description language (PDL) or the like via the communication I/F. The control device14performs control so that individual electrostatic latent images will be formed on the photoconductor drums24to30for images of the individual colors, which are Y, M, C, and K, for each page. Note that the printing device12may be a duplex color printing apparatus which forms individual four types of toner images on each side of the continuous paper22so that the toner images will be superimposed on each other.

Furthermore, the control device14controls a transport mechanism, which is not illustrated, of the image forming apparatus4so that the continuous paper22will be transported at a predetermined transport speed.

FIG. 2is a block diagram illustrating a functional configuration of the control device14that is realized by executing the above-mentioned program.

As illustrated inFIG. 2, the control device14includes a print-job accepting unit40, a render processing unit42, a print controller44, a transport-information managing unit46, a transport controller48, a state-notification accepting unit50, a checking-target-image position setting unit52, and a checking-result accepting unit54.

The print-job accepting unit40accepts, via the above-mentioned communication IF, a print job that has been received from, for example, an external apparatus. The print-job accepting unit40in the present exemplary embodiment receives PDL data.

The render processing unit42functions as a raster image processor (RIP) that renders images (bitmap data) for pages on the basis of the PDL data accepted by the print-job accepting unit40.

Here, in the case of rendering images for pages, the render processing unit42renders a checking-target image at a position that is set by the checking-target-image position setting unit52described below in each of the pages. Note that the checking-target image is an image that is to be used in checking performed by the image checking apparatus6. The checking-target image may be a portion or entirety of an image that is to be rendered on the basis of the PDL data accepted by the print-job accepting unit40or may be an image that is not included in the PDL data accepted by the print-job accepting unit40. In the case of rendering an image that is not included in the PDL data accepted by the print-job accepting unit40as the checking-target image, the render processing unit42adds the checking-target image to an image that is to be rendered on the basis of the PDL data, thereby obtaining an image for each of the pages, and renders the image for each of the pages. As an example of the checking-target image to be added, for example, an image representing a page number of a page including an image that is to be rendered on the basis of a print job is used.

The print controller44performs control so that the bitmap data processed by the render processing unit42will be printed. Note that the print controller44may perform control so that a print position will be adjusted on the basis of the position of a registration mark shown on the continuous paper22. In this case, for example, the print controller44detects a registration mark using a sensor, which is not illustrated, to obtain detection information, and performs control so that a print position will be adjusted on the basis of the detection information.

Furthermore, in the case where the print controller44has received an instruction to stop a process from the checking-result accepting unit54described below, the print controller44performs control so as to stop a print process.

The transport-information managing unit46manages transport-speed information concerning a transport speed of the continuous paper22. The transport-speed information may be information concerning a transport speed measured by a measurement device that is not illustrated and that is used for a transport speed, or may be a set value of the transport speed. The transport-speed information managed by the transport-information managing unit46is used for control of the image forming apparatus4. In the present exemplary embodiment, the transport-speed information is used for control, which is performed by the transport controller48, of the transport mechanism. Note that, as the configuration of the measurement device used for a transport speed, for example, a configuration is used, in which the number of rotations of a main motor that drives the transport mechanism or the number of rotations of a roller that transports the recording medium is measured by a rotary encoder or the like.

The transport controller48controls the transport mechanism, which transports the recording medium in the image forming apparatus4and which is not illustrated, on the basis of the transport-speed information managed by the transport-information managing unit46. For example, the transport controller48controls the transport mechanism so that the continuous paper22will be transported at a set value of the transport speed indicated by the transport-speed information. Additionally, for example, the transport controller48compares an actual transport speed that has been measured by the measurement device used for a transport speed with the set value of the transport speed, and further performs control of the transport mechanism on the basis of a result of comparison.

Moreover, in the case where the transport controller48has been notified, from the state-notification accepting unit50, of information indicating that the image checking apparatus6is in a state of performing checking, the transport controller48performs control so as to maintain the current transport speed of the transport mechanism. The transport controller48may perform control so as to maintain the current transport speed of the transport mechanism until the transport controller48is notified, from the state-notification accepting unit50, of information indicating that the image checking apparatus6is in a state of having finished checking.

Furthermore, in the case where the transport controller48has received an instruction to stop a process from the checking-result accepting unit54described below, the transport controller48performs control so as to stop transport of the continuous paper22.

The state-notification accepting unit50accepts information concerning an operation state of the image checking apparatus6. Examples of the operation state of the image checking apparatus6that is to be accepted by the state-notification accepting unit50include the state of performing checking or the state of having finished checking. The state-notification accepting unit50notifies the checking-target-image position setting unit52and the transport controller48of the accepted information.

The checking-target-image position setting unit52sets the print position of the checking-target image. The checking-target-image position setting unit52notifies the render processing unit42and the image checking apparatus6of the set print position.

The checking-target-image position setting unit52sets the print position of the checking-target image. Note that, in the case where an image that is to be rendered on the basis of the PDL data accepted by the print-job accepting unit40is used as the checking-target image, the checking-target-image position setting unit52sets the position of a region that is included in the image and that is to be used as the checking-target image. The checking-target-image position setting unit52notifies the render processing unit42of the set print position.

Moreover, when the print position of the checking-target image is set, the positional relationship between a mark, which is described below, and the checking-target image is determined on the basis of the print position. The checking-target-image position setting unit52notifies the render processing unit42and the image checking apparatus6of information indicating the positional relationship between the mark and the checking-target image.

Note that, in the case where the checking-target-image position setting unit52has been notified, from the state-notification accepting unit50, of information indicating that the image checking apparatus6is in the state of performing checking, the checking-target-image position setting unit52performs control so that the print position will not be changed or set to another position, the set print position will be maintained, and the positional relationship between the mark and the checking-target image will be maintained.

The checking-result accepting unit54accepts information concerning a result of checking performed by the image checking apparatus6. In the case where the checking-result accepting unit54in the present exemplary embodiment accepts information concerning a checking result indicating abnormality, the checking-result accepting unit54instructs the print controller44and the transport controller48to stop processes.

FIG. 3is a schematic diagram illustrating an example of the continuous paper22printed by the printing device12. In the example illustrated inFIG. 3, on each page, a mark60and a checking-target image62are shown. The checking-target image62is printed at a position that is located upstream from the mark60in a transport direction and that is a distance D distant from the mark60. However, the mark60may be shown on the continuous paper22in advance, or printed when the checking-target image62is printed. Furthermore, the mark60and the checking-target image62are individually printed on different sides of the continuous paper22. Note that, in the case where the checking-target image62is not the entirety of an image that is to be rendered on the basis of the PDL data, in addition to the mark60and the checking-target image62, the image that has been rendered on the basis of the PDL data accepted by the print-job accepting unit40is printed on either side of the continuous paper22.

In the example illustrated inFIG. 3, the mark60is a registration mark that is used for registration of a print position in each page in the case of printing with the printing device12. However, the mark60is not limited thereto. The mark60may be a mark shown on each page of the continuous paper22.

Furthermore, in the example illustrated inFIG. 3, the checking-target image62is an image representing a page number of a page including a printed image. However, the checking-target image62may be an image that is printed at a position which is located upstream from the mark60in the transport direction and which is a predetermined distance (the distance D in the example illustrated inFIG. 3) distant from the mark60.

Next, the image checking apparatus6will be described.

As described inFIG. 1, the image checking apparatus6in the present exemplary embodiment includes the image-checking-apparatus body16, the detection sensor18, and the image capture camera20.

The detection sensor18is provided at any position downstream from the photoconductor drums24to30of the printing device12in the transport direction of the continuous paper22, and may be provided at any position downstream from the fixing unit32in the transport direction of the continuous paper22. The detection sensor18detects the mark. The detection sensor18is, for example, an optical sensor, and irradiates the continuous paper22with light and receives light reflected from the mark using a light receiving element, thereby detecting the mark.

The image capture camera20is configured to capture an image under control performed by a reading controller96described below. Furthermore, the image capture camera20is provided at a certain position so as to be, when or after the detection sensor18has detected the mark, capable of capturing an image of the checking-target image which is the predetermined distance (the distance D in the example illustrated inFIG. 3) distant from the mark. Note that the image capture camera20is provided so as to perform image capture for a side that has been printed by the printing device12. Moreover, the image capture camera20captures an image of the checking-target image under control performed by the reading controller96.

FIG. 4is a schematic diagram illustrating a hardware configuration of the image-checking-apparatus body16. As illustrated inFIG. 4, the image-checking-apparatus body16has a configuration of a computer that is configured by connecting a CPU70, a memory72, a storage device74such as an HDD, a communication I/F76, which performs transmission/reception of data, and a UI device78with each other via a control bus80.

The CPU70performs processes based on a program that is stored in the memory72or the storage device74, thereby controlling an operation of the image checking apparatus6. Note that, instead of being supplied from the memory72or the storage device74, the program may be stored on a recording medium such as a CD-ROM, and supplied. This recording medium may be a magnetic disk, a semiconductor memory, or another recording medium. Moreover, the program may be supplied via the above-mentioned communication I/F76.

FIG. 5is a block diagram illustrating a functional configuration of the image checking apparatus6that is realized by executing the program with the CPU70.

As illustrated inFIG. 5, the image checking apparatus6includes a position-information acquisition unit90, a transport-speed acquisition unit92, a detector94, the reading controller96, a checking unit98, a checking-result notification unit100, and an operation-state notification unit102.

The position-information acquisition unit90receives and acquires information concerning the print position of the checking-target image from the image forming apparatus4. More specifically, the position-information acquisition unit90acquires, from the checking-target-image position setting unit52of the image forming apparatus4, information (hereinafter, referred to as position information) concerning the positional relationship between the mark and the checking-target image. In the example illustrated inFIG. 3, the position-information acquisition unit90acquires, as the position information, information indicating that the print position of the checking-target image62is a position which is located upstream of the mark60in the transport direction and which is the distance D distant from the mark60. Accordingly, even when the position information has been changed on the image forming apparatus4side, control of the reading controller96described below is performed on the basis of the position information that has been changed.

The transport-speed acquisition unit92receives and acquires, from the image forming apparatus4, information (hereinafter, referred to as transport-speed information), which is used as control information of the image forming apparatus4, concerning the transport speed of the continuous paper22. Accordingly, even when the transport speed has been changed on the image forming apparatus4side, control of the reading controller96described below is performed on the basis of the transport-speed information that has been changed.

As described above, the transport-speed acquisition unit92acquires the transport-speed information by receiving information that is used as control information of the image forming apparatus4, instead of by providing a measurement device, which is used for a transport speed, in the transport mechanism or the like of the image checking apparatus6and by acquiring the transport-speed information. Thus, no measurement device needs to be provided.

Moreover, for example, in order to acquire the transport speed, in the case where a measurement device such as a rotary encoder is provided so as to be in contact with an axis that is used to transport the continuous paper22or in contact with the continuous paper22, an issue such as a reduction in the transport performance or stains on the continuous paper22may occur because the measurement device is provided. However, in the case where the transport-speed acquisition unit92acquires the transport-speed information, because no measurement device is provided, occurrence of such an issue is reduced.

The detector94receives a signal from the detection sensor18, thereby detecting whether or not the mark has passed a position at which the detection sensor18is provided. Furthermore, when the detector94has detected that the mark has passed the position, the detector94outputs, to the reading controller96, information indicating that the mark has passed the position.

The reading controller96determines image capture timing, at which image capture is to be performed by the image capture camera20, on the basis of the position information, which has been acquired by the position-information acquisition unit90, concerning the positional relationship between the mark and the checking-target image, and the transport-speed information, which has been acquired by the transport-speed acquisition unit92. The reading controller96controls the image capture camera20so that an image of the checking-target image62will be captured by the image capture camera20. Note that the image capture timing is a time period from when the detector94detects the mark to when image capture is performed by the image capture camera20.

In the case where a detection position at which the detection sensor18detects the mark and an image capture position at which image capture is performed by the image capture camera20are the same, in the example illustrated inFIG. 3, for example, the reading controller96determines a time period D/V as the image capture timing on the basis of the distance D that is indicated by the position information acquired by the position-information acquisition unit90and a transport speed V that is indicated by the transport-speed information acquired by the transport-speed acquisition unit92. The reading controller96performs control so that image capture will be performed for the continuous paper22by the image capture camera20after the time period D/V has elapsed since the detector94detected that the mark had passed the position at which the detection sensor18is provided.

Here, even when the positional relationship between the mark and the checking-target image has been changed in the image forming apparatus4, the reading controller96acquires position information concerning the positional relationship that has been changed from the position-information acquisition unit90, thereby dealing with the change in the positional relationship.

Note that, in the present exemplary embodiment, the position information concerning the positional relationship is received and acquired by the position-information acquisition unit90from the image forming apparatus4. However, the reading controller96may determine the image capture timing on the basis of position information input by the UI device78or position information that is stored in the storage device74in advance.

Additionally, the reading controller96outputs, to the checking unit98, an image that has been captured by the image capture camera20at the determined image capture timing.

The checking unit98performs checking based on the image output by the reading controller96. Note that, checking performed by the checking unit98may be checking based on the checking-target image whose image has been captured by the image capture camera20. In the example illustrated inFIG. 3, for example, the checking unit98checks whether or not the page number shown as the checking-target image on each page continuously changes in accordance with the order of pages. In this case, for example, in the case where a page number is missing, the checking unit98determines that predetermined printing has not been performed by the image forming apparatus4.

Note that, for example, the checking unit98may consider, as the checking-target image, a rendered image that has been rendered using the PDL data accepted by the print-job accepting unit40of the image forming apparatus4. The checking unit98may compare the image captured by the image capture camera20with the rendered image, and may check whether stains caused by printing are present on the continuous paper22or whether any of the contents that should have been printed are missing.

Moreover, the checking unit98outputs, to the checking-result notification unit100, a result of checking based on the checking-target image whose image has been captured by the image capture camera20. Additionally, the checking unit98outputs an operation state to the operation-state notification unit102. The checking unit98outputs, for example, the state of performing checking or the state of having finished checking.

The checking-result notification unit100notifies the UI device78and the image forming apparatus4of the checking result output from the checking unit98. Note that, in the present exemplary embodiment, the checking-result accepting unit54of the image forming apparatus4accepts a checking result of which the checking-result notification unit100has notified the UI device78and the image forming apparatus4.

The operation-state notification unit102notifies the image forming apparatus4of the operation state output from the checking unit98. Note that, in the present exemplary embodiment, the state-notification accepting unit50of the image forming apparatus4accepts the operation state of which the operation-state notification unit102has notified the image forming apparatus4.

Next, the operation of the image checking apparatus6will be described.

FIG. 6is a flowchart illustrating an example of the operation of the image checking apparatus6.

In step S100, the operation-state notification unit102notifies the image forming apparatus4that the image checking apparatus6is in the state of performing checking. Note that, in the image forming apparatus4, when this notification has been received, the setting of the print position of the checking-target image and the transport speed are prohibited from being changed.

In step S102, the position-information acquisition unit90receives and acquires the position information from the image forming apparatus4.

In step S104, the transport-speed acquisition unit92receives and acquires the transport-speed information from the image forming apparatus4.

In step S106, the reading controller96determines the image capture timing on the basis of the position information and the transport speed, which have been acquired in steps S102and S104, respectively.

In step S108, the process waits until the detector94detects the mark shown on the continuous paper22(NO in step S108). When the detector94has detected the mark (YES in S108), the process proceeds to step S110.

In step S110, the reading controller96waits until a time period that has elapsed since the time at which the detector94detected the mark in S108reaches the image capture timing determined in step S106(NO in step S110). When the time period has reached the image capture timing (YES in step S110), the process proceeds to step S112.

In step S112, the reading controller96performs control so that image capture will be performed for the continuous paper22by the image capture camera20. Accordingly, an image of the checking-target image is captured by the image capture camera20.

In step S114, the checking unit98performs predetermined checking on the basis of the checking-target image whose image has been captured by the image capture camera20.

In step S116, the checking-result notification unit100notifies the image forming apparatus4of a checking result. Note that, in the case where the image forming apparatus4has been notified of a checking result that indicates abnormality, the image forming apparatus4performs control so as to stop the process performed in the image forming apparatus4. Note that, notification of a checking result may be notification of only a checking result indicating abnormality.

In step S118, the checking unit98determines whether or not a predetermined checking end condition is satisfied. When the checking end condition is satisfied, the process proceeds to step S120. When the checking end condition is not satisfied, the process returns to step S108, and checking of subsequent pages is continuously performed. For example, in the case where checking of pages up to the last page that have been printed by the image forming apparatus4has been completed or in the case where an instruction to finish checking has been received via the UI device78, it is determined that the checking end condition is satisfied, and the process proceeds to step S120.

In step S120, the operation-state notification unit102notifies the image forming apparatus4that the image checking apparatus6is in the state of having finished checking. Note that, in the image forming apparatus4, when this notification has been received, the prohibition of changing the transport speed is cancelled, and, for example, transport of the continuous paper22is stopped. Accordingly, for example, until a page which is a page of the continuous paper22and which is the last page that has been printed passes the image capture camera20, the transport speed is maintained.

Note that, with reference to the flowchart illustrated inFIG. 6, an example has been described, in which the position information and the transport speed have been acquired in steps S102and S104, respectively, and in which image capture is repeated at the image capture timing determined in step S106. However, the image capture timing may be changed while checking is being performed.

For example, information for estimating an amount of transport speed change of the continuous paper22in the image forming apparatus4is held in a table in advance. When the transport speed has changed, the image capture timing may be determined again on the basis of the estimated amount of transport speed change while checking is being performed, and image capture may be performed at the image capture timing that has been determined again. The estimated amount of transport speed change may be held in the table.

Moreover, the position information and the transport speed may also be acquired in step S108or any step thereafter. In this case, the reading controller96may determine new timing as the image capture timing on the basis of the position information and the transport speed that have been newly acquired, and may perform control so that image capture will be performed at the new image capture timing.

Furthermore, although a configuration in which the control device14is provided separately from the printing device12is used in the description given above, the control device14may be built into, for example, the printing device12.