Image forming apparatus

Abstract

An image forming apparatus is disclosed. The image forming apparatus includes an image forming unit configured to form an image on a sheet based on a mode selected from a plurality of modes, the plurality of modes having different image forming speeds; a memory configured to store first data for a first mode included in the plurality of modes, the first data indicating a correspondence between a type of the sheet and the image forming speed for the first mode, and second data for a second mode included in the plurality of modes, the second data indicating a correspondence between a type of the sheet and the image forming speed for the second mode; a display; and a controller configured to determine a first image forming speed for the first mode from the first data based on a type of the sheet, and determine a second image forming speed for the second mode from the second data.

Description

Technical Field

[0001] This disclosure relates to image forming apparatus for forming images on paper, such as copiers, printers, and fax machines. Background Technology

[0002] Image forming apparatuses are required to have multi-media compatibility and high productivity, allowing them to print images on various types of sheets, including thin paper, thick paper, and coated paper (matte coated paper, matte coated paper, etc.). As the basis weight of the sheet increases, the heat applied to the sheet during the fixing of the image transferred to the paper needs to be increased. Generally, to increase the heat applied per unit area of ​​the paper, the image forming speed is set lower as the sheet basis weight becomes heavier. For this reason, the image forming apparatus can operate at multiple image forming speeds depending on the basis weight and surface properties of each sheet. Image forming speed refers to the operating speed of the image forming unit, such as the photosensitive drum, developing equipment, and intermediate transfer belt described later, the sheet transport speed during image transfer to the paper, and the paper transport speed during the fixing of the toner on the paper, etc.

[0003] Users' priorities may differ depending on the output printout. For example, for text printing such as documents, many users prioritize productivity over maximizing image quality. For image printing such as photographs, many users prioritize image quality over maximizing productivity. U.S. Patent No. 7,965,955B2 describes an image forming apparatus with selectable modes: a productivity-priority mode and an image quality-priority mode. In the productivity-priority mode, the image forming speed is high while maintaining image quality within a predetermined range; in the image quality-priority mode, the image forming speed is set to maximize image quality. The image is printed at an image forming speed corresponding to the user-selected operating mode.

[0004] Image forming apparatuses of recent years have processed many types of paper. Therefore, in some cases, multiple sheets of paper with the same basis weight can differ significantly in properties. For example, stiffness is given as a paper characteristic. Stiffness, also known as the flexural stiffness of paper, is an indicator of the paper's resistance to bending when bent. In cases of high stiffness, when the paper enters the transfer unit (transfer gripper) where the image is transferred, the paper exerts a significant impact on the transfer unit. This becomes a cause of unevenness in the image transferred to the paper. In such cases, reducing the speed at which the paper enters the transfer unit (image forming speed) can mitigate the impact, thereby reducing the cause of image unevenness.

[0005] Image quality priority mode is a mode that maximizes the image quality level on each sheet of paper with the same basis weight, regardless of its characteristics. To this end, consider setting the image forming speed based on, for example, the image forming speed for paper with the highest stiffness. The image forming speed for paper with the highest stiffness is lower than the image forming speed for other papers. This means setting a low image forming speed corresponding to the paper with the highest stiffness among multiple sheets of paper with the same basis weight, although a higher image forming speed can be set for other papers with lower stiffness. Therefore, in image quality priority mode, images are formed at a low image forming speed regardless of paper characteristics, making it difficult to increase productivity. Therefore, it is necessary to improve productivity while maintaining image quality when forming images with priority. Summary of the Invention

[0006] The image forming apparatus according to this disclosure includes: an image forming unit configured to form an image on a sheet based on a mode selected from a plurality of modes, the plurality of modes having different image forming speeds; a memory configured to store first data for a first mode included in the plurality of modes and second data for a second mode included in the plurality of modes, the first data indicating a correspondence between sheet type and image forming speed for the first mode, and the second data indicating a correspondence between sheet type and image forming speed for the second mode; a display; and a controller configured to: determine a first image forming speed for the first mode based on the sheet type from the first data; determine a second image forming speed for the second mode based on the sheet type from the second data; display a screen on the display for receiving user instruction information regarding a change in the second image forming speed for the second mode corresponding to a first type of sheet; and change the second image forming speed corresponding to the first type of sheet based on the user instruction information.

[0007] Further features of the invention will become clear from the following description of exemplary embodiments (with reference to the accompanying drawings). Attached Figure Description

[0008] Figure 1 This is a configuration diagram of the image forming apparatus.

[0009] Figure 2 This is an explanatory diagram of the controller.

[0010] Figure 3A and Figure 3B This is an explanatory diagram of the operation unit.

[0011] Figure 4 This is a diagram illustrating the image formation speed.

[0012] Figure 5 This is an explanatory diagram of the image formation speed for each sheet category.

[0013] Figure 6 This is an example image used to illustrate the operation mode selection screen.

[0014] Figure 7 This is an example diagram used to illustrate the registration screen of sheet material.

[0015] Figure 8 This is an example image used to illustrate the sheet type selection screen.

[0016] Figure 9 This is an example diagram used to illustrate the sheet type selection screen when a new type of sheet has been added.

[0017] Figure 10 This is an example of how to change the image using sheet settings.

[0018] Figure 11 This is an example diagram used to illustrate the base weight settings screen.

[0019] Figure 12 This is a diagram used to illustrate the image formation speed setting screen in image quality priority mode.

[0020] Figure 13 It is a flowchart used to illustrate the image formation process.

[0021] Figure 14 It is a flowchart used to illustrate the image formation process.

[0022] Figure 15 This is a flowchart used for processing image formation speed limits.

[0023] Figure 16 This is a diagram illustrating an example of a table indicating the limits of image formation speed.

[0024] Figure 17 This is an example diagram used to illustrate the settings screen for setting upper and lower limits.

[0025] Figure 18 It is a flowchart used to illustrate the process of determining the upper and lower limits.

[0026] Figure 19 This is a flowchart used to process display settings for changing the image on the graphic sheet.

[0027] Figure 20 It is a flowchart used to change the display process of the illustrated sheet.

[0028] Figure 21 This is an example diagram used to illustrate changes in the settings of the sheet material in screen A. Detailed Implementation

[0029] Exemplary embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0030] <First Embodiment>

[0031] Figure 1 This is a configuration diagram of an image forming apparatus 100 according to a first embodiment of the present disclosure. The image forming apparatus 100 is an electrophotographic panchromatic image forming apparatus. The image forming apparatus 100 includes a reader 1 and a printer 5. The reader 1 is provided on the housing of the printer 5. In the first embodiment, the reader 1 is an image reading device that reads a color image from an original document. The printer 5 in the first embodiment is a color printer that prints a color image on a sheet of material S, such as paper. The image forming apparatus 100 described above is, for example, a copier, a multifunction printer, etc.

[0032] The reader 1 includes a platform 2, a pancolor sensor 3, and an image processor 4. The original document, printed with the image to be read, is placed on the platform 2. The pancolor sensor 3 is, for example, an optical sensor, such as a charge-coupled device (CCD) image sensor. The pancolor sensor 3 receives reflected light emitted onto the original document and converts the received reflected light into an electrical signal (color separation image signal). The color separation image signal is processed by the image processor 4 and transmitted to the printer 5.

[0033] Printer 5 has a configuration in which four image forming units (first to fourth image forming units UY, UM, UC, and UK) are arranged in series. Each of the first to fourth image forming units UY, UM, UC, and UK is an electrophotographic processing mechanism that uses laser exposure and forms an image, for example, during a copying process, based on a color separation image signal acquired from reader 1. Printer 5 includes a primary transfer unit 6, an intermediate transfer belt 7, a secondary transfer unit 8, a fixing device 12, a cassette sheet feed mechanism 9, and a manual sheet feeder 11. Printer 5 is connected to a deck sheet feeder 10.

[0034] Each of the first to fourth image forming units UY, UM, UC, and UK includes a photosensitive drum Dr, a charging device Ch, an exposure device LS, a developing device Dev, etc. Figure 1In this diagram, only each unit in the first image forming unit UY is represented by a reference symbol, and the reference symbols for each unit in the second to fourth image forming units UM, UC, and UK are omitted. The photosensitive drum Dr is a drum-shaped photosensitive member having a photosensitive layer in its surface. The charging device Ch uniformly charges the surface of the photosensitive drum Dr. The exposure device LS includes a light source. The light source of the exposure device LS emits laser light modulated with a color-separated image signal according to its corresponding color onto the charged surface of the photosensitive drum Dr, thereby forming an electrostatic latent image on the surface of the photosensitive drum Dr. The developing device Dev develops the electrostatic latent image using a toner of its corresponding color, thereby forming a toner image on the photosensitive drum Dr.

[0035] The first image forming unit UY forms a yellow toner image on the surface of the photosensitive drum Dr. The second image forming unit UM forms a magenta toner image on the surface of the photosensitive drum. The third image forming unit UC forms a cyan toner image on the surface of the photosensitive drum. The fourth image forming unit UK forms a black toner image on the surface of the photosensitive drum. The first to fourth image forming units UY, UM, UC and UK form toner images at their respective timings.

[0036] The toner images formed on the photosensitive drums of the first to fourth image forming units UY, UM, UC, and UK are sequentially superimposed by the primary transfer unit 6 and transferred onto the intermediate transfer belt 7. As a result, a full-color toner image with four colors overlapping each other is formed on the intermediate transfer belt 7. The intermediate transfer belt 7 rotates, thereby conveying the full-color toner image to the secondary transfer unit 8.

[0037] The sheet S can be fed from the cassette sheet feed mechanism 9, the manual sheet feeder 11, and the tabletop sheet feeder 10. According to the timing of image formation by the first to fourth image forming units UY, UM, UC, and UK, the sheet S is fed from any one of the cassette sheet feed mechanism 9, the manual sheet feeder 11, and the tabletop sheet feeder 10 to the secondary transfer unit 8. The secondary transfer unit 8 includes a transfer clamping section formed between the secondary transfer unit 8 and the intermediate transfer belt 7. At the transfer clamping section, the secondary transfer unit 8 transfers the full-tone toner image (unfixed image) carried by the intermediate transfer belt 7 onto the fed sheet S. The sheet S with the transferred toner image (unfixed image) is then conveyed from the secondary transfer unit 8 to the fixing device 12.

[0038] The fixing device 12 fixes the unfixed toner image onto the sheet S while conveying the sheet S. In this case, the fixing device 12 conveys the sheet S with the transferred toner image while gripping the sheet S using the fixing clamping part. During the gripping and conveying process, the unfixed toner image melts and mixes colors due to heat and pressure to fix it onto the sheet S as an attached image. The sheet S with the fixed image is discharged as a print product into either the upward-facing sheet discharge tray 14 or the downward-facing sheet discharge tray 15. A baffle 13 is placed at the rear of the fixing device 12. The sheet S is discharged through the baffle 13 into either the upward-facing sheet discharge tray 14 or the downward-facing sheet discharge tray 15.

[0039] For double-sided printing, the sheet S with an image formed on one surface (the first surface) is first conveyed from the fixing device 12 to a conveying path closer to the face-down sheet discharge tray 15, and then conveyed in a folded-back manner to the re-transfer sheet path 16. As a result, the printed surface of the sheet S is reversed. The sheet S is conveyed to the secondary transfer unit 8 via the re-transfer sheet path 16. Then, the toner image is transferred to a second surface different from the first surface of the sheet S, and the image is fixed by the fixing device 12 in the same manner as the image printed on the first surface. In this way, the image is printed on the second surface. The sheet S with images printed on both surfaces is discharged to either the face-up sheet discharge tray 14 or the face-down sheet discharge tray 15.

[0040] Figure 2 This is an explanatory diagram of a controller that controls the operation of the image forming apparatus 100. The controller 200 is an information processing device that includes a central processing unit (CPU) 204, a read-only memory (ROM) 205, and a random access memory (RAM) 203. The CPU 204 controls the overall operation of the image forming apparatus 100 by executing a computer program stored in the ROM 205. The RAM 203 is a memory that provides a working area used by the CPU 204 during processing. The controller 200 is connected to the reader 1 and the printer 5, and also to the operation unit 300. The controller 200 is provided, for example, in the housing of the printer 5.

[0041] The reader 1 transmits a color separation image signal to the controller 200. The controller 200 controls the operation of the printer 5 as described above based on the color separation image signal, and prints an image on the sheet S. The printer 5 operates the first to fourth image forming units UY, UM, UC, and UK, the secondary transfer unit 8, the fixing device 12, etc., according to instructions from the controller 200, thereby performing the image forming process (printing process) mentioned above. As described above, the printer 5 includes a cassette sheet feeding mechanism 9, a tabletop sheet feeder 10, and a manual sheet feeder 11. The printer 5 feeds the sheet S for printing from any one of the cassette sheet feeding mechanism 9, the tabletop sheet feeder 10, and the manual sheet feeder 11 according to instructions from the controller 200. The printer 5 controls the conveying speed of the sheet S during feeding according to instructions from the controller 200.

[0042] Figure 3A and Figure 3B This is an explanatory diagram of the operation unit 300. Users can input various conditions and information regarding image formation into the image forming apparatus 100 using the operation unit 300 to execute settings. The operation unit 300 is a user interface, which includes input interfaces and output interfaces. The input interfaces include various buttons, touchpads, etc. The output interfaces include a display 301, speakers, etc. The operation unit 300 is used to display printing information, information about the printing progress, etc., and to execute various settings for the printer 5.

[0043] Figure 3A This is a plan view of the operation unit 300. The operation unit 300 includes a display 301, a reset button 302, a start button 303, a stop button 304, a clear button 305, a numeric keypad 306, a color mode selection button 307, and a user mode button 308. Figure 3B An example of a settings screen displayed on monitor 301 during copying is shown. In the settings screen during copying, the number of copies, selected sheet size, magnification, copy density, etc., can be set.

[0044] The reset key 302 is used to reset settings and is operated, for example, when returning from copy mode to standard mode. The start key 303 is used, for example, to give an instruction to start the copying operation. The stop key 304 is used, for example, to give an instruction to stop the copying operation. The clear key 305 is used, for example, when returning the operation mode from copy mode to standard mode. The numeric keypad 306 is used, for example, to set values ​​such as the number of copies. When pressed, the user mode key 308 displays a selection screen, described later, on the display 301.

[0045] The color mode selection key 307 includes an "ACS" key, a "Color" key, and a "Black" key. The "ACS" key is used to enable the reader 1 to automatically determine whether the image of the original document being read is a color image or a black and white image. For a color image, the "ACS" key is used to enable the reader 1 to output a color image signal, and for a black and white image signal, the "ACS" key is used to enable the reader 1 to output a black and white image signal. The "Color" key is used to enable the reader 1 to output a color image signal regardless of the original image. The "Black" key is used to enable the reader 1 to output a black and white image signal regardless of the original image. In a first embodiment, the color mode selection key 307 is configured to illuminate the selected key.

[0046] <Image Quality Priority Mode and Productivity Priority Mode>

[0047] When the toner image transferred onto the sheet S is fixed by the fixing device 12, the optimal image forming speed is set according to the weight of the sheet S because the heat applied to the sheet S per unit time varies with the weight of the sheet S. Setting the weight for each sheet S requires complex operations from the user. Therefore, in the image forming apparatus 100, the same transfer conditions, the same fixing conditions, and the same sheet transport speed (image forming speed) are set for each of the predetermined weight ranges. The weight range mentioned above is referred to as the "sheet category". In the example below, the sheet category of sheet S with a weight of 64 gsm to 150 gsm is referred to as "plain paper", the sheet category of sheet S with a weight of 151 gsm to 250 gsm is referred to as "thick paper 1", and the sheet category of sheet S with a weight of 251 gsm to 350 gsm is referred to as "thick paper 2".

[0048] Figure 4 This is an explanatory diagram of the image forming speed of the image forming apparatus 100. When the image forming speed is changed, the rotation speed of the photosensitive drum Dr and the rotation speed of the intermediate transfer belt 7 are controlled such that each rotation speed is set based on the image forming speed. The image forming apparatus 100 of the first embodiment can operate at a first to a third speed as the image forming speed. In the first embodiment, the first speed is the highest image forming speed and is 400 mm / s. The second speed is a lower image forming speed than the first speed and is 300 mm / s. The third speed is the lowest image forming speed and is 200 mm / s.

[0049] In a productivity-priority mode that prioritizes the productivity of printed products, the image forming speed is set to the highest speed at which an image can be formed. In an image quality-priority mode that prioritizes the image quality of printed products, the image forming speed is set to a lower speed than that in the productivity-priority mode. In the image quality-priority mode, the image of the printed product is printed with a higher image quality than that in the productivity-priority mode. In other words, in the productivity-priority mode, the image forming apparatus 100 has a higher production capacity than in the image quality-priority mode. Each of the productivity-priority mode and the image quality-priority mode is described.

[0050] The productivity-priority mode is an operation mode that forms an image at the maximum image forming speed that can be formed. In productivity-priority mode, image quality is maintained within a predetermined range, and productivity is maximized. The image quality-priority mode is an operation mode that forms an image at a lower image forming speed than in productivity-priority mode in order to maximize the image quality of the image printed on the printed product. For example, in image quality-priority mode, the conveying speed of the sheet S when it enters the secondary transfer unit 8 (i.e., the conveying speed of the sheet S through the transfer clamp) is reduced to reduce the impact given when the sheet S enters the secondary transfer unit 8, thereby improving the transfer image quality. In addition, in image quality-priority mode, the conveying speed of the sheet S in the fixing device 12 (i.e., the conveying speed of the fixing device 12 transporting the sheet S) is reduced to allow the fixing device 12 to apply more heat to the sheet S, thereby making the sheet more glossy.

[0051] Figure 5 This is an explanatory diagram of the image forming speed for each sheet category under each operating mode (productivity-first mode and image quality-first mode). Figure 5 In this process, the sheet types are plain paper, thick paper 1, and thick paper 2. The image forming speed is determined based on the operating mode and the sheet type. For example, the image forming speed of plain paper is equal to the first speed (400 mm / s) in productivity-priority mode and equal to the second speed (300 mm / s) in image quality-priority mode. Thick paper 1 and thick paper 2 each have a heavier basis weight, thus requiring a more significant reduction in the impact on the secondary transfer unit 8 when the sheet enters. Therefore, in image quality-priority mode, the image forming speed of thick paper 1 and thick paper 2 is equal to the third speed (200 mm / s), which is the lowest speed. In productivity-priority mode, the image forming speed of thick paper 1 is equal to the first speed (400 mm / s). In productivity-priority mode, the image forming speed of thick paper 2 is equal to the second speed (300 mm / s) because the sheet S requires more heat from the fixing device 12 than thick paper 1.

[0052] The first embodiment discusses plain paper / thick paper with the surface characteristics of wood pulp-free paper, but the image forming speed can be determined in the same manner as described above based on information about surface characteristics (surface treatment) (i.e., information about whether the sheet has a surface coated with a coating agent (such as coated paper)). Furthermore, it has been described that the image forming speed of plain paper in image quality priority mode is equal to the second speed, but it is not always required that the image forming speed be equal to the second speed, as long as the image forming speed is lower than the first speed. For example, the image forming speed can be equal to a third speed or a fourth speed different from the second and third speeds. In other words, the image forming speed can be set to a speed faster than the first, second, and third speeds. It has been described that the image forming speed in image quality priority mode is lower than the image forming speed in productivity priority mode, but depending on the basis weight of the sheet, the individual image forming speeds can be the same. For example, the image forming speed of plain paper in both image quality priority mode and productivity priority mode can be equal to the same first speed.

[0053] Figure 5 The information (table) regarding the image forming speed for each sheet type in each operating mode is pre-stored in RAM 203 or ROM 205. CPU 204 determines the image forming speed during image forming based on this information and prints the image on the sheet S.

[0054] <Operation Mode Selection>

[0055] Figure 6 This is an example diagram illustrating an operation mode selection screen. The selection screen is displayed on the display 301 of the operation unit 300. The user can select an operation mode (productivity priority mode or image quality priority mode) on the selection screen using the input interface of the operation unit 300. Information indicating the result of the operation mode selection is stored in RAM 203.

[0056] When user mode key 308 is pressed Figure 6 The selection screen is displayed on the monitor 301. Before printing, the user selects either the selection button 601 for productivity priority mode or the selection button 602 for image quality priority mode using the operation unit 300. The controller 200 receives the selection from the operation unit 300 and sets the image forming apparatus 100 to the selected operation mode. Information about the set operation mode is stored in RAM 203.

[0057] When selection button 601 for productivity-priority mode is selected, image forming apparatus 100 can form images on all sheets stored in all sheet feed stages (cassette sheet feed mechanism 9, manual sheet feeder 11, and benchtop sheet feeder 10) with maximized productivity. When selection button 602 for image quality-priority mode is selected, image forming apparatus 100 can form images on all sheets stored in all sheet feed stages with maximized image quality.

[0058] <Registration of sheets in each sheet feed stage>

[0059] The type and category of the sheet S stored in each of the sheet feeding stages of the cassette sheet feeding mechanism 9, the manual sheet feeder 11, and the benchtop sheet feeder 10 are registered in the image forming apparatus 100. Figure 7 This is an example diagram used to illustrate a sheet material registration screen. The user displays it on the display 301 using the operation unit 300. Figure 7 In the registration screen, select the sheet feed level for the sheet to be registered. The cassette sheet feed mechanism 9 includes cassettes 1 to 4. Selecting a sheet feed level allows you to select the type of sheet stored in the selected sheet feed level.

[0060] Figure 8 This is an example diagram illustrating a sheet type selection screen displayed when a sheet feed stage is selected. The controller 200 stores a list of sheet types that can be used in the image forming apparatus 100 in RAM 203. The list of sheet types is stored for each of the predetermined sheet categories in the image forming apparatus 100. The user selects the type of sheet S stored in the cassette sheet feed mechanism 9, the benchtop sheet feeder 10, and the manual sheet feeder 11 from the list and presses the confirmation button. Then, in Figure 7 The registration of the selected sheet feed stage is complete. The registration information is stored in RAM 203.

[0061] When using typical types of sheet material, the sheet is registered in the manner described above. However, since a wide variety of sheet materials are processed in the image forming apparatus 100, in some cases, the image forming apparatus 100 changes the pre-created sheet material settings. For this reason, it is important that the image forming apparatus 100 has a configuration that allows users to change the sheet material settings.

[0062] To change the sheet settings, the user... Figure 8 In the sheet type selection screen, select the sheet whose settings you wish to change and press the copy button. As a result, the settings of the selected sheet are copied, along with information about the new sheet type. Figure 9This is an example diagram illustrating the sheet type selection screen when a new sheet type has been added. Figure 9 In the middle, "Thick Paper 1" was copied and "Thick Paper 1_Modified" was added. The sheet settings for the newly added sheet type were then executed.

[0063] Figure 10 This is an example of a screen used to illustrate changes in sheet settings. In this screen, sheet settings for the newly added sheet type are performed. When in... Figure 9 When the sheet to be changed is selected using the operation unit 300 in the selection screen, the sheet setting change screen is displayed on the display 301. The sheet settings include, for example, "basis weight", "transfer voltage", "fixing temperature" and "image forming speed in image quality priority mode", but other settings related to the sheet can be changed.

[0064] The "Basis Weight" button is used to change the basis weight of the sheet. When the "Basis Weight" button is pressed, Figure 11 The weight setting screen shown in the example is displayed on monitor 301. The user can input the sheet weight in GSM using the numeric keypad 306. After inputting the weight, the user presses the confirmation button to set the sheet weight.

[0065] The "Transfer Voltage" button is used to set the voltage value during the transfer of the image (toner image) to the sheet in the secondary transfer unit 8. The sheet varies in resistance depending on its type (brand), therefore the transfer voltage must be adjusted for each brand. When the "Transfer Voltage" button is pressed, a transfer voltage setting screen (not shown) is displayed on the monitor 301. The user can change the transfer voltage according to the characteristics of the sheet. The transfer voltage is one of the parameters included in the image formation conditions.

[0066] The "Fixing Temperature" button is used to change the temperature (fixing temperature) of the fixing device 12 during the fixing of the toner image onto the sheet. Sheets vary in thickness depending on their type (brand), therefore the heat required for fixing the image varies with each type of sheet. For this reason, the fixing temperature is adjustable. When the "Fixing Temperature" button is pressed, a fixing temperature setting screen (not shown) is displayed on the monitor 301. The user can change the fixing temperature according to the characteristics of the sheet. The fixing temperature is one of the parameters included in the image forming conditions.

[0067] The "Image Forming Speed ​​in Image Quality Priority Mode" button is used to change the image forming speed in image quality priority mode. When the "Image Forming Speed ​​in Image Quality Priority Mode" button is pressed, Figure 12The image forming speed settings screen in image quality priority mode, as illustrated in the example, is displayed on monitor 301. Users can change the image forming speed in image quality priority mode from the preset default speed by pressing the "+" or "-" buttons using the numeric keypad 306. When the "+" button is pressed, the image forming speed in image quality priority mode is changed to a speed higher than the default speed. When the "-" button is pressed, the image forming speed in image quality priority mode is changed to a speed lower than the default speed.

[0068] The result of changing the image forming speed in image quality priority mode by pressing the "+" or "-" button is displayed as follows: Figure 12 The settings displayed on the screen are (-2 / -1 / 0 / +1 / +2). The result of the change is user instruction information regarding the change in image forming speed in image quality priority mode corresponding to "Thick Paper 1_Modification". The user checks the displayed settings and presses the confirmation button, thereby inputting the settings into the CPU 204, and then the CPU 204 sets the image forming speed in image quality priority mode based on the result of the change. The image forming speed does not change in productivity priority mode.

[0069] When the sheet S has a basis weight of, for example, 180 gsm, the controller 200 is based on Figure 5 The image forming speed in image quality priority mode will be set to the default speed of 200mm / s. Therefore, when "0" is displayed as the setting value... Figure 12 When the image is displayed, the image forming speed in image quality priority mode is set to 200mm / s. Additionally, when in... Figure 12 When the "+" button is pressed once (when the setting value is +1), based on Figure 4 In image quality priority mode, the image forming speed is set to 300 mm / s, one level higher than the default speed. Figure 12 When the "+" button is pressed twice (when the setting value is +2), based on Figure 4 In image quality priority mode, the image forming speed is set to 400mm / s, which is two levels higher than the default speed.

[0070] As mentioned above, in Figure 10 The user changes each item in the sheet settings change screen. After changing each item, the user presses the confirmation button. When the confirmation button is pressed, the controller 200 stores the settings of each entered item as sheet settings for the type of sheet obtained through copying into RAM 203. In this way, the type of sheet obtained through copying is added to the sheet list.

[0071] <Image Formation Rate Determination Processing>

[0072] Figure 13 This is a flowchart illustrating an image forming process that includes determining the image forming speed. In this process, an image forming speed is determined in a productivity-priority mode and an image forming speed is determined in an image quality-priority mode. An image is formed at the determined image forming speed.

[0073] The user presses the start button 303 of the operation unit 300, thereby giving the controller 200 (CPU 204) a command to start the operation. To this end, the controller 200 waits for the operation to begin until the start button 303 is pressed (step S101: No). When the user presses the start button 303 of the operation unit 300, the controller 200 starts the operation (step S101: Yes). The controller 200 obtains the sheet settings provided by the sheet feed stage storing the sheet S for image forming operations (step S102). The controller 200 checks the "basis weight" of the sheet S based on the sheet settings and determines the basis weight accordingly. Figure 5 The sheet type shown (step S103).

[0074] The controller 200 determines whether the operating mode is a productivity-priority mode by referring to the operating mode stored in RAM 203 (step S104). When the operating mode is a productivity-priority mode (step S104: Yes), the controller 200 selects the sheet type determined in the processing step S103 from... Figure 5 The table shown determines the image formation rate in productivity-priority mode (step S105).

[0075] When the operating mode is image quality priority mode (step S104: No), the controller 200 checks the setting value of "image forming speed in image quality priority mode" included in the sheet settings obtained in the processing step S102 (step S111). The controller 200 determines whether the obtained setting value is "0" (step S112). When the setting value is "0" (step S112: Yes), the controller 200 selects the sheet type determined in the processing step S103 from... Figure 5 The table shown determines the image formation rate in image quality priority mode (step S113).

[0076] When the setting value is not "0" (step S112: No), the controller 200 selects the default image forming speed in the same manner as the processing step in step S113 (step S121). The controller 200 assigns an offset to the selected image forming speed according to the setting value, thereby determining the image forming speed in the image quality priority mode (step S122).

[0077] After determining the image forming speed through the processing steps S105, S113, or S122, the controller 200 starts the image forming operation by using the transfer voltage and fixing temperature set on the sheet obtained in the processing step S102, and the determined image forming speed (step S106). Then, the image forming apparatus 100 forms an image on the sheet S, thereby producing a printed product.

[0078] The controller 200 repeatedly executes steps S102 to S106, S111 to S113, S121, and S122 for each page indicated by the job until the last page (step S107: No). After executing steps S102 to S106, S111 to S113, S121, and S122 for each page indicated by the job until the last page, and outputting the printed product of the last page, the controller 200 ends the processing (step S107).

[0079] In the aforementioned process, the operation mode is determined for each page, but the operation mode can be stored in RAM 203 at the beginning of the job, and the process can be performed with reference to the stored content.

[0080] The image forming apparatus 100 according to the first embodiment can operate in both a productivity-priority mode and an image quality-priority mode, and the image forming speed is determined based on the type of sheet and the operating mode. The image forming speed in the image quality-priority mode can be changed (adjusted). This allows the image forming operation to be performed at an image forming speed suitable for the sheet, even in the image quality-priority mode, which maintains image quality while enabling image forming operations with increased productivity. Therefore, the image forming apparatus 100 according to the first embodiment can perform image forming operations with increased productivity while maintaining image quality when forming an image with priority given to image quality.

[0081] <Second Embodiment>

[0082] The image forming apparatus 100 and controller 200 in the second embodiment of this disclosure have a configuration similar to that of the image forming apparatus 100 and controller 200 in the first embodiment, and therefore their description is omitted. The following description discusses the differences from the image forming apparatus 100 according to the first embodiment.

[0083] In the first embodiment, the image forming speed in image quality priority mode can be changed by the user. This allows for achieving the user's desired image forming speed, but depending on the setting value, an image forming speed that cannot guarantee image quality may be set. Therefore, in the second embodiment, the following operation is performed.

[0084] Figure 14 This is a flowchart illustrating an image forming process, including the process of determining the image forming speed in the second embodiment. The controller 200 (CPU 204) executes... Figure 13 The processing steps S101 to S105, S111 to S113, S121 and S122 are similar to the processing steps (steps S901 to S905, S911 to S913, S921 and S922) to determine the image forming speed.

[0085] When the operating mode is image quality priority mode and an offset is given to the image forming speed based on the setting value (step S922), the controller 200 performs the image forming speed limiting process described later, thereby keeping the image forming speed with the offset within a predetermined limit range (step S923).

[0086] After determining the image forming speed, the controller 200 starts the image forming operation (step S906) by using the transfer voltage and fixing temperature set on the sheet obtained in the processing step S902, and the determined image forming speed. Then, the image forming apparatus 100 forms an image on the sheet S, thereby producing a printed product.

[0087] The controller 200 repeatedly executes steps S902 to S906, S911 to S913, and S921 to S923 for each page indicated by the job until the last page (step S907: No). After executing steps S902 to S906, S911 to S913, and S921 to S923 for each page indicated by the job until the last page, and outputting the printed product of the last page, the controller 200 ends the processing (step S907).

[0088] In the above process, the operation mode is determined for each page, but the operation mode can be stored in RAM 203 at the beginning of the job, and the processing can be performed with reference to the stored content.

[0089] Figure 15 This is a flowchart for the image forming speed limitation processing used in step S923.

[0090] Figure 16 This is an example diagram used to illustrate a table indicating the limit range of image forming speed corresponding to each basis weight (sheet category). The limit range of image forming speed for each sheet category is defined by an upper limit speed and a lower limit speed. Figure 16 The table is stored in RAM 203.

[0091] The controller 200 initiates the image forming speed limiting process and checks the type of sheet S used for image forming. The controller 200 determines whether the type of sheet S is set to plain paper (with a basis weight from 64 gsm to 150 gsm) (step S1201). When plain paper is set (step S1201: Yes), the controller 200 sets the upper limit speed X of the image forming speed to the upper limit speed 1. Figure 16 ), and set the lower limit speed Y to the lower limit speed 1 ( Figure 16 (Step S1202).

[0092] When plain paper is not set (step S1201: No), the controller 200 determines whether the type of sheet S is set to thick paper 1 (with a basis weight from 151 gsm to 250 gsm) (step S1203). When thick paper 1 is set (step S1203: Yes), the controller 200 sets the upper limit speed X of the image forming speed to the upper limit speed 2. Figure 16 And set the lower limit speed Y to the lower limit speed 2 ( Figure 16 (Step S1204).

[0093] When no thick paper 1 is set (step S1203: No), the controller 200 determines that the sheet S is thick paper 2 (with a basis weight from 251 gsm to 350 gsm). In this case, the controller 200 sets the upper limit speed X of the image forming speed to the upper limit speed 3 ( Figure 16 And set the lower limit speed Y to the lower limit speed 3 ( Figure 16 (Step S1205).

[0094] like Figure 16 The reason for setting the upper and lower limits of the image forming speed for each basis weight of the sheet is to allow the image forming apparatus 100 to form an image within a suitable range of image forming speeds. For example, if an image is formed at an image forming speed exceeding the upper limit speed 1 for ordinary paper, the photosensitive drum Dr may not be charged evenly, and the image quality may be degraded as a result. Conversely, if an image is formed at an image forming speed below the lower limit speed 1, more heat may be applied to the sheet S as it passes through the fixing device 12, and the image quality may be degraded as a result. For these reasons, the RAM 203 stores in advance the maximum image forming speed (upper limit speed) and the minimum image forming speed (lower limit speed) that guarantees image quality for each basis weight of the sheet. Figure 16 The table.

[0095] In the second embodiment, the upper limit speed is set to not exceed the image forming speed in productivity-priority mode. This is because the image forming speed in productivity-priority mode is typically the maximum speed at which the image forming apparatus 100 can form an image while maintaining image quality.

[0096] Controller 200 obtains in Figure 14 The image forming speed determined in step S922 (step S1206). The controller 200 determines whether the image forming speed exceeds the upper limit speed X set in any of the processing steps S1202, S1204, and S1205 (step S1207). To do this, the controller 200 compares the image forming speed with the upper limit speed X set corresponding to the type of sheet S. When the image forming speed exceeds the upper limit speed X (step S1207: Yes), the controller 200 changes the image forming speed to the upper limit speed X (step S1208). After changing the image forming speed, the controller 200 ends the image forming speed limiting process.

[0097] When the image forming speed does not exceed the upper limit speed X (step S1207: No), the controller 200 determines whether the image forming speed has dropped below the lower limit speed Y set in any of the processing steps S1202, S1204, and S1205 (step S1209). To do this, the controller 200 compares the image forming speed with the lower limit speed Y set to correspond to the type of sheet S. When the image forming speed drops below the lower limit speed Y (step S1209: Yes), the controller 200 changes the image forming speed to the lower limit speed Y (step S1210). After changing the image forming speed, the controller 200 ends the image forming speed limiting process. When the image forming speed does not drop below the lower limit speed Y (step S1209: No), the controller 200 ends the image forming speed limiting process without changing the image forming speed.

[0098] For example, in Figure 11 In the image, with the basis weight of sheet S set to 180 gsm, based on Figure 5 In image quality priority mode, the default image forming speed is set to 200 mm / s. Then, when in... Figure 12 When the image forming speed in the frame is set to "-1" or "-2", the image forming speed is changed to 200 mm / s or lower. However, through image forming speed limiting processing, the image forming speed after the change is changed back to 200 mm / s. This allows the image forming apparatus 100 to form an image on the sheet S at an image forming speed that ensures image quality.

[0099] Figure 17This is an example diagram illustrating a settings screen for setting the upper and lower limits of a variable range for image forming speed. This screen is displayed on monitor 301. The upper limit 1802 and lower limit 1801 vary depending on the basis weight of the sheet. Figure 18 This is a flowchart illustrating the process of determining the upper limit value 1802 and the lower limit value 1801. When the user... Figure 10 When you select "Image Forming Speed ​​in Image Quality Priority Mode" in the film settings change screen and press the OK button, this process will begin.

[0100] The controller 200 determines whether the image quality priority mode is set by referring to the operating mode stored in the RAM 203 (step S1301). When the operating mode is the image quality priority mode (step S1301: Yes), the controller 200 obtains the image quality priority mode stored in the RAM 203. Figure 8 The type of sheet material selected in the selection screen (step S1302). The controller 200, based on the acquired sheet material type, selects... Figure 5 The table shown determines the sheet category (step S1303).

[0101] After determining the sheet type, controller 200 determines an upper limit value 1802, and subsequently determines a lower limit value 1801. The upper limit value 1802 and the lower limit value 1801 can be determined in the reverse order mentioned above. Here, as an example, information regarding... Figure 11 The description of the case where the sheet weight is set to 180gsm in the weight setting screen.

[0102] Controller 200 is based on the determined sheet type from Figure 5 The table shown selects the image forming speed in image quality priority mode. The controller 200 sets the selected image forming speed as the speed in image quality priority mode to a variable Z stored in RAM 203 (step S1304). For a basis weight of 180 gsm, the sheet type is "thick paper 1", and the image forming speed (= variable Z) in image quality priority mode is 200 mm / s. After setting variable Z, the controller 200 clears the upper limit setting value stored in RAM 203 to "0" (step S1305).

[0103] Controller 200 is based on a defined sheet type from Figure 5 The table shown selects the image forming speed in productivity-priority mode. Controller 200 compares the selected image forming speed in productivity-priority mode with the image forming speed set as variable Z (step S1306). For a basis weight of 180 gsm, the image forming speed in productivity-priority mode is 400 mm / s. The image forming speed set as variable Z is 200 mm / s.

[0104] When the image forming speed in productivity-priority mode is higher than the image forming speed set as variable Z (step S1306: Yes), the controller 200 increments the upper limit setting value by one (step S1307). The controller 200 then... Figure 4 Any of the settable speeds in the image forming apparatus 100 shown will change the image forming speed, which is set as variable Z, to a higher level (step S1308). For a basis weight of 180 gsm, the variable Z of the image forming speed is changed from 200 mm / s to 300 mm / s, which is a higher level.

[0105] During the duration when the image forming speed in productivity-priority mode is higher than the image forming speed set as variable Z, the controller 200 repeatedly executes the processing steps S1306 to S1308. When the image forming speed in productivity-priority mode becomes equal to or less than the image forming speed set as variable Z (step S1306: No), the controller 200 determines that the upper limit setting value updated by repeating the processing steps S1306 to S1308 is the upper limit value 1802 (step S1310).

[0106] For a basis weight of 180 gsm, the speed in productivity-priority mode is 400 mm / s, and the image forming speed set to variable Z is 200 mm / s. When the upper limit setting value is incremented by one and the image forming speed variable Z is changed to a higher level, the image forming speed set to variable Z is changed to 300 mm / s. The processing steps S1306 to S1308 are repeated again so that the image forming speed in productivity-priority mode is equal to the image forming speed set to variable Z, specifically, 400 mm / s. The upper limit setting value is "+2". At this time, the process proceeds to step S1310, and the upper limit setting value of "+2" is determined to be the upper limit value 1802.

[0107] After determining the upper limit value 1802, the controller 200 sets the image forming speed in image quality priority mode to variable Z in the same manner as the processing step S1304 (step S1311). After setting variable Z, the controller 200 clears the lower limit setting value stored in RAM 203 to "0" (step S1311). Figure 4 The image forming apparatus 100 shown has a settable speed selection for a minimum image forming speed (200 mm / s). The controller 200 compares the selected minimum image forming speed with the image forming speed set as variable Z (step S1313).

[0108] When the minimum image forming speed is equal to or higher than the image forming speed set as variable Z (step S1313: Yes), the controller 200 determines the lower limit setting value to be lower limit value 1801 (step S1321). For a basis weight of 180 gsm, the minimum speed is 200 mm / s, and the variable Z of the image forming speed is 200 mm / s. Therefore, the lower limit setting value of "0" is determined to be lower limit value 1801.

[0109] When the minimum image forming speed is lower than the image forming speed set as variable Z (step S1313: No), the controller 200 decrements the lower limit setting value by one (step S1314). The controller 200 then... Figure 4 Any of the settable speeds in the image forming apparatus 100 shown will change the image forming speed, which is set to variable Z, to a lower level (step S1315). The controller 200 repeatedly executes the processing steps S1313 to S1315 during the period when the lowest image forming speed is lower than the image forming speed set to variable Z.

[0110] When the minimum image forming speed becomes equal to or higher than the image forming speed set as variable Z (step S1313: No), the controller 200 determines that the lower limit setting value, which has been updated by repeating the processing steps S1313 to S1315, is the lower limit value 1801 (step S1321). For a basis weight of 180 gsm, the minimum speed is 200 mm / s, and the image forming speed set as variable Z is 200 mm / s. Therefore, in this case, the processing steps S1313 to S1315 are not executed.

[0111] After determining the upper limit 1802 and the lower limit 1801, the controller 200 displays the determined upper limit 1802 and the determined lower limit 1801 on the display 301 (step S1322). For a basis weight of 180 gsm, such as Figure 17 As illustrated, "+2" is displayed as the upper limit value of 1802, and "0" is displayed as the lower limit value of 1801.

[0112] When the operating mode is productivity priority mode (step S1301: No), the controller 200 determines that each of the upper limit value 1802 and the lower limit value 1801 is "0" (steps S1331 and S1332). The determined upper limit value 1802 and the determined lower limit value 1801 are displayed on the display 301 (step S1322). Although "0" is displayed as the upper limit value 1802 and the lower limit value 1801 in productivity priority mode, it is possible to press the indicator in productivity priority mode. Figure 18 The "+" and "-" buttons do not work in any display mode.

[0113] Setting the upper limit value 1802 and the lower limit value 1801 as described above can prevent the setting of an image forming speed that cannot guarantee image quality when the user changes the image forming speed. Therefore, the image forming apparatus according to the second embodiment can perform image forming operations with increased productivity while maintaining image quality when forming an image, given priority to image quality.

[0114] <Third Embodiment>

[0115] The image forming apparatus 100 and controller 200 in the third embodiment of this disclosure have a configuration similar to that of the image forming apparatus 100 and controller 200 in the first embodiment, and therefore their description is omitted. The following description discusses the differences from the image forming apparatus 100 according to the first and second embodiments.

[0116] In the first embodiment, "image forming speed in image quality priority mode" is displayed as Figure 10 The sheet settings change modifiable items in the image regardless of whether the operating mode is set to Image Quality Priority or Productivity Priority. However, in Productivity Priority mode, the "Image Formation Speed ​​in Image Quality Priority Mode" is not used during image formation. Therefore, even when the user sets the image formation speed to Image Quality Priority Mode, unexpected results may occur in Productivity Priority mode. This reduces usability.

[0117] In the third embodiment, in the productivity-first mode, "image formation speed in image quality-first mode" is not included as a changeable item in the sheet setting that changes the image. Figure 19 This is a flowchart used to process display settings for changing the image on the graphic sheet.

[0118] Controller 200 determines in Figure 6 The operation mode selection screen checks whether the productivity priority mode has been selected via the user mode key 308 (step S650). When the productivity priority mode is selected (step S650: Yes), the controller 200 sets the state of the image forming speed setting disable flag stored in RAM 203 to ON (step S651). When the image quality priority mode is selected (step S650: No), the controller 200 sets the state of the image forming speed setting disable flag in image quality priority mode to OFF (step S652). The state of the image forming speed setting disable flag in image quality priority mode is stored in RAM 203.

[0119] Figure 20 It is a flowchart used to change the display process of the illustrated sheet.

[0120] Controller 200 waits until via Figure 9 The selection screen selects the sheet whose settings are to be changed using the operation unit 300 and gives an instruction to display the sheet setting change screen (step S700: No). When the instruction to display the sheet setting change screen is given (step S700: Yes), the controller 200 checks the status of the image forming speed setting disable flag stored in the RAM 203 in image quality priority mode (S701).

[0121] When the state of the setting disable flag is ON (step S701: Yes), the controller 200 displays the sheet setting change screen A on the display 301 (step S702). Figure 21 This is an example of a screen showing changes to sheet settings (screen A). Screen A shows the removal of the "Image Forming Speed ​​in Image Quality Priority Mode" option. Figure 10 The sheet setting change screen. When the setting disable flag is OFF (step S701: No), the controller 200 displays the sheet setting change screen B on the display 301 (step S703). The sheet setting change screen B is... Figure 10 The film settings change the image.

[0122] Using the above processing, in productivity-priority mode, the "Image Forming Speed ​​in Image Quality-Priority Mode" item is not displayed on the sheet settings change screen, and input for changing the setting value of image forming speed is disabled. This prevents a reduction in usability.

[0123] While the invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the appended claims is to be given the broadest interpretation in order to cover all such modifications and equivalent structures and functions.

[0124] This application claims the benefit of Japanese Patent Application No. 2022-008457, filed on January 24, 2022, which is hereby incorporated herein by reference in its entirety.

Claims

1. An image forming apparatus, comprising: An image forming component includes a rotationally driven photosensitive element and is configured to form an image on the photosensitive element and transfer the image to a sheet, wherein the image forming component is controlled based on multiple modes; A memory configured to store first data for a first mode included in the plurality of modes and second data for a second mode included in the plurality of modes, the first data indicating a correspondence between sheet type and image forming speed for the first mode, and the second data indicating a correspondence between sheet type and image forming speed for the second mode; A display configured to display a screen for changing the image forming speed of a sheet to be imaged in the second mode; as well as The controller is configured to: When the image forming component forms an image based on the first mode, the rotation speed of the photosensitive component is controlled based on the image forming speed corresponding to the type of sheet indicated in the first data; and When the image forming component forms an image based on the second mode, the rotation speed of the photosensitive component is controlled based on the image forming speed corresponding to the type of sheet indicated in the second data; and When the sheet on which the image forming component is to form an image based on the second mode is a sheet on which the image forming speed under the second mode has been changed on the screen, the rotation speed of the photosensitive component is controlled based on the changed image forming speed.

2. The image forming apparatus according to claim 1, The image forming component includes: A light source configured to expose the photosensitive element to form an electrostatic latent image on the photosensitive element; A developing component, the developing component being configured to develop an electrostatic latent image on the photosensitive element; An intermediate transfer component is used to transfer the image on the photosensitive component to the intermediate transfer component. as well as A transfer component configured to transfer an image from the intermediate transfer member to a sheet at a transfer clamping portion formed between the transfer component and the intermediate transfer member.

3. The image forming apparatus according to claim 1, The image forming component includes: A light source configured to expose the photosensitive element to form an electrostatic latent image on the photosensitive element; A developing component, the developing component being configured to develop an electrostatic latent image on the photosensitive element; An intermediate transfer component is used to transfer the image on the photosensitive component to the intermediate transfer component. as well as A transfer component is configured to transfer an image from the intermediate transfer member to a sheet at a transfer clamping portion, the transfer clamping portion being formed between the transfer component and the intermediate transfer member. The controller is configured as follows: When the image forming component forms an image based on the first mode, the rotation speed of the transfer component is controlled based on the image forming speed corresponding to the type of sheet indicated in the first data; and When the image forming component forms an image based on the second mode, the rotation speed of the transfer component is controlled based on the image forming speed corresponding to the type of sheet indicated in the second data; and If the sheet on which the image forming component is to form an image based on the second mode is a sheet on which the image forming speed under the second mode has been changed on the screen, the rotation speed of the transfer component is controlled based on the changed image forming speed.

4. The image forming apparatus according to claim 1, The image formation speed corresponding to the first type of sheet in the first data is higher than the image formation speed corresponding to the first type of sheet in the second data, and The image formation speed corresponding to the first type of sheet in the first data is different from the image formation speed corresponding to the second type of sheet in the first data, and the second type is different from the first type.

5. The image forming apparatus according to claim 4, wherein the basis weight of the first type of sheet is lighter than that of the second type of sheet.

6. The image forming apparatus according to claim 4, The image formation speed corresponding to the third type of sheet in the first data is equal to the image formation speed corresponding to the third type of sheet in the second data. The third type is different from both the first and second types. The image formation speed corresponding to the third type of sheet in the second data is higher than the image formation speed corresponding to the first type of sheet in the second data.

7. The image forming apparatus according to claim 6, wherein the basis weight of the third type of sheet is lighter than that of the first type of sheet.

8. The image forming apparatus according to claim 1, The image formation speed corresponding to the first type of sheet in the first data is higher than the image formation speed corresponding to the first type of sheet in the second data, and The image formation speed corresponding to the first type of sheet in the first data is higher than the image formation speed corresponding to the second type of sheet in the first data, and the second type is different from the first type.

9. The image forming apparatus according to claim 8, The image formation speed corresponding to the third type of sheet in the first data is equal to the image formation speed corresponding to the third type of sheet in the second data. The third type is different from both the first and second types. The image formation speed corresponding to the third type of sheet in the second data is higher than the image formation speed corresponding to the first type of sheet in the second data.

10. The image forming apparatus according to claim 1, wherein the image forming speed of the first type of sheet for the second mode is changed using the image, such that the changed image forming speed is within a speed range corresponding to the first type.

11. The image forming apparatus of claim 10, wherein the image forming speed of the first type of sheet for the second mode is changed using the image to prevent the changed image forming speed from exceeding the upper limit of the speed range.

12. The image forming apparatus of claim 10, wherein the image forming speed of the first type of sheet for the second mode is changed using the image to prevent the changed image forming speed from falling below the lower limit of the speed range.

13. The image forming apparatus of claim 1, wherein the type of sheet is determined based on the basis weight of the sheet.

14. The image forming apparatus of claim 1, wherein the type of sheet is determined based on the surface characteristics of the sheet.

15. The image forming apparatus according to claim 1, The controller is configured to also receive mode instruction information, and The controller is configured to select a mode from the plurality of modes based on the mode instruction information.

16. The image forming apparatus of claim 15, wherein when the first mode is selected, the image is prevented from being displayed on the display.

17. The image forming apparatus according to claim 1, wherein, In the first mode, the image forming apparatus has a higher production capacity than in the second mode.

Images