JP6331742B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus capable of changing a fixing temperature as a control target for each printing surface of a recording sheet and collectively allocating and printing a plurality of print data on a printing surface. The present invention relates to technology for reducing energy consumption.

In image forming apparatuses such as printers and copiers, print data indicating an image of each page is received, and print data of two or more pages is aggregated and allocated in a predetermined allocation order on the printing surface of a recording sheet, and the aggregated print data Are widely used that have a function of executing aggregate printing in which the image is formed on the printing surface and thermally fixed.
In addition, the fixing temperature necessary for thermally fixing the image of the print data formed on the printing surface of the recording sheet varies depending on conditions such as the amount of toner adhered and the type of the image required for forming the image. In order to prevent a fixing failure from occurring even if these conditions are different, a fixing temperature (control target) at which the surface temperature of the heating rotator should be maintained at the time of thermal fixing of the image on the printing surface of the recording sheet. (Hereinafter referred to as “target fixing temperature”) is always set to a temperature at which good fixability can be ensured even under printing conditions that require the largest amount of heating to thermally fix the image. However, if such a setting is made, energy (electric power) will be consumed more than necessary when heat fixing the image of the print data that does not require the heating amount as described above. It is not desirable from the viewpoint of energy saving.

  As a technique for reducing the energy consumption at the time of such heat fixing, for example, in Patent Document 1, the target fixing temperature of the print data image of the page is set for each page according to the image content of the print data of each page. A technique is disclosed that determines and thermally fixes the image of the page at the determined target fixing temperature. As a result, the target fixing temperature for each page can be adjusted to the optimum temperature so that the fixing temperature does not become excessive or insufficient according to the image content of the print data for each page, reducing the energy consumption required for thermal fixing. can do.

JP 2012-118496 A

  However, in the technique disclosed in Patent Document 1, when multiple pages of print data are collectively allocated to the print surface of a recording sheet and print is performed, print data having different target fixing temperatures are concentrated on the same print surface. If assigned, in order to ensure good fixability, the printing surface must be thermally fixed at the fixing temperature with the higher target fixing temperature, and as a result, printing with the lower target fixing temperature is performed. The image of the data is heat-fixed at a temperature higher than necessary, and a problem arises in that much energy is consumed for the heat-fixing.

  In this case, it is possible to change the print data allocation order so that pages of print data having the same target fixing temperature are collectively allocated to the recording sheet. In such a case, the print data allocation order is This is different from the predetermined allocation order defined for aggregate printing, and print data cannot be aggregated and allocated to recording sheets in the order of page numbers desired by the user, resulting in a problem that impairs user convenience. .

  The present invention has been made in view of the above-described problems. In an image forming apparatus having an aggregate printing function, the energy consumption during fixing is reduced without impairing user convenience. An object of the present invention is to provide an image forming apparatus that can perform the above-described process.

  In order to achieve the above object, an image forming apparatus according to an aspect of the present invention can change a fixing temperature as a control target for each printing surface of a recording sheet and print data for N pages (N is An image forming apparatus having an aggregate printing function that prints by assigning an integer of 3 or more to a printing surface of 2 or more and less than N, and acquires a fixing temperature to be a control target for fixing on a single page for each page. A first acquisition unit that performs, an allocation pattern generation unit that generates a plurality of types of allocation patterns for each print surface of the print data for N pages, and a fixing of a print surface on which two or more pages of print data are collectively allocated Setting means to set the target fixing temperature at the highest temperature among the target fixing temperatures acquired for each page that is assigned to the print surface in an aggregated manner, and each type of assignment A second acquisition unit that acquires an index value indicating a total amount of energy consumption required for fixing all print surfaces based on a target fixing temperature of each print surface set by the setting unit, and a total energy consumption amount And an aggregate printing unit that selects an allocation pattern of the smallest index value and executes aggregate printing.

Here, in the layout pattern, the print data is aggregated and allocated to two print surfaces on both sides of two or more recording sheets, the recording sheets are overlapped and saddle stitched, and the print data of each page is stored. An allocation pattern for booklets arranged in page order may be included.
The booklet layout pattern is generated by dividing the entire print data by allocating all print data and creating one booklet, and generating the partial print data by dividing the print data. And a second booklet layout pattern for creating a booklet separation every time.

  When the number of pages of the divided print data obtained by dividing all the print data is a multiple of 4, the layout pattern creating unit sets the divided print data as the partial print data, and the number of pages is not a multiple of 4. The partial print data can be generated by adding blank page print data to the divided print data so that the total number of pages is a minimum multiple of 4 larger than the number of divided print data pages. .

  The creating means includes a group of print data in which all the print data are two or more pages, the page numbers are continuous in each group, and the target fixing temperature for each acquired page When the print data groups are the same, all the print data can be divided into the print data groups to create the divided print data.

The aggregate printing program according to an aspect of the present invention can change the fixing temperature as a control target for each printing surface of the recording sheet and print data for N pages (N is an integer of 3 or more). Is a centralized printing program for causing a computer to execute a centralized printing process by assigning to a print surface of 2 or more and less than N, and acquiring a fixing temperature to be a control target for fixing on a single page for each page. An acquisition step; a creation step for creating a plurality of types of layout patterns for each print surface of print data for N pages; and a target fixing temperature when fixing a print surface on which print data of two or more pages are collectively allocated. The setting step for setting the highest fixing temperature among the target fixing temperatures acquired for each page collectively allocated to the printing surface, and the allocation of each type. A second acquisition step of acquiring an index value indicating a total energy consumption required for fixing all print surfaces based on the target fixing temperature of each print surface set in the setting step, and a total energy consumption amount It is possible to select the allocation pattern of the smallest index value and cause the computer to execute an aggregate printing step for executing aggregate printing.

  By providing the above configuration, multiple types of layout patterns for each print surface are created during consolidated printing, and the index value of the total energy consumption required for fixing all print surfaces for each type of layout pattern Is acquired, and the layout pattern with the smallest total energy consumption is selected and the aggregate printing is executed, so that the energy consumption during fixing in the aggregate printing can be reduced.

In addition, since the aggregate printing is executed with an allocation pattern selected from a plurality of predetermined allocation patterns, the allocation pattern can be prevented from being changed randomly, and user convenience is not impaired. Can be.
In this case, the image forming apparatus has the same target fixing temperature acquired for each page of print data of two or more pages collectively allocated on the same printing surface with respect to the allocation pattern selected by the aggregate printing unit. If it is not the same as the determination means for determining whether or not the image is based on the print data of each page that is collectively assigned to the printing surface when executing the aggregate printing by the aggregate printing means, the sheet passing direction of the recording sheet The surface temperature of the heating rotator when the image of each page formed on the printing surface passes through the fixing position of the heating rotator is acquired for each page. It is good also as providing the control means which controls to become.

  Thus, in the selected layout pattern, when the target fixing temperature of each page of two or more pages of print data collectively allocated on the same printing surface is not the same, the image of each page is formed so as to be aligned in the sheet passing direction. Since the surface temperature of the heating rotator when the image of each page passes through the fixing position of the heating rotator is controlled so as to become the target fixing temperature acquired for the page, the printing that is assigned in an aggregated manner It is possible to prevent thermal fixing of data pages from being performed at an excessive fixing temperature, and it is possible to further reduce the total energy consumption during fixing of aggregate printing.

Here, the image forming apparatus notifies the user of a message that recommends aggregate printing with an allocation pattern with the smallest total energy consumption to be indexed, and whether or not to perform aggregate printing with the recommended allocation pattern. Accepting means for accepting the selection,
When the selection is negative, a prohibition unit that prohibits the aggregate printing by the aggregate printing unit may be provided.

  As a result, even if the allocation pattern has the smallest total energy consumption, if the user does not desire the aggregate printing with the allocation pattern, the aggregate printing with the allocation pattern is prohibited. Thus, it is possible to prevent the aggregate printing from being executed without permission by the allocation pattern not to be performed, and it is possible to improve the convenience of the user in selecting the allocation pattern for the aggregate printing.

Here, the image forming apparatus has an accepting unit for accepting an instruction as to whether or not to select an energy saving mode that is an operation mode for reducing the total energy consumption required for fixing in aggregate printing, and the energy saving mode is not selected. In this case, a prohibiting unit that prohibits the aggregate printing by the aggregate printing unit may be provided.
As a result, only when the energy saving mode is selected, the allocation pattern with the smallest total energy consumption is selected and consolidated printing is executed, and when the energy saving mode is not selected, the aggregate printing is prohibited. Therefore, when the user does not select the energy saving mode and does not want to save energy, the execution of aggregate printing with the allocation pattern with the smallest total energy consumption is not forced against the user's intention. It is possible to improve the convenience of the user in selecting the allocation pattern.

Here, the image forming apparatus according to an aspect of the present invention can change the fixing temperature as a control target for each printing surface of the recording sheet, and print data for N pages (N is an integer of 3 or more). ) Is integrated and assigned to each printing surface on both sides of the recording sheet, the recording sheets are overlapped and saddle stitched, and the print data for each page is arranged in page order. An image forming apparatus having an acquisition unit that acquires, for each page, a fixing temperature that should be a control target when fixing on a single page, and fixing a print surface on which print data of two pages are collectively allocated The setting means for setting the target fixing temperature to the highest temperature among the target fixing temperatures acquired for each page that is assigned to the print surface and the number of pages for all print data Partial print data that is a multiple of 4 and can be divided into partial print data in which the page numbers are continuous in each partial print data and the target fixing temperature for each acquired page is the same. Determination means for determining whether or not,
If the determination result is negative, all print data is allocated to create a first layout pattern that creates one booklet. If the determination result is affirmative, all print data Creating means for creating a second layout pattern for creating a booklet for each partial print data, and aggregate print means for executing aggregate printing with the layout pattern created by the creation means It is good also as providing these.

The aggregate printing program according to an aspect of the present invention can change the fixing temperature as a control target for each printing surface of the recording sheet and print data for N pages (N is an integer of 3 or more). Is a process of performing aggregate printing for booklet creation in which print data of each page is arranged in page order by allocating two pages to each printing surface on both sides of the recording sheet, overlapping each recording sheet and performing saddle stitching. Is a centralized printing program that causes a computer to execute an acquisition step for acquiring, for each page, a fixing temperature that should be a control target when fixing on a single page, and a printing surface on which two pages of print data are collectively allocated. Setting to set the target fixing temperature at the time of fixing to the highest temperature among the target fixing temperatures acquired for each page that is assigned to the print surface. Both the print data and the print data are partial print data whose page number is a multiple of 4, and the page number is continuous in each partial print data, and the target for each acquired page A determination step for determining whether or not the print data can be divided into partial print data having the same fixing temperature, and if the determination result is negative, all print data is allocated to create one booklet. 1 allocation pattern is created. If the determination result is affirmative, all print data is divided into partial print data, and a second allocation pattern is created that creates a booklet for each partial print data. It is also possible to cause the computer to execute a creation step to perform and an aggregate printing step to execute aggregate printing with the allocation pattern created in the creation step.

  As a result, in aggregate printing for booklet creation, all print data is partial print data in which the number of pages is a multiple of four, and the page numbers are continuous in each partial print data and are acquired. When a single booklet is created by assigning all print data, as in the case where it can be divided into partial print data with the same target fixing temperature for each page, pages with different target fixing temperatures are aggregated on the same printing surface. When the frequency of allocation increases, all print data is divided into partial print data, and a booklet is created for each partial print data so that pages with different target fixing temperatures are not allocated to the same print surface. can do.

That is, when a separate volume is created for each partial print data, pages of print data having the same target fixing temperature are collectively allocated on the same print surface of the recording sheet. In this case, pages of print data having different target fixing temperatures on the same print surface can be prevented from being collectively allocated.
As a result, the user can perform consolidated printing for booklet creation with the second assignment pattern for creating a separate booklet, and when executing with the first assignment pattern for creating one booklet. The total energy consumption can be reduced.

  Here, when the determination result is affirmative, the image forming apparatus performs notifying means for informing a message recommending that the second allocation pattern is used for the aggregate printing, and the recommended aggregate printing. An accepting unit that accepts a selection as to whether or not to perform, and a prohibiting unit that prohibits the aggregated printing by the aggregated printing unit when the selection is negative.

  As a result, when the user does not desire the aggregate printing for creating a booklet for creating a booklet for each partial print data obtained by dividing the entire print data, the aggregate printing is prohibited. Therefore, it is possible to prevent the central printing from being executed, and it is possible to improve the convenience of the user in selecting the allocation pattern in the central printing for booklet creation.

  Here, the image forming apparatus further performs page-order intensive printing in which print data for N pages is printed by allocating and allocating two or more pages of print data in order of page numbers on a print surface of 2 or more and less than N. If the determination result is affirmative, a notification means for informing a message recommending that the page order aggregation printing is performed, and a selection of whether or not to perform the recommended page order aggregation printing are selected. An accepting unit that accepts, and, if the selection is positive, an aggregated print control unit that prohibits the aggregated printing by the aggregated printing unit and causes the aggregated printing unit to execute the page order aggregated printing. It is good as well.

  As a result, in aggregate printing for booklet creation, all print data is partial print data in which the number of pages is a multiple of four, and the page numbers are continuous in each partial print data and are acquired. When a single booklet is created by assigning all print data, as in the case where it can be divided into partial print data with the same target fixing temperature for each page, pages with different target fixing temperatures are aggregated on the same printing surface. When the frequency of allocation is increased, the total energy consumption at the time of fixing is reduced by encouraging the selection of page order consolidated printing that can reduce the frequency compared to consolidated printing for booklet creation. Can be.

  That is, in the case of page order consolidated printing, the print data is aggregated and allocated on the same print surface in the order of page numbers. Therefore, in the case where it can be divided as described above, print data having the same target fixing temperature on the same print surface. Therefore, the total energy consumption at the time of fixing can be reduced as compared with the case of collective printing for creating a booklet.

  Here, the image forming apparatus further allocates N pages of print data to each print surface on both sides of two or more recording sheets, and folds the recording sheets at the center to align the folding side. When binding is performed, it is possible to perform combined printing of wireless binding in which print data of each page is arranged in page order, and when the determination result is affirmative, a message recommending that the combined printing of wireless binding be performed An informing means for informing the user, a receiving means for accepting a selection as to whether or not to perform the recommended consolidated printing of the perfect binding, and if the selection is affirmative, the aggregate printing by the aggregate printing means is prohibited. The aggregate printing control unit may cause the aggregate printing unit to execute the aggregate binding printing of the perfect binding.

  As a result, in aggregate printing for booklet creation, all print data is partial print data in which the number of pages is a multiple of four, and the page numbers are continuous in each partial print data and are acquired. When a single booklet is created by assigning all print data, as in the case where it can be divided into partial print data with the same target fixing temperature for each page, pages with different target fixing temperatures are aggregated on the same printing surface. If the frequency of allocation is increased, the total energy consumption at the time of fixing will be reduced by prompting the user to select the combined printing of simple binding that can reduce the frequency compared to the integrated printing for booklet creation. Can be.

  In other words, in the case of collective printing with simple binding, pages with consecutive page numbers of print data or pages with similar page numbers are collectively allocated on the same printing surface of the recording sheet, and thus can be divided as described above. In this case, it is possible to increase the frequency with which the pages of the print data with the same target fixing temperature on the same printing surface are collectively allocated, and accordingly, the total consumption at the time of fixing compared with the case of the aggregate printing for booklet creation. The amount of energy can be reduced.

1 is a diagram illustrating a configuration of an image forming apparatus 1. FIG. 3 is a diagram illustrating a relationship between a configuration of a control unit 60 and main components that are controlled by the control unit 60. FIG. A specific example of the “2 in 1” allocation pattern is shown. A specific example of the “wireless binding” allocation pattern is shown. A specific example of the “booklet” allocation pattern is shown. FIG. 6 is a diagram conceptually illustrating a state in which pages of print data with page numbers 1 to 8 are collectively allocated in the allocation patterns of FIGS. 3 to 5. It is a flowchart which shows operation | movement of the energy-saving layout printing process which the control part 60 performs. It is a flowchart which shows operation | movement of the energy index value determination process classified by printing surface. It is a flowchart which shows the operation | movement of an energy-saving allocation pattern selection process. When pages of each print data to be allocated are different from the case of FIG. 6, pages of each print data are collectively allocated according to each allocation pattern of “2 in 1”, “wireless binding”, and “booklet” FIG. When pages of each print data to be allocated are different from the case of FIG. 6, pages of each print data are collectively allocated according to each allocation pattern of “2 in 1”, “wireless binding”, and “booklet” It is the figure which showed another example of no. It is a flowchart which shows the modification 1 of operation | movement of an energy-saving allocation pattern selection process. It is a flowchart which shows the modification 2 of operation | movement of an energy-saving allocation pattern selection process. When the “booklet” layout pattern is created by dividing the page group of the print data to be allocated, and when it is not divided, the pages of the print data with the page numbers 1 to 16 are collectively allocated. It is the figure which showed the mode in an image. It is a part of flowchart which shows another modification 3 of operation | movement of an energy-saving allocation pattern selection process. It is another part of the flowchart which shows another modification 3 of the operation | movement of an energy-saving allocation pattern selection process. The page number is 1 when the “Booklet” layout pattern is created by adjusting and dividing all print data to be assigned, and when creating one booklet without adjusting and dividing all print data. It is the figure which showed a mode that the page of each print data of -12 was each collectively allocated. It is a flowchart which shows the modification of operation | movement of an energy-saving layout printing process. It is a flowchart which shows operation | movement of an energy saving consolidated printing process. FIG. 6 is an image diagram illustrating a sheet passing direction of recording sheets on which print data page images are collectively allocated. 6 is a flowchart illustrating an operation of a fixing temperature switching printing process.

(Embodiment)
Hereinafter, an embodiment of an image forming apparatus according to an embodiment of the present invention will be described with reference to an example in which the image forming apparatus is applied to a tandem type image forming apparatus (hereinafter simply referred to as “image forming apparatus”).
[1] Configuration of Image Forming Apparatus First, the configuration of the image forming apparatus 1 according to the present embodiment will be described. FIG. 1 is a diagram illustrating a configuration of an image forming apparatus 1 according to the present embodiment. As shown in FIG. 1, the image forming apparatus 1 includes an image processing unit 3, a paper feeding unit 4, a fixing device 5, and a control unit 60.

  When the image forming apparatus 1 is connected to a network (for example, a LAN) and receives a print instruction from an external terminal device (not shown) or an operation panel having a display unit (not shown), yellow, magenta, cyan, and cyan are received based on the instruction. A black toner image is formed, and these are multiplex-transferred onto a recording sheet to form a full-color image, thereby executing a printing process on the recording sheet. Hereinafter, the reproduction colors of yellow, magenta, cyan, and black are expressed as Y, M, C, and K, and Y, M, C, and K are added as subscripts to the numbers of the components related to the reproduction colors.

The image processing unit 3 includes image forming units 3Y, 3M, 3C, and 3K, an exposure unit 10, an intermediate transfer belt 11, a secondary transfer roller 45, and the like. Since the image forming units 3Y, 3M, 3C, and 3K have the same configuration, the configuration of the image forming unit 3Y will be mainly described below.
The image forming unit 3Y includes a photosensitive drum 31Y, a charger 32Y, a developing unit 33Y, a primary transfer roller 34Y, a cleaner 35Y for cleaning the photosensitive drum 31Y, and the like disposed around the photosensitive drum 31Y. Then, a Y-color toner image is formed on the photosensitive drum 31Y. The developing device 33Y faces the photosensitive drum 31Y and conveys charged toner to the photosensitive drum 31Y. The intermediate transfer belt 11 is an endless belt, is stretched around a driving roller 12 and a driven roller 13, and is driven to rotate in the direction of arrow C.

A cleaner 21 for removing toner remaining on the intermediate transfer belt is disposed in the vicinity of the driven roller 13.
The exposure unit 10 includes a light emitting element such as a laser diode, emits laser light L for forming images of Y to K colors based on print data for printing output from the control unit 60, and forms the image forming unit 3Y, Each of the 3M, 3C, and 3K photosensitive drums is exposed and scanned. By this exposure scanning, an electrostatic latent image is formed on the photosensitive drum 31Y charged by the charger 32Y. Similarly, electrostatic latent images are formed on the photosensitive drums of the image forming units 3M, 3C, and 3K.

  The electrostatic latent image formed on each photoconductor drum is developed by the developing units of the image forming units 3Y, 3M, 3C, and 3K, and the corresponding color toner image (unfixed image) on each photoconductor drum. Is formed. The formed toner image is assigned to each primary transfer roller corresponding to the image forming units 3Y, 3M, 3C, and 3K (in FIG. 1, only the primary transfer roller corresponding to the image forming unit 3Y is denoted by reference numeral 34Y, and the other primary transfer rollers). As for the roller, the reference numerals are omitted.) Thus, the secondary transfer roller is sequentially transferred to the intermediate transfer belt 11 at a different timing so that the rollers are superimposed at the same position on the intermediate transfer belt 11. The toner images on the intermediate transfer belt 11 are collectively transferred onto the recording sheet by the action of the electrostatic force 45.

The recording sheet onto which the toner image has been secondarily transferred is further conveyed to the fixing device 5, and the toner image on the recording sheet is heated and pressed by the fixing device 5 and thermally fixed to the recording sheet.
The recording sheet after heat fixing is discharged to a discharge tray 72 by a discharge roller 71 during single-sided printing. At the time of duplex printing, the recording sheet on which one printing surface is thermally fixed is conveyed to the discharge roller 71, and then along the reverse conveyance path 78 from the discharge roller 71 via the conveyance rollers 74, 75, 76, 77. It is conveyed and turned upside down and conveyed to a timing roller 44 described later. The conveyance path is switched by the guide member 73, and the operation of the guide member 73 is controlled by the control unit 60.

  Thereafter, the recording sheet is conveyed to the secondary transfer position 46 via the timing roller 44, and the toner image is secondarily transferred to the other printing surface of the recording sheet by the secondary transfer roller 45, and further, the recording sheet Is discharged to the discharge tray 72 by the discharge roller 71 after being conveyed to the fixing device 5 and thermally fixing the other printing surface. As a result, the toner image can be secondarily transferred and thermally fixed on the other printing surface where the toner image has not been secondarily transferred.

The paper feed unit 4 is fed with paper feed cassettes 40 and 41 for storing recording sheets represented by reference sign S, and feed rollers 42A and 42B for feeding the recording sheets in the paper feed cassette 41 one by one onto the transport path 43. A timing roller 44 that transports the recording sheet at a timing for feeding the recording sheet to the secondary transfer position 46 is provided.
Here, the recording sheet S is set in the paper feed cassette 40 in the horizontal direction (the long side of the recording sheet is orthogonal to the recording sheet conveyance direction), and the recording sheet S is set in the vertical direction (recording) in the paper feed cassette 41. It is assumed that the short side of the sheet is set in the direction orthogonal to the recording sheet conveyance direction. The feeding roller 42A feeds the horizontal recording sheets S set in the paper feed cassette 40 one by one to the conveyance path 43, and the feeding roller 42B feeds the vertical recording sheets S set in the paper feed cassette 41. One sheet is fed out to the conveyance path 43 one by one. The control unit 60 controls the driving of the feeding rollers 42 </ b> A and 42 </ b> B to feed either the horizontal or vertical recording sheet to the conveyance path 43.

  The timing roller 44 transfers the recording sheet to the second transfer position 46 in accordance with the timing at which the toner image primarily transferred onto the intermediate transfer belt 11 is conveyed to the secondary transfer position 46 so as to be superimposed at the same position on the intermediate transfer belt 11. It is conveyed to the next transfer position 46. Then, at the secondary transfer position 46, the toner images on the intermediate transfer belt 11 are collectively transferred onto the recording sheet by the secondary transfer roller 45.

Each of the rollers such as the feeding rollers 42A and 42B, the timing roller 44, the discharge roller 71, and each of the transport rollers uses a transport motor (not shown) as a power source and a power transmission mechanism (not shown) such as a gear gear or a belt. Driven by rotation. As the transport motor, for example, a stepping motor capable of controlling the rotational speed with high accuracy is used.
Here, the fixing device 5 is an electromagnetic induction heating type fixing device, and includes a heating roller 51 having an electromagnetic induction heating layer, a pressure roller 52 pressing the heating roller 51, and an electromagnetic induction heating layer of the heating roller 51. The magnetic flux generator 53 includes an exciting coil that generates magnetic flux for generating heat. A fixing nip is formed between the heating roller 51 and the pressure roller 52, and the toner image is thermally fixed in the fixing nip. Hereinafter, the position where the fixing nip is formed is referred to as a “fixing position”, and in FIG. 1, reference numeral 54 indicates the fixing position. A temperature sensor (not shown) that measures the surface temperature of the heating roller 51 is installed in the vicinity of the heating roller 51.

The magnetic flux generator 53 generates a magnetic flux by power supplied from a power supply unit (not shown). The amount of power supplied to the magnetic flux generation unit 53 is controlled by the control unit 60, and thereby, the surface temperature of the heating roller 51 is controlled to be a predetermined temperature.
Although not shown, the fixing device 5 is provided with a frame that supports both ends of the heating roller 51 and the pressure roller 52 in the longitudinal direction and covers these members. In this frame, a gap is provided as necessary in the vicinity of the inlet / outlet portion of the recording sheet and the longitudinal end portions of the heating roller 51 and the pressure roller 52.

[2] Configuration of Control Unit FIG. 2 is a diagram illustrating a relationship between the configuration of the control unit 60 and main components that are controlled by the control unit 60. The control unit 60 is a so-called computer, and as shown in the figure, a CPU (Central Processing Unit) 600, a communication interface (I / F) unit 601, a ROM (Read Only Memory) 602, a RAM (Random Access Memory). 603, a print data storage unit 604, an image analysis unit 605, a page layout processing unit 606, a sheet passing direction selection unit 607, an image rotation unit 608, and the like.

The communication I / F unit 601 is an interface for connecting to a LAN such as a LAN card or a LAN board. The ROM 602 stores a program for controlling the image processing unit 3, the sheet feeding unit 4, the fixing device 5, the operation panel 6, the image reading unit 7, and the like, a program for executing an energy saving layout printing process described later, and the like. .
The RAM 603 is used as a work area when the CPU 600 executes the program.
The print data storage unit 604 stores print data for printing input via the communication I / F unit 601 and the image reading unit 7.

  The image analysis unit 605 determines whether the image of each page indicated by the print data is a character image. The technique for determining whether or not the image is a character image is a known technique, and various methods can be used as the determination technique. For example, the distribution of the total number of pixels in the main scanning direction and the sub-scanning direction of pixels of print data for printing for one page stored in the print data storage unit 604 is acquired, and the periodicity of the distribution is detected. Thus, the determination can be performed.

In the case of a character image, since the total pixel number of toner adhering pixels is 0 between the rows and columns where the characters are arranged, the periodicity that the portions where the total pixel number is 0 continues at a constant interval. Is recognized. The determination can be made by detecting this periodicity (see JP 2007-259466 A, paragraphs 0058 to 0060, and FIGS. 6 and 7).
When this periodicity is recognized in the entire print data for one page or when the print data is composed of a portion where the periodicity is recognized and a blank area, the image of the page is “a character image”. When the periodicity is recognized only in a part of the image (when it is determined that a character image and an image other than the character image are included) or the periodicity is not recognized in the entire image, If the entire image is an image other than a character image, it is determined as “non-character image”.

Here, the image other than the character image corresponds to, for example, a pattern image such as a photograph or a graphic image, a monochrome or single color solid image, or the like.
Even when the following alternative determination method is used, the determination is performed in the same manner as described above. That is, when the page image includes only a character image or includes a character image and a margin area, it is determined that the image is a character image, and only the image other than the character image or the character image and the character image is determined. When an image other than an image is included, it is determined that it is a “non-character image”.

  As an alternative determination method for determining whether or not the image is a character image, the following edge detection method can be used. Each pixel of the print data for one page is sequentially set as a pixel of interest, the pixel of interest and peripheral pixels are extracted, and filter processing using an edge detection filter is performed on these pixels to form an image outline. Edge detection processing for detecting edge pixels is performed. When an edge pixel is detected by this edge detection process, the target pixel is determined to be an edge pixel, and a difference between pixel values (gradation values) between the target pixel and a pixel adjacent to the target pixel is determined. When there is a certain number or more having a value greater than a predetermined threshold, the pixel of interest is determined to be an edge pixel constituting the character image, and the edge pixel thus determined is determined in advance. If it is greater than or equal to the threshold value, it is determined to be “character image”, and if it is less than the threshold value, it is determined to be “non-character image” (see JP 2013-74495 A, paragraph 0065) .

When print data described in a page description language (PDL) is acquired from a terminal device, whether or not the image indicated by the print data of each page is a character image is analyzed by analyzing the PDL. The determination can be made based on whether or not related commands (for example, a command for specifying a character size and a command for setting a font) are included.
The page layout processing unit 606 allocates print data for N (N is an integer of 3 or more) pages to pages on the printing surface of a plurality of recording sheets less than N in a predetermined allocation order. Create a pattern. Here, the “allocation pattern” refers to a table indicating a correspondence relationship between the page number of the printing surface of the recording sheet and the page numbers of print data of a plurality of pages collectively allocated to the page with the page number.

The page layout processing unit 606 creates a plurality (for example, three types) of allocation patterns having different allocation orders. Specifically, three types of allocation patterns of “2 in 1” (here, “2 in 1” on both front and back sides), “wireless binding”, and “booklet” are created.
3 shows a specific example of the “2 in 1” allocation pattern, FIG. 4 shows a specific example of the “wireless binding” allocation pattern, and FIG. 5 shows a specific example of the “booklet” allocation pattern. 3 to 5 show specific examples of the allocation patterns when the total number of pages of print data is 8, respectively.

FIG. 6 is a diagram conceptually showing how pages of print data with page numbers 1 to 8 are collectively allocated in the allocation patterns of FIGS.
Each rectangle in FIG. 6A indicates a page of each print data to be allocated. FIG. 6B shows a state in which pages of each print data are sequentially allocated and allocated to pages on the printing surface of the recording sheet with an allocation pattern of “2 in 1”, and FIG. 6C shows an allocation pattern of “wireless binding”. FIG. 6D shows a state in which the pages of the print data are sequentially and collectively allocated to the pages on the print side of the recording sheet. FIG. 6D shows the pages of the print sheet on the print side of the print sheet according to the “booklet” allocation pattern. Shows the state of intensive allocation.

The numbers in each rectangle in FIGS. 6A to 6D indicate the page number of the page of each print data, and the “character” in each rectangle indicates that the image content of the page is a character image. “Non-character” in the rectangle indicates that the image content of the page is a non-character image.
The numbers “(1) to (4)” in parentheses in FIGS. 6B to 6D indicate the page numbers on the printed surfaces on the front and back of the recording sheet, and the parenthesized characters “(table ")" And "(Back)" indicate the front and back surfaces of the recording sheet, respectively. Also, the white arrows in FIGS. 6B to 6D indicate the target fixing temperature of the page on the printing surface of each recording sheet (the heating roller 51 prevents the fixing defect from occurring during thermal fixing of the page on the printing surface). This indicates whether the fixing temperature as a control target for which the surface temperature is to be maintained is the lower limit temperature or the upper limit temperature.

Here, the “lower limit temperature” refers to a temperature at which a character image can be thermally fixed, and refers to a lower limit heat fixing temperature at which the surface temperature of the heating roller 51 should be maintained during heat fixing. The “upper limit temperature” refers to a temperature at which a non-character image can be thermally fixed, and refers to an upper limit heat fixing temperature at which the surface temperature of the heating roller 51 should be maintained during heat fixing.
The lower limit temperature and the upper limit temperature are determined by the manufacturer of the image forming apparatus by performing a test or the like in advance. Here, the lower limit temperature is, for example, 150 ° C., and the upper limit temperature is, for example, 165 ° C.

The target fixing temperature of the page on the printing surface of the recording sheet is determined to be the highest target fixing temperature among the target fixing temperatures of the pages of a plurality of print data collectively assigned to the printing surface by the energy saving layout printing process described later. Is done.
“2 in 1” is an allocation order shown in FIG. 6B, in which the pages of the print data are sequentially allocated and allocated to the pages of each print surface of the recording sheet, and an image based on the print data is assigned to each page of the print surface. Is an allocation pattern for forming the print data in the order of the page numbers of the print data.

In addition, “wireless binding” is an allocation sequence shown in FIG. 6C, in which two pages of print data are sequentially allocated and allocated to each page of each print side of two or more recording sheets. This is an allocation pattern that forms an image based on the print data, folds the recording sheet at the center, aligns the folding side and binds the pages, and arranges the print data of each page in the order of page numbers.
In addition, the “booklet” is printed in the order shown in FIG. 6 (d) by sequentially allocating two pages of print data to each page of the print side of the front and back (both sides) of two or more recording sheets. This is an allocation pattern in which print data of each page is arranged in the order of page numbers when an image based on data is formed and each recording sheet is overlapped and saddle-stitched.

The sheet feeding direction selection unit 607 selects the feeding roller 42A or 42B as the feeding roller to be driven, thereby feeding the recording sheet horizontally or vertically to the conveyance path 43, and feeding the recording sheet to the fixing device 5. Adjust the direction to landscape or portrait.
The image rotation unit 608 rotates or does not rotate print data of pages that are collectively allocated to the recording sheet according to the sheet passing direction of the recording sheet adjusted by the sheet passing direction selection unit 607. Here, it is assumed that the print data is not rotated when the paper passing direction is horizontal, and the print data is rotated 90 ° clockwise when the paper passing direction is vertical.

The operation panel 6 includes a liquid crystal display, a touch panel stacked on the liquid crystal display, operation buttons for inputting various instructions, and the like, and receives input of various instructions from the user through operations of the touch panel, the operation buttons, and the like.
The image reading unit 7 includes an image input device such as a scanner, and reads image information such as characters, graphics, and photographs described on a recording sheet such as paper, and forms print data.

[3] Energy Saving Layout Printing Process FIG. 7 is a flowchart showing the operation of the energy saving layout printing process performed by the control unit 60. The control unit 60 prints N pages of print data to be assigned to the printing surface of a plurality of recording sheets and aggregate printing via the operation panel 6 and the image reading unit 7 or via the communication I / F unit 601. Is received (step S701), image processing is performed on all print data (step S702), and print data for N pages for bitmap printing is acquired as image information (step S702). S703).

Then, an energy index value determination process for each printing surface, which will be described later, and an energy saving allocation pattern selection process are executed (steps S704 and S705), and aggregate printing is executed with the allocation pattern selected in the energy saving allocation pattern selection process (steps). S706).
FIG. 8 is a flowchart showing the operation of the printing surface-specific energy index value determination process. The control unit 60 determines whether the image of each page indicated by the acquired print data for N pages is a character image or a non-character image, determines a target fixing temperature of the page based on the determination result, and determines the page The page number and the determined target fixing temperature are associated with each other and recorded in the RAM 603 (step S801). In the above determination, the control unit 60 determines the target fixing temperature as the lower limit temperature when the image is a character image, and determines the target fixing temperature as the upper limit temperature when the image is a non-character image.

  Next, the control unit 60 sequentially creates allocation patterns of “2 in 1” (“2 in 1” on both front and back sides), “wireless binding”, and “booklet” for the acquired print data of each page (step S802). In the created layout pattern, the target fixing temperature of the page of each print data collectively allocated to the page of the printing surface of each recording sheet is the correspondence between the page number of the page recorded in the RAM 603 and the target fixing temperature. The relationship is specified by referring to the relationship (step S803).

  Then, the control unit 60 determines the highest target fixing temperature among the specified target fixing temperatures as the target fixing temperature of the page of the printing surface (step S804), and uses the determined target fixing temperature of the printing surface. It is determined as an index value of energy consumption required for heat fixing of the page (hereinafter referred to as “energy index value”), and is recorded in the RAM 603 in association with the page number of the page on the printing surface (step S805).

  Further, the control unit 60 determines whether or not the energy index value has been determined for the pages of the printing surface of all the recording sheets related to the allocation pattern (step S806), and the determination result of step S806 is negative (Step S806: NO), the process proceeds to step S803, and when the determination result is affirmative (step S806: YES), the process of determining the energy index value is completed for all the created allocation patterns. It is determined whether or not (step S807: YES).

If the determination result of step S807 is negative (step S807: NO), the control unit 60 proceeds to the process of step S802 and ends the energy index value determination process for all the created allocation patterns. Until this is done (step S807: YES), the processing from step S803 to step S806 is repeated.
FIG. 9 is a flowchart showing the operation of the energy saving allocation pattern selection process. The control unit 60 assigns an index value of the total energy consumption amount during thermal fixing of aggregate printing from the energy index value for each page of the printing surface of the recording sheet determined in each allocation pattern recorded in the RAM 603. It is calculated separately (step S901).

Specifically, the energy index values for each page of the printing surface of the recording sheet are added together for each allocation pattern, and the total value is used as the index value of the total energy consumption. Since the total energy consumption corresponds to the total value, here, the total energy consumption in each allocation pattern is calculated using the total value of the energy index values by a simple method.
Of course, the calculation method is not limited to the above method as long as it can obtain the amount corresponding to the total energy consumption. For example, the power supply amount required to maintain the surface temperature of the heating roller 51 at the target fixing temperature at the time of heat fixing is measured in advance, and a table showing the relationship between the target fixing temperature and the measured power supply amount is created. It is good also as recording on recording media, such as ROM602, and calculating the total energy consumption in each allocation pattern as a total value of supplied electric power using the said table.

  Next, the control unit 60 compares the calculated index values of the total energy consumption, identifies the allocation pattern with the minimum total energy consumption indexed by the calculated index values (step S902), and the operation panel 6 A selection screen for selecting an allocation pattern and a message recommending consolidated printing with the specified allocation pattern are displayed on the liquid crystal display (step S903).

  For example, when the page of each print data to be allocated is a page having a mode as shown in FIG. 6A, the print surface of the recording sheet in each allocation pattern of FIGS. 6B to 6D. When comparing the target fixing temperature (energy index value) for each page, the “booklet” allocation pattern in FIG. 6D has the highest minimum temperature, and the index value of the total energy consumption is the smallest. In this case, for example, a message “Recommended to print in a booklet” is displayed.

  Further, when the page of each print data to be allocated is a page having a mode as shown in FIG. 10A, the printing surface of the recording sheet in each allocation pattern of FIGS. 10B to 10D. When the target fixing temperature (energy index value) of each page is compared, the allocation pattern of “wireless binding” in FIG. 10C has the highest minimum temperature, and the index value of the total energy consumption is the smallest. In this case, for example, a message “Recommended to perform consolidated printing with“ wireless binding ”” is displayed.

FIGS. 10A to 10D are diagrams respectively corresponding to FIGS. 6A to 6D when the page modes of the print data to be allocated are different. The same applies to FIGS. 11A to 11D described later.
In addition, when the page of each print data to be allocated is a page having a mode as shown in FIG. 11A, the printing surface of the recording sheet in each allocation pattern of FIGS. 11B to 11D. When comparing the target fixing temperature (energy index value) for each of the pages, the allocation pattern of “2 in 1” in FIG. 11B has the highest lower limit temperature and the index value of the total energy consumption is the smallest. In this case, for example, a message “Recommended to perform consolidated printing at“ 2 in 1 ”” is displayed.

  Then, when selection of an allocation pattern is received via the operation panel 6 (step S904: YES), the process proceeds to step S706 in FIG. In other words, when the recommended allocation pattern is selected in the displayed message, aggregate printing is performed with the allocation pattern with the smallest total energy consumption, and when the recommended allocation pattern is not selected, the total Execution of aggregate printing with an allocation pattern with the smallest amount of energy consumption is prohibited, and aggregate printing with an allocation pattern selected other than the allocation pattern with the smallest total energy consumption is performed.

  As described above, in the present embodiment, an allocation pattern with the smallest total energy consumption at the time of heat fixing is identified from among a plurality of allocation patterns that can be created before executing aggregate printing. When intensive printing is recommended and the recommended layout pattern is selected, it is possible to reduce energy consumption during thermal fixing during intensive printing.

Further, since the collective printing is executed with an allocation pattern in which the page order of the print data is ordered in advance, the convenience for the user is not impaired.
(Modification)
As described above, the present invention has been described based on the embodiment. However, the present invention is not limited to the above-described embodiment, and the following modifications can be implemented.

(1) In this embodiment, in the energy saving layout printing process, the allocation pattern selection is accepted before executing the aggregate printing with the allocation pattern having the minimum total energy consumption, but the selection is not accepted. The collective printing may be forcibly executed with an allocation pattern having the minimum total energy consumption.
Specifically, the energy saving allocation pattern selection process of FIG. 9 may be modified as shown in FIG. In FIG. 12, the same processing contents as those in FIG. 9 are given the same step numbers as those in FIG. 9, and the description thereof will be omitted. Differences will be described below.

After performing the processing of step S901, the control unit 60 compares the calculated index values of the total energy consumption, and assigns the allocation pattern having the minimum total energy consumption indexed by the calculated index values to the aggregate printing. The allocation pattern to be used is selected (step S1201).
As a result, the allocation pattern with the minimum total energy consumption is forcibly selected and consolidated printing is executed, so that the energy saving effect can be enhanced as compared with the case of selecting the allocation pattern.

  The image forming apparatus 1 can select an energy saving mode that is an operation mode for reducing the total energy amount required for heat fixing in aggregate printing. The layout printing process may be performed, and the energy saving layout printing process of the present embodiment may be performed when the energy saving mode is not selected. Alternatively, when the energy saving mode is not selected, selection of an allocation pattern from the user may be accepted, and aggregate printing may be executed using the allocation pattern selected by the user.

  (2) In this embodiment, there are three types of allocation patterns to which the energy saving layout printing process is applied: “2 in 1”, “wireless binding”, and “booklet”. However, the allocation patterns to which the energy saving layout printing process is applied are as follows. The arrangement pattern is not limited to the above. Any other allocation pattern can be applied as long as it is an allocation pattern that collectively allocates the pages of print data to each page of the printing surface of the recording sheet in an ordered predetermined order.

Further, the allocation pattern to be applied may be two or more types, and is not limited to the above three types.
(3) When the allocation pattern is “booklet”, there is almost no case where pages with consecutive page numbers of print data to be allocated are collectively allocated on the printing surface of the same recording sheet. Therefore, when all the print data to be allocated is composed only of partial print data in which a plurality of pages having the same target fixing temperature are continuous in the page number, pages having the same target fixing temperature are The frequency of intensive allocation to the printing surface of the same recording sheet decreases, and as a result, the frequency of intensive allocation of pages with different target fixing temperatures to the printing surface of the same recording sheet increases, and the total energy consumption during thermal fixing Will become bigger.

Therefore, in such a case, the entire print data to be allocated is divided to generate partial print data, an allocation pattern for generating a booklet separate for each partial print data is generated, and aggregate printing is performed. It is good as well.
Specifically, the energy saving allocation pattern selection process of FIG. 9 may be modified as shown in FIG. In FIG. 13, the same processing as the processing content of FIG. 9 is given the same step number as the step number of FIG. 9, description thereof is omitted, and differences will be described below.

  When the allocation pattern selected in step S904 is a booklet (an allocation pattern for creating one non-divided booklet) (step S904: YES, step S1301: YES), the control unit 60 acquires N pages. The print data is partial print data in which the number of pages is a multiple of four, the page numbers are continuous in each partial print data, and the step of FIG. 8 is performed for each page in each partial print data. It is determined whether or not the print data can be divided into partial print data having the same target fixing temperature determined in S801 (step S1302).

  If the determination result in step S1302 is affirmative (step S1302: YES), the control unit 60 divides all print data to generate partial print data, and creates a booklet separate volume for each partial print data. A pattern (hereinafter referred to as “divided allocation pattern”) is created (step S1303), and the same processing as in steps S803 to S805 is performed on the created divided allocation pattern, and the page target of the printing surface of each recording sheet is obtained. The fixing temperature is determined, the determined target fixing temperature is determined as the energy index value of the printing surface, and is recorded in the RAM 603 in association with the page number of the page of the printing surface (step S1304).

Then, the control unit 60 selects a split layout pattern on the liquid crystal display of the operation panel 6 and a message recommending aggregate printing with the split layout pattern (for example, split layout for creating a “booklet” booklet). Message is recommended ”(step S1305).
When the division allocation pattern is selected (step S1306: YES), the control unit 60 proceeds to the process of step S706 in FIG. When the determination result of either step S1302 or step S1306 is negative (step S1302: NO or step S1306: NO), the control unit 60 assigns “booklet” to create a non-divided booklet. It is determined that a pattern (an allocation pattern in which the entire pages of a plurality of acquired print data are to be allocated) is selected (step S1307), and the process proceeds to step S706 in FIG.

FIG. 14 shows a case where the booklet allocation pattern is divided into all print data pages to be assigned to create a booklet separate volume, and one booklet is created without dividing all print data. FIG. 4 is a diagram conceptually showing how pages of print data with page numbers 1 to 16 are collectively allocated.
FIG. 14A shows two pieces of partial print data (each of which the number of pages is a multiple (8) of 4 and the same target fixing temperature for each page is continuous in page numbers 1 to 8 and 9 to 16). Pages of all print data to be allocated (pages 1 to 16).

  FIG. 14 (b) shows that the pages of page numbers 1 to 16 are printed on the front and back sides of the recording sheet in the order of allocation of the “booklet” layout pattern in which all print data pages are not divided and one booklet is created. FIG. 14C shows the allocation of divided allocation patterns in which pages of all print data are divided to generate partial print data, and a booklet is created for each partial print data. A state in which each page of each partial print data (partial print data of page numbers 1 to 8 and page numbers 9 to 16) is sequentially allocated and allocated to the print surfaces on the front and back sides of the recording sheet in order.

In FIG. 14, numbers in each rectangle indicate page numbers of print data, “lower limit temperature” in each rectangle indicates that the target fixing temperature of the page is the lower limit temperature, and “upper limit temperature” in each rectangle. "Indicates that the target fixing temperature of the page is the upper limit temperature.
In the same figure, the numbers in parentheses indicate the page numbers on the printing surfaces on the front and back of the recording sheet, and the letters “(front)” and “(back)” next to the numbers in parentheses are the recording sheets. The front and back of the are shown. Each white arrow in FIGS. 14B and 14C indicates whether the target fixing temperature on the printing surface of each recording sheet is the lower limit temperature or the upper limit temperature, and the black arrow in FIG. This shows that the entire print data for booklet creation is divided into two partial print data for booklet creation at the position of the black arrow.

  As shown in FIG. 14B, when the pages of all the print data are not divided, pages having different target fixing temperatures are collectively allocated to each printing surface of the recording sheet, and the aggregate printing is performed with the allocation pattern. In this case, pages that have the target fixing temperature and the lower limit temperature that are collectively allocated to each printing surface are thermally fixed at the upper limit temperature, and energy is excessively consumed accordingly.

On the other hand, as shown in FIG. 14C, when pages of all print data are divided for each partial print data for creating a separate volume, pages having the same target fixing temperature are collectively allocated to each print surface of the recording sheet. Thus, the energy is not excessively consumed as in the case of FIG.
In this way, in the aggregate printing with the “booklet” allocation pattern, all the print data to be allocated is composed of a plurality of partial print data, and the number of pages of each partial print data is a multiple of four. Therefore, it is possible to reduce the total energy consumption when performing the aggregate printing with the divided allocation pattern than when executing the aggregate printing with the allocation pattern for creating one booklet.

  In the case of this modification as well, as in the modification (1), it is also possible to forcibly perform aggregate printing with the divided allocation pattern without accepting selection of the divided allocation pattern. That is, in FIG. 13, instead of performing the processes of steps S1305 and S1306, a divided allocation pattern may be automatically selected as an allocation pattern used for aggregate printing.

  (4) In the modified example of (3), when the determination result in step S1302 is affirmative (step S1302: YES), the divided allocation pattern is created. Instead of creating the divided allocation pattern, Selection of “2 in 1” may be recommended as an allocation pattern that can reduce the total energy consumption at the time of aggregate printing as compared with the case of performing aggregate printing with an allocation pattern for creating one booklet.

  Specifically, when the determination result of step S1302 of FIG. 13 is affirmative (step S1302: YES), instead of executing the processing of steps S1303 to S1306, an allocation pattern of “2 in 1” is selected. And a message recommending consolidated printing at “2 in 1” (for example, a message that recommends consolidated printing at “2 in 1”), and “2 in 1” is selected. It is good also as shifting to the process of step S706 of 7.

Note that the layout pattern that can be recommended in this modification is not limited to “2 in 1” in which print data is aggregated and allocated in order of page numbers two pages at a time. (M is an integer of 2 or more).
If the determination result in step S1302 of FIG. 13 is affirmative (step S1302: YES), instead of executing the processing of steps S1303 to S1306, a selection for selecting an allocation pattern of “wireless binding” When a screen and a message that recommends consolidated printing with “wireless binding” (for example, a message that recommends consolidated printing with “wireless binding”) are displayed, and “wireless binding” is selected It is good also as shifting to the process of step S706 of FIG.

In this case as well, the total energy consumption at the time of aggregate printing can be reduced as compared with the case of performing aggregate printing with an allocation pattern for creating one booklet.
(5) In the modified example of (3), when the number of pages of partial print data is a multiple of 4, the divided allocation pattern is created. However, the number of pages is not a multiple of 4 It is good also as creating a division | segmentation allocation pattern.

Specifically, the energy saving allocation pattern selection process of FIG. 13 may be modified as shown in FIGS. 15 and 16. In FIG. 15 and FIG. 16, the same processing contents as those in FIG. 13 are given the same step numbers as those in FIG.
When the determination result in step S1301 is affirmative (step S1301: YES), the control unit 60 uses the acquired print data for N pages as partial print data having two or more pages, It is determined whether the page numbers are continuous in the partial print data and can be divided into partial print data having the same target fixing temperature determined in step S801 in FIG. 8 for each page in each partial print data. (Step S1501).

  If the determination result in step S1501 is affirmative (step S1501: YES), the control unit 60 generates partial print data so that the entire print data is divided and the number of pages is a multiple of four. Specifically, if the number of pages of the partial print data is not a multiple of 4, a page of blank print data is added to the partial print data (the page number is the last page number of the partial print data) So that the number of pages of the partial print data after adding the blank print data page is a multiple of 4, and the number of pages of the partial print data is If it is a multiple of 4, adjustment is made not to add a page of blank print data (step S1502). Thus, the number of pages of each partial print data after adjustment is a multiple of four.

  Next, the control unit 60 creates an allocation pattern (hereinafter referred to as “adjustment division allocation pattern”) that creates a booklet for each adjusted partial print data (step S1601), and creates the adjusted division allocation pattern. In Steps S803 to S805, the target fixing temperature of the page on the printing surface of each recording sheet is determined, the determined target fixing temperature is determined as the energy index value of the page on the printing surface, It is recorded in the RAM 603 in association with the page number of the page on the printing surface (step S1602). Here, it is assumed that the target fixing temperature of the blank page is determined as the lower limit temperature.

  Then, the control unit 60 calculates the index value of the total energy consumption during the thermal fixing of the aggregate printing in the adjustment division allocation pattern from the energy index value for each page of the printing surface of the recording sheet determined in the adjustment division allocation pattern ( E1) is calculated, and E1 and the index value (E0) of the total energy consumption at the time of heat fixing of aggregate printing in the booklet allocation pattern for creating the non-divided booklet calculated in step S901, The size is compared (step S1603).

  If E0 is larger (step S1604: YES), the control unit 60 recommends a selection screen for selecting an adjustment division allocation pattern on the liquid crystal display of the operation panel 6 and aggregate printing with the adjustment division allocation pattern. A message (for example, a message that “It is recommended to perform aggregate printing with an adjustment division allocation pattern for creating a separate booklet”) is displayed (step S1605).

  When the adjustment division allocation pattern is selected (step S1606: YES), the control unit 60 proceeds to the process of step S706 in FIG. When the determination result of any of step S1501, step S1604, and step S1606 is negative (step S1501: NO, or step S1604: NO, or step S1606: NO), the control unit 60 is a non-divided book. It is determined that the “booklet” layout pattern for creating the booklet is selected (step S1307), and the process proceeds to step S706 in FIG.

  FIG. 17 shows the booklet allocation pattern, and the pages of all print data to be allocated are divided by inserting blank print data pages (hereinafter referred to as “adjustment division”). And a case where all print data is not adjusted and divided and one booklet is created, the pages of the print data with the page numbers 1 to 12 are categorically allocated. FIG.

FIG. 17A shows two partial print data (prints in which the number of pages is 7 and 5, respectively, and the pages having the same target fixing temperature for each page are continuous in page numbers 1 to 7 and 8 to 12, respectively. Data) are pages of all print data to be allocated (pages with page numbers 1 to 12).
FIG. 17B shows the pages printed on the front and back sides of the recording sheet with pages numbered 1 to 12 in the order of the “booklet” layout pattern that creates one booklet with all print data pages undivided. FIG. 17 (c) shows that the pages of all print data are adjusted and divided to generate each partial print data so that the number of pages is a multiple of four. Each page of the generated partial print data (partial print data of page numbers 1 to 7 and page numbers 8 to 12) is assigned to each of the front and back sides of the recording sheet in the allocation order of the adjustment division allocation pattern for creating a booklet. A state in which the print surface is sequentially allocated and allocated is shown.

In FIG. 17, numbers in each rectangle indicate page numbers of print data, “blank” in each rectangle indicates that a page of blank print data is inserted, and “lower limit temperature” in each rectangle Indicates that the target fixing temperature of the page is the lower limit temperature, and the “upper limit temperature” in each rectangle indicates that the target fixing temperature of the page is the upper limit temperature.
In the same figure, the numbers in parentheses indicate the page numbers on the printing surfaces on the front and back of the recording sheet, and the letters “(front)” and “(back)” next to the numbers in parentheses are the recording sheets. The front and back of the are shown. Each of the white arrows in FIGS. 17B and 17C indicates whether the target fixing temperature on the printing surface of each recording sheet is the lower limit temperature or the upper limit temperature, and the black arrow in FIG. It shows that the entire print data for booklet creation is adjusted and divided into two partial print data for booklet creation at the position of the black arrow.

  In the case of this modification, as shown in FIG. 17C, the pages of all print data to be allocated are adjusted and divided to generate partial print data so that the number of pages is a multiple of all four. When the print data is allocated and allocated with the adjustment division allocation pattern that creates a separate volume for each partial print data, the “booklet” allocation pattern that creates a single booklet with all print data pages undivided is used. Compared to the case of FIG. 17B in which print data is intensively allocated, a larger number of pages of print data having the same target fixing temperature can be intensively allocated on each printing surface of the recording sheet, and accordingly, the amount of energy consumption Can be reduced.

  On the other hand, in the former adjustment division allocation pattern, depending on the number of pages in the partial print data, when the number of thermal fixings on the printing surface of the recording sheet is the latter non-division allocation pattern due to the addition of blank print data pages There may be more cases than For example, comparing the cases of FIG. 17B and FIG. 17C, the latter case requires two more heat fixings, and the amount of energy consumption increases by that amount compared to the former case. become.

Therefore, in the present modification, the processing of steps S1602 to S1604 in FIG. 16 is executed to compare the index values of the total energy consumption amount of both, and the index value of the total energy consumption amount than the case of the non-divided allocation pattern. Only when the number of prints is small, the aggregate printing with the adjustment allocation division pattern is executed.
Also in the case of this modification, as in the modification (1), it is also possible to forcibly perform collective printing with the adjustment division allocation pattern without accepting the selection of the adjustment division allocation pattern. That is, in FIG. 16, instead of performing the processes of steps S1605 and S1606, the adjustment division allocation pattern may be automatically selected as the allocation pattern used for the aggregate printing.

(6) In addition to the cases of (3) and (5), when the user selects a booklet layout pattern, even when the creation of a split layout pattern is instructed in order to create a separate booklet, An allocation pattern may be created.
For example, a user receives an instruction to create a division allocation pattern in which a page range of print data for creating a separate volume is specified by page number via the operation panel, and for each partial print data in the range of the specified page number, Processing similar to that in steps S1502 in FIG. 15 and steps S1601 to S1603 in FIG. 16 is performed.

Then, when the total energy consumption (E1) when the specified division allocation pattern is created is larger than the non-division total energy consumption (E0), a message recommending aggregate printing of the non-divided booklet is displayed. If it is displayed and does not become large, it is also possible to execute aggregate printing with the specified divided allocation pattern.
If the total energy consumption (E1) when the specified division allocation pattern is created is larger than the non-division total energy consumption (E0), the message is not displayed forcibly and not displayed. It is also possible to perform collective printing with the division allocation pattern.

(7) In the present embodiment, the amount of energy consumption in the aggregate printing is reduced by selecting the allocation pattern with the smallest total energy consumption.
When pages of print data with different target fixing temperatures are allocated to the same printing surface of the recording sheet in the selected allocation pattern, the fixing temperature is set for each of the allocated pages when the printing surface is thermally fixed. It is also possible to perform heat fixing by switching.

  Specifically, the energy saving layout printing process of FIG. 7 may be modified as shown in FIG. In FIG. 18, the same processing as the processing content of FIG. 7 is assigned the same step number as that of FIG. After the processing in step S705, the control unit 60 executes target fixing energy saving intensive printing processing described later (step S1801).

  FIG. 19 is a flowchart showing the operation of the energy saving intensive printing process. The control unit 60 refers to the correspondence between the page number of the page of the print data recorded in the RAM 603 in step S801 in FIG. 8 and the target fixing temperature, and determines the recording sheet in the allocation pattern selected in step S904 in FIG. The target fixing temperatures of the pages of the print data that are collectively assigned to each printing surface are compared (step S1901). When the recording sheets are assigned to both sides of the recording sheet, the target fixing temperatures of the pages of the print data that are assigned to the printing faces are compared for both sides.

  When the target fixing temperature is different (in the case of both sides, when the target fixing temperature is different on at least one of the front and back printing surfaces) (step S1902: NO), the control unit 60 fixes the fixing temperature during the thermal fixing period. A fixing temperature switching printing process to be described later is performed (step S1903), and if the target fixing temperature is the same (step S1902: YES), a printing process (default printing process) that does not change the fixing temperature during the thermal fixing period is executed. (Step S1904).

  Here, in the default printing process, as shown in FIG. 20A, the sheet passing direction to the fixing device 5 is horizontal so that the period during which the recording sheet passes the fixing position is shortened. It is assumed that the direction selection unit 607 adjusts. In the fixing temperature switching printing process to be described later, as shown in FIG. 20B, the sheet passing direction is arranged so that the pages of the print data pages collectively allocated on the printing surface of the recording sheet are aligned in the sheet passing direction. It is assumed that the sheet passing direction selection unit 607 adjusts so that is vertically oriented. Reference numeral 191 in both figures indicates a character image, and reference numeral 192 indicates a non-character image.

Then, the control unit 60 repeats the processing from step S1901 to step S1904 until the printing process is completed for pages on the printing surface of all recording sheets to which pages of print data are collectively allocated (step S1905: YES).
FIG. 21 is a flowchart showing the operation of the fixing temperature switching printing process. The control unit 60 rotates (in this case, 90 ° rotation) the print data of the pages that are collectively assigned to the print surface, and outputs it to the image processing unit 3 to form an image based on the print data (step). S2101), the recording sheet is fed vertically from the sheet feeding unit 4 (step S2102), and an image based on the print data of the pages allocated and allocated on the printing surface of the recording sheet is displayed in FIG. As shown in FIG. 4, the sheet is formed so as to be aligned in the sheet passing direction (step S2103).

Then, each time the leading edge of the image forming area of each page that is collectively assigned to the recording sheet reaches the fixing position, the magnetic flux generation unit 53 so that the surface temperature of the heating roller 51 becomes the target fixing temperature of the page. The temperature of the recording sheet is controlled by controlling the power supplied to the recording sheet, and the thermal fixing process is performed on the printing surface of the recording sheet (step S2104).
The timing at which the leading edge of the image forming area of each page reaches the fixing position is, for example, a paper passing sensor that detects the passage of the recording sheet between the secondary transfer position 46 and the fixing position. It can be detected by measuring the time after the leading edge of the recording sheet is detected by the sensor.

Specifically, the arrival time from the detection of the leading edge by the paper passing sensor until the leading edge of the image forming area of each page reaches the fixing position is determined in advance by experiments or the like. It can be detected by whether or not the arrival time has been reached.
In addition, when the leading edge of the image forming area of each page reaches the fixing position, the surface temperature is raised or lowered so that the surface temperature of the heating roller 51 becomes the target temperature of the page. It starts a predetermined time before the arrival. The predetermined time is determined in advance by experiments or the like.

  As a result, even when pages with different target fixing temperatures in the selected allocation pattern are collectively allocated, it is possible to perform heat fixing at the target fixing temperature determined for the page. Thermal fixing can be prevented from being performed at an excessive fixing temperature, and the total energy consumption during intensive printing can be further reduced.

Note that the modified example (1) may be applied to this modified example, and the above-described energy saving intensive printing process may be performed for the allocation pattern with the minimum total energy consumption selected in step S1201 in FIG.
(8) In the present embodiment and the modified examples of (3) to (5), in the energy saving allocation pattern selection process, a message for recommending an allocation pattern is displayed. The message may be notified by (output).

(9) Although the electromagnetic induction heating type fixing device is used in the present embodiment, the heating method of the fixing device to which the present embodiment can be applied is not limited to the electromagnetic induction heating method, and other heating methods (for example, Heater heating method).
(10) In the present embodiment, the target fixing temperature is switched between two stages of the upper limit temperature and the lower limit temperature. However, the target fixing temperature is not limited to the two stages, and the temperature is two or more. It is good also as switching. For example, the temperature may be switched at five stages according to the number of toner-attached pixels in the print data page image.

  The present invention relates to an image forming apparatus capable of changing a fixing temperature as a control target for each printing surface of a recording sheet and collectively allocating and printing a plurality of print data on a printing surface. It can be used as a technology to reduce energy consumption.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 3 Image process part 3Y-3K Image forming part 4 Paper feed part 5 Fixing device 6 Operation panel 7 Image reading part 10 Exposure part 11 Intermediate transfer belt 12 Drive roller 13 Driven roller 21, 35Y Cleaner 31Y Photoconductor drum 32Y Charger 33Y Developer 34Y Primary transfer rollers 40, 41 Paper feed cassettes 42A, 42B Feed roller 43 Transport path 44 Timing roller 45 Secondary transfer roller 46 Secondary transfer position 51 Heating roller 52 Pressure roller 53 Magnetic flux generator 54 Fixing position 60 Control Unit 71 Discharge Roller 72 Discharge Tray 73-77 Transport Roller

Claims (14)

The fixing temperature as a control target can be changed for each printing surface of the recording sheet, and N pages of printing data (N is an integer of 3 or more) are allocated to printing surfaces of 2 or more and less than N for printing. An image forming apparatus having a printing function,
First acquisition means for acquiring, for each page, a fixing temperature to be a control target when fixing on a single page;
Layout pattern creating means for creating a plurality of types of layout patterns for each print surface of the print data for N pages;
Set the target fixing temperature when fixing the printing surface to which print data of two or more pages are collectively assigned to the highest temperature among the target fixing temperatures acquired for each page assigned to the printing surface. Setting means to
A second acquisition unit that acquires an index value indicating a total energy consumption required for fixing of all print surfaces based on a target fixing temperature of each print surface set by the setting unit for each type of allocation pattern;
An aggregate printing means for selecting an index value allocation pattern having the smallest total energy consumption and executing aggregate printing;
An image forming apparatus comprising: The allocation pattern includes
Booklet layout in which print data is aggregated and assigned to each print surface on both sides of two or more recording sheets, each recording sheet is superimposed and saddle stitched, and the print data of each page is arranged in page order The image forming apparatus according to claim 1, further comprising a pattern. The layout pattern for the booklet is:
A first booklet layout pattern for allocating all print data and creating one booklet;
The image forming apparatus according to claim 2, further comprising: a second booklet layout pattern that divides all print data to generate partial print data and creates a booklet for each partial print data. When the number of pages of each divided print data obtained by dividing all the print data is a multiple of 4, the layout pattern creating unit sets the divided print data as the partial print data, and the number of pages is not a multiple of 4 Is characterized in that the partial print data is generated by adding blank page print data to the divided print data so that the total number of pages is a minimum multiple of 4 larger than the number of divided print data pages. The image forming apparatus according to claim 3. The creating means includes a group of print data in which all the print data are two or more pages, the page numbers are continuous in each group, and the target fixing temperature for each acquired page 5. The image forming apparatus according to claim 4, wherein the divided print data is created by dividing all print data for each print data group when the print data groups are configured in the same manner. A determination unit that determines whether or not the target fixing temperature acquired for each page of two or more pages of print data collectively allocated on the same print surface is the same for the allocation pattern selected by the aggregate printing unit;
If they are not the same, an image based on the print data of each page aggregated and assigned to the printing surface when executing the aggregate printing by the aggregate printing unit is formed so as to be aligned in the sheet passing direction of the recording sheet, and the print Control means for controlling the surface temperature of the heating rotator when the image of each page formed on the surface passes the fixing position of the heating rotator to a target fixing temperature acquired for the page; ,
The image forming apparatus according to claim 1, further comprising: An informing means for informing a user of a message recommending aggregate printing with an allocation pattern with the smallest total energy consumption to be indexed;
An accepting means for accepting selection of whether or not to perform consolidated printing with the recommended allocation pattern;
If the selection is negative, a prohibiting unit that prohibits the aggregate printing by the aggregate printing unit;
The image forming apparatus according to claim 1, further comprising: Accepting means for accepting an instruction as to whether or not to select an energy saving mode, which is an operation mode for reducing the total energy consumption required for fixing in consolidated printing;
When the energy saving mode is not selected, a prohibiting unit that prohibits the aggregate printing by the aggregate printing unit;
The image forming apparatus according to claim 1, further comprising: The fixing temperature that is the control target can be changed for each printing surface of the recording sheet, and N pages of print data (N is an integer of 3 or more) are aggregated on each printing surface on both sides of the recording sheet by two pages. An image forming apparatus having an aggregate printing function for creating a booklet in which printing sheets are arranged and printed by superimposing and binding each recording sheet, and print data of each page is arranged in page order,
Acquisition means for acquiring, for each page, a fixing temperature to be a control target when fixing on a single page;
The target fixing temperature when fixing the printing surface on which the print data of two pages are collectively assigned is set to the highest temperature among the target fixing temperatures acquired for each page assigned to the printing surface. Setting means;
All the print data is partial print data in which the number of pages is a multiple of four. In each partial print data, the page number is continuous, and the target fixing temperature for each acquired page is Determination means for determining whether or not the same partial print data can be divided;
If the determination result is negative, all print data is allocated to create a first layout pattern that creates one booklet. If the determination result is affirmative, all print data Creating means for creating a second allocation pattern that divides each of the partial print data and creates a booklet for each partial print data;
Aggregate printing means for executing aggregate printing with the allocation pattern created by the creating means;
An image forming apparatus comprising: Informing means for informing a message that recommends performing aggregate printing with the second allocation pattern when the determination result is affirmative;
Accepting means for accepting selection of whether to perform the recommended aggregate printing;
If the selection is negative, a prohibiting unit that prohibits the aggregate printing by the aggregate printing unit;
The image forming apparatus according to claim 9, further comprising: The image forming apparatus can further perform page-order intensive printing in which print data for N pages is printed by allocating and allocating two or more pages of print data in order of page numbers on a print surface of 2 or more and less than N. Yes,
Informing means for informing a message that recommends performing the page order aggregation printing when the determination result is affirmative;
Accepting means for accepting selection as to whether or not to perform the recommended page order consolidated printing;
If the selection is affirmative, prohibit the aggregate printing by the aggregate printing means,
Aggregate print control means for causing the aggregate print means to execute the page order aggregate printing;
The image forming apparatus according to claim 9, further comprising: The image forming apparatus further allocates two pages of print data for N pages to each print surface on both sides of two or more recording sheets, folds the recording sheet at the center, aligns the folding side, and binds each page. It is possible to perform combined printing of simple binding in which the print data of pages is arranged in page order,
When the determination result is affirmative, an informing means for informing a message recommending that the simple binding integrated printing is performed;
Accepting means for accepting selection of whether or not to perform the recommended integrated binding binding;
If the selection is affirmative, prohibit the aggregate printing by the aggregate printing means,
Aggregate print control means for causing the aggregate print means to execute the aggregate printing of the perfect binding;
The image forming apparatus according to claim 9, further comprising: The fixing temperature, which is a control target, can be changed for each printing surface of the recording sheet, and print data for N pages (N is an integer of 3 or more) is allocated to printing surfaces of 2 or more and less than N and collectively printed. An aggregate printing program for causing a computer to execute processing,
A first acquisition step of acquiring, for each page, a fixing temperature to be a control target when fixing on a single page;
A creation step of creating a plurality of types of layout patterns for each print surface of the print data for N pages;
Set the target fixing temperature when fixing the printing surface to which print data of two or more pages are collectively assigned to the highest temperature among the target fixing temperatures acquired for each page assigned to the printing surface. A setting step to
A second acquisition step of acquiring an index value indicating the total energy consumption necessary for fixing all the printing surfaces based on the target fixing temperature of each printing surface set by the setting step for each type of allocation pattern;
An aggregate printing step of selecting an index value allocation pattern with the smallest total energy consumption and executing aggregate printing;
An aggregate printing program that causes a computer to execute . The fixing temperature that is the control target can be changed for each printing surface of the recording sheet, and N pages of print data (N is an integer of 3 or more) are aggregated on each printing surface on both sides of the recording sheet by two pages. An aggregate printing program that causes a computer to execute a process of performing aggregate printing for booklet creation in which each recording sheet is allocated and saddle-stitched, and the print data of each page is arranged in page order,
An acquisition step of acquiring, for each page, a fixing temperature to be a control target when fixing on a single page;
The target fixing temperature when fixing the printing surface on which the print data of two pages are collectively assigned is set to the highest temperature among the target fixing temperatures acquired for each page assigned to the printing surface. Configuration steps;
All the print data is partial print data in which the number of pages is a multiple of four. In each partial print data, the page number is continuous, and the target fixing temperature for each acquired page is A determination step for determining whether the print data can be divided into the same partial print data;
If the determination result is negative, all print data is allocated to create a first layout pattern that creates one booklet. If the determination result is affirmative, all print data Creating a second layout pattern that divides each of the partial print data and creates a booklet for each partial print data;
An aggregate printing step of executing aggregate printing with the allocation pattern created by the creating step;
An aggregate printing program that causes a computer to execute .

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