Image forming apparatus and determination method

Abstract

To provide an image forming apparatus and a determination method capable of determining whether a toner image to be transferred protrudes to the outside of a contact area with a sheet on an image carrier.SOLUTION: An image forming apparatus 100 comprises: an intermediate transfer belt that conveys toner images including a toner image to be transferred that is to be transferred to a sheet; a movement processing unit 52 that moves an image to be formed corresponding to the toner image to be transferred included in image data used for formation of the toner images, in the image data; and a determination processing unit 53 that determines whether the toner image to be transferred based on the image to be formed after the movement by the movement processing unit 52 protrudes from a contact area in contact with the sheet on the intermediate transfer belt.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus and a determination method. [Background technology]

[0002] The electrophotographic image forming apparatus includes an image carrier and a transfer unit. The image carrier transports a toner image including a toner image to be transferred onto a sheet. The transfer unit transfers the toner image transported by the image carrier onto the sheet in contact with the image carrier.

[0003] In addition, an image forming device capable of moving an image to be formed corresponding to the transferred toner image contained in image data used to form the toner image from the center of the main scanning direction in the image data to the end side of the main scanning direction is known as related technology (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-337552 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when the target image is moved toward an end of the image data in the main scanning direction, the toner image to be transferred based on the target image after the movement may extend beyond the contact area of ​​the image carrier where the sheet comes into contact with the image carrier. However, there has been no conventional configuration that can determine whether the toner image to be transferred based on the target image after the movement extends beyond the contact area of ​​the image carrier.

[0006] SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus and a method for determining whether a toner image to be transferred extends outside the contact area between the image carrier and the sheet. [Means for solving the problem]

[0007] According to one aspect of the present invention, an image forming apparatus includes an image carrier, a transfer unit, a movement processing unit, and a determination processing unit. The image carrier transports a toner image including a transferee toner image to be transferred to a sheet. The transfer unit transfers the transferee toner image transported by the image carrier to the sheet that contacts the image carrier. The movement processing unit moves a formation target image corresponding to the transferee toner image included in image data used to form the toner image within the image data. The determination processing unit determines whether the transferee toner image based on the formation target image after movement by the movement processing unit extends beyond the contact area of ​​the image carrier that contacts the sheet.

[0008] A determination method according to another aspect of the present invention is executed by an image forming apparatus including an image carrier that transports a toner image including a transferee toner image to be transferred to a sheet, and a transfer unit that transfers the transferee toner image transported by the image carrier to the sheet that contacts the image carrier, and includes a moving step and a determining step. In the moving step, a formation target image corresponding to the transferee toner image included in image data used to form the toner image is moved within the image data. In the determining step, it is determined whether the transferee toner image based on the formation target image after movement by the moving step extends beyond a contact area of ​​the image carrier that contacts the sheet. [Effects of the Invention]

[0009] According to the present invention, it is possible to determine whether or not the transferred toner image extends outside the contact area between the image carrier and the sheet. [Brief explanation of the drawings]

[0010] [Figure 1]FIG. 1 is a cross-sectional view showing the configuration of an image forming apparatus according to an embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram showing the system configuration of the image forming apparatus according to the embodiment of the present invention. [Figure 3] FIG. 3 is a cross-sectional view showing the configuration of the image forming unit of the image forming apparatus according to the embodiment of the present invention. [Figure 4] FIG. 4 is a bottom view showing the configuration of the intermediate transfer belt of the image forming apparatus according to the embodiment of the present invention. [Figure 5] FIG. 5 is a flowchart showing an example of a print data output process executed by the image forming apparatus according to the embodiment of the present invention. [Figure 6] FIG. 6 is a diagram showing an example of print data generated by the image forming apparatus according to the embodiment of the present invention. [Figure 7] FIG. 7 is a diagram showing a state in which the image to be formed included in the print data shown in FIG. 6 has been moved. [Figure 8] FIG. 8 is a diagram showing a state in which a part of the image to be formed included in the printing data shown in FIG. 7 has been cut off. [Figure 9] FIG. 9 is a diagram showing a state in which a test image is added to the printing data shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Note that the following embodiment is an example of a specific embodiment of the present invention and does not limit the technical scope of the present invention.

[0012] [Configuration of image forming apparatus 100] First, the configuration of an image forming apparatus 100 according to an embodiment of the present invention will be described with reference to FIGS.

[0013] For ease of explanation, the vertical direction in the installation state where image forming apparatus 100 is usable (the state shown in FIG. 1) is defined as the up-down direction D1. Also, the front-to-back direction D2 is defined with the left side of image forming apparatus 100 on the paper surface shown in FIG. 1 as the front (front face). Also, the left-to-right direction D3 is defined with the front face of image forming apparatus 100 in the installation state as the reference point.

[0014] Image forming apparatus 100 is a multifunction peripheral that has multiple functions, such as a scanning function for reading an image from an original document, a printing function for forming an image based on image data, a fax function, and a copy function. Note that the present invention may also be applied to image forming apparatuses such as printers, fax machines, and copy machines that are capable of forming images using an electrophotographic method.

[0015] As shown in Figures 1 and 2, the image forming apparatus 100 includes an ADF (Auto Document Feeder) 1, an image reading unit 2, an image forming unit 3, a paper feeding unit 4, an operation display unit 5, a memory unit 6, a control unit 7, and an image processing unit 8.

[0016] The ADF 1 transports documents to be scanned by the scanning function, and includes a document setting section, a plurality of transport rollers, a document holder, and a paper ejection section.

[0017] The image reading unit 2 realizes the scanning function and includes a document table, a light source, a plurality of mirrors, an optical lens, and a CCD (Charge Coupled Device).

[0018] The image forming unit 3 realizes the printing function. Specifically, the image forming unit 3 forms a color or monochrome image on a sheet fed from the paper feed unit 4 according to an electrophotographic method.

[0019] The paper feed unit 4 supplies sheets to the image forming unit 3. The paper feed unit 4 includes a paper feed cassette, a manual feed tray, and a plurality of transport rollers.

[0020] The operation display unit 5 is a user interface of the image forming apparatus 100. The operation display unit 5 includes a display unit and an operation unit. The display unit displays various information in response to control instructions from the control unit 7. For example, the display unit is a flat panel display such as a liquid crystal display. The operation unit inputs various information to the control unit 7 in response to user operations. For example, the operation unit includes operation keys and a touch panel.

[0021] The storage unit 6 is a non-volatile storage device, such as a flash memory.

[0022] The control unit 7 performs overall control of the image forming apparatus 100. As shown in FIG. 2, the control unit 7 includes a CPU 11, a ROM 12, and a RAM 13. The CPU 11 is a processor that executes various types of arithmetic processing. The ROM 12 is a non-volatile storage device that stores in advance information such as control programs for causing the CPU 11 to execute various types of processing. The RAM 13 is a volatile or non-volatile storage device that is used as a temporary storage memory (work area) for the various types of processing executed by the CPU 11. The CPU 11 performs overall control of the image forming apparatus 100 by executing the various control programs that are stored in advance in the ROM 12.

[0023] The image processing unit 8 generates printing data X10 (see FIG. 6) used to form an image on a sheet. The printing data X10 generated by the image processing unit 8 is input to the image forming unit 3. The image forming unit 3 forms an image on a sheet based on the printing data X10 input from the image processing unit 8. For example, the image processing unit 8 is configured with electronic circuits such as integrated circuits (ASIC, DSP).

[0024] [Configuration of image forming unit 3] Next, the configuration of the image forming section 3 will be described with reference to Figures 1 to 4. Here, Figure 3 is a cross-sectional view showing the configuration of multiple image forming units 20, intermediate transfer belt 26, and secondary transfer roller 27. Also, Figure 4 is a bottom view showing the configuration of photosensitive drum 31 of image forming unit 24, intermediate transfer belt 26, drive roller 26A, and secondary transfer roller 27.

[0025] 1, the image forming section 3 includes four image forming units 20, an optical scanning device 25, an intermediate transfer belt 26, a secondary transfer roller 27, a fixing device 28, and a paper discharge tray 29. In addition, as shown in FIG. 2, the image forming section 3 includes a density sensor 41.

[0026] Of the four image forming units 20, image forming unit 21 (see FIG. 3) forms a Y (yellow) toner image. The toner image includes a transfer toner image to be transferred to a sheet. The toner image may also include a test toner image used to adjust image forming conditions. Of the four image forming units 20, image forming unit 22 (see FIG. 3) forms a C (cyan) toner image. Of the four image forming units 20, image forming unit 23 (see FIG. 3) forms an M (magenta) toner image. Of the four image forming units 20, image forming unit 24 (see FIG. 3) forms a K (black) toner image. As shown in FIGS. 1 and 3, the four image forming units 20 are arranged side by side in the order of yellow, cyan, magenta, and black from the front side of image forming apparatus 100 along the front-rear direction D2.

[0027] 3, each image forming unit 20 includes a photosensitive drum 31, a charging roller 32, a developing device 33, a primary transfer roller 34, and a drum cleaning unit 35. Each image forming unit 20 also includes a toner container 36 shown in FIG.

[0028] An electrostatic latent image is formed on the surface of the photosensitive drum 31. The photosensitive drum 31 receives a rotational driving force supplied from a motor (not shown) and rotates in a drum rotation direction D4 shown in Fig. 3. As a result, the photosensitive drum 31 transports the electrostatic latent image formed on its surface.

[0029] A preset charging voltage is applied to the charging roller 32, which charges the surface of the photosensitive drum 31. The surface of the photosensitive drum 31 charged by the charging roller 32 is irradiated with light based on the printing data X10 emitted from the optical scanning device 25. As a result, an electrostatic latent image is formed on the surface of the photosensitive drum 31.

[0030] The developing device 33 develops the electrostatic latent image formed on the surface of the photosensitive drum 31. The developing device 33 includes a pair of stirring members, a magnet roller, and a developing roller. The pair of stirring members stir the developer, which contains toner and a carrier, contained inside the developing device 33. The magnet roller draws up the developer stirred by the pair of stirring members and supplies the toner contained in the developer to the developing roller. The developing roller transports the toner supplied from the magnet roller to a position facing the photosensitive drum 31. The developing roller also receives a preset development bias voltage and supplies the toner transported to the position facing the photosensitive drum 31 to the photosensitive drum 31. This selectively supplies toner to an exposure area of ​​the photosensitive drum 31 irradiated with light emitted from the optical scanning device 25, thereby developing the electrostatic latent image formed on the surface of the photosensitive drum 31. The developing device 33 receives toner from a toner container 36.

[0031] The primary transfer roller 34 receives a supply of a preset primary transfer current and transfers the toner image formed on the surface of the photosensitive drum 31 onto the outer circumferential surface of the intermediate transfer belt 26. As shown in Fig. 3, the primary transfer roller 34 is disposed opposite the photosensitive drum 31 with the intermediate transfer belt 26 sandwiched therebetween.

[0032] The drum cleaning unit 35 removes the toner remaining on the surface of the photosensitive drum 31 after the toner image has been transferred by the primary transfer roller 34 .

[0033] The optical scanning device 25 emits light based on the print data X10 toward the surface of the photosensitive drum 31 of each image forming unit 20.

[0034] The intermediate transfer belt 26 is an endless belt member onto which the toner image formed on the surface of the photosensitive drum 31 of each image forming unit 20 is transferred. The intermediate transfer belt 26 is stretched with a predetermined tension by a drive roller 26A (see FIG. 3) and a tension roller 26B (see FIG. 3). The intermediate transfer belt 26 rotates in a belt rotation direction D5 shown in FIG. 3 when the drive roller 26A rotates due to a rotational driving force supplied from a motor (not shown). As a result, the intermediate transfer belt 26 transports the toner image transferred from each photosensitive drum 31 to a transfer position onto a sheet by a secondary transfer roller 27. The intermediate transfer belt 26 is an example of an image carrier of the present invention. After the toner image to be transferred is transferred by the secondary transfer roller 27, the outer peripheral surface of the intermediate transfer belt 26 is cleaned by a belt cleaning unit 26C (see FIG. 3).

[0035] The secondary transfer roller 27 receives a supply of a preset secondary transfer current and transfers the toner image to be transferred, of the toner images transported by the intermediate transfer belt 26, onto a sheet in contact with the intermediate transfer belt 26. As shown in FIG. 3, the secondary transfer roller 27 is disposed opposite the drive roller 26A with the intermediate transfer belt 26 sandwiched therebetween. The secondary transfer roller 27 is urged toward the drive roller 26A by an urging member (not shown). This forms a transfer nip portion that pinches the sheet between the secondary transfer roller 27 and the intermediate transfer belt 26. The toner image to be transferred, transported by the intermediate transfer belt 26, is transferred to the sheet in contact with the intermediate transfer belt 26 at the transfer nip portion. The secondary transfer roller 27 is an example of a transfer portion of the present invention.

[0036] As shown in FIG. 4, the size of the secondary transfer roller 27 in the axial direction (left-right direction D3) is smaller than the width (size in the left-right direction D3) of the intermediate transfer belt 26. Therefore, a non-contact area RE12 (see FIG. 4) that does not come into contact with the secondary transfer roller 27 is generated on the outer circumferential surface of the intermediate transfer belt 26. The non-contact area RE12 is an area outside the roller contact area RE11 (see FIG. 4) that comes into contact with the secondary transfer roller 27 on the outer circumferential surface of the intermediate transfer belt 26, and includes the ends of the intermediate transfer belt 26 in the width direction. The toner image to be transferred is transferred to the roller contact area RE11. Furthermore, the test toner image is transferred to the non-contact area RE12.

[0037] The fixing device 28 fixes the transferred toner image, which has been transferred onto the sheet by the secondary transfer roller 27, onto the sheet.

[0038] The sheet onto which the transferred toner image has been fixed by the fixing device 28 is discharged to a paper discharge tray 29 .

[0039] The density sensors 41 are provided corresponding to the respective non-contact areas RE12 (see FIG. 4) on the outer circumferential surface of the intermediate transfer belt 26. The density sensors 41 detect the density of the test toner images transferred to the non-contact areas RE12 of the intermediate transfer belt 26. For example, the density sensors 41 are reflective photosensors including a light-emitting element that emits light toward the non-contact areas RE12 of the intermediate transfer belt 26 and a light-receiving element that receives the light emitted from the light-emitting element and reflected by the non-contact areas RE12 of the intermediate transfer belt 26. As shown in FIG. 3, the density sensors 41 are disposed downstream in the belt rotation direction D5 of the transfer position (the transfer nip) of the transferred toner images by the secondary transfer roller 27 and upstream in the belt rotation direction D5 of the cleaning position of the outer circumferential surface of the intermediate transfer belt 26 by the belt cleaning unit 26C. The density sensors 41 input an electrical signal corresponding to the density of the test toner images to the control unit 7. The control unit 7 adjusts the image forming conditions, such as the developing bias voltage and the amount of light emitted from the optical scanning device 25, based on the detection result of the density of the test toner image by the density sensor 41.

[0040] [Configuration of image processing unit 8] Next, the configuration of the image processing unit 8 will be described with reference to FIG.

[0041] 2, the image processing unit 8 includes a generation processing unit 51, a movement processing unit 52, a determination processing unit 53, a removal processing unit 54, and an addition processing unit 55. The CPU 11 of the control unit 7 may function as each of the above-mentioned processing units by executing the control program stored in the ROM 12.

[0042] The generation processing unit 51 generates print data X10 (an example of image data of the present invention) used to form the toner image.

[0043] Fig. 6 shows an example of print data X10 generated by the generation processing unit 51. Note that in Fig. 6, the boundaries of the first region RE21, the pair of second regions RE22, and the third region RE23 are indicated by dashed lines. Also, in Fig. 6, the formation target image X11 is hatched.

[0044] As shown in FIG. 6, the printing data X10 includes a first region RE21, a pair of second regions RE22, and a third region RE23. The first region RE21 corresponds to the roller contact region RE11 (see FIG. 4) of the intermediate transfer belt 26. Each of the second regions RE22 corresponds to a non-contact region RE12 (see FIG. 4) of the intermediate transfer belt 26. The third region RE23 corresponds to the sheet contact region RE13 (see FIG. 4) of the intermediate transfer belt 26 that comes into contact with the sheet. The third region RE23 is set based on the size of the sheet used for printing. The third region RE23 is set at the center of the main scanning direction D6 (see FIG. 6) of the printing data X10. The main scanning direction D6 is the direction corresponding to the width direction (left-right direction D3) of the intermediate transfer belt 26.

[0045] 6, the print data X10 also includes a target image X11 corresponding to the toner image to be transferred. The target image X11 is positioned at the center of the sheet contact area RE13.

[0046] The area of ​​the print data X10 outside the image to be formed X11 is made up of colorless pixels, which are pixels that are not developed with toner.

[0047] For example, when a printing process is executed to form an image on a sheet, the control unit 7 inputs image data including a target image X11 to be printed to the image processing unit 8. When image data including the target image X11 is input from the control unit 7, the generation processing unit 51 generates printing data X10 based on the target image X11 included in the image data. Note that when the target image X11 includes a margin area, the generation processing unit 51 may generate printing data X10 based on the target image X11 from which the margin area has been removed.

[0048] The movement processing unit 52 moves, within the printing data X10, a formation target image X11 that corresponds to the toner image to be transferred and is included in the printing data X10 used to form the toner image.

[0049] Specifically, the movement processing unit 52 moves the image to be formed X11 along the main scanning direction D6.

[0050] The movement processing unit 52 also moves the formation target image X11 based on the amount of movement set in advance by the user's operation on the operation display unit 5.

[0051] However, when the image to be formed X11 is moved toward the end of the main scanning direction D6 in the printing data X10, the transferred toner image based on the image to be formed X11 after the movement may extend beyond the sheet contact area RE13 (see Figure 4) where the intermediate transfer belt 26 comes into contact with the sheet.

[0052] However, conventionally, there has been no configuration capable of determining whether the transferred toner image based on the image to be formed X11 after movement extends beyond the sheet contact area RE13 on the intermediate transfer belt .

[0053] In contrast to this, the image forming apparatus 100 according to the embodiment of the present invention can determine whether the transferred toner image extends outside the sheet contact area RE13 on the intermediate transfer belt 26, as will be described below.

[0054] The determination processing unit 53 determines whether the transferred toner image based on the image to be formed X11 after movement by the movement processing unit 52 protrudes from a sheet contact area RE13 (an example of a contact area of ​​the present invention) on the intermediate transfer belt 26 that contacts the sheet.

[0055] Specifically, when the image to be formed X11 after movement by the movement processing unit 52 extends beyond the third area RE23 (see Figure 7), the judgment processing unit 53 determines that the transferred toner image based on the image to be formed X11 after movement by the movement processing unit 52 extends beyond the sheet contact area RE13 on the intermediate transfer belt 26.

[0056] When the judgment processing unit 53 determines that the transferred toner image extends beyond the sheet contact area RE13, the cutting processing unit 54 cuts out a partial image of the transferred toner image in the image to be formed X11 that corresponds to the portion that extends beyond the sheet contact area RE13.

[0057] Specifically, the cutting processing unit 54 identifies a portion of the target image X11 that extends beyond the third region RE23 as the partial image, and cuts out the identified partial image. More specifically, the cutting processing unit 54 replaces the pixels that make up the identified partial image with the colorless pixels. Note that in Figure 8, the cut-out partial image is indicated by a dotted line.

[0058] The addition processing unit 55 adds a test image X12 corresponding to the test toner image to the second region RE22 in the print data X10 generated by the generation processing unit 51.

[0059] For example, the test image X12 is a monochrome rectangular image (see FIG. 9). Note that in FIG. 9, the test image X12 is hatched.

[0060] For example, the addition processing unit 55 adds the test image X12 to each second region RE22 (see FIG. 9).

[0061] [Print data output processing] 5, an example of the procedure of the print data output process executed by the image processing unit 8 in the image forming apparatus 100 will be described along with the determination method of the present invention. Here, steps S11, S12, etc. represent the numbers of the processing procedures (steps) executed by the image processing unit 8. Note that the image processing unit 8 executes the print data output process when image data including the image to be formed X11 is input from the control unit 7.

[0062] <Step S11> First, in step S11, the image processing unit 8 generates print data X10. The process of step S11 is executed by the generation processing unit 51 of the image processing unit 8.

[0063] Specifically, the image processing unit 8 generates print data X10 (see FIG. 6) based on the image to be formed X11 included in the image data input from the control unit 7.

[0064] <Step S12> In step S12, the image processing unit 8 moves the image to be formed X11 along the main scanning direction D6 based on the amount of movement previously set by the user's operation on the operation display unit 5. The processing of step S12 is an example of a movement step of the present invention, and is executed by the movement processing unit 52 of the image processing unit 8.

[0065] <Step S13> In step S13, the image processing unit 8 determines whether the transferred toner image based on the image to be formed X11 after the movement in step S12 protrudes from the sheet contact area RE13 on the intermediate transfer belt 26. The process in step S13 is an example of a determination step of the present invention, and is executed by the determination processing unit 53 of the image processing unit 8.

[0066] Specifically, when the image to be formed X11 after movement by the processing of step S12 protrudes from the third area RE23 (see Figure 7), the image processing unit 8 determines that the transferred toner image based on the image to be formed X11 after movement protrudes from the sheet contact area RE13.

[0067] Here, if the image processing unit 8 determines that the transferred toner image based on the moved image to be formed X11 will extend beyond the sheet contact area RE13 (Yes in S13), it shifts the process to step S14. On the other hand, if the transferred toner image based on the moved image to be formed X11 will not extend beyond the sheet contact area RE13 (No in S13), the image processing unit 8 shifts the process to step S15.

[0068] <Step S14> In step S14, the image processing unit 8 cuts out the partial image corresponding to the protruding portion of the toner image in the image to be formed X11 that protrudes from the sheet contact area RE13. The process of step S14 is executed by the cutting processing unit 54 of the image processing unit 8.

[0069] In addition, instead of processing step S14, the image processing unit 8 may perform a process of moving the image to be formed X11 in the direction opposite to the movement direction in the processing step S12 so that the image to be formed X11 fits inside the third region RE23.

[0070] Alternatively, instead of the process of step S14, the image processing unit 8 may execute a process of notifying the control unit 7 that the transferred toner image based on the moved image to be formed X11 will extend outside the sheet contact area RE13. In this case, when the control unit 7 receives the notification from the image processing unit 8, it may stop the printing process and notify the user that the transferred toner image based on the moved image to be formed X11 will extend outside the sheet contact area RE13.

[0071] <Step S15> In step S15, the image processing unit 8 adds the test image X12 (see FIG. 9) to the second region RE22 in the printing data X10 generated by the processing in step S11. The processing in step S15 is executed by the addition processing unit 55 of the image processing unit 8.

[0072] <Step S16> In step S16, the image processing unit 8 outputs the print data X10 to which the test image X12 has been added.

[0073] Specifically, the image processing unit 8 separates the print data X10 into color component data corresponding to each color of YCMK, and outputs the four color component data.

[0074] The printing data X10 output by the processing of step S16 is input to the image forming unit 3. In the image forming unit 3, the toner images including the transferred toner image and the test toner image are formed based on the input printing data X10.

[0075] In this way, the image forming apparatus 100 can determine, based on the printing data X10 including the image X11 to be formed after movement by the movement processing unit 52, whether the transferred toner image based on the image X11 to be formed after movement will extend beyond the sheet contact area RE13 on the intermediate transfer belt 26.

[0076] The movement processing unit 52 may move the image to be formed X11 along the sub-scanning direction that is perpendicular to the main scanning direction D6.

[0077] [Notes on the Invention] The following is a summary of the invention extracted from the above-described embodiment. Note that the configurations and processing functions described in the following supplementary notes can be selected and combined as desired.

[0078] <Appendix 1> an image forming apparatus comprising: an image carrier that transports a toner image including a toner image to be transferred to a sheet; a transfer unit that transfers the toner image transported by the image carrier to the sheet that comes into contact with the image carrier; a movement processing unit that moves within image data an image to be formed that corresponds to the toner image to be transferred and is included in image data used to form the toner image; and a judgment processing unit that judges whether the toner image to be transferred, based on the image to be formed after movement by the movement processing unit, extends beyond the contact area on the image carrier that comes into contact with the sheet.

[0079] <Appendix 2> The image forming apparatus described in Appendix 1 is provided with an excision processing unit that, when the judgment processing unit determines that the transferred toner image extends beyond the contact area, excises a partial image of the transferred toner image in the image to be formed that corresponds to the portion that extends beyond the contact area.

[0080] <Appendix 3> A determination method executed in an image forming apparatus equipped with an image carrier that transports a toner image including a transfer toner image to be transferred to a sheet, and a transfer unit that transfers the transfer toner image transported by the image carrier to the sheet that comes into contact with the image carrier, the determination method including: a moving step that moves within the image data an image to be formed that corresponds to the transfer toner image contained in image data used to form the toner image; and a determination step that determines whether the transfer toner image based on the image to be formed after movement by the moving step extends beyond the contact area on the image carrier that comes into contact with the sheet. [Explanation of symbols]

[0081] 1 ADF 2 Image reading unit 3 Image forming unit 4 Paper feed section 5 Operation display section 6 Memory section 7 Control Unit 8 Image processing section 20 Image forming unit 25 Optical scanning device 26 Intermediate transfer belt 27 Secondary transfer roller 28 Fixing device 29 Paper output tray 31 Photosensitive drum 32 Charging roller 33 Developing device 34 Primary transfer roller 35 Drum Cleaning Department 36 Toner container 41 Concentration sensor 51 Generation processing unit 52 Movement processing section 53 Judgment processing unit 54 Excision processing section 55 Additional processing section 100 Image forming device

Claims

1. an image carrier that carries a toner image including a toner image to be transferred onto a sheet; a transfer section that transfers the toner image to be transferred, which is conveyed by the image carrier, onto the sheet that is in contact with the image carrier; a movement processing unit that moves, within image data, a formation target image corresponding to the toner image to be transferred that is included in image data used to form the toner image; a determination processing unit that determines whether the toner image to be transferred based on the image to be formed after the movement by the movement processing unit extends beyond a contact area of ​​the image carrier that contacts the sheet; An image forming apparatus comprising:

2. a cutting processing unit that cuts out a partial image corresponding to a protruding portion of the toner image in the image to be formed that protrudes from the contact area when the determination processing unit determines that the toner image protrudes from the contact area, The image forming apparatus according to claim 1 .

3. A determination method executed in an image forming apparatus including an image carrier that conveys a toner image including a toner image to be transferred onto a sheet, and a transfer unit that transfers the toner image conveyed by the image carrier onto the sheet that comes into contact with the image carrier, a moving step of moving, within the image data, a formation target image corresponding to the toner image to be transferred, which is included in the image data used to form the toner image; a determining step of determining whether or not the toner image to be transferred based on the image to be formed after the movement in the moving step extends beyond a contact area of ​​the image carrier that contacts the sheet; A determination method including:

Images