Image forming apparatus and image forming method

Abstract

To provide an image forming apparatus capable of suppressing wasteful consumption of ink.SOLUTION: The image forming apparatus 100 includes an image forming unit 3, a reading unit 54, a determination unit 61, a specifying unit 62, and an inspection unit 63. The inspection unit 63 inspects the image forming unit 3. The image forming unit 3 includes a plurality of nozzle groups 31, each of the plurality of nozzle groups 31 includes a plurality of nozzles 32, each of the plurality of nozzle groups 31 discharges an ink of a different color, and the inspection unit 63 uses the nozzle group 31 that discharges the ink of the color specified by the specifying unit 62 to: An image forming part 3 is controlled to form a check image on a check sheet S, a reading part 54 is controlled to read the check image formed on the check sheet S, and a specifying part 62 specifies an abnormal nozzle 3 among a plurality of nozzles 3 included in a nozzle group 31 based on the check image read by the reading part 54.SELECTED DRAWING: Figure 6

Description

[Technical Field]

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

[0002] 2. Description of the Related Art Conventionally, inkjet image forming devices have been known as one type of image forming device, which have multiple nozzles that eject ink, and form an image on paper by ejecting ink from the multiple nozzles onto a recording medium such as paper.

[0003] In image forming devices, if ink cannot be ejected normally from the nozzles during printing (hereinafter referred to as "ejection failure"), the ejected ink may become non-uniform. This can result in defects (faults) such as low ink adhesion density in some areas on the paper (called "white streaks"), no ink adhesion at all (called "white out"), or high ink adhesion density (called "black streaks").

[0004] Therefore, a technique is known in which a test chart for detecting ejection defects is printed on paper to detect the ejection defects (see, for example, Patent Document 1). The image forming apparatus described in Patent Document 1 includes an image forming unit, a reading unit, a content defect detection unit, a chart defect detection unit, and a chart defect processing unit.

[0005] The image forming unit forms a content image and a test chart on paper using ink ejected from an ejection unit that ejects ink toward the paper. The reading unit generates a scanned image by reading the image formed on the paper. The content defect detection unit determines whether or not there is a defect in the content image of the scanned image generated by the reading unit. The chart defect detection unit determines whether or not there is a defect in the test chart of the scanned image. If it is determined that there is a defect in the test chart of the scanned image, the chart defect processing unit performs processing to suppress ejection defects on subsequent paper. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2021-104606 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the image forming device described in Patent Document 1 only determines whether or not there are defects in the content image of the scanned image generated by the reading unit, but does not identify the color of the ink that is ejected improperly in the content image, which results in a large amount of ink being consumed for the test chart.

[0008] The present invention has been made in view of the above-mentioned problems, and has an object to provide an image forming apparatus and an image forming method that can suppress the wasteful consumption of ink. [Means for solving the problem]

[0009] The image forming apparatus according to the present invention includes an image forming unit, a reading unit, a determination unit, an identification unit, and an inspection unit. The image forming unit forms a color image on a sheet using ink of multiple colors. The reading unit reads the color image formed on the sheet. The determination unit determines whether or not the color image has a defect based on the color image read by the reading unit. When the determination unit determines that the color image has a defect, the identification unit identifies the color of the ink of the multiple colors that is ejecting improperly. The inspection unit inspects the image forming unit. The image forming unit has a plurality of nozzle groups, each of which has a plurality of nozzles and ejects ink of a different color, and the inspection unit controls the image forming unit to form a check image on a check sheet using the nozzle group that ejects ink of the color identified by the identification unit, and controls the reading unit to read the check image formed on the check sheet, and the identification unit identifies an abnormal nozzle from among the plurality of nozzles included in the nozzle group based on the check image read by the reading unit.

[0010] The image forming method of the present invention is an image forming method used in an image forming apparatus that includes an image forming unit that forms a color image on a sheet using multiple colors of ink, a reading unit that reads the color image formed on the sheet, a judgment unit that determines whether the color image has a defect based on the color image read by the reading unit, an identification unit that, when the judgment unit determines that the color image has a defect, identifies the color of ink from among the multiple colors of ink that is ejecting poorly, and an inspection unit that inspects the image forming unit, wherein the image forming unit includes multiple nozzle groups, each of which has multiple nozzles, and each of the multiple nozzle groups ejects ink of a different color, and the image forming method includes a step of controlling the image forming unit to form a check image on a check sheet using the nozzle group that ejects the ink of the color identified by the identification unit, a step of controlling the reading unit to read the check image formed on the check sheet, and a step of the identification unit identifying an abnormal nozzle from among the multiple nozzles included in the nozzle groups based on the check image read by the reading unit. [Effects of the Invention]

[0011] According to the present invention, it is possible to suppress wasteful consumption of ink. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a diagram illustrating a configuration of an inkjet recording apparatus according to an embodiment of the present invention. [Figure 2] FIG. 2 is a plan view of an image forming unit according to the embodiment. [Figure 3] FIG. 2 is a plan view of the conveyor belt according to the embodiment. [Figure 4] This is an example of a sheet on which a color image without defects is formed. [Figure 5] 1 is an example of a sheet of paper on which a defective color image is formed. [Figure 6] 1 is a block diagram of an inkjet recording apparatus according to an embodiment of the present invention. [Figure 7]10 is an example of a check sheet on which a check image without defects is formed. [Figure 8] 10 is an example of a check sheet on which a defective check image is formed. [Figure 9] 5 is a flowchart illustrating an example of the operation of the inkjet recording apparatus according to the present embodiment. [Figure 10] 10 is a flowchart showing another example of the operation of the inkjet recording apparatus according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated. In addition, the drawings mainly show each component in a schematic manner for ease of understanding.

[0014] An inkjet recording apparatus 100 according to an embodiment of the present invention will be described with reference to FIG. 1. FIG. 1 is a diagram showing the configuration of the inkjet recording apparatus 100 according to an embodiment of the present invention. The inkjet recording apparatus 100 is an example of an "image forming apparatus." The X, Y, and Z directions in the figure are perpendicular to one another. The X and Y directions are parallel to the horizontal direction, and the Z direction is parallel to the vertical direction.

[0015] 1, the inkjet recording apparatus 100 is a multifunction peripheral. The inkjet recording apparatus 100 may also be a printer, a copier, or a facsimile machine. A multifunction peripheral has at least two functions, for example, a copy function, a printer function, and a facsimile function.

[0016] The inkjet recording apparatus 100 forms an image on the front and back sides of a sheet of paper S. The sheet of paper S is a sheet having a front and back side. The sheet of paper S may be, for example, plain paper, copy paper, recycled paper, thin paper, thick paper, glossy paper, or overhead projector (OHP) paper.

[0017] Specifically, the inkjet recording apparatus 100 includes a housing 1, a paper feed unit 2, an image forming unit 3, an operation unit 4, a conveying unit 5, a reading unit 54, a control unit 6, and a suction unit 8.

[0018] The housing 1 accommodates therein a paper feed unit 2, an image forming unit 3, a conveying unit 5, a reading unit 54, a control unit 6, and a suction unit 8. The housing 1 is formed in a box shape.

[0019] The operation unit 4 outputs an operation signal to the control unit 6 in response to an operation by the user. The operation by the user includes, for example, an operation to start forming an image on the paper S. The operation unit 4 is disposed, for example, on the upper surface of the housing 1. The operation unit 4 includes, for example, a display. The display displays various screens. The operation unit 4 also has a touch panel function.

[0020] The paper feed unit 2 supplies paper S to the transport unit 5. The paper feed unit 2 has a paper feed cassette 21 and a manual feed tray (not shown). The paper feed cassette 21 is arranged at the bottom of the housing 1. The paper feed cassette 21 is detachably attached to the housing 1. Multiple sheets of paper S can be stored in a stacked state inside the paper feed cassette 21. A portion of the manual feed tray is exposed to the outside from the housing 1. Multiple sheets of paper S can be placed in a stacked state on the manual feed tray.

[0021] The transport unit 5 transports the paper S along a transport path. The transport unit 5 has, for example, multiple roller pairs 50 and a transport belt 51. The transport belt 51 forms part of the transport path for the paper S. The transport belt 51 transports the paper S to a position facing the image forming unit 3. The multiple roller pairs 50 and the transport belt 51 can send the paper S downstream in the transport direction of the transport path.

[0022] The transport section 5 is divided into a main transport section 52 and a sub-transport section 53. The main transport section 52 extends from the paper feed section 2 through the image forming section 3 to the discharge tray 11. The main transport section 52 transports the paper S in a first transport direction V1. The first transport direction V1 is the direction along the main transport section 52 from the paper feed section 2 through the image forming section 3 toward the discharge tray 11.

[0023] The sub-conveyor 53 branches off from the main conveyor 52 at a branching point P1. The branching point P1 is located on the conveyance path downstream of the image forming unit 3 in the first conveyance direction V1 and upstream of the discharge tray 11 in the first conveyance direction V1. The sub-conveyor 53 merges with the main conveyor 52 at a merging point P2. The merging point P2 is located on the conveyance path upstream of the image forming unit 3 in the first conveyance direction V1 and downstream of the paper feed unit 2 in the first conveyance direction V1. The sub-conveyor 53 extends from the branching point P1 to the merging point P2. The sub-conveyor 53 conveys the sheet S in the second conveyance direction V2. The second conveyance direction V2 is the direction from the branching point P1 toward the merging point P2 along the sub-conveyor 53. The sheet S conveyed by the sub-conveyor 53 is switched back, and the front and back sides of the sheet S are reversed.

[0024] In this embodiment, the reading unit 54 is disposed downstream of the junction P2 in the first transport direction V1 and upstream of the image forming unit 3 in the first transport direction V1, but the location of the reading unit 54 is not particularly limited. The reading unit 54 is disposed alongside the conveyor belt 51 facing the image forming unit 3. The reading unit 54, for example, reads the width in the first transport direction V1 of the paper sheet S sent from the paper feed unit 2 and conveyed by the main conveyor unit 52. The reading unit 54 generates image data indicating the read width of the paper sheet S and outputs the image data to the control unit 6. The control unit 6 determines, for example, the size of the paper sheet S based on the image data indicating the width of the paper sheet S.

[0025] The reading unit 54 also reads an image from the paper S. In this embodiment, the reading unit 54 reads an image from the paper S that has been reversed by the sub-conveyor unit 53 and transported to the junction P2. The reading unit 54 generates image data representing the read image and outputs it to the control unit 6. The reading unit 54 is, for example, a CIS (Contact Image Sensor) unit. The CIS unit has an LED (Light Emitting Diode), an imaging lens, and an image sensor.

[0026] Next, the configuration of the image forming unit 3 will be further described with reference to Fig. 2. Fig. 2 is a plan view of the image forming unit 3 according to this embodiment. As shown in Fig. 2, the image forming unit 3 forms an image on the surface of the paper S transported by the main transport unit 52.

[0027] The image forming unit 3 forms a color image (content image) on the paper S using multiple colors of ink. Specifically, the image forming unit 3 has color planes 31k, 31m, 31c, and 31y. The color planes 31k, 31m, 31c, and 31y are examples of "nozzle groups." The color planes 31k, 31m, 31c, and 31y form an image on the paper S using ink. The color planes 31k, 31m, 31c, and 31y include a color plane 31k corresponding to black, a color plane 31m corresponding to magenta, a color plane 31c corresponding to cyan, and a color plane 31y corresponding to yellow. The multiple color planes 31k, 31m, 31c, and 31y are arranged in this order from the upstream side to the downstream side in the first transport direction V1.

[0028] Color plane 31k is connected to a black ink tank. The nozzles 32 of color plane 31k eject black ink. Color plane 31m is connected to a magenta ink tank. The nozzles 32 of color plane 31m eject magenta ink. Color plane 31c is connected to a cyan ink tank. The nozzles 32 of color plane 31c eject cyan ink. Color plane 31y is connected to a yellow ink tank. The nozzles 32 of color plane 31y eject yellow ink.

[0029] In this embodiment, the multiple color planes 31k, 31m, 31c, and 31y are arranged in a staggered pattern for each color. Multiple nozzles 32 are arranged in each of the multiple color planes 31k, 31m, 31c, and 31y. Each of the multiple nozzles 32 ejects ink toward the paper S. More specifically, each of the multiple nozzles 32 ejects ink toward a landing position set on the paper S by the control unit 6.

[0030] Each of the color planes 31k, 31c, 31m, and 31y can employ an ink ejection method such as a piezoelectric method. In the piezoelectric method, ink is ejected using a piezoelectric element. More specifically, in the piezoelectric method, a pulse of a predetermined waveform is input to the piezoelectric element, causing the piezoelectric element to deform in response to the pulse. As a result, pressure due to the deformation of the piezoelectric element is transmitted to the ink in the nozzle 32, causing the ink meniscus to vibrate, thereby ejecting ink from the nozzle 32.

[0031] Next, the configuration of the conveyor belt 51 will be further described with reference to Fig. 3. Fig. 3 is a plan view of the conveyor belt 51 according to this embodiment. As shown in Fig. 3, the conveyor belt 51 has a plurality of openings 55 and a plurality of holes 56. The plurality of openings 55 and the plurality of holes 56 penetrate the front and back of the conveyor belt 51 in a first direction D1. The first direction D1 extends along the Z direction.

[0032] The hole 56 has a smaller opening area than the opening 55. A suction unit 8 is disposed on the first direction D1 side of the hole 56. The suction unit 8 has, for example, an intake fan that sucks in air. When the suction unit 8 is activated at the timing when an image is formed on the sheet S, air is sucked in the first direction D1 through the hole 56. During image formation, the sheet S is adsorbed to the surface (conveyance surface) of the conveyor belt 51 via the multiple hole 56.

[0033] The ejected ink passes through the opening 55 when flushing (cleaning) is performed. Flushing is a process for removing residue accumulated in the nozzles 32. In this embodiment, in order to remove residue accumulated in the nozzles 32, ink is ejected toward the opening 55 at a timing different from the timing for forming an image on the paper S. Specifically, when the conveyor belt 51 travels and the opening 55 comes to a position opposite the color planes 31k, 31c, 31m, and 31y, ink is ejected from the nozzles 32 toward the opening 55.

[0034] In a region of the conveyor belt 51 facing the nozzles 32, a suction unit 8 and a waste liquid device (not shown) are arranged on the first direction D1 side of the openings 55. The suction unit 8 sucks air in the first direction D1 through the multiple openings 55. When flushing is performed, ink ejected toward the openings 55 is sucked toward the openings 55 by the suction unit 8. The ink that has passed through the openings 55 is collected by the waste liquid device.

[0035] Next, an inkjet recording apparatus 100 according to this embodiment will be described with reference to Fig. 1 to Fig. 6. Fig. 4 shows an example of a sheet S on which a color image without defects has been formed. Fig. 5 shows an example of a sheet S on which a color image with defects has been formed. Fig. 6 is a block diagram of the inkjet recording apparatus 100 according to this embodiment.

[0036] As shown in Fig. 4, a cyan pentagonal star image, a magenta heptagonal star image, and a yellow tetragonal star image are formed on the paper S. On the other hand, as shown in Fig. 5, a cyan pentagonal star image, a magenta heptagonal star image, and a yellow tetragonal star image are formed on the paper S, but there are "whiteouts" in the cyan pentagonal star image.

[0037] As shown in FIG. 6, the control unit 6 includes, for example, a processor and a memory unit (not shown). The processor is, for example, a CPU (Central Processing Unit). The memory unit includes, for example, a semiconductor memory and an HDD (Hard Disk Drive). The processor controls the paper feed unit 2, image forming unit 3, operation unit 4, conveyance unit 5, suction unit 8, and reading unit 54 based on a computer program stored in the memory unit. The control unit 6 sets ink droplet positions on the paper S based on, for example, image data indicating an image to be formed on the paper S, and controls the image forming unit 3 to eject ink at the droplet positions set on the paper S.

[0038] Specifically, the control unit 6 further includes a determination unit 61, a specification unit 62, and an inspection unit 63.

[0039] The determination unit 61 determines whether or not the color image has a defect based on the color image read by the reading unit 54. For example, the determination unit 61 divides the reference image and the read image into specific regions, calculates the SSIM value of the reference image and the read image for each region, and determines that there is a defect if there is even one region where the SSIM value is equal to or greater than the threshold. Specifically, the determination unit 61 determines that there is no defect in the color image if there is no "white streak," "white gap," or "black streak" in the color image. Specifically, the determination unit 61 determines that there is no defect in the image shown in FIG. 4. On the other hand, the determination unit 61 determines that there is a defect in the color image if there is a "white streak," "white gap," or "black streak" in the color image. Specifically, the determination unit 61 determines that there is a defect in the image shown in FIG. 5.

[0040] When the determination unit 61 determines that there is a defect in the color image, the determination unit 62 determines the color of the ink that is ejecting improperly from among the multiple colors of ink. In detail, the determination unit 62 determines whether a normal image is formed with black ink. The determination unit 62 also determines whether a normal image is formed with magenta ink. The determination unit 62 then determines whether a normal image is formed with cyan ink. Furthermore, the determination unit 62 determines whether a normal image is formed with yellow ink. Specifically, the determination unit 62 determines that a normal image is not formed with cyan ink in the image shown in FIG. 5.

[0041] Next, the inspection unit 63 of the inkjet recording apparatus 100 according to this embodiment will be described with reference to Fig. 1 to Fig. 8. Fig. 7 shows an example of a check sheet S on which a check image without defects is formed. Fig. 8 shows an example of a check sheet S on which a check image with defects is formed.

[0042] As shown in FIG. 7, a cyan rectangular check image is formed on the check sheet S. The check sheet S is a sheet on which a check image is formed on paper S. The check image extends from one end of the check sheet S to the other in the Y direction. On the other hand, as shown in FIG. 8, a cyan rectangular check image is formed on the check sheet S, but there are "white spaces" in the cyan rectangular check image.

[0043] As shown in FIGS. 1 to 8 , the inspection unit 63 inspects the image forming unit 3. In particular, the inspection unit 63 controls the image forming unit 3 to form a check image on the check sheet S using a color plane that ejects ink of the color specified by the specification unit 62. Specifically, the inspection unit 63 controls the image forming unit 3 to form a check image on the check sheet S using a color plane 31c that ejects cyan ink specified by the specification unit 62. The inspection unit 63 also controls the reading unit 54 to read the check image formed on the check sheet S.

[0044] The identifying unit 62 identifies an abnormal nozzle from among the plurality of nozzles 32 included in the color plane 31 based on the check image read by the reading unit 64. Specifically, the identifying unit 62 identifies an abnormal nozzle from among the plurality of nozzles 32 included in the color plane 31c. For example, in the check image shown in FIG. 8, the position of the "white space" in the check image in the Y direction is the center, so the identifying unit 62 determines that the abnormal nozzle is the central nozzle from among the plurality of nozzles 32.

[0045] Therefore, according to this embodiment, a check image of the color having the ejection defect is formed on the check sheet S, thereby reducing the wasteful consumption of ink other than the color having the ejection defect. For example, according to this embodiment, a cyan check image is formed on the check sheet S, thereby reducing the wasteful consumption of black, magenta, and yellow ink. As a result, clogged nozzles can be efficiently identified, and defects in the color image can be reduced.

[0046] Next, an example of processing in the inkjet recording apparatus 100 according to this embodiment will be described with reference to Fig. 9. Fig. 9 is a flowchart showing an example of the operation of the inkjet recording apparatus 100 according to this embodiment. As shown in Fig. 9, the processing of the inkjet recording apparatus 100 includes steps S101 to S107. Steps S101 to S107 are executed by the processor of the inkjet recording apparatus 100 executing a computer program.

[0047] In step S101, the image forming unit 3 forms a color image on the paper S using ink of multiple colors.

[0048] In step S102, the reading unit 54 reads a color image from the paper S.

[0049] In step S103, the determination unit 61 determines whether or not the color image has a defect based on the color image read by the reading unit 54. If the determination unit 61 determines that the color image has no defect (No in step S103), the process ends. On the other hand, if the determination unit 61 determines that the color image has a defect (Yes in step S103), the process proceeds to step S104.

[0050] In step S104, the identifying unit 62 identifies the color of ink that is experiencing ejection defects from among the multiple colors of ink.

[0051] In step S105, the inspection unit 63 controls the image forming unit 3 to form a check image on the check sheet S using a color plane that ejects ink of the color specified by the specification unit 62.

[0052] In step S106, the inspection unit 63 controls the reading unit 54 to read the check image formed on the check sheet S.

[0053] In step S107, the identifying unit 62 identifies an abnormal nozzle from among the plurality of nozzles 32 included in the color plane 31 based on the check image read by the reading unit 64. Then, the process ends.

[0054] Therefore, according to this embodiment, it is possible to reduce wasteful consumption of ink other than the defectively ejected color, because a check image of the defectively ejected color is formed on the check sheet S. For example, according to this embodiment, it is possible to reduce wasteful consumption of black, magenta, and yellow ink, because a cyan check image is formed on the check sheet S.

[0055] Next, another example of processing in the inkjet recording apparatus 100 according to this embodiment will be described with reference to FIG. 10. FIG. 10 is a flowchart showing another example of the operation of the inkjet recording apparatus 100 according to this embodiment. As shown in FIG. 10, processing in the inkjet recording apparatus 100 includes steps S101 to S114. Steps S101 to S114 are executed by the processor of the inkjet recording apparatus 100 executing a computer program. Below, differences between the flowchart shown in FIG. 10 and the flowchart shown in FIG. 9 will be described, and explanations of parts that overlap with the flowchart shown in FIG. 9 will be omitted.

[0056] In step S108, the identifying unit 62 adjusts the nozzles 32 surrounding the abnormal nozzle 32. For example, the amount of ink ejected from the nozzles on both sides of the abnormal nozzle is increased.

[0057] In step S109, the image forming unit 3 forms a color image on the paper S using ink of multiple colors.

[0058] In step S110, the reading unit 54 reads a color image from the paper S.

[0059] In step S111, the determination unit 61 determines whether or not the color image has a defect based on the color image read by the reading unit 54. At this time, the determination unit 61 may store the color image read in step S102 in a storage unit and compare the color image stored in the storage unit to determine whether or not the defect has been improved. If the determination unit 61 determines that the color image has no defect (No in step S111), the process ends. On the other hand, if the determination unit 61 determines that the color image has a defect (Yes in step S111), the process proceeds to step S112.

[0060] In step S112, the specifying unit 62 issues a notification, for example, the specifying unit 62 causes the operation unit 4 to display a message that the recording head needs to be cleaned.

[0061] In step S113, the operation unit 4 determines whether or not an operation signal has been received. If the operation unit 4 determines that an operation signal has not been received (No in step S113), the processing ends. On the other hand, if the operation unit 4 determines that an operation signal has been received (Yes in step S113), the processing proceeds to step S114.

[0062] In step S114, the identifying unit 62 cleans the color plane 31 that contains the abnormal nozzle, and then the process ends.

[0063] Therefore, according to this embodiment, a check image of the color having the ejection defect is formed on the check sheet S, so that it is possible to suppress the wasteful consumption of ink other than the color having the ejection defect.

[0064] Furthermore, the specifying unit 62 adjusts the nozzles 32 around the abnormal nozzle 32, so that it is possible to prevent a defective color image from being formed on the paper S.

[0065] Furthermore, even if a color plane 31 including an adjusted nozzle 32 is used, if a defective color image is formed, a notification is issued, so that it is possible to further prevent a defective color image from being formed on the paper S.

[0066] Furthermore, if a defective color image is formed even when a color plane 31 including an adjusted nozzle 32 is used, the color plane 31 including the abnormal nozzle is cleaned, thereby further preventing a defective color image from being formed on the paper S.

[0067] The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the above embodiments and can be implemented in various forms without departing from the spirit of the present invention. For example, some components may be omitted from all components shown in the embodiments. The drawings mainly show each component in a schematic manner to facilitate understanding. Furthermore, the components shown in the above embodiments are merely examples and are not particularly limited, and various modifications are possible without substantially departing from the effects of the present invention. [Industrial Applicability]

[0068] The present invention can be used in an image forming apparatus. [Explanation of symbols]

[0069] 3 Image forming unit 6 Control Unit 8 Suction part 31 color planes (nozzle groups) 32 nozzles 51 Conveyor belt 54 Reading unit 55 Opening 61 Judgment section 62 Specific part 63 Inspection Department 100 Inkjet recording device (image forming device) S Paper (sheet)

Claims

1. an image forming unit that forms a color image on a sheet using ink of a plurality of colors; a reading unit that reads the color image formed on the sheet; a determination unit that determines whether or not the color image has a defect based on the color image read by the reading unit; an identifying unit that identifies a color of ink having a discharge defect from among the plurality of colors of ink when the determining unit determines that the color image has a defect; an inspection unit that inspects the image forming unit; Equipped with the image forming unit includes a plurality of nozzle groups, each of the plurality of nozzle groups includes a plurality of nozzles; The plurality of nozzle groups each eject ink of a different color, The inspection unit controlling the image forming unit to form a check image on a check sheet using a nozzle group that ejects ink of the color specified by the specifying unit; controlling the reading unit to read the check image formed on the check sheet; The identifying unit identifies an abnormal nozzle from among a plurality of nozzles included in the nozzle group based on the check image read by the reading unit.

2. The image forming apparatus according to claim 1 , wherein the identifying unit adjusts nozzles around the abnormal nozzle.

3. the image forming unit forms the color image on the sheet using a plurality of nozzle groups including the nozzles adjusted by the specifying unit; The reading unit reads the color image formed on the sheet, the determining unit determines whether or not the color image has a defect based on the color image read by the reading unit; The image forming apparatus according to claim 2 , wherein the specifying unit issues a notification when the determining unit determines that the color image has a defect.

4. the image forming unit forms the color image on the sheet using a plurality of nozzle groups including the nozzles adjusted by the specifying unit; The reading unit reads the color image formed on the sheet, the determining unit determines whether or not the color image has a defect based on the color image read by the reading unit; The image forming apparatus according to claim 2 , wherein the specifying unit cleans a nozzle group including the abnormal nozzle when the determining unit determines that the color image has a defect.

5. an image forming unit that forms a color image on a sheet using ink of a plurality of colors; a reading unit that reads the color image formed on the sheet; a determination unit that determines whether or not the color image has a defect based on the color image read by the reading unit; an identifying unit that identifies a color of ink having a discharge defect from among the plurality of colors of ink when the determining unit determines that the color image has a defect; an inspection unit that inspects the image forming unit; An image forming method used in an image forming apparatus comprising: the image forming unit includes a plurality of nozzle groups, each of the plurality of nozzle groups includes a plurality of nozzles; The plurality of nozzle groups each eject ink of a different color, controlling the image forming unit to form a check image on a check sheet using a nozzle group that ejects ink of the color specified by the specifying unit; controlling the reading unit to read the check image formed on the check sheet; the identifying unit identifies an abnormal nozzle from among a plurality of nozzles included in the nozzle group based on the check image read by the reading unit; An image forming method comprising:

Images