Image formation apparatus and method

Abstract

To enable appropriate placement of an adjustment pattern so as to avoid overlapping with a content image of a user.SOLUTION: An image formation apparatus comprises: image formation means which forms a user image on a sheet; reading means which reads the sheet to generate a read image; and control means which causes display means to display a preview screen related to the user image. The image formation means is capable of forming an adjustment pattern used for adjusting image formation conditions on the sheet together with the user image. The image formation conditions are adjusted on the basis of the detection results of the adjustment pattern in the read image. The control means causes an object representing the adjustment pattern to be displayed on the preview screen according to the placement of the adjustment pattern on the sheet. The control means changes the placement of the adjustment pattern on the sheet from one of the ends in the main scanning direction and the ends in the sub-scanning direction to the other in response to a user input.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present disclosure relates to an image forming apparatus and method.

Background Art

[0002] Conventionally, a technique is known in which a sheet on which an image is formed by an image forming apparatus is read by a reader, and image forming conditions are automatically adjusted based on the read image.

[0003] For example, Patent Document 1 discloses a technique of using a gamma curve generated based on the result of reading a gradation pattern formed on a sheet by an optical sensor for each of a plurality of color components constituting a color image to adjust the density output conditions of an image forming apparatus. Patent Document 1 shows an example in which a gradation pattern is formed in a peripheral region of a sheet that is assumed to be separated by cutting.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Depending on the user, content may be arranged in the peripheral region of the sheet. For example, the user may arrange codes (e.g., serial numbers, one-dimensional barcodes, or two-dimensional barcodes) used for job management or content management, or unique color patches, etc., in the peripheral region of the input image. If the pattern for adjusting the image forming conditions overlaps with the user's content on the sheet, it may cause a failure in adjusting the image forming conditions due to inaccurate reading of the pattern, or an adverse effect on job management or content management using the content image. Therefore, there has been a demand for a mechanism that enables the adjustment pattern to be appropriately arranged.

[0006] In view of the above circumstances, an object of the present invention is to provide a mechanism capable of appropriately arranging an adjustment pattern used for adjusting image formation conditions while avoiding overlap with a user's content image.

Means for Solving the Problems

[0007] According to one aspect, an image forming apparatus includes: an image forming unit that forms a user image on a sheet based on at least one image forming condition; a reading unit that optically reads the sheet to generate a read image; and a control unit that causes a display unit to display a preview screen related to the user image formed by the image forming unit. The image forming unit can form an adjustment pattern used for adjusting the at least one image forming condition on the sheet together with the user image. The adjustment pattern is arranged at an end in the main scanning direction of the sheet or an end in a sub-scanning direction orthogonal to the main scanning direction. The image forming apparatus further includes an adjustment unit that adjusts the at least one image forming condition based on a detection result of the adjustment pattern in the read image generated by the reading unit. The control unit causes a display object representing the adjustment pattern to be displayed on the preview screen according to the arrangement of the adjustment pattern on the sheet. The control unit changes the arrangement of the adjustment pattern on the sheet from one of the end in the main scanning direction and the end in the sub-scanning direction to the other in response to a user input instructing a change in the arrangement of the adjustment pattern, and causes the display object to be displayed on the preview screen according to the changed arrangement of the adjustment pattern. An image forming apparatus is provided. A corresponding method is also provided.

Advantages of the Invention

[0008] According to the present disclosure, it is possible to appropriately arrange the adjustment pattern so as to avoid overlap with the user's content image.

Brief Description of the Drawings

[0009]

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MODE FOR CARRYING OUT THE INVENTION

[0010] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims. Although a plurality of features are described in the embodiments, not all of these plurality of features are essential to the invention, and the plurality of features may be arbitrarily combined. Further, in the accompanying drawings, the same or similar configurations are denoted by the same reference numerals, and redundant descriptions are omitted.

[0011] <1. Overview of the System> FIG. 1 is a schematic diagram showing the configuration of a printing system 1 according to an embodiment. Referring to FIG. 1, the printing system 1 includes a host computer 10 and an image forming apparatus 100. The host computer 10 is connected to the image forming apparatus 100 via a network 20. The network 20 may be a wired communication network or a wireless communication network. For example, the network 20 may include one or more of a LAN (Local Area Network), a WAN (Wide Area Network), and a public communication line. Although FIG. 1 shows one host computer 10 and one image forming apparatus 100, the printing system 1 may include more host computers and image forming apparatuses.

[0012] The host computer 10 is a device that issues a printing job to be executed by the image forming apparatus 100. As an example, the host computer 10 may be a terminal device such as a PC (Personal Computer) or a smartphone having a user interface including a display. As another example, the host computer 10 may be a server device that receives a printing request from another terminal device (not shown) and issues a printing job. The printing job typically includes input image data representing a user image to be printed, as well as job parameters such as the number of copies to be printed, the type of sheet specified (e.g., size), and double-sided / single-sided.

[0013] The image forming apparatus 100 is an apparatus that executes a print job to form an image on a sheet. In the present embodiment, it is assumed that the image forming apparatus 100 is a color laser printer capable of printing a color image by an electrophotographic method. In other embodiments, the image forming apparatus 100 may be any other type of image forming apparatus such as a monochrome laser printer or an inkjet printer.

[0014] <2. Configuration of Image Forming Apparatus> As shown in FIG. 1, the image forming apparatus 100 includes an operation panel 110, a printer unit 120, a reader unit 150, a finisher 190, and a controller 200.

[0015] <2-1. Operation Panel> The operation panel 110 is a unit that provides a user interface (UI) including an input interface and an output interface. The input interface may include, for example, one or more of buttons, numeric keys, a touch panel, switches, and a microphone. The output interface may include, for example, one or more of a display, a speaker, and a lamp. The operation panel 110 receives user input via the input interface and outputs the received user input to the controller 200. Also, the operation panel 110 outputs information generated by the controller 200 via the output interface (for example, displays an image on the display or outputs sound from the speaker). The user can, for example, instruct the image forming apparatus 100 to execute a job and change job-related settings by operating the operation panel 110.

[0016] <2-2. Printer Unit> The printer unit 120 is an image forming means for forming an image on a sheet based on at least one image forming condition. In the example of FIG. 1, the printer unit 120 has paper feed trays 131, 132, image forming units 140Y, 140M, 140C, 140K, an intermediate transfer member 146, a transfer unit 147, a fixing unit 148, and a cleaner 149.

[0017] Each of the paper feed trays 131 and 132 accommodates a stack of sheets. Here, it is assumed that the paper feed tray 131 accommodates sheets of the first size (for example, A4), and the paper feed tray 132 accommodates sheets of the second size (for example, A5) smaller than the first size. Although two paper feed trays 131 and 132 are shown in FIG. 1, the number of paper feed trays provided in the image forming apparatus 100 is not limited to two. When a printing job is executed, the sheets are picked up one by one from the paper feed tray 131 or 132 (for example, the paper feed tray corresponding to the size specified by the job parameters) by the paper feed mechanism and conveyed along the conveyance path 133.

[0018] The image forming unit 140Y forms a yellow (Y) toner image on the intermediate transfer member 146. The image forming unit 140M forms a magenta (M) toner image on the intermediate transfer member 146. The image forming unit 140C forms a cyan (C) toner image on the intermediate transfer member 146. The image forming unit 140K forms a black (K) toner image on the intermediate transfer member 146. Since the image forming units 140Y, 140M, 140C, and 140K have the same configuration as each other, the configuration of the image forming unit 140Y will be described here as an example. The image forming unit 140Y includes a photosensitive drum 141, a charger 142, an exposure device 143, and a developing device 144. The photosensitive drum 141 is a drum-shaped photoreceptor having a photosensitive layer on its surface. The photosensitive drum 141 rotates about the drum axis in the direction of arrow R in the figure. The charger 142 uniformly charges the surface of the rotating photosensitive drum 141. The exposure device 143 irradiates the photosensitive drum 141 with laser light according to image data (here, representing a yellow image) input from the controller 200. The laser light output from the exposure device 143 scans the surface of the charged photosensitive drum 141 in the drum axis direction, thereby forming an electrostatic latent image on the surface of the photosensitive drum 141. In the following description, the direction in which the laser light scans (the depth direction in FIG. 1) is also referred to as the main scanning direction, and the direction orthogonal to the main scanning direction on the surface of the drum or sheet is also referred to as the sub-scanning direction. The developing device 144 supplies (here, yellow) toner to the surface of the photosensitive drum 141 to develop the electrostatic latent image on the photosensitive drum 141. As a result, a toner image is formed on the surface of the photosensitive drum 141. The yellow toner image formed on the surface of the photosensitive drum 141 in the image forming unit 140Y is transferred to the intermediate transfer member 146. Further, the magenta, cyan, and black toner images formed on the surfaces of the respective photosensitive drums 141 in the image forming units 140M, 140C, and 140K are transferred to the intermediate transfer member 146 in order in a manner that they overlap the yellow toner image. Thereby, a full-color toner image is formed on the intermediate transfer member 146. The intermediate transfer member 146 is an endless belt member and rotates in the clockwise direction in the figure. The intermediate transfer member 146 conveys the full-color toner image to the position of the transfer unit 147 (transfer nip).

[0019] The sheet picked up from the paper feed tray 131 or 132 is conveyed to the transfer nip in accordance with the timing at which the toner image on the intermediate transfer member 146 reaches the transfer nip under the control of the controller 200. The transfer unit 147 transfers the toner image carried on the intermediate transfer member 146 to the sheet at the transfer nip. The fixing device 148 includes a heater and a pressure roller. The fixing device 148 heats the toner image transferred to the sheet by the heater and applies pressure by the pressure roller. Thereby, the toner on the sheet melts and the toner image is fixed to the sheet. Although FIG. 1 shows an example in which the image forming apparatus 100 includes one fixing device 148, the image forming apparatus 100 may further include a second fixing device used, for example, for increasing gloss or improving fixability. The cleaner 149 is disposed on the downstream side of the transfer nip on the orbit of the intermediate transfer member 146 and removes the toner remaining on the intermediate transfer member 146 after the transfer of the toner image.

[0020] The conveyance path 133 branches into conveyance paths 134 and 135 downstream of the fixing device 148. The sheet that has passed through the fixing device 148 is once conveyed from the conveyance path 133 to the conveyance path 135. When the trailing edge of the sheet enters the conveyance path 135, the conveyance direction is reversed and the sheet is discharged from the discharge roller 137 to the reader unit 150. Through such conveyance, the sheet is discharged in a state where the surface on which the image is formed faces downward (referred to as face down). When double-sided printing is performed, the sheet that has entered the conveyance path 135 is conveyed to the conveyance path 136, returns from the conveyance path 136 to the conveyance path 133, and passes through the transfer nip again in a form where the front and back are reversed. A toner image is formed on the back surface of the sheet by the transfer unit 147 at the transfer nip, and the toner image is fixed to the sheet by the fixing device 148. The sheet with images formed on both sides is discharged from the discharge roller 137 to the reader unit 150.

[0021] In this embodiment, the image forming apparatus 100 has a function of automatically adjusting the image forming conditions in the printer unit 120. For automatic adjustment of the image forming conditions, the printer unit 120 can form one or more adjustment patterns on a sheet together with (or separately from) the user image. For example, the image forming conditions include conditions related to the density of the image formed by the printer unit 120. In this case, the adjustment pattern includes one or more gradation patterns used for automatic density adjustment. Automatic adjustment of the image forming conditions using such adjustment patterns will be described in detail later.

[0022] <2-3. Reader Unit> The reader unit 150 is a reading means for optically reading a sheet and generating a read image. In the example of FIG. 1, the reader unit 150 includes a conveyance path 151, conveyance rollers 152, an original sensor 153, a platen glass 154a, a platen glass 154b, conveyance rollers 155, a first line sensor 161a, a second line sensor 161b, a small spectroscopic sensor 162, a retraction tray 159, and a detection circuit 180. The conveyance roller 152 receives the sheet discharged from the image forming apparatus 100 and conveys the sheet along the conveyance path 151. The original sensor 153 may be a photo interrupter including, for example, a light emitting element and a light receiving element, and detects the leading edge of the sheet that has passed through the conveyance roller 152. The first line sensor 161a optically reads the lower surface of the sheet passing over the platen glass 154a to generate read image data, and outputs the generated read image data to the detection circuit 180. The second line sensor 161b optically reads the upper surface of the sheet passing under the platen glass 154b to generate read image data, and outputs the generated read image data to the detection circuit 180. The first line sensor 161a and the second line sensor 161b may be, for example, CIS (Contact Image Sensor). The timing at which the first line sensor 161a and the second line sensor 161b read the sheet can be controlled by the controller 200 based on the timing at which the original sensor 153 detects the leading edge of the sheet. In the following description, when it is not necessary to distinguish between the first line sensor 161a and the second line sensor 161b from each other, they are collectively referred to as the line sensor 161 by omitting the alphabet at the end of the reference numeral. The conveyance path 151 branches downstream of the second line sensor 161b into a path leading to the finisher 190 via the conveyance roller 155 and a path leading to the small spectroscopic sensor 162. A normal sheet on which a user image (and an adjustment pattern) is formed is conveyed to the former and discharged to the finisher 190 by the conveyance roller 155. When density unevenness correction in the main scanning direction described later is performed, a sheet on which a correction pattern is formed is conveyed to the latter. The small spectroscopic sensor 162 optically reads the correction pattern on this sheet. The sheet that has passed through the small spectroscopic sensor 162 is discharged to the retraction tray 159.

[0023] <2-4. Finisher> The finisher 190 is post-processing means for performing post-processing on the sheet on which the image is formed. In the present embodiment, the finisher 190 receives the sheet discharged from the reader unit 150, conveys the sheet along the internal conveyance path, and discharges it to either of the discharge trays 191 and 192 (for example, the discharge tray specified by the job parameters). The post-processing performed by the finisher 190 may include one or more of sorting, cutting, stapling, sorting, and binding. For example, when the finisher 190 has a cutting mechanism (not shown), the cutting mechanism cuts the sheet to a specified size and separates the peripheral region of the sheet. The cut pieces of the sheet can be discarded into a purge tray (not shown) inside the finisher 190.

[0024] <2-5. Controller> The controller 200 controls the overall operations of the image forming apparatus 100 described above. For example, when the execution of a print job is instructed by the user, the controller 200 controls the image forming apparatus 100 to form a user image on the sheet based on the input image data. Also, in the present embodiment, when it is determined that automatic adjustment should be performed, the controller 200 controls the printer unit 120 to form an adjustment pattern on the sheet. The automatic adjustment of the image forming conditions may be executed, for example, when instructed by the user, or when the execution timing arrives when it is set to be executed periodically. A more detailed configuration related to the automatic adjustment of the image forming conditions will be further described in the next section. In addition, in one embodiment, the controller 200 controls the printer unit 120 to form a correction pattern used for correcting density unevenness on the sheet prior to the execution of the print job. The configuration related to the correction of density unevenness will be further described later.

[0025] <3. Automatic Adjustment of Image Forming Conditions> <3-1. Detailed Configuration of Reader Unit> FIG. 2 is a block diagram showing an example of a more detailed configuration of a reader unit related to automatic adjustment of image forming conditions. Referring to FIG. 2, the reader unit 150 includes a document sensor 153, an image memory 156, a first line sensor unit 160a, a second line sensor unit 160b, a spectral sensor unit 160c, a detection circuit 180, and a measurement circuit 188. The first line sensor unit 160a includes a first line sensor 161a, a first analog-to-digital converter (ADC) 163a, and a memory 164a. The second line sensor unit 160b includes a second line sensor 161b, a second ADC 163b, and a memory 164b. The spectral sensor unit 160c includes a small spectral sensor 162, a third ADC 163c, and a memory 164c.

[0026] FIG. 3 is a schematic diagram showing an example of the configuration of the line sensor 161 (first line sensor 161a and second line sensor 161b). Referring to FIG. 3, the line sensor 161 includes light sources 171a and 171b, light guides 172a and 172b, a lens array 173, and a plurality of sensor chips 174a, 174b,... (also referred to as a sensor chip group 174). Each of the light sources 171a and 171b may be, for example, a light emitting diode (LED) that emits white light. The light guide 172a guides the light emitted from the light source 171a toward the sheet while diffusing it. The light guide 172b guides the light emitted from the light source 171b toward the sheet. The light guides 172a and 172b have linear optical paths parallel to the main scanning direction of the sheet, whereby the entire area of each line parallel to the main scanning direction of the sheet being conveyed is irradiated with white light. The lens array 173 is an optical system that forms an image of the white light reflected from the surface of the sheet on the light receiving surface of the sensor chip group 174. The sensor chip group 174 is a set of optical sensor chips arranged in a row along the main scanning direction of the sheet. In the present embodiment, the sensor chip group 174 includes three columns of color filters for three color components of red (R), green (G), and blue (B), and corresponding three columns of photoelectric conversion elements. Each photoelectric conversion element receives the color component light that has passed through the corresponding color filter and generates a corresponding electrical signal. As a result, the line sensor 161 outputs an analog image signal representing an RGB image of each line constituting the read image of the sheet while the sheet is passing through the read position.

[0027] Returning to FIG. 2, the first ADC 163a converts an analog image signal (representing a read image of the first surface of the sheet) input from the first line sensor 161a into read image data in digital format, and outputs the converted read image data to the detection circuit 180. The memory 164a stores correction values (for example, values corresponding to variations in the amount of light) used to equalize the amount of light for each element of the first line sensor 161a. The second ADC 163b converts an analog image signal (representing a read image of the second surface of the sheet) input from the second line sensor 161b into read image data in digital format, and outputs the converted read image data to the detection circuit 180. The memory 164b stores correction values used to equalize the amount of light for each element of the second line sensor 161b.

[0028] FIG. 4 is a schematic diagram showing an example of the configuration of the small spectroscopic sensor 162. Referring to FIG. 4, the small spectroscopic sensor 162 includes a white LED 176, a transmission window 177, a diffraction grating 178, and a light receiving element group 179. The white LED 176 irradiates a sheet for density unevenness measurement with white light. A correction pattern including a plurality of line patterns 382 is formed on the sheet for density unevenness measurement. The light reflected from the surface of the sheet on which the line pattern is formed is incident on the diffraction grating 178. The reflected light is split into a plurality of different wavelength components by the diffraction grating 178. The n light receiving elements of the light receiving element group 179 respectively detect the light of the corresponding wavelength components and output wavelength component signals in analog format.

[0029] Returning to FIG. 2, the third ADC 163c converts the wavelength component signal input from the small spectroscopic sensor 162 into spectroscopic sensor data in digital format, and outputs the spectroscopic sensor data to the measurement circuit 188. The memory 164c stores correction values used to equalize the amount of light for each wavelength of the small spectroscopic sensor 162.

[0030] The image memory 156 stores the read image data generated or processed in the reader unit 150. The detection circuit 180 is a detection means for detecting one or more adjustment patterns in the read image when automatic adjustment of the image formation conditions in the printer unit 120 is performed. The detection circuit 180 may be implemented as a dedicated processing circuit such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC), or may be implemented as a combination of a general-purpose processor and software.

[0031] The detection circuit 180 is a detection means for detecting each of one or more adjustment patterns used for automatic adjustment by searching within the read image when automatic adjustment of the image formation conditions of the printer unit 120 is performed. Typically, the search for each adjustment pattern is performed within a known limited search range where the adjustment pattern is assumed to exist, thereby shortening the processing time. The detection circuit 180 outputs the detection result for each adjustment pattern to the controller 200. For example, when automatic adjustment of density (density output characteristics) is performed, the detection result may indicate density-related information (e.g., the average value of luminance or density for each patch) for each detected adjustment pattern. An example of the detailed configuration of the detection circuit 180 will be further described later.

[0032] The measurement circuit 188 measures density unevenness in the main scanning direction based on the spectroscopic sensor data input from the spectroscopic sensor unit 160c when correction of density unevenness in the main scanning direction is performed. The measurement circuit 188 outputs the measurement result for the correction pattern to the controller 200. For example, the measurement result may indicate the average value of the density measured in a plurality of measurement sections that divide the line in the main scanning direction for each of the four color components. An example of the configuration of the correction pattern used for such measurement of density unevenness will be further described later.

[0033] Note that the CPU 215 of the controller 200 described later may have a detection function similar to that of the detection circuit 180 instead of the detection circuit 180 described above. Similarly, the CPU 215 may have a measurement function similar to that of the measurement circuit 188 instead of the measurement circuit 188 described above. Generally, various functions of the image forming apparatus 100 described in this specification may be realized by any combination of hardware and software.

[0034] <3-2. Detailed Configuration of Controller> FIG. 5 is a block diagram showing an example of a more detailed configuration of a controller related to automatic adjustment of image forming conditions. Referring to FIG. 5, the controller 200 includes a communication interface 211, a ROM 212, a RAM 213, a storage 214, a CPU 215, an operation interface 216, a printer interface 217, and a reader interface 218. These components are interconnected by a system bus 219.

[0035] The communication interface 211 is a communication means for the image forming apparatus 100 to communicate with the host computer 10 and other apparatuses via the network 20. The read-only memory (ROM) 212 is a non-volatile memory and stores, for example, one or more computer programs for the operation of the image forming apparatus 100. The random access memory (RAM) 213 is a volatile memory and provides a temporary storage area for calculations to the CPU 215. The storage 214 is a large-capacity storage device such as, for example, a hard disk drive (HDD) or a solid state drive (SSD). The storage 214 stores computer programs and various data such as setting data and image data. The central processing unit (CPU) 215 is a processing circuit that realizes various control functions of the image forming apparatus 100 by executing the computer programs stored by the ROM 212 or the storage 214. In the present embodiment, the CPU 215 functions as an adjustment unit 221, a correction unit 222, and a UI control unit 223. The adjustment unit 221 adjusts at least one image forming condition of the printer unit 120 based on the detection result of the adjustment pattern in the read image generated by the reader unit 150. The correction unit 222 corrects density unevenness in the main scanning direction of the image formed by the printer unit 120. The UI control unit 223 causes the display means to display a preview screen related to the user image formed by the printer unit 120. The display means here may be, for example, the operation panel 110 of the image forming apparatus 100 or the display of the host computer 10. The functions of the adjustment unit 221, the correction unit 222, and the UI control unit 223 will be described in detail later. The operation interface 216 is an interface for input and output of signals between the controller 200 and the operation panel 110. The printer interface 217 is an interface for input and output of data and signals between the controller 200 and the printer unit 120. The reader interface 218 is an interface for input and output of data and signals between the controller 200 and the reader unit 150.

[0036] <3-3. Automatic adjustment function> (1) Adjustment of Image Formation Conditions The adjustment unit 221 of the controller 200 controls the printer unit 120 to form one or more adjustment patterns on a sheet for automatic adjustment of image formation conditions in the printer unit 120. The adjustment pattern may be, for example, a tone pattern used for automatic density adjustment. FIG. 6 shows a state in which a tone pattern as an example is formed on a sheet 300.

[0037] Referring to FIG. 6, the sheet 300 includes a main printing area 310 and a peripheral area 315. The peripheral area 315 is an area surrounding the outside of the main printing area 310. The user's content to be printed is mainly arranged in the main printing area 310, but some content may also be arranged in the peripheral area 315. Four tone patterns 320Y, 320M, 320C, and 320K are formed in the peripheral area 315. The tone patterns 320Y, 320M, 320C, and 320K are used to adjust the density output characteristics of yellow (Y), magenta (M), cyan (C), and black (K), respectively. Each tone pattern 320 consists of a patch area 321 and a mask area 322 surrounding the patch area 321. The patch area 321 includes a plurality of patch images of the corresponding color component, and the tone values can be different between these patch images. The plurality of patch images in the patch area 321 are arranged along the longitudinal direction of the tone pattern 320. The mask area 322 is a single-color area of the same color as the background color (for example, white). When the peripheral area 315 is cut off from the sheet by cutting after printing, the peripheral area 315 is also referred to as a cutting area. That is, in the present embodiment, the printer unit 120 can form an adjustment pattern (for example, a tone pattern) in the cutting area to be cut of the sheet.

[0038] The detection circuit 180 of the reader unit 150 detects each tone pattern 320 based on the read image data, extracts the patch area 321 in the detected tone pattern 320, and calculates the average pixel value (RGB value) for each patch image. Then, the detection circuit 180 outputs the average pixel value of each tone of each color component to the controller 200.

[0039] FIG. 7 is a block diagram showing an example of a detailed configuration of the detection circuit 180. Referring to FIG. 7, the detection circuit 180 includes a color selection unit 181, a left end determination unit 182, a range determination unit 183, a writing unit 184, a reading unit 185, and an average calculation unit 186.

[0040] The color selection unit 181 selects any one of the RGB color component images constituting the read image data. In order to detect the gradation pattern 320 with good accuracy, the selection of the color component here may be made according to the background color of the sheet (for example, the color component with the largest color difference from the background color may be selected).

[0041] The left end determination unit 182 determines the position of the left end of the patch region 321 of each gradation pattern 320 to be detected in the read image of the color component selected by the color selection unit 181. The "left" here corresponds to the upstream side in the pixel array along the line in the main scanning direction. For example, the left end determination unit 182 may scan the pixel values of each line of the read image in order and compare each pixel value with a predefined threshold value to determine the left end of the patch region 321. When the background color of the sheet is white, the patch region 321 may be detected when the pixel value (or luminance value) is below the threshold value. In the present embodiment, the search for each adjustment pattern based on the scanning of the pixel values by the left end determination unit 182 can be performed within the corresponding known search range as described above. Note that the left end determination unit 182 may scan the pixel values of a plurality of lines simultaneously and use the plurality of pixel values to determine the position of the left end of the patch region 321 in order to improve the determination accuracy.

[0042] Based on the determination result by the left end determination unit 182, the range determination unit 183 determines the range of each patch image (hereinafter referred to as the cut-out range) to be cut out from the read image. For example, assume that the determination result by the left end determination unit 182 indicates the position coordinates of the upper left corner of the patch area 321 of the tone pattern 320Y described with reference to FIG. 6. For the range determination unit 183, the sizes in the main scanning direction and the sub-scanning direction of the patch area 321 are known. Therefore, the range determination unit 183 can determine the cut-out range of the patch images of each tone in the tone pattern 320Y based on the position coordinates of the upper left corner and the known sizes. The cut-out range determined here may be, for example, a somewhat smaller range excluding the vicinity of the four sides among the patch images constituting the patch area 321.

[0043] The writing unit 184 cuts out the patch images within the respective ranges determined by the range determination unit 183 from the read image (RGB image), and writes the patch image data representing the cut-out patch images into the image memory 156. The reading unit 185 reads out the patch image data written into the image memory 156 and outputs it to the average calculation unit 186.

[0044] Based on the respective patch image data input from the reading unit 185, the average calculation unit 186 calculates the average pixel value (RGB value) of each tone of the patch image (cut out from the read image) for the four color components of Y, M, C, and K. Then, the average calculation unit 186 outputs the calculated average pixel value to the adjustment unit 221 of the controller 200.

[0045] The adjustment unit 221 adjusts the density output characteristics of the image forming units 140Y, 140M, 140C, and 140K based on the average pixel value input from the detection circuit 180. The adjustment here can be performed, for example, using some conversion formula or look-up table that receives a set of average pixel values as input and outputs parameters for specifying the density output characteristics after adjustment. As an example, when the detection result of the gradation pattern 320Y indicates that the printing density is too low in the middle gradation range of the Y component, the adjustment unit 221 may increase the density output in the middle gradation range of the image forming unit 140Y. As another example, when the detection result of the gradation pattern 320M indicates that the printing density is too high in the low gradation range of the M component, the adjustment unit 221 may decrease the density output in the low gradation range of the image forming unit 140M.

[0046] (2) Correction of density unevenness Prior to the formation of an image by the printer unit 120, the correction unit 222 controls the printer unit 120 to form a correction pattern on the sheet for correcting density unevenness (i.e., equalizing density) in the main scanning direction. In a certain embodiment, the correction of density unevenness by the correction unit 222 is executed only when conditions related to the settings for the adjustment pattern are satisfied. The conditions for executing the correction of density unevenness will be described later.

[0047] FIG. 8 shows a state where a correction pattern 381 is formed on a sheet 380 as an example. Referring to FIG. 8, the correction pattern 381 includes four color component patterns 382Y, 382M, 382C, and 382K. The color component patterns 382Y, 382M, 382C, and 382K are used to measure density unevenness of yellow (Y), magenta (M), cyan (C), and black (K), respectively. Each color component pattern 382 includes two line patterns extending in the main scanning direction, and each line pattern is divided into a plurality of measurement sections 383 arranged in the main scanning direction. In the figure, the boundaries of the measurement sections 383 are indicated by dashed-dotted lines. Different from the adjustment pattern described with reference to FIG. 6, the correction pattern 381 can be formed across the main printing area of the sheet in this way. Therefore, the correction pattern 381 is formed on a sheet different from the sheet on which the user image is formed. The density of the image of each line pattern is uniform as a pixel value except for a rectangular small area at one end, but can be non-uniform (that is, density unevenness can occur) on the printed sheet due to variations in the characteristics of the printer unit 120.

[0048] The measurement circuit 188 of the reader unit 150 calculates an average measurement value of the density for each measurement section 383 of each color component based on the spectroscopic sensor data input from the spectroscopic sensor unit 160c. Then, the measurement circuit 188 outputs the calculated average measurement value to the controller 200.

[0049] The correction unit 222 calculates, for example, for each of the four color components, an overall average measurement value over all the measurement sections in the main scanning direction based on the average measurement value for each measurement section input from the measurement circuit 188. Then, the correction unit 222 determines a correction amount for the density for each measurement section based on the difference between this overall average measurement value and the average measurement value for each measurement section. The density correction can be performed by controlling the laser power of the exposure device 143 of the corresponding image forming unit 140 for each measurement section according to the determined correction amount. For example, the correction amount may be an offset with respect to a reference value of the laser power, and the correction amount can be determined so that the density difference from the overall average measurement value is canceled out.

[0050] <4. Provision of Preview Screen> The printer unit 120 can form the above-described adjustment pattern for the automatic adjustment function by superimposing it on the image area where the user image of the sheet is formed. That is, the adjustment pattern can typically be formed in the peripheral area (or cutting area) of the sheet as described with reference to FIG. 6, and the peripheral area can at least partially overlap the area where the user image is formed. Therefore, one or more adjustment patterns in the peripheral area may be in positional conflict with the content arranged by the user. For example, the user may arrange codes (such as serial numbers, one-dimensional or two-dimensional barcodes) used for job management or content management, marks serving as marks for operations such as cutting, or unique color patches, etc. in the peripheral area of the input image. Thus, the UI control unit 223 shall present the preview of each adjustment pattern to the user on the print preview screen that presents the preview of the user image. The arrangement of each display object on the preview screen corresponds to the arrangement on the sheet where the corresponding adjustment pattern is to be formed. Also, the UI control unit 223 shall be able to receive user input for instructing changes (such as changes in position and orientation) of the arrangement of each adjustment pattern on the sheet via a similar preview screen. The preview screen can be called from, for example, a print setting screen (or any other arbitrary setting screen) provided for setting the print job to be executed.

[0051] <4-1. Print Setting Screen> FIG. 9 is an explanatory diagram showing an example of the configuration of a print setting screen 400 that can be provided by the UI control unit 223. Referring to FIG. 9, the print setting screen 400 includes a basic setting button 410, an automatic adjustment button 420, an automatic adjustment setting area 421, a post-processing button 430, a cancel button 431, and a print start button 432.

[0052] The basic settings button 410 is a button for calling up basic setting items of a print job. The automatic adjustment button 420 is a button for calling up setting items related to the above-described automatic adjustment function of the image forming apparatus 100. The post-processing button 430 is a button for calling up setting items related to the post-processing function of the image forming apparatus 100. The cancel button 431 is a button for canceling the issuance of a print job and closing the print setting screen 400. The print start button 432 is a button for issuing a print job and starting image formation by the printer unit 120. In the example of FIG. 9, as a result of the user operating the automatic adjustment button 420, an automatic adjustment setting area 421 is displayed on the print setting screen 400. The automatic adjustment setting area 421 includes a density adjustment checkbox 422, a position adjustment checkbox 423, and a preview button 424.

[0053] The density adjustment checkbox 422 is an object for enabling or disabling automatic density adjustment. The position adjustment checkbox 423 is an object for enabling or disabling automatic adjustment of the image formation position. In the example of FIG. 9, since the density adjustment checkbox 422 is on and the position adjustment checkbox 423 is off, only automatic density adjustment is enabled. In this specification, automatic adjustment of the image formation position is not described. Operation of the preview button 424 is possible when at least one of the checkboxes 422 and 423 is on. For example, when the user operates the preview button 424 with only the density adjustment checkbox 422 on, a preview screen described below is displayed on the display.

[0054] <4-2. Preview Screen> (1) First Configuration Example FIG. 10 is an explanatory diagram showing a first example of the configuration of the preview screen. Referring to FIG. 10, the preview screen 500 includes a preview area 510, a back button 531, a page number field 532, page transition buttons 533, a slider 534, and a decision button 535. The UI control unit 223 presents a preview of the user image based on the input image data of the print job to the user in the preview area 510. Further, since automatic density adjustment is enabled, the UI control unit 223 superimposes display objects 511Y, 511M, 511C, and 511K representing the gradation patterns 320Y, 320M, 320C, and 320K at their respective display positions.

[0055] In the example of FIG. 10, the user image includes auxiliary content 542 representing a two-dimensional barcode in addition to the central main content 541. The auxiliary content 542 is arranged in the peripheral area on the left side of the user image, but in the preview area 510, the display object 511Y corresponding to the gradation pattern 320Y partially hides the auxiliary content 542. This means that if the print job is executed as it is, the auxiliary content 542 will be partially missing on the sheet because the gradation pattern 320Y is superimposed. The user can notice the need to rearrange the auxiliary content 542 so as not to overlap with the adjustment pattern by looking at this preview screen 500. Alternatively, the user can also choose to disable automatic density adjustment in the current print job.

[0056] In the first configuration example shown in FIG. 10, the UI control unit 223 receives a user input for instructing a change in the arrangement of the adjustment pattern on the sheet. The user input may be a touch input on the screen or an operation input via another input device (for example, a physical button) of the operation panel 110.

[0057] For example, the adjustment pattern is arranged at an end in the main scanning direction or an end in the sub-scanning direction of the sheet. The UI control unit 223 causes the display objects 511Y, 511M, 511C, and 511K to be displayed on the preview screen 500 according to the arrangement of the adjustment patterns on the sheet. When a user input instructing a change in the arrangement of the adjustment patterns is detected, the UI control unit 223 changes the arrangement of the adjustment patterns on the sheet from one of the ends in the main scanning direction and the ends in the sub-scanning direction to the other according to the detected user input. Then, the UI control unit 223 causes the display objects 511Y, 511M, 511C, and 511K to be displayed on the preview screen 500 according to the changed arrangement of the adjustment patterns. The UI control unit 223 may collectively change the arrangements of all the adjustment patterns (and the display objects on the screen) in response to a single user input. Alternatively, the UI control unit 223 may change only the arrangement of the corresponding adjustment pattern (and the display object on the screen) in response to a user input for an individual display object (for example, tapping on an individual object).

[0058] For example, in the first arrangement, the longitudinal direction of each adjustment pattern may be parallel to the sub-scanning direction, and in the second arrangement, the longitudinal direction of each adjustment pattern may be parallel to the main scanning direction.

[0059] In addition, when a user input instructing a translation of the adjustment pattern is detected, the UI control unit 223 may change the position where each adjustment pattern is formed on the sheet from a first position to a second position according to the detected user input. Then, the UI control unit 223 causes each display object to be displayed at the display position on the preview screen 500 corresponding to the second position on the sheet. The UI control unit 223 may collectively translate the positions of all the adjustment patterns (and the display objects on the screen) in response to a single user input. Alternatively, the UI control unit 223 may translate only the position of the corresponding adjustment pattern (and the display object on the screen) in response to a user input for an individual display object (for example, dragging an individual object).

[0060] When the position of a certain adjustment pattern is changed to the second position, the UI control unit 223 may change the search range (for example, the range for scanning pixel values) in which the detection circuit 180 searches for the adjustment pattern in the read image to the range corresponding to the changed second position.

[0061] User input for these arrangement changes may be received via a UI object on the preview screen, as in the second configuration example described below.

[0062] The back button 531 is a button for closing the preview screen 500 and returning to the print settings screen 400. The page number field 532 is a field for displaying the total number of pages and the page number of the currently displayed page when the content to be printed spans multiple pages. The page transition button 533 is a button for transitioning the page displayed in the preview area 510 to the previous or next page. The slider 534 is an object that enables changing the scale of the preview image displayed on the screen in the preview area 510. The OK button 535 is a button for reflecting the arrangement changes made by the user on the preview screen 600 in the print job settings.

[0063] (2) Second Configuration Example FIG. 11 is an explanatory diagram showing a second example of the configuration of the preview screen. Referring to FIG. 11, the preview screen 600 includes a preview area 510, a back button 531, a page number field 532, a page transition button 533, a slider 534, and an OK button 535. The UI control unit 223 causes the preview area 510 to display a preview of the user image based on the input image data of the print job. Further, since automatic density adjustment is enabled, the UI control unit 223 causes display objects 511Y, 511M, 511C, and 511K representing the gradation patterns 320Y, 320M, 320C, and 320K to be displayed according to their respective default arrangements.

[0064] The preview screen 600 further includes input objects 611 for respectively instructing the translation of the tone patterns 320Y, 320M, 320C, and 320K. The input object 611 includes four pairs of numerical input fields capable of inputting the relative translation amounts when translating each of the four tone patterns 320 in the x-direction and the y-direction. Here, the x-direction may correspond to the main scanning direction, and the y-direction may correspond to the sub-scanning direction. In addition, the preview screen 600 includes a switching button 612.

[0065] When the switching button 612 is operated by the user, the UI control unit 223 switches the arrangement of the tone patterns 320Y, 320M, 320C, and 320K on the sheet between a first arrangement and a second arrangement. As described above, in the first arrangement, the tone patterns are arranged at both ends (the left end and the right end) in the main scanning direction. Both ends in the main scanning direction are also referred to as the left and right ends. Also, in the second arrangement, the tone patterns are arranged at both ends (the front end and the rear end) in the sub-scanning direction. Both ends in the sub-scanning direction are also referred to as the front and rear ends. FIG. 12 shows the state of the preview screen 600 after the switching button 612 is operated. As shown in the figure, the arrangements of the display objects 511Y, 511M, 511C, and 511K corresponding to the tone patterns 320Y, 320M, 320C, and 320K have been changed from the first arrangement to the second arrangement. As a result, the overlap between the auxiliary content 542 of the display object 511Y has been eliminated. In this state, when the switching button 612 is operated again by the user, the UI control unit 223 may change the arrangement of the tone patterns 320Y, 320M, 320C, and 320K from the second arrangement to the first arrangement.

[0066] For example, when the user operates the decision button 535 in the state shown in FIG. 12, the UI control unit 223 closes the preview screen 600 and redisplays the print setting screen 400. Then, when the user operates the print start button 432 (see FIG. 9) on the print setting screen 400, a print job is issued and image formation by the printer unit 120 is started. In the print job, the printer unit 120 forms the adjustment pattern on the sheet according to the arrangement after the change by the user. When the return button 531 is operated by the user, the change in the arrangement made by the user on the preview screen 600 is canceled.

[0067] FIG. 13 shows an example of the adjustment pattern whose arrangement has been changed. The adjustment pattern in the example of FIG. 13 includes the same four gradation patterns 320Y, 320M, 320C, and 320K as those shown in FIG. 6. However, in FIG. 6, the four gradation patterns 320 are arranged at the ends (left and right ends) in the main scanning direction of the sheet 300, while in FIG. 13, the four gradation patterns 320 are arranged at the ends (front and rear ends) in the sub-scanning direction of the sheet 300.

[0068] By providing a simple user interface for switching the arrangement of the adjustment pattern as in the above-described embodiment, the user can easily avoid the overlap between the adjustment pattern and the content image.

[0069] <4-3. Conditional correction of density unevenness> When the longitudinal direction of the adjustment pattern is parallel to the main scanning direction (when the second arrangement of the adjustment pattern is set), density unevenness in the main scanning direction may cause an error in the adjustment of the image formation conditions. Therefore, in one embodiment, when the adjustment pattern is formed on the sheet in the second arrangement (see FIG. 13), the UI control unit 223 causes the correction unit 222 to correct the density unevenness in the main scanning direction. When density unevenness is corrected, prior to the execution of the print job, the printer unit 120 forms a correction pattern 381 on the sheet, the spectral sensor unit 160c reads the correction pattern 381, and the measurement circuit 188 measures the average density for each measurement section 383. The correction unit 222 controls the laser power of the exposure device 143 of the image forming unit 140 so as to cancel the difference in the average density for each measurement section 383 from the reference density during the execution of the print job. In this way, by eliminating the influence of density unevenness from the plurality of patch images of the adjustment pattern formed along the main scanning direction, it is possible to prevent a decrease in the accuracy of the adjustment of the image formation conditions and maintain high print quality.

[0070] <4-4. Flow of processing> FIG. 14 is a flowchart showing an example of the flow of job execution processing that can be performed by the image forming apparatus 100.

[0071] First, in S201, the UI control unit 223 of the controller 200 of the image forming apparatus 100 causes the display of the host computer 10 or the operation panel 110 to display a preview screen related to the print job in response to a call by the user. When the function of automatically adjusting at least one image formation condition is enabled, the preview screen displayed here includes a display object representing the adjustment pattern. On this preview screen, it is possible to accept user input for changing the arrangement of the adjustment pattern.

[0072] Next, in S202, the UI control unit 223 changes the arrangement of at least one adjustment pattern on the sheet from the default arrangement to the arrangement specified by the user according to the user input received via, for example, the preview screen.

[0073] Next, in S203, when the user instructs to start executing the print job, the UI control unit 223 receives the print job. The print job includes input image data representing the user image to be printed. At this time, the page counter p, which is a variable for identifying the page to be printed, is initialized to zero.

[0074] Next, in S204, the UI control unit 223 acquires the job parameters of the received print job. The job parameters include, in addition to the parameters for the basic settings described above, a parameter indicating whether the automatic adjustment function is enabled for at least one image formation condition. When the automatic adjustment function is enabled, the job parameters include a parameter indicating the arrangement of one or more adjustment patterns on the sheet (for example, the position and orientation after the change in S202).

[0075] Next, in S205, the UI control unit 223 determines whether the automatic adjustment function is enabled and the arrangement of the adjustment pattern is the second arrangement (or the longitudinal direction of the adjustment pattern is parallel to the main scanning direction). When the automatic adjustment function is enabled and the arrangement of the adjustment pattern is the second arrangement, in S206, the printer unit 120 forms the correction pattern 381 on the sheet, and the measurement circuit 188 measures the average density for each measurement section 383. Next, in S207, the correction unit 222 determines, for each color component and for each measurement section 383, the correction amount of the laser power for correcting the density unevenness in the main scanning direction based on the measurement result of the average density. When the automatic adjustment function is not enabled or there is no adjustment pattern set in the second arrangement, S206 and S207 described above are skipped.

[0076] Subsequent processing branches in S208 depending on whether the automatic adjustment function is enabled. When the automatic adjustment function is enabled, the processing proceeds to S221. When the automatic adjustment function is not enabled, the processing proceeds to S211.

[0077] When the automatic adjustment function is not enabled, in S211, the printer unit 120 forms the user image of the p-th page on the sheet under the control of the controller 200. Then, in S213, the page counter p is incremented. Next, in S215, it is determined whether the execution of the print job is completed. For example, if the page counter p has not reached the total number of sheets to be printed, it is determined that the execution of the print job is not completed, and the process returns to S208. On the other hand, if the page counter p has reached the total number of sheets to be printed, it is determined that the execution of the print job is completed, and the flowchart of FIG. 14 ends.

[0078] When the automatic adjustment function is enabled, in S221, the printer unit 120 forms the user image of the p-th page on the sheet under the control of the controller 200. At this time, the adjustment unit 221 superimposes one or more adjustment patterns used for automatic adjustment on the user image according to the arrangement indicated by the job parameters acquired in S204. Also, when the arrangement of the adjustment pattern is the second arrangement, the laser power of the exposure device 143 is corrected by the correction amount determined in S207, and density unevenness is suppressed.

[0079] Next, in S223, the line sensor 161 of the reader unit 150 optically reads the sheet on which the user image and the adjustment pattern are formed and generates a read image. Then, in S225, the detection circuit 180 of the reader unit 150 searches for each of one or more adjustment patterns used for automatic adjustment in the read image generated in S223 and detects each adjustment pattern. Here, the range in which each adjustment pattern is searched is changed according to the change in the arrangement on the sheet where the adjustment pattern is to be formed when the arrangement is changed.

[0080] Next, in S227, the adjustment unit 221 of the controller 200 adjusts the image formation conditions of the printer unit 120 based on the detection result input from the detection circuit 180. For example, the detection result may indicate the average pixel value for each color component and each gradation, calculated based on the patch image of the gradation pattern detected in the read image. The adjustment unit 221, for example, converts the average pixel value into a density value and adjusts the density output characteristics of each image forming unit 140Y, 140M, 140C, 140K so that the density difference from the desired density is compensated. Note that the adjustment of the density output characteristics based on the reading of the gradation pattern or the patch image may be performed according to any known method, and the detailed description thereof is omitted here.

[0081] Next, the process proceeds to S213, and as described above, the page counter p is incremented. Next, in S215, it is determined whether the execution of the print job has been completed. If it is determined that the execution has not been completed, the process returns to S208. On the other hand, if it is determined that the execution of the print job has been completed, the flowchart of FIG. 14 ends.

[0082] Note that the adjustment pattern may be superimposed only on the first page (or any page specified by the user). The adjustment of the image formation conditions may be applied to subsequent pages of the same print job or to subsequent print jobs.

[0083] <4-5. Modification Example> (1) First Modification Example Regarding the above-described embodiments, it is possible to conceive of various modifications. In a first modification, the UI control unit 223 may control whether to accept a user input for changing the arrangement of the adjustment pattern depending on the settings of the print job. For example, when the printer unit 120 is set to form an image on a sheet of a first size, the UI control unit 223 enables accepting a user input for changing the arrangement of the adjustment pattern. On the other hand, when the printer unit 120 is set to form an image on a sheet of a second size smaller than the first size, the UI control unit 223 disables accepting the user input. For example, the sheet of the first size is A4, and the sheet of the second size is A5.

[0084] FIG. 15 shows a state where a change in the arrangement of the adjustment pattern is prohibited in the preview screen 600 similar to that shown in FIG. 11. In the example of FIG. 15, since the switching button 612 is disabled, the user cannot change the arrangement of the adjustment pattern from the default arrangement. It is allowed to displace the adjustment pattern by specifying the relative movement amount of the adjustment pattern. In particular, when the sheet size is small, a situation may occur where the upper and lower or left and right peripheral areas of the sheet become short and sufficient area width for arranging the adjustment pattern cannot be ensured. Therefore, by conditionally prohibiting a change from the default arrangement of the adjustment pattern in this way, it is possible to avoid a shortage of the area for arranging the adjustment pattern and guarantee the reliable execution of the adjustment of the image formation conditions.

[0085] (2) Second modification In the above-described embodiment, an example in which a plurality of patch images of each adjustment pattern are arranged in a row and the longitudinal direction thereof is parallel to the main scanning direction or the sub-scanning direction has been described. However, the configuration of each adjustment pattern is not limited to such an example. In the second modification, a plurality of patch images of each adjustment pattern may be arranged so as to be different between the first arrangement and the second arrangement. For example, in the first arrangement, a plurality of patch images of each adjustment pattern are arranged in a row, and the longitudinal direction thereof is parallel to the sub-scanning direction. This first arrangement may be the same as the arrangement of the display objects 511Y, 511M, 511C, and 511K in FIGS. 10 and 11 described above. On the other hand, in the second arrangement, a plurality of patch images of each adjustment pattern are arranged in a plurality of rows, and the number of rows is selected so that the length occupied by each adjustment pattern in the sub-scanning direction fits within the peripheral region (or cutting region) of the sheet.

[0086] FIG. 16 shows a preview screen 600 after the switching button 612 of the preview screen 600 (corresponding to the first arrangement) in the second modification is operated. As shown in the figure, the arrangement of the display objects 511Y, 511M, 511C, and 511K corresponding to the gradation patterns 320Y, 320M, 320C, and 320K, respectively, is changed from the first arrangement to the second arrangement. The positions of the four display objects in the second arrangement are substantially the same as those in the example of FIG. 12, but the patch images included in each display object form a 2×3 two-dimensional array. As a result, the length of the gradation pattern in the sub-scanning direction corresponding to each display object fits within the peripheral region of the sheet. Also in the example of FIG. 16, the overlap with the auxiliary content 542 of the display object 511Y is eliminated. When the switching button 612 is operated again by the user, the UI control unit 223 may change the arrangement of the gradation patterns 320Y, 320M, 320C, and 320K from the second arrangement to the first arrangement described with reference to FIG. 11.

[0087] <5. Summary> So far, various embodiments, examples, and modifications have been described with reference to FIGS. 1 to 16. According to the above-described embodiments, before executing a print job, a user can appropriately change the arrangement of an adjustment pattern while checking the positional relationship between the content arranged by the user and the adjustment pattern formed by an image forming apparatus on a preview screen. That is, the user can avoid the adjustment pattern used for adjusting image forming conditions from overlapping with the user's content image through interaction with the system.

[0088] <6. Other Embodiments> The above embodiments can also be realized in a form in which a program for realizing one or more functions is supplied to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus read and execute the program. Further, it can also be realized by a circuit (for example, ASIC) for realizing one or more functions.

[0089] The invention is not limited to the above embodiments, and various changes and modifications are possible without departing from the spirit and scope of the invention. Therefore, claims are attached to disclose the scope of the invention.

Description of Reference Numerals

[0090] 1: Printing system, 10: Host computer, 20: Network, 100: Image forming apparatus, 110: Operation panel (display means), 120: Printer unit (image forming means), 150: Reader unit (reading means), 180: Detection circuit, 188: Measurement circuit, 190: Finisher, 200: Controller (control means), 221: Adjustment unit (adjustment means), 222: Correction unit (correction means), 223: UI control unit (control means), 300, 380: Sheet, 310: Main image area, 315: Peripheral area, 320Y, 320M, 320C, 320K: Tone pattern, 381: Correction pattern, 400: Print setting screen, 500, 600: Preview screen, 511Y, 511M, 511C, 511K: Display object, 542: Auxiliary content

Claims

1. Image forming means for forming a user image on a sheet based on at least one image forming condition; Reading means for optically reading the sheet to generate a read image; Control means for causing a display means to display a preview screen related to the user image formed by the image forming means; An image forming apparatus comprising: The image forming means can form an adjustment pattern used for adjusting the at least one image forming condition on the sheet together with the user image; The adjustment pattern is arranged at an end in the main scanning direction of the sheet or an end in the sub-scanning direction orthogonal to the main scanning direction; The image forming apparatus: Adjustment means for adjusting the at least one image forming condition based on a detection result of the adjustment pattern in the read image generated by the reading means; Further comprising: The control means causes the display object representing the adjustment pattern to be displayed on the preview screen according to the arrangement of the adjustment pattern on the sheet; The control means, in response to a user input instructing a change in the arrangement of the adjustment pattern, Changes the arrangement of the adjustment pattern on the sheet from one of the end in the main scanning direction and the end in the sub-scanning direction to the other, And causes the display object to be displayed on the preview screen according to the changed arrangement of the adjustment pattern; Image forming apparatus.

2. The image forming apparatus according to claim 1, wherein the image forming means can form the adjustment pattern in a cutting region to be cut of the sheet.

3. The image forming apparatus according to claim 2, wherein the adjustment pattern is arranged at both ends in the main scanning direction in a first arrangement and at both ends in the sub-scanning direction in a second arrangement.

4. The adjustment pattern includes a plurality of patch images arranged along the longitudinal direction of the adjustment pattern, In the first arrangement, the longitudinal direction of the adjustment pattern is parallel to the sub-scanning direction, In the second arrangement, the longitudinal direction of the adjustment pattern is parallel to the main scanning direction; The image forming apparatus according to claim 3.

5. The image forming apparatus: Correction means for correcting density unevenness in the main scanning direction of the image formed by the image forming means; Further comprising: When the second arrangement is set as the arrangement of the adjustment pattern, the control means causes the correction means to correct density unevenness in the main scanning direction. The image forming apparatus according to claim 4.

6. The at least one image forming condition includes a condition related to the density of an image formed by the image forming means. The plurality of patch images of the adjustment pattern include two or more patch images with different gradations. The image forming apparatus according to claim 5.

7. The image forming means can form an image on a sheet of a first size and a sheet of a second size smaller than the first size. The control means When the image forming means is set to form an image on a sheet of the first size, enables reception of the user input. When the image forming means is set to form an image on a sheet of the second size, disables reception of the user input. The image forming apparatus according to claim 1.

8. The image forming apparatus includes the display means, and is the image forming apparatus according to any one of claims 1 to 7.

9. The image forming apparatus further includes communication means for communicating with another apparatus including the display means, and is the image forming apparatus according to any one of claims 1 to 7.

10. A method executed by an image forming apparatus, comprising: forming an adjustment pattern used for adjusting at least one image forming condition on a sheet together with a user image; acquiring a read image generated by optically reading the sheet; adjusting the at least one image forming condition based on a detection result of the adjustment pattern in the read image; causing a display device to display a preview screen related to the user image prior to forming the adjustment pattern on the sheet together with the user image; including The adjustment pattern is arranged at an end in the main scanning direction of the sheet or an end in the sub-scanning direction orthogonal to the main scanning direction. The preview screen includes a display object representing the adjustment pattern arranged according to the arrangement of the adjustment pattern on the sheet. The method receiving a user input for instructing a change in the arrangement of the adjustment pattern; in response to the user input changing the arrangement of the adjustment pattern on the sheet from one of an end in the main scanning direction and an end in the sub-scanning direction to the other; displaying the display object on the preview screen according to the changed arrangement of the adjustment pattern; A method further comprising.

Images