Image forming apparatus, color adjustment method and program

Abstract

To suppress unnecessary consumption of color materials and improve operability. [Solution] The image forming device includes an image forming unit capable of forming images in multiple colors on paper (recording medium), and a control unit that performs color adjustment for the image forming unit. The control unit determines the type of paper held in a paper feed unit (supply unit) to be supplied to the image forming unit (step S2). The control unit switches the color adjustment to be performed before inputting a job depending on the type of paper (steps S3 to S6). For example, the control unit switches the target color for color adjustment depending on the type of paper.

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus, a color adjustment method, and a program. [Background technology]

[0002] The image forming apparatus performs color adjustment on the image forming unit when starting up, when returning from power saving mode, when auto-resetting, etc. Color adjustment includes, for example, density correction, halftone correction, color registration correction, etc. After color adjustment is complete, the image forming apparatus performs image formation operations such as copying and printing. The image forming apparatus performs color adjustment for each color of color material (toner, ink, etc.) used in the image forming unit.

[0003] Such color adjustment is generally performed for all colors, so in the case of black and white output, the image forming operation must wait until the color adjustment is completed, even though color adjustment is not necessary.

[0004] Patent Document 1 discloses a technology that allows a user to set color output or monochrome output as a default setting depending on the user's usage situation. The image forming device described in Patent Document 1 performs color color adjustment at startup when the default setting is color output. In this case, the image forming device can immediately start image formation regardless of whether the input job is color or monochrome. On the other hand, if the default setting is monochrome output, this image forming device does not perform color color adjustment at startup, thereby reducing processing time and color material consumption. In this state, if a color output job is input, the image forming device performs color color adjustment before executing the job. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-244829 Summary of the Invention [Problem to be solved by the invention]

[0006] However, depending on the type of recording medium on which an image is formed, color adjustment may not be necessary. For example, if the recording medium is an envelope, embossed paper, or the like, monochrome printing is typically assumed, and color printing is unlikely. With the technology described in Patent Document 1, even if only recording media that do not require color adjustment are installed at startup, color adjustment is always performed if the default setting is color output. This results in unnecessary consumption of color materials and the image formation operation having to wait until color adjustment is complete.

[0007] The present invention has been made in consideration of the above-mentioned problems in the prior art, and aims to reduce the wasteful consumption of color materials and improve operability. [Means for solving the problem]

[0008] In order to solve the above problem, the invention described in claim 1 is an image forming apparatus comprising an image forming unit capable of forming an image on a recording medium in multiple colors, and a control unit that performs color adjustment for the image forming unit, wherein the control unit switches the color adjustment to be performed before a job is input depending on the type of recording medium held in a supply unit to be supplied to the image forming unit.

[0009] In a second aspect of the present invention, in the image forming apparatus of the first aspect, the control unit switches the target color for the color adjustment depending on the type of the recording medium.

[0010] In a third aspect of the present invention, in the image forming apparatus of the first aspect, the control unit switches whether or not to perform the color adjustment depending on the type of the recording medium.

[0011] The invention described in claim 4 is the image forming apparatus described in claim 1, wherein the control unit acquires the type of recording medium held in the supply unit from setting information in which the type of recording medium is pre-set.

[0012] In a fifth aspect of the present invention, in the image forming apparatus of the first aspect, the control unit determines the type of the recording medium based on a detection result of a detection unit that detects the type of the recording medium.

[0013] The invention described in claim 6 is the image forming apparatus described in claim 1, wherein when multiple types of recording media are held in the supply section, the control section switches the color adjustment according to the multiple types of recording media.

[0014] The invention described in claim 7 is the image forming apparatus described in claim 1, wherein when the recording medium is replaced in the supply unit, the control unit performs the color adjustment according to the type of recording medium after the replacement.

[0015] The invention described in claim 8 is an image forming apparatus according to claim 1, further comprising a memory unit that stores the color adjustment contents for each type of recording medium, and the control unit switches the color adjustment according to the color adjustment contents stored in the memory unit depending on the type of recording medium.

[0016] In a ninth aspect of the present invention, in the image forming apparatus of the third aspect, the control unit does not perform the color adjustment when the type of the recording medium is an envelope, a postcard, carbonless paper, or book paper.

[0017] In a tenth aspect of the present invention, in the image forming apparatus according to the ninth aspect, the color adjustment is color registration correction.

[0018] In an eleventh aspect of the present invention, in the image forming apparatus according to the second aspect, the control unit reduces the number of target colors for color adjustment when the type of the recording medium is an envelope, a postcard, carbonless paper, or book paper.

[0019] The invention described in claim 12 is the image forming apparatus described in claim 2, wherein the control unit performs the color adjustment using black as the target color for the color adjustment when the type of the recording medium is an envelope, a postcard, carbonless paper, or book paper.

[0020] The invention described in claim 13 is the image forming apparatus described in claim 2, wherein when the type of the recording medium is colored paper, transparent paper, or metallized paper, the control unit performs the color adjustment by using white as the target color for the color adjustment in addition to yellow, magenta, cyan, and black.

[0021] In the image forming apparatus of the present invention, the color adjustment includes at least one of maximum density correction, halftone correction, toner refresh, and color registration correction.

[0022] In the image forming apparatus of claim 15, the period before the job is input includes at least one of when the image forming apparatus is started, when the image forming apparatus is returned from a power saving mode, and when the image forming apparatus is auto-reset.

[0023] The invention described in claim 16 is a color adjustment method for performing color adjustment on an image forming unit in an image forming apparatus equipped with an image forming unit capable of forming an image on a recording medium in multiple colors, in which the color adjustment to be performed before inputting a job is switched depending on the type of recording medium held in a supply unit to be supplied to the image forming unit.

[0024] The invention described in claim 17 is a program for causing a computer of an image forming device equipped with an image forming unit capable of forming images on a recording medium in multiple colors to function as a control unit that performs color adjustment for the image forming unit, wherein the control unit switches the color adjustment to be performed before a job is input depending on the type of recording medium held in a supply unit to be supplied to the image forming unit. [Effects of the Invention]

[0025] According to the present invention, it is possible to suppress unnecessary consumption of color materials and improve operability. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a schematic diagram illustrating the configuration of an image forming apparatus according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram showing a functional configuration of the image forming apparatus. [Figure 3] FIG. 10 is a diagram illustrating an example of the data configuration of a target color table. [Figure 4] 10 is a flowchart showing a first color adjustment process. [Figure 5] 10A and 10B are diagrams showing examples of combinations of the types of paper stored in each paper feed tray and the target colors for color adjustment determined comprehensively for a plurality of types of paper; [Figure 6] FIG. 11 is a diagram illustrating an example of the data configuration of an itemized table in the second embodiment. [Figure 7] 10 is a flowchart showing a second color adjustment process. [Figure 8] 10 is a flowchart showing a color registration correction determination process. [Figure 9] FIG. 1 is a schematic diagram illustrating the configuration of an image forming apparatus that uses roll paper. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Advantages and features provided by the embodiments will be understood from the following detailed description and drawings. However, the scope of the present invention is not limited to the embodiments disclosed below or the examples shown in the drawings.

[0028] [First embodiment] First, a first embodiment of the image forming apparatus according to the present invention will be described. 1 is a schematic diagram of an image forming apparatus 100. The image forming apparatus 100 forms an image on a recording medium, such as paper, using an electrophotographic method. The image forming apparatus 100 forms an image based on image data obtained by reading an image from an original document or image data received from an external device. The image forming apparatus 100 includes an operation unit 10, a display unit 20, an original document reading unit 30, an image forming unit 40, a paper feed unit 50, media sensors 61, 62, and 63, an image reading unit 70, and the like.

[0029] The operation unit 10 outputs an operation signal based on a user's operation to the control unit 81 (see FIG. 2). The operation unit 10 includes various operation keys and a touch screen. The various operation keys accept various operations from the user. The touch screen is formed to cover the display screen of the display unit 20. The touch screen accepts touch operations on the display screen and detects the touch position.

[0030] The display unit 20 is configured by an LCD (Liquid Crystal Display). The display unit 20 displays various screens in accordance with instructions of a display signal input from the control unit 81.

[0031] The document reading unit 30 includes an ADF (automatic document feeder), a scanner, etc. The document reading unit 30 reads the image of the document and outputs the image data obtained to the control unit 81.

[0032] The image forming unit 40 forms an image on paper supplied from the paper feed unit 50. The image forming unit 40 forms an image using color materials (toners) for the usual process colors of yellow (Y), magenta (M), cyan (C), and black (K), as well as white (W) as a special color. In other words, the image forming unit 40 is capable of forming images on paper in multiple colors. The image forming unit 40 includes photoconductor drums 41Y, 41M, 41C, 41K, and 41W corresponding to the colors yellow, magenta, cyan, black, and white, respectively. The image forming unit 40 further includes an intermediate transfer belt 42, a secondary transfer roller 43, a fixing unit 44, and the like.

[0033] After being uniformly charged, the photosensitive drum 41Y is scanned and exposed to a laser beam based on yellow image data to form an electrostatic latent image, which is then developed by a developing unit that applies yellow toner to the electrostatic latent image on the photosensitive drum 41Y. The photosensitive drums 41M, 41C, 41K, and 41W are similar to the photosensitive drum 41Y except for the colors they handle, and therefore, a description thereof will be omitted.

[0034] The toner images of each color formed on the photosensitive drums 41Y, 41M, 41C, 41K, and 41W are transferred one by one (primary transfer) onto the rotating intermediate transfer belt 42. That is, a color toner image in which toner images of up to five colors are superimposed can be formed on the intermediate transfer belt 42. The toner images on the intermediate transfer belt 42 are transferred all at once onto a sheet of paper by the secondary transfer roller 43 (secondary transfer).

[0035] The fixing unit 44 fixes the toner image to the paper by applying heat and pressure. The fixing unit 44 includes a heating roller and a pressure roller. The heating roller heats the paper onto which the toner image has been transferred. The pressure roller presses the paper onto which the toner image has been transferred.

[0036] The paper feed unit 50 (supply unit) includes paper feed trays 51, 52, and 53, and supplies paper to the image forming unit 40. Paper feed trays 51, 52, and 53 store paper of predetermined paper types and sizes for each paper feed tray. The paper feed unit 50 holds paper to supply to the image forming unit 40.

[0037] Media sensors 61, 62, and 63 are provided in paper feed trays 51, 52, and 53 of paper feed unit 50, respectively. Media sensors 61, 62, and 63 are detection units that detect the type of paper held in paper feed trays 51, 52, and 53. Media sensors 61, 62, and 63 detect the physical properties of the paper and output the detection results to control unit 81. Paper physical properties include paper color, basis weight, surface roughness, material, etc.

[0038] Instead of media sensors 61, 62, and 63, media sensor 64 may be provided on the transport path after the sheets transported from paper feed trays 51, 52, and 53 join (see FIG. 1). In this case, only one media sensor 64 is required. However, when detecting the physical properties of the paper using media sensor 64, the paper needs to be transported from paper feed trays 51, 52, and 53 to the position of media sensor 64.

[0039] The image reading unit 70 is provided downstream of the image forming unit 40. The image reading unit 70 reads an image on paper and outputs read image data to the control unit 81. The image reading unit 70 is a color sensor that receives light emitted from a light source and reflected by the surface of the paper with a light receiving element and outputs a signal according to the intensity of the light. The image reading unit 70 is configured as a line sensor in which multiple light receiving elements are arranged at predetermined intervals in a direction perpendicular to the paper transport direction. For example, during color adjustment, the image reading unit 70 reads a color adjustment image formed on the paper and generates read image data. The color adjustment image includes patch images of each color, gradation patterns, etc.

[0040] FIG. 2 is a block diagram showing the functional configuration of the image forming apparatus 100. As shown in FIG. 2, the image forming apparatus 100 includes an operation unit 10, a display unit 20, a document reading unit 30, an image forming unit 40, a paper feeding unit 50, media sensors 61, 62, and 63, an image reading unit 70, a control unit 81, a storage unit 82, a communication unit 83, and a conveying unit 84. Note that a description of the functional units that have already been described will be omitted.

[0041] The control unit 81 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), etc. The CPU of the control unit 81 reads out various processing programs stored in the storage unit 82 and loads them into the RAM. The CPU of the control unit 81 executes various processes in accordance with the loaded programs.

[0042] The storage unit 82 is a non-volatile storage device such as a hard disk, a flash memory, etc. The storage unit 82 stores various programs executed by the control unit 81 and various data required for executing the programs.

[0043] The storage unit 82 stores a target color table T1. 3 shows an example of the data configuration of the target color table T1. In the target color table T1, paper types are associated with target colors for color adjustment. That is, the storage unit 82 (target color table T1) stores color adjustment details for each paper type. In the first embodiment, the target color for color adjustment is used as the color adjustment details. Note that for envelopes and postcards, the color adjustment details may differ depending on whether they are on the address side or not.

[0044] The communication unit 83 transmits and receives data to and from external devices connected to a communication network such as a LAN (Local Area Network).

[0045] Conveying section 84 includes a conveying roller for conveying paper. Conveying section 84 conveys paper within image forming apparatus 100. Conveying section 84 supplies paper stored in paper feed trays 51, 52, and 53 of paper feed section 50 to image forming section 40. Conveying section 84 ejects paper after image formation to the outside of image forming apparatus 100.

[0046] The control unit 81 performs color adjustment on the image forming unit 40. Color adjustment is a process for adjusting colors. However, adjustment of a single color (for example, black) is also called "color adjustment." Color adjustment includes generating a lookup table used for color conversion, updating adjustment values ​​for various parameters, and the like. The color adjustment includes at least one of maximum density correction, halftone correction, toner refresh, and color registration correction.

[0047] The maximum density correction includes density adjustment to correct the maximum density of each color forming an image. The control unit 81 controls the image forming unit 40 to form an image for maximum density correction for each color on paper. For example, a patch image of each color is used as the image for maximum density correction. The control unit 81 obtains read image data obtained by reading the image for maximum density correction from the image reading unit 70. The control unit 81 corrects the maximum density of each color based on the read image data of the image for maximum density correction.

[0048] Halftone correction is a process for correcting the halftone gradation of each color forming an image. The control unit 81 controls the image forming unit 40 to form an image for halftone correction of each color on paper. For example, a gradation pattern including patch images of a plurality of different gradations is used as the image for halftone correction. The control unit 81 obtains read image data obtained by reading the image for halftone correction from the image reading unit 70. The control unit 81 corrects the halftone of each color based on the read image data of the image for halftone correction.

[0049] Toner refresh is a process in which the toner contained in the developing unit of the image forming unit 40 is discharged in the amount that should be discharged and replaced with new toner.

[0050] Color registration correction is a process for correcting misalignment of the image positions of each color that forms an image. The control unit 81 controls the image forming unit 40 to form an image for color registration correction on paper. For example, an image including thin lines of each color is used as the image for color registration correction. The control unit 81 acquires read image data obtained by reading the image for color registration correction from the image reading unit 70. The control unit 81 corrects the misalignment of the image positions of each color based on the read image data of the image for color registration correction.

[0051] The control unit 81 switches the color adjustment to be performed before a job is input depending on the type of paper held in the paper feed unit 50. "Color adjustment to be performed before a job is input" refers to color adjustment that is performed before a job for image formation is input, by operation from the operation unit 10 or by receiving data via the communication unit 83. In other words, "color adjustment to be performed before a job is input" is not color adjustment that is performed after the job has been input and the contents of the job have been recognized.

[0052] The period before a job is input includes at least one of when the image forming apparatus 100 is started, when the image forming apparatus 100 returns from a power saving mode, and when the image forming apparatus 100 is auto-reset. The start-up of the image forming apparatus 100 is when the power to the image forming apparatus 100 is turned on. The power saving mode is a mode for reducing power consumption of the image forming apparatus 100. For example, when a predetermined time has passed without any operation being performed on the image forming apparatus 100, the image forming apparatus 100 transitions to the power saving mode. When a predetermined operation is performed on the image forming apparatus 100 in the power saving mode, the image forming apparatus 100 returns from the power saving mode to the normal mode. When a predetermined time has passed without any operation being performed on the image forming apparatus 100, the various conditions that have been set are reset. This automatic reset is called auto-reset.

[0053] The control unit 81 determines the type of paper based on the detection results of the media sensors 61, 62, and 63 that detect the type of paper. The control unit 81 switches the target color for color adjustment depending on the type of paper.

[0054] The control unit 81 switches the color adjustment depending on the paper type and in accordance with the adjustment contents of the color adjustment stored in the storage unit 82. Specifically, the control unit 81 acquires the target color for color adjustment corresponding to the paper type from the target color table T1, and performs color adjustment on the target color.

[0055] When the type of paper is an envelope, a postcard, carbonless paper, or book paper, the control unit 81 reduces the number of target colors for color adjustment. When the paper type is an envelope, postcard, carbonless paper, or book paper, the control unit 81 performs color adjustment using black as the target color for color adjustment. For envelopes, postcards, carbonless paper, and book paper, images are generally formed in black alone. When the paper type is colored paper, transparent paper, or metallized paper, the control unit 81 performs color adjustment using white as the target color in addition to yellow, magenta, cyan, and black. For colored paper, transparent paper, and metallized paper, forming a white layer on the image base has the effect of improving the color reproduction of the image (whiteout printing).

[0056] Next, the operation of the image forming apparatus 100 of the first embodiment will be described. 4 is a flowchart showing the first color adjustment process executed in image forming apparatus 100. This process is realized by software processing in cooperation between the CPU of control unit 81 and a program stored in storage unit 82.

[0057] The control unit 81 detects that the image forming apparatus 100 is powered on (step S1). Here, the timing to start the process will be described using the start-up of the image forming apparatus 100 as an example. Instead of step S1, the control unit 81 may detect the return from the power saving mode or the auto-reset.

[0058] Next, the control unit 81 causes the media sensors 61, 62, and 63 to detect the types of paper stored in the paper feed trays 51, 52, and 53 of the paper feed unit 50 (step S2). Specifically, the control unit 81 acquires the detection results from each of the media sensors 61, 62, and 63. The control unit 81 determines the type of paper based on the detection results.

[0059] Next, the control unit 81 refers to a target color table T1 (see FIG. 3) stored in the storage unit 82 to determine the target color for color adjustment (step S3). For example, if the paper type is "colored paper," "transparent paper / transparent film," or "metallized paper / hologram film," the control unit 81 determines the target color for color adjustment to be "YMCK+W (full color and white)." If the paper type is "envelope," "postcard," "carbonless paper / copy paper," or "book paper," the control unit 81 determines the target color for color adjustment to be "K (black)." If the paper type is "other paper," the control unit 81 determines the target color for color adjustment to be "YMCK (full color)."

[0060] In step S3, if the target color for color adjustment is "YMCK+W" (step S3; YMCK+W), the control unit 81 performs color adjustment for yellow, magenta, cyan, black, and white (step S4). For example, the control unit 81 performs maximum density correction, halftone correction, toner refresh, color registration correction, etc. for yellow, magenta, cyan, black, and white.

[0061] In step S3, if the target color for color adjustment is "YMCK" (step S3; YMCK), the control unit 81 performs color adjustment for yellow, magenta, cyan, and black (step S5).

[0062] In step S3, if the target color for color adjustment is "K" (step S3; K), the control unit 81 performs color adjustment on black (step S6). After step S4, step S5, or step S6, the first color adjustment process ends.

[0063] As described above, according to the first embodiment, the control unit 81 of the image forming apparatus 100 switches the color adjustment to be performed before a job is input depending on the type of paper held in the paper feed unit 50. The control unit 81 can reduce unnecessary consumption of color materials by not performing unnecessary color adjustment depending on the type of paper. For example, the control unit 81 can reduce consumption of toner for forming a color adjustment image and toner discharged during toner refresh. Furthermore, by not performing unnecessary color adjustment depending on the type of paper, the control unit 81 can shorten processing time and avoid making the user wait unnecessarily. Therefore, the control unit 81 can efficiently perform color adjustment and improve operability.

[0064] The control unit 81 switches the target color for color adjustment depending on the type of paper. By not performing color adjustment on colors that are not normally used depending on the type of paper, the control unit 81 can reduce unnecessary consumption of color materials and improve operability.

[0065] The control unit 81 determines the type of paper based on the detection results of the media sensors 61, 62, and 63 that detect the type of paper. Because the media sensors 61, 62, and 63 detect the type of paper actually stored in the paper feed trays 51, 52, and 53, the control unit 81 can accurately determine the type of paper.

[0066] The control unit 81 switches the color adjustment according to the type of paper and in accordance with the adjustment contents of the color adjustment stored in the storage unit 82 (target color table T1). By referencing the target color table T1, the control unit 81 can easily determine the adjustment contents of the color adjustment corresponding to the type of paper.

[0067] For example, when the paper type is an envelope, postcard, carbonless paper, or book paper, the control unit 81 reduces the number of colors to be adjusted. In particular, when the paper type is an envelope, postcard, carbonless paper, or book paper, the control unit 81 performs color adjustment using black as the color to be adjusted. Thus, the control unit 81 can reduce unnecessary consumption of color materials and improve operability.

[0068] Furthermore, when the type of paper is colored paper, transparent paper, or metallized paper, the control unit 81 performs color adjustment using white as the target color in addition to yellow, magenta, cyan, and black. For paper on which white is often used, the control unit 81 sets white as the target color for color adjustment, thereby enabling image formation to be performed immediately when a job is input.

[0069] In the paper feed unit 50 of the image forming apparatus 100, the "types of paper" stored in the paper feed trays 51, 52, and 53 may be different from each other. When multiple types of paper are held in the paper feed unit 50, the control unit 81 switches the color adjustment to be performed before the job is input depending on the multiple types of paper.

[0070] 5 shows an example of a combination of the "paper type" stored in each of paper feed trays 51, 52, and 53 and the "target color for color adjustment" determined comprehensively for multiple types of paper. Specifically, control unit 81 obtains the "target color for color adjustment" corresponding to the "paper type" from target color table T1 for each of paper feed trays 51, 52, and 53. Then, control unit 81 determines the "target color for color adjustment" for the entire paper feed unit 50 so that it includes all of the obtained "target colors for color adjustment."

[0071] 5, a case will be described in which the paper in paper feed tray 51 is "envelope," the paper in paper feed tray 52 is "postcard," and the paper in paper feed tray 53 is "colored paper." According to target color table T1, the "target color for color adjustment" corresponding to "envelope" is "K," the "target color for color adjustment" corresponding to "postcard" is "K," and the "target color for color adjustment" corresponding to "colored paper" is "YMCK+W." Therefore, control unit 81 determines that the "target color for color adjustment" for the entire paper feed unit 50 is "YMCK+W." The control unit 81 can perform the minimum necessary color adjustment in the image forming apparatus 100 that can use multiple types of paper.

[0072] [Second embodiment] Next, a second embodiment to which the present invention is applied will be described. The image forming apparatus of the second embodiment has a configuration similar to that of the image forming apparatus 100 shown in the first embodiment. Therefore, the same components as those in the first embodiment are designated by the same reference numerals, and illustrations and descriptions thereof will be omitted. The configuration and processing characteristic of the second embodiment will be described below.

[0073] The storage unit 82 stores an itemized table T2. FIG. 6 shows an example of the data configuration of item table T2. In item table T2, for each color adjustment item, a paper type is associated with information indicating whether or not color adjustment is to be performed. Furthermore, in item table T2, when color adjustment is to be performed for a color adjustment item, the target color for color adjustment is stored. In other words, the storage unit 82 (item table T2) stores the adjustment details for color adjustment for each paper type. In the second embodiment, the color adjustment item and target color are used as the adjustment details for color adjustment. Note that in item table T2, when it is set to perform color adjustment, the target color for color adjustment is stored instead of "perform"

[0074] The control unit 81 switches the color adjustment to be performed before the job is input, depending on the type of paper held in the paper feed unit 50. The control unit 81 switches whether or not to perform color adjustment depending on the type of paper.

[0075] The control unit 81 switches color adjustment according to the adjustment content of color adjustment stored in the storage unit 82 depending on the paper type. Specifically, the control unit 81 references the item-specific table T2 and determines for each color adjustment item according to the paper type whether or not to perform color adjustment corresponding to the item. The control unit 81 further obtains from the item-specific table T2 the target color for color adjustment corresponding to the paper type for the item for which color adjustment is to be performed, and performs color adjustment for the target color.

[0076] The control unit 81 does not perform color adjustment if the paper type is an envelope, postcard, carbonless paper, or book paper. Specifically, the control unit 81 does not perform color registration correction if the paper type is an envelope, postcard, carbonless paper, or book paper. Images are often formed in monochrome black on envelopes, postcards, carbonless paper, and book paper.

[0077] Next, the operation of the image forming apparatus 100 of the second embodiment will be described. 7 is a flowchart showing the second color adjustment process executed in image forming apparatus 100. This process is realized by software processing in cooperation between the CPU of control unit 81 and a program stored in storage unit 82.

[0078] The processing in steps S11 and S12 is similar to the processing in steps S1 and S2 of the first color adjustment processing (see FIG. 4), and therefore a description thereof will be omitted.

[0079] Next, the control unit 81 performs maximum density correction for the color corresponding to the paper type (step S13). Specifically, the control unit 81 references the item-specific table T2 and acquires the "target color for maximum density correction" from the "maximum density correction" field corresponding to the "paper type." The control unit 81 performs maximum density correction for this "target color for maximum density correction."

[0080] Next, the control unit 81 performs halftone correction on the color corresponding to the paper type (step S14). Specifically, the control unit 81 references the item-specific table T2 and acquires the "target color for halftone correction" from the "halftone correction" field corresponding to the "paper type." The control unit 81 performs halftone correction on this "target color for halftone correction."

[0081] Next, the control unit 81 performs toner refresh for the color corresponding to the paper type (step S15). Specifically, the control unit 81 references the item-specific table T2 and acquires the "target color for toner refresh" from the "toner refresh" field corresponding to the "paper type." The control unit 81 performs toner refresh for this "target color for toner refresh."

[0082] Next, the control unit 81 executes a color registration correction determination process (step S16). The color registration correction determination process will be described with reference to FIG. The control unit 81 determines whether or not to perform color registration correction (step S21). Specifically, the control unit 81 references the item-specific table T2, and if the "color registration correction" field corresponding to the "paper type" is "not performed," it determines not to perform color registration correction. The control unit 81 references the item-specific table T2, and if the "color registration correction" field corresponding to the "paper type" is anything other than "not performed," it determines to perform color registration correction.

[0083] If color registration correction is to be performed (step S21; YES), the control unit 81 performs color registration correction for the color corresponding to the paper type (step S22). Specifically, the control unit 81 references the item-specific table T2 and acquires the "target color for color registration correction" from the "color registration correction" field corresponding to the "paper type." The control unit 81 performs color registration correction for this "target color for color registration correction."

[0084] After step S22, or in step S21, if color registration correction is not performed (step S21; NO), the color registration correction determination process ends. After the color registration correction determination process, the process returns to FIG. 7, and the second color adjustment process ends.

[0085] As described above, according to the second embodiment, the control unit 81 of the image forming apparatus 100 switches whether or not to perform color adjustment depending on the type of paper. By not performing color adjustment for colors that are not normally used depending on the type of paper, the control unit 81 can reduce unnecessary consumption of color materials and improve operability.

[0086] The control unit 81 switches the color adjustment according to the type of paper and in accordance with the adjustment contents of the color adjustment stored in the storage unit 82 (item-specific table T2). Specifically, the control unit 81 can easily determine the adjustment contents of the color adjustment corresponding to the type of paper by referring to the item-specific table T2.

[0087] The control unit 81 does not perform color adjustment when the paper type is an envelope, postcard, carbonless paper, or book paper. The control unit 81 does not perform color registration correction when the paper type is an envelope, postcard, carbonless paper, or book paper. Therefore, the control unit 81 can reduce unnecessary consumption of color materials and improve operability.

[0088] The above-described embodiments are merely examples of the image forming apparatus, color adjustment method, and program according to the present invention, and the present invention is not limited to these. The detailed configuration and operation of each part constituting the apparatus may be modified as appropriate without departing from the spirit of the present invention. For example, characteristic processes in each embodiment may be combined and executed.

[0089] In the above-described embodiments, the control unit 81 of the image forming apparatus 100 determines the type of paper based on the detection results of the media sensors 61, 62, and 63. Alternatively, the types of paper stored in the paper feed trays 51, 52, and 53 may be stored in advance in the storage unit 82. For example, the types of paper stored in the paper feed unit 50 for each of the paper feed trays 51, 52, and 53 are set in advance as setting information in the storage unit 82. The setting information may be changeable by a user's operation on the operation unit 10. The control unit 81 obtains the types of paper stored in each of the paper feed trays 51, 52, and 53 from the setting information stored in the storage unit 82. Specifically, instead of step S2 of the first color adjustment process (FIG. 4), the control unit 81 may obtain the types of paper stored in each of the paper feed trays 51, 52, and 53 from the setting information stored in the storage unit 82. In addition, instead of step S12 of the second color adjustment process (Figure 7), the control unit 81 may obtain the type of paper stored in each of the paper feed trays 51, 52, and 53 from the setting information stored in the memory unit 82.

[0090] Furthermore, when paper is replaced in the paper feed unit 50, the control unit 81 of the image forming apparatus 100 may perform color adjustment according to the type of paper after the replacement. For example, an open / close detection sensor is provided in each of the paper feed trays 51, 52, and 53 of the image forming apparatus 100. The open / close detection sensor detects whether the paper feed tray 51, 52, or 53 is open or closed. When the open / close detection sensor detects that the paper feed tray 51, 52, or 53 has been opened and then closed, the control unit 81 determines that paper has been replaced in the paper feed tray 51, 52, or 53. Specifically, when paper is replaced in the paper feed unit 50, the control unit 81 may perform step S2 and subsequent steps of the first color adjustment process (see FIG. 4). When paper is replaced in the paper feed unit 50, the control unit 81 may perform step S12 and subsequent steps of the second color adjustment process (see FIG. 7). The control unit 81 can efficiently perform color adjustment at the timing when there is a possibility that the paper type has been changed.

[0091] Furthermore, the timing at which the control unit 81 of the image forming apparatus 100 switches the color adjustment does not have to coincide with the timing at which the color adjustment is performed. That is, the control unit 81 may determine whether or not to perform the color adjustment or the target color for the color adjustment according to the type of paper before the timing at which the color adjustment is performed. Then, when the timing to perform the color adjustment arrives, the control unit 81 may perform or not perform the color adjustment according to the determined content.

[0092] In addition, in the above-described embodiments, the electrophotographic image forming apparatus 100 has been described. However, the present invention may be applied to an image forming apparatus other than the electrophotographic image forming apparatus. An example of an image forming apparatus other than the electrophotographic image forming apparatus is an inkjet image forming apparatus. However, the toner refresh function of the color adjustment is limited to the electrophotographic image forming apparatus 100.

[0093] In addition, in each of the above embodiments, in maximum density correction, halftone correction, and color registration correction, the control unit 81 controls the image forming unit 40 to form a color adjustment image on paper, and obtains read image data obtained by reading the color adjustment image from the image reading unit 70. Alternatively, the control unit 81 may control the image forming unit 40 to form the color adjustment images on the photosensitive drums 41Y, 41M, 41C, 41K, and 41W. In this case, the image reading unit 70 is provided at a position where the images formed on the photosensitive drums 41Y, 41M, 41C, 41K, and 41W are read. The control unit 81 obtains read image data obtained by reading the color adjustment images from the image reading unit 70, and performs various color adjustments based on the read image data of the color adjustment images. Alternatively, the control unit 81 may control the image forming unit 40 to form the color adjustment image on the intermediate transfer belt 42. In this case, the image reading unit 70 is provided at a position where the image formed on the intermediate transfer belt 42 is read. The control unit 81 obtains read image data obtained by reading the color adjustment image from the image reading unit 70, and performs various color adjustments based on the read image data of the color adjustment image.

[0094] In the above embodiments, the paper on which an image is formed is a sheet of paper. Alternatively, the paper on which an image is formed may be roll paper (continuous paper). FIG. 9 shows a schematic configuration of an image forming apparatus 200 that uses roll paper. In image forming apparatus 200, the same components as those in image forming apparatus 100 are designated by the same reference numerals, and a description thereof will be omitted. The functional configuration of image forming apparatus 200 is substantially the same as that of image forming apparatus 100 shown in FIG. 2, and therefore FIG. 2 will be used. Below, the parts of image forming apparatus 200 that are different from image forming apparatus 100 will be described.

[0095] Image forming apparatus 200 includes a paper feed section 50A and a winding section 90 instead of paper feed section 50 of image forming apparatus 100. Image forming apparatus 200 includes a media sensor 65 instead of media sensors 61, 62, and 63 of image forming apparatus 100.

[0096] The paper feed unit 50A (supply unit) supplies roll paper to the image forming unit 40. The paper feed unit 50A sends out the roll paper wound around a support shaft 54 ​​to the image forming unit 40. The image forming unit 40 forms an image on the roll paper. The winding unit 90 winds the roll paper, on which the image has been formed by the image forming unit 40, around a support shaft 91. The media sensor 65 detects the physical properties of the roll paper sent from the paper feed unit 50A to the image forming unit 40, and outputs the detection results to the control unit 81.

[0097] In image forming apparatus 200, only one type of roll paper (recording medium) is held in paper feed unit 50A. Therefore, this does not apply to image forming apparatus 200 when multiple types of paper are held in paper feed unit 50A.

[0098] The computer-readable medium for storing the program for executing each process is not limited to the above examples. A carrier wave may also be used as a medium for providing program data via a communication line.

[0099] The above-disclosed embodiments are for the purpose of explanation and example only, and are not intended to be limiting. The scope of the present invention should be interpreted by the claims. [Explanation of symbols]

[0100] 10 Control section 20 Display section 30 Document reading unit 40 Image forming unit 41Y, 41M, 41C, 41K, 41W Photoconductor drum 42 Intermediate transfer belt 43 Secondary transfer roller 44 Fixing section 50 Paper feed section 51, 52, 53 Paper tray 61, 62, 63 Media Sensor 70 Image reading unit 81 Control Unit 82 Memory section 83 Communications Department 84 Conveyor 100 Image forming device T1 Target Color Table T2 Itemized table

Claims

1. an image forming unit capable of forming an image on a recording medium in a plurality of colors; a control unit that performs color adjustment for the image forming unit; Equipped with The control unit switches color adjustment to be performed before a job is input in accordance with the type of recording medium held in a supply unit to be supplied to the image forming unit.

2. The image forming apparatus according to claim 1 , wherein the control unit switches the target color for the color adjustment depending on the type of the recording medium.

3. The image forming apparatus according to claim 1 , wherein the control unit switches whether or not to perform the color adjustment depending on the type of the recording medium.

4. The image forming apparatus according to claim 1 , wherein the control unit acquires the type of recording medium held in the supply unit from setting information in which the type of recording medium is preset.

5. 2. The image forming apparatus according to claim 1, wherein the control unit determines the type of the recording medium based on a detection result of a detection unit that detects the type of the recording medium.

6. The image forming apparatus according to claim 1 , wherein, when the supply unit holds a plurality of types of recording media, the control unit switches the color adjustment in accordance with the plurality of types of recording media.

7. The image forming apparatus according to claim 1 , wherein, when the recording medium is replaced in the supply unit, the control unit performs the color adjustment in accordance with the type of the recording medium after the replacement.

8. a storage unit for storing the color adjustment details for each type of recording medium; 2. The image forming apparatus according to claim 1, wherein the control unit switches the color adjustment in accordance with the adjustment contents of the color adjustment stored in the storage unit, depending on the type of the recording medium.

9. 4. The image forming apparatus according to claim 3, wherein the control unit does not perform the color adjustment when the type of the recording medium is an envelope, a postcard, carbonless paper, or book paper.

10. 10. The image forming apparatus according to claim 9, wherein the color adjustment is color registration correction.

11. The image forming apparatus according to claim 2 , wherein the control unit reduces the number of target colors for the color adjustment when the type of the recording medium is an envelope, a postcard, carbonless paper, or book paper.

12. 3. The image forming apparatus according to claim 2, wherein the control unit performs the color adjustment using black as a target color for the color adjustment when the type of the recording medium is an envelope, a postcard, carbonless paper, or book paper.

13. 3. The image forming apparatus according to claim 2, wherein the control unit performs the color adjustment by adjusting white in addition to yellow, magenta, cyan, and black when the type of the recording medium is colored paper, transparent paper, or metallized paper.

14. 2. The image forming apparatus according to claim 1, wherein the color adjustment includes at least one of maximum density correction, halftone correction, toner refresh, and color registration correction.

15. 2. The image forming apparatus according to claim 1, wherein the period before the job is input includes at least one of when the image forming apparatus is started, when the image forming apparatus is returned from a power saving mode, and when the image forming apparatus is auto-reset.

16. 1. A color adjustment method for performing color adjustment on an image forming apparatus equipped with an image forming unit capable of forming an image on a recording medium in a plurality of colors, the method comprising: A color adjustment method in which color adjustment performed before input of a job is switched depending on the type of recording medium held in a supply unit to be supplied to the image forming unit.

17. A computer of an image forming apparatus having an image forming unit capable of forming an image on a recording medium in a plurality of colors, A program for causing the image forming unit to function as a control unit that performs color adjustment for the image forming unit, The control unit is a program for switching color adjustment to be performed before a job is input, depending on the type of recording medium held in a supply unit to be supplied to the image forming unit.

Images