Image forming device

Abstract

To provide an image forming device that performs processing for image formation under an appropriate image formation condition in accordance with a sheet type in which the image formation is performed.SOLUTION: An image forming device comprises: a sheet-feeding / conveying roller that conveys a sheet along a sheet conveyance passage; an image forming part that forms an image on the conveyed sheet, under an image formation condition; and a media sensor, provided in the sheet conveyance passage, which senses physical properties including basis weight of the conveyed sheet. A control part of the image forming device selects a category of the sheet on the basis of a sensed result by the media sensor, and presents candidates for default media, user-defined media or the like, for each category, to a user through a display screen of an operation part. When a selected result by the user is inputted through the operation part, the control part controls the image formation condition in accordance with the received selected result, so that image formation is performed.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus that forms an image based on image forming conditions according to the type of sheet. [Background technology]

[0002] Known image forming devices include those that develop an electrostatic latent image formed on a photoreceptor with a laser beam using toner (developer), transfer the toner image to a sheet, and heat fix it. In such image forming devices, optimal image formation conditions can be set for each type of sheet, resulting in high-quality prints. One known method for setting the image formation conditions is for the user to specify the type of sheet to be used for printing from an operation unit provided on the image forming device or from a driver screen on a computer connected to the image forming device. In recent years, devices have appeared that are equipped with media sensors inside image forming devices that detect the physical properties of sheets, such as the basis weight and surface texture of the sheet, and that can identify the type of sheet from the detected properties.In addition, a wide variety of types of sheets are used on the market, and there are cases where good quality prints cannot be obtained under the image forming conditions corresponding to the sheet types that are pre-set in the image forming device.

[0003] Patent Document 1 proposes a technology that allows a user to partially change pre-prepared image forming conditions and set image forming conditions as a new sheet type (hereinafter referred to as a user-defined sheet). With this technology, a user who feels that the quality of the printed matter is not good can customize the image forming conditions to improve the quality of the printed matter. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-270872 Summary of the Invention [Problem to be solved by the invention]

[0005] In a configuration where an image forming apparatus automatically sets sheets using a media sensor and also creates user-defined sheets, there may be cases where multiple candidate sheets match the characteristics detected by the media sensor. For example, it may be possible that both the default sheet and one or more newly created user-defined sheets match the characteristics detected by the media sensor. In this case, the image forming apparatus cannot determine which sheet's image formation conditions are appropriate for printing, which could result in a decrease in the quality of the printed output.

[0006] SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide an image forming apparatus that performs image forming processing under appropriate image forming conditions according to the sheet type. [Means for solving the problem]

[0007] An image forming apparatus according to one embodiment of the present invention includes a conveying unit that conveys a sheet along a conveying path, an image forming unit that forms an image on the sheet conveyed by the conveying unit based on image formation conditions, a detecting unit that detects the type of the sheet conveyed along the conveying path, a setting unit, and a control unit, wherein the detecting unit is capable of detecting at least a first type as a sheet type and a second type different from the first type, and the first type includes at least a first subtype and a second subtype different from the first subtype, even among the same sheet type, and when the detecting unit detects the first type, the setting unit sets which of a plurality of subtypes is to be preferentially set before detection by the detecting unit, and when the detecting unit detects the first type, the control unit controls the image forming conditions based on the sheet subtype set by the setting unit. and a receiving means for receiving user instruction information instructing which of the plurality of subtypes is to be prioritized, and the setting means sets which of the plurality of subtypes is to be prioritized based on the user instruction information received from the receiving means. It is characterized by: An image forming apparatus according to another embodiment of the present invention includes a conveying unit that conveys a sheet along a conveying path, an image forming unit that forms an image on the sheet conveyed by the conveying unit based on image formation conditions, a detection unit that detects the type of the sheet conveyed along the conveying path, a setting unit, and a control unit, wherein the detection unit is capable of detecting at least a first type as a sheet type and a second type different from the first type, and the first type includes at least a first subtype and a second subtype different from the first subtype even among the same sheet type, and when the detection unit detects the first type, the setting unit sets which of a plurality of subtypes should be preferentially set after detection by the detection unit, and when the detection unit detects the first type, the control unit controls the image forming conditions based on the sheet subtype set by the setting unit. and a receiving means for receiving user instruction information instructing which of the plurality of subtypes is to be prioritized, and the setting means sets which of the plurality of subtypes is to be prioritized based on the user instruction information received from the receiving means. It is characterized by: According to yet another embodiment of the present invention, an image forming apparatus includes a conveying means for conveying a sheet along a conveying path, an image forming means for forming an image on the sheet conveyed by the conveying means based on image forming conditions, a detecting means for detecting the type of the sheet conveyed along the conveying path, a setting means, and a control means, wherein the detecting means is capable of detecting at least a first type as the type of sheet and a second type different from the first type, and the first type includes at least a first subtype and a second subtype different from the first subtype even among the same type of sheet, and the setting means is When the first type is detected, the detection means sets which of multiple subtypes to prioritize before detection, and when the detection means detects the first type, the control means controls the image formation conditions based on the sheet subtype set by the setting means, and when image formation conditions corresponding to the same subtype have been set for the sheet type detected by the detection means a predetermined number of times in succession, the control means sets image formation conditions corresponding to the same subtype for the sheet type detected by the detection means. According to yet another embodiment of the present invention, an image forming apparatus includes a conveying means for conveying a sheet along a conveying path, an image forming means for forming an image on the sheet conveyed by the conveying means based on image forming conditions, a detecting means for detecting the type of the sheet conveyed along the conveying path, a setting means, and a control means, wherein the detecting means is capable of detecting at least a first type as the type of sheet and a second type different from the first type, and the first type includes at least a first subtype and a second subtype different from the first subtype even among the same type of sheet, and the setting means is When the first type is detected, the detection means sets which of multiple subtypes to prioritize after detection, and when the first type is detected by the detection means, the control means controls the image formation conditions based on the sheet subtype set by the setting means, and when image formation conditions corresponding to the same subtype have been set for the sheet type detected by the detection means a predetermined number of times in succession, the control means sets image formation conditions corresponding to the same subtype for the sheet type detected by the detection means. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an image forming apparatus that performs image forming processing under appropriate image forming conditions depending on the sheet type. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic cross-sectional view of an image forming apparatus. [Figure 2] FIG. 2 is a control block diagram of the image forming apparatus. [Figure 3] FIG. [Figure 4] 1A is an explanatory diagram of a screen for creating a user-defined sheet, and FIG. 1B is an explanatory diagram of a fixing temperature correction setting screen for the user-defined sheet. [Figure 5] FIG. 2 is a diagram illustrating a schematic configuration of a media sensor. [Figure 6] FIG. [Figure 7]10A to 10C are explanatory diagrams of a display screen in an automatic seat setting mode. [Figure 8] 10 is a flowchart of a sheet selection control process. DETAILED DESCRIPTION OF THE INVENTION

[0010] The following description of the preferred embodiments of the present invention will be given with reference to the accompanying drawings. The embodiments described below are subject to various limitations that are technically preferable for carrying out the present invention, but the scope of the invention is not limited to the following embodiments and illustrated examples.

[0011] FIG. 1 is a diagram showing a schematic cross-sectional configuration of an image forming apparatus 100 that forms an image on a recording medium such as a sheet. FIG. 2 is an explanatory diagram of a control unit that controls the operation of the image forming apparatus 100. In FIG. 2, the control unit 9 controls the entire image forming apparatus 100 and is built into the image forming apparatus 100. The control unit 9 includes a central processing unit (CPU) 10, a read-only memory (ROM) 11, and a random access memory (RAM) 12 as a storage unit. The CPU 10 executes a computer program stored in the ROM 11 to control the operation of the image forming apparatus 100 so as to realize the image formation procedures and flowchart procedures described below. The RAM 12 stores various information under the control of the CPU 10. The RAM 12 provides a working area for the CPU 10 when executing the computer program. The control unit 9 is connected to an operation unit 13, a media sensor 14, an external device 15, an image forming unit 17, and a fixing unit 170.

[0012] The operation unit 13 is a user interface equipped with an input interface and an output interface, and includes a panel and buttons as a display screen capable of displaying an operation screen. The input interface is a key button, a touch panel, etc. The output interface is a display, a speaker, etc. The operation unit 13 functions as an instruction / display unit that displays various screens, such as a setting screen and an instruction screen, on the display under the control of the CPU 10. The CPU 10 accepts various settings and instructions to start operations from the operation unit 13. When a user inputs instruction information, such as an instruction to start a print operation, the operation unit 13 sends the instruction information to the CPU 10. The instruction information may be input from an external device 15, such as a personal computer, a tablet terminal, or a smartphone connected via a network, etc. When the instruction information to start a print operation is input, the CPU 10 drives and controls a paper feed motor (not shown) in accordance with the instruction information to feed a sheet. The CPU 10 also sets image formation conditions for the image forming unit 17 and the fixing unit 170, and the image forming apparatus 100 forms an image according to the set image formation conditions.

[0013] The image forming unit 17 includes cartridges 120a, 120b, 120c, and 120d, which are the image creating units shown in FIG. 1, and laser scanners 122a, 122b, 122c, and 122d. The image forming unit 17 also includes an intermediate transfer belt 130, primary transfer units 123a, 123b, 123c, and 123d, a secondary transfer unit 140, and the like. The image forming unit 17 forms an image on a sheet under the control of the CPU 10. The image forming unit 17 drives these components based on the image formation conditions set by the CPU 10 to form an image on the sheet. The fixing unit 170 heats and fixes the image formed by the image forming unit 17 to the sheet based on the image formation conditions set by the CPU 10. Details will be described later. The media sensor 14 is provided in the paper transport path and detects physical characteristics (also called media characteristics) such as basis weight and surface texture of a sheet such as paper fed via the paper transport path. The CPU 10 identifies the sheet based on the detection results of the media characteristics by the media sensor 14. Details will be described later. The sheets on which an image is to be printed are stored in a paper feed tray 110 or a plurality of paper feed cassettes 220, 221, which serve as a feeding means. The types of sheets stored in the paper feed tray 110 or each of the paper feed cassettes 220, 221 may be the same or different.

[0014] Next, a basic image forming operation will be described with reference to FIGS. 1 and 2. When a command to start a print operation is input from the operation unit 13 or the like, the CPU 10 starts a sheet feeding operation from the specified paper feed slot, i.e., from the paper feed tray 110 or one of the paper feed cassettes 220 and 221 shown in FIG. 1. In the case of the paper feed tray 110, the CPU 10 drives a paper feed conveyance motor (not shown) that serves as the drive source for the paper feed conveyance roller 111. This rotates the paper feed conveyance roller 111, feeding the sheets on the paper feed tray 110 one by one along the paper conveyance path. Similarly, in the case of the paper feed cassette 220 or 221, the CPU 10 rotates the paper feed conveyance roller 151 or 152 to feed the sheets in the paper feed cassette 221 or 220 one by one. When the automatic sheet setting mode (described later) is set, the media sensor 14 detects the media characteristics of the fed sheets. Then, the CPU 10 sets image forming conditions such as fixing temperature and transfer voltage according to the sheet identified from the detected characteristics or the sheet set from the operation unit 13 or the like.

[0015] The CPU 10 starts the image forming operation by the cartridges 120a to 120d so as to be ready in time for the sheet to arrive at the secondary transfer unit 140. The cartridge 120a is for forming a yellow image, the cartridge 120b is for forming a magenta image, the cartridge 120c is for forming a cyan image, and the cartridge 120d is for forming a black image. The cartridges 120a to 120d are configured to be attachable and detachable by the user.

[0016] Each of the cartridges 120a, 120b, 120c, and 120d has the same configuration. Each of the cartridges 120a, 120b, 120c, and 120d includes a photosensitive member, a charging roller, and a developing unit. After the photosensitive member is uniformly charged by the charging roller, an electrostatic latent image is formed on the photosensitive member by laser light irradiated from laser scanners 122a, 122b, 122c, and 122d. The developing unit develops the formed electrostatic latent image with toner (developer). This forms a toner image on the photosensitive member. The toner image formed in the cartridges 120a, 120b, 120c, and 120d is transferred to the intermediate transfer belt 130 by applying a primary transfer voltage to primary transfer units 123a, 123b, 123c, and 123d. The intermediate transfer belt 130 rotates, and toner images are transferred from the photosensitive elements of the cartridges 120a, 120b, 120c, and 120d at timings that correspond to the rotation speed. Toner images of each color are transferred and superimposed on the intermediate transfer belt 130, forming a full-color toner image. The intermediate transfer belt 130 conveys the transferred toner images to the secondary transfer unit 140 as it rotates.

[0017] CPU 10 detects the position of the sheet conveyed by conveyance rollers 155 by monitoring the output from pre-registration conveyance sensor 160. Then, CPU 10 controls the conveyance of the sheet, taking into account the timing when the leading edge of the sheet reaches pre-registration conveyance sensor 160, so that the leading edge of the sheet and the leading edge of the toner image on intermediate transfer belt 130 coincide at secondary transfer unit 140. For example, if pre-registration conveyance sensor 160 detects the sheet at a timing when the sheet reaches secondary transfer unit 140 earlier than the toner image, CPU 10 stops the sheet at pre-registration conveyance rollers 161 for a predetermined time. After the predetermined time has elapsed, CPU 10 resumes conveyance of the sheet by pre-registration conveyance rollers 161 and controls the transfer position of the toner image onto the sheet.

[0018] As described above, the sheet and toner image reach secondary transfer unit 140 and a secondary transfer voltage is applied, whereby the toner image is transferred from intermediate transfer belt 130 to the sheet. The sheet onto which the toner image has been transferred is transported to fuser 170. Fuser 170 applies heat and pressure to the toner image to fuse it to the sheet. CPU 10 transports the sheet onto which the image has been fixed by fuser 170 downstream. A paper transport sensor 171 is disposed downstream of fuser 170. When the leading edge of the sheet after fixing reaches paper transport sensor 171, CPU 10 determines whether the sheet should be transported to paper transport path 230 or paper transport path 231, in accordance with an instruction set from operation unit 13 or the like. Then, CPU 10 switches transport flapper 172 based on that determination, thereby switching the destination of the sheet. For example, if the instruction from the operation unit 13 is a double-sided printing instruction and the front side is being printed, the CPU 10 causes the paper to be transported to the paper transport path 230, and if the instruction is a single-sided printing or the back side of a double-sided print is being printed, the CPU 10 causes the paper to be transported to the paper transport path 231.

[0019] When a sheet is conveyed to paper conveyance path 231, the conveyed sheet is further conveyed downstream by conveyance rollers 232 and discharged to paper discharge tray 196. On the other hand, when a sheet is conveyed to paper conveyance path 230, the sheet is conveyed by reverse conveyance rollers 162 located downstream and drawn into reversal unit R. After the sheet is drawn into reversal unit R, CPU 10 switches conveyance flapper 173 and reverses the rotation of reverse conveyance rollers 162 to switch back the sheet and convey it toward secondary transfer unit 140. Note that in order to switch back, the length of the sheet in the conveyance direction must be shorter than the length L of reversal unit R. Then, CPU 10 again detects the position of the sheet by monitoring the output of pre-registration conveyance sensor 160 and controls the conveyance of the sheet so that the leading edge of the sheet and the leading edge of the toner image on intermediate transfer belt 130 coincide with each other at secondary transfer unit 140. Thereafter, CPU 10 transfers a toner image to the sheet, fixes the transferred toner image using fixation unit 170, and switches conveyance flapper 172. As a result, the sheet is conveyed to the paper conveying path 231 and discharged to the paper discharge tray 196, thereby achieving double-sided printing.

[0020] <Explanation of the fixing unit> FIG. 3 is a schematic cross-sectional view of the fixing device 170. The fixing device 170 includes a heater holder 207, a fixing heater 204 fixedly disposed along the longitudinal direction (perpendicular to the drawing) of the underside of the heater holder 207, an assembly including a fixing film 203 serving as an elastic layer, and a pressure roller 205. Also shown in FIG. 3 is a sheet M onto which a toner image T is transferred and which is conveyed in the direction of the arrow in the drawing. The heater holder 207 is a U-shaped member extending in the depth direction of the drawing. The fixing heater 204 is fixedly disposed along the longitudinal direction of the heater holder 207 on the underside of the heater holder 207. The fixing device 170 is arranged parallel to the pressure roller 205 with the fixing heater 204 side facing in contact with the pressure roller 205, and both ends of the heater holder 207 are pressed with a predetermined pressure by a biasing mechanism (not shown). The pressure roller 205 is disposed with both ends of its core metal rotatably supported between the side plates of the fixing device.

[0021] The fixing heater 204 is disposed parallel to the pressure roller 205 within the fixing film 203, on the pressure roller 205 side. The fixing heater 204 and fixing film 203 are biased toward the pressure roller 205 with a predetermined pressure. The fixing heater 204 is pressed against the pressure roller 205, sandwiching the fixing film 203, against the elasticity of the pressure roller 205, to form a fixing nip 206 of a predetermined width. The pressure roller 205 is driven to rotate counterclockwise at a predetermined peripheral speed by a drive mechanism (not shown). The fixing film 203 rotates clockwise in response to the rotation of the pressure roller 205. The sheet is pressurized and heated in the fixing nip 206, thereby fixing the toner image, and is transported downstream from the fuser 170 by the rotation of the pressure roller 205. The fixing heater 204 is a ceramic substrate with a resistance heating element formed on it. A temperature detection sensor 208 abuts against the fixing heater 204. The CPU 10 detects the temperature of the fixing heater 204 from the detection result output from the temperature detection sensor 208, and controls the power supply to the fixing heater 204 based on the detected temperature so that the fixing heater 204 reaches a predetermined target temperature. In this way, the CPU 10 performs feedback control of the temperature of the fixing heater 204.

[0022] <User-defined sheet description> Next, the user-defined sheet will be described with reference to FIGS. 4(a) and 4(b). In this embodiment, a group (or sheet type) to which a sheet belongs, such as plain paper or thick paper, is referred to as a category. A user-defined sheet is a sheet that is uniquely defined by a user. For sheet types (default types) predefined in image forming apparatus 100, such as plain paper or thick paper, characteristics such as basis weight are set, and image formation conditions such as fixing temperature and transfer voltage are set. Similarly, characteristics such as basis weight can be set for user-defined sheets, and image formation conditions such as fixing temperature and transfer voltage can be set. RAM 12 stores one default sheet, its characteristics, and its image formation conditions for each category, and can also store multiple user-defined sheets, their characteristics, and their image formation conditions, by adding them to RAM 12.

[0023] FIG. 4(a) is an explanatory diagram that shows a model of a user-defined sheet creation screen that is displayed when a user issues an instruction to create a user-defined sheet via the operation unit 13. The user-defined sheet creation screen is displayed, for example, by displaying a user-defined sheet creation button (not shown) on the operation unit 13 and the user pressing the creation button. The figure shows an entry section 401 where the name of the user-defined sheet is entered by the user, a setting button 405 for the entry, and a basis weight value (g / m 2) as numbers, and a setting button 406 for the same. Also shown are a selection button 403 and a setting button 407 for the user to select a fixing temperature correction condition from among “low,” “standard,” and “high” as an image formation condition. Furthermore, a selection button 404 and a setting button 408 for displaying the transfer voltage correction selected by the user from among “low,” “standard,” and “high” are shown. After setting these image formation conditions, the user presses a create button 409 to create a user-defined sheet. Regarding the entry section 401, the “name” is an identifier for the sheet and is used in check buttons 711 to 713, 721 to 723, etc., shown in FIGS. 7(b) and 7(c) (to be described later). The user presses a setting button 405 corresponding to the entry section 401 to input characters into the entry section 401 from the operation unit 13, and sets a name for the user-defined sheet that does not overlap with any existing sheet.

[0024] In the entry section 402, "basis weight" is the weight per unit area of ​​the sheet. In this embodiment, the CPU 10 determines the category to which the sheet belongs based on the basis weight, and sets reference values ​​for image formation conditions such as the fixing temperature and secondary transfer voltage according to the category. The user presses the setting button 406 corresponding to the basis weight and inputs a numerical value within a predetermined range into the entry section 402 from the operation unit 13 to set the basis weight.

[0025] Regarding the selection button 403, "Fixing Temperature Correction" is a correction to the reference value of the fixing temperature. FIG. 4B is an explanatory diagram of a setting screen for fixing temperature correction that is displayed on the operation unit 13 when the user presses the setting button 407 corresponding to the selection button 403 in FIG. 4A. In this example, "Low" is displayed in the selection button 421, "Standard" in the selection button 422, and "High" in the selection button 423, and fixing temperature correction is performed by selecting one of these. When "Standard" in the selection button 422 is selected, the CPU 10 does not perform correction to the reference value of the fixing temperature. When "Low" in the selection button 421 or "High" in the selection button 423 is selected, the CPU 10 performs fixing temperature correction so that the fixing temperature is lowered or raised by a predetermined value from the reference value of the fixing temperature. Similarly, regarding the selection button 404, "Transfer Voltage Correction" is a correction to the reference value of the secondary transfer voltage. By pressing the setting button 408 corresponding to the selection button 404, the user can select one of "low," "standard," or "high" to correct the transfer temperature, as in the example of FIG. 4(b) for fixing temperature correction.

[0026] To explain an example of creating a user-defined sheet, for example, if the basis weight of the sheet used by the user is slightly smaller than the default sheet setting for plain paper, using the default sheet setting as is may result in a large amount of curl. Therefore, by selecting "Low" instead of "Standard" for the fixing temperature correction using selection button 403 for the default sheet setting for plain paper and creating and using a user-defined sheet, it is possible to expect a reduction in the amount of curl.

[0027] <Media sensor> 5 is a schematic diagram illustrating the configuration of the media sensor 14. The media sensor 14 is an optical sensor that includes an LED (Light Emitting Diode) 581 as a light-emitting element, a photodiode 580 as a light-receiving element, and a guide member 583 that guides the insertion of the sheet M. The LED 581 emits light onto the sheet M. The photodiode 580 receives the light reflected by the sheet M. The photodiode 580 outputs an electrical signal corresponding to the received reflected light, which allows the photodiode 580 to detect the amount of reflected light emitted by the LED 581.

[0028] The CPU 10 receives the input signal from the photodiode 580 as the output value of the media sensor 14. The CPU 10 identifies the sheet being used based on differences in output values ​​due to the basis weight and surface properties of each sheet. Details will be described later. Identifying the sheet using the media sensor in this manner eliminates the need for the user to manually set the sheet. For this reason, the image forming apparatus 100 of this embodiment provides a mode (automatic sheet setting mode) in which the media sensor 14 is used to identify the sheet and image formation conditions are set according to the identified sheet. On the other hand, the image forming apparatus 100 of this embodiment also provides a mode (manual sheet setting mode) in which the user manually sets the sheet as in the conventional case. The user pre-sets either the automatic sheet setting mode or the manual sheet setting mode for each paper feed slot using the operation unit 13 or the like. 5 is an example, and the present invention is not limited to this configuration. For example, the media sensor 14 may have other configurations, such as a configuration that combines an ultrasonic sensor such as a piezoelectric element in addition to a light-emitting element and a light-receiving element.

[0029] FIG. 6 is an explanatory diagram of the sheet discrimination process using the media sensor 14. Here, the media sensor 14 uses the basis weight of the sheet as the media characteristic. Therefore, the output value of the media sensor varies depending only on the basis weight of the detected sheet. As shown in the figure, discrimination threshold 1 and discrimination threshold 2 are defined for the output value of the media sensor 14. Depending on the magnitude relationship between the output value of the media sensor 14 and discrimination threshold 1 and discrimination threshold 2, it is possible to determine the sheet category as one of thin paper 601, plain paper 602, and thick paper 603 as the detection result of the media characteristic by the media sensor 14. Note that determining the category based on the output value of the media sensor 14 is sometimes referred to as detecting the category.

[0030] In this example, thin paper_default, plain paper_default, and thick paper_default are predefined as default sheets, which are preset sheet types. The media sensor output values ​​and corresponding basis weights are indicated by arrows 604, 605, and 606, respectively. Additionally, the user has added plain paper_user-defined 1, plain paper_user-defined 2, and thick paper_user-defined 3 as user-defined sheet types set by the user. The corresponding media sensor output values ​​and basis weights are indicated by arrows 607, 608, and 609. Default sheets are defined so that one type corresponds to one category. Therefore, if no user-defined sheets have been defined by the user, the CPU 10 can uniquely determine the sheet type by determining the category. On the other hand, if a user-defined sheet has been created, both the default sheet and the user-defined sheet may correspond to one category. In this case, because multiple sheet types correspond to one category, the CPU 10 cannot uniquely determine the sheet type by simply determining the category.

[0031] Explaining this with reference to the example of FIG. 6, when the CPU 10 determines that the sheet category is thin paper 601 based on the magnitude relationship between the media sensor output value and discrimination threshold 1 and discrimination threshold 2, the sheet type can be uniquely determined to be thin paper_default. On the other hand, as shown by arrows 607, 605, and 608, three sheet types correspond to plain paper 602: plain paper_user-defined 1, plain paper_default, and plain paper_user-defined 2. Therefore, when the sheet category is determined to be plain paper 602, the user may use these three sheet types depending on the situation. Conversely, the user may use only plain paper_user-defined 1 for plain paper 602, and not plain paper_default or plain paper_user-defined 2.

[0032] Therefore, the CPU 10 cannot uniquely determine the appropriate sheet type simply by determining the sheet category using the media sensor 14. The same is true for the thick paper 603. The user may be using two sheets, thick paper_default and thick paper_user-defined 3, or may be using only the additional user-defined sheet, making it impossible to uniquely determine the appropriate sheet type. Thus, in the automatic sheet setting mode, there may be multiple sheet types corresponding to the category detected by the media sensor. In this case, the sheet type determined by the CPU 10 may differ from the sheet type intended by the user, which may result in undesirable image formation conditions being set and result in a decrease in the quality of the printed matter.

[0033] <Sheet discrimination control> In the sheet discrimination control, when a plurality of sheet types are defined as candidates for the type of sheet in one category, the user can specify or set in advance the sheet type to be selected in the automatic sheet setting mode. In this embodiment, before the printing operation, a "job common setting" is provided that applies each category set for the sheet in common regardless of the print job. Also, during printing, a "job individual setting" is provided that sets the sheet type for each job for the detected category, providing two setting methods.

[0034] When multiple sheet types are defined for one category and the user uses multiple sheet types differently, such as the example of plain paper 602 and thick paper 603 in Figure 6, if the frequency of different sheet types is low, "job common settings" can be used. On the other hand, if the frequency of different sheet types is high, "job individual settings" can be used, making it possible to improve convenience according to the use case. The following explanation will be given using the example in Figure 6.

[0035] 7A to 7C are explanatory diagrams of display screens in the automatic sheet setting mode that are displayed in response to user instructions as user instruction information entered through the operation unit 13. FIG. 7A is a display screen for selecting a sheet category in the job-common setting. This screen is displayed, for example, when the user presses a "job-common setting for automatic sheet setting mode" button (not shown) displayed on the operation unit 13. In FIG. 7A, selection buttons 701, 702, and 703 respectively display "thin paper," "plain paper," and "thick paper" as sheet categories that can be set in the image forming apparatus 100. In the drawing, the selection button 701 corresponding to thin paper is grayed out and cannot be selected. As shown in FIG. 6, the only sheet type set for the thin paper category is "thin paper_default," and even if the user selects the selection button 701, the sheet type cannot be changed to another sheet type. Therefore, the selection button 701 is grayed out and cannot be selected. In this embodiment, the automatic seat setting mode is displayed to the user on the display screen, but the automatic seat setting mode can be presented to the user by other methods. For example, the contents of the screen display in Figures 7(a) to 7(c) may be presented to the user by voice guidance.

[0036] On the other hand, for plain paper, three sheet types are defined: "Plain Paper_Default," "Plain Paper_User Defined 1," and "Plain Paper_User Defined 2," as shown in FIG. 6. Therefore, the user has multiple options for the sheet type to select. For this reason, the selection button 702 corresponding to plain paper is not grayed out, and the user can select a single desired sheet type from the multiple sheet types. As shown in FIG. 6, two sheet types are defined for cardboard: "Cardboard_Default" and "Cardboard_User Defined 3." In this case, although multiple sheet types are defined for the single category of cardboard, there is only one type of user-defined sheet: "Cardboard_User Defined 3." If only one type of user-defined sheet has been created and that user-defined sheet is used frequently, the selection button can be displayed in gray out, reducing the effort required for the user to set the sheet. FIG. 7(a) shows an example of this, in which the selection button 703 corresponding to cardboard is displayed in gray out.

[0037] The CPU 10 may control the display of the operation unit 13 so that, when the same sheet type is selected consecutively a predetermined number of times or more in a category in which multiple types of sheets are defined, the selection button corresponding to that category is grayed out based on the user's input from the operation unit 13. For example, there may be a case where the same sheet type (e.g., "Cardboard_User Defined 3") is selected consecutively a predetermined number of times or more for "cardboard," which is the result of detection of the media characteristics by the media sensor 14, and image formation conditions are set. In this case, the CPU 10 grays out the selection button 703 corresponding to cardboard. Then, the CPU 10 sets image formation conditions according to the same sheet type selected consecutively a predetermined number of times or more, and causes the image forming unit 17 to form an image.

[0038] In this way, when the selection buttons are grayed out even though multiple sheets have been defined, the user may select a grayed-out button. In this case, a screen for the user to select a sheet may be displayed, similar to the case of a selection button that is not grayed out (e.g., selection button 702 in FIG. 7(a)). Also, when multiple types of sheets are defined for one category, the corresponding selection button 703 may be displayed without being grayed out, regardless of the number of user-defined sheets, so that the user can select a sheet. In this case, the selection button 703 corresponding to cardboard is displayed without being grayed out, so that the user can select the desired sheet.

[0039] 7(b) is an explanatory diagram of a sheet type selection display screen that is displayed on the operation unit 13 when the user selects plain paper using the selection button 702 in FIG. 7(a). In this example, a screen is displayed that reads, "Please select the sheet type to be set when 'plain paper' is detected." Following this display, the user selects which sheet type the image forming apparatus 100 will set and use for printing when the sheet category is detected to be "plain paper."

[0040] In the figure, "Plain Paper_Default," "Plain Paper_User Defined 1," and "Plain Paper_User Defined 2" are displayed as sheet types, and corresponding check buttons 711, 712, and 713 are displayed. The user selects a sheet type by pressing the check button corresponding to the desired sheet type to select it, and the selected sheet type is selected as the job-wide setting in the image forming apparatus 100. In the example of FIG. 7B, check button 712 is selected, indicating that the user has selected "Plain Paper_User Defined 1" as the sheet type as the job-wide setting. Therefore, in subsequent processing, when plain paper is detected by the media sensor 14, "Plain Paper_User Defined 1" is set as the sheet type. The CPU 10 then causes the image forming apparatus 100 to form an image under the image formation conditions corresponding to "Plain Paper_User Defined 1."

[0041] In this way, after the user selects a sheet type using one of the check buttons 711 to 713 in the automatic sheet setting mode, the CPU 10 sets the sheet type selected by the user for the job executed in the automatic sheet setting mode. Thereafter, the CPU 10 performs printing control based on the image formation conditions. Therefore, in the automatic sheet setting mode, the sheet selected in FIG. 7(b) is automatically set, so the user does not need to select a sheet individually. Also shown in the figure is "Set individually for each job" and a corresponding check button 714. If the user desires to set a sheet type for each job rather than as a common job setting, the user selects the check button 714 corresponding to "Set individually for each job." In this case, the CPU 10 displays a screen on the operation unit 13 for selecting which sheet type to select for each job executed in the automatic sheet setting mode.

[0042] FIG. 7(c) is an explanatory diagram of the display screen for job-specific settings. This display screen is displayed on the operation unit 13 when the check button 714 corresponding to "Job-specific settings" in FIG. 7(b) has been selected and plain paper has been detected in the image forming apparatus 100. As shown, this display screen displays "Plain Paper" detected. Please select the sheet to be set." This indicates that the sheet category has already been detected as "plain paper" in the image forming apparatus 100. This display screen displays the sheet types defined for "plain paper"—"Plain Paper_Default," "Plain Paper_User Defined 1," and "Plain Paper_User Defined 2"—and displays corresponding check buttons 721, 722, and 723. The user selects the desired sheet type by depressing the check button corresponding to the desired sheet type to select it. In the example of FIG. 7(c), check button 722 is selected, indicating that the user has selected "Plain Paper_User Defined 1" as the sheet type. The CPU 10 sets the selected sheet type, "plain paper_user defined 1," in the image forming apparatus 100 and performs image formation.

[0043] Furthermore, in the example of FIG. 7(c), an option "Set as job common" and a corresponding check button 724 are displayed. There is a case where the user selects "Set as job common" by selecting check button 724 on the screen of FIG. 7(c), and the image forming apparatus 100 detects that the sheet category is plain paper. In this case, in subsequent image formation, the sheet type selected in FIG. 7(c), "Plain Paper_User Defined 1," is automatically set. Therefore, the result is the same as when the check button 712 is pressed in the "Job Common Settings" of FIG. 7(b) and "Plain Paper_User Defined 1" is selected.

[0044] FIG. 8 is a flowchart showing the sheet selection control process. Note that the letter "S" in the flowchart represents a processing step. Furthermore, each processing step is executed by the CPU 10 unless otherwise specified. Note that in the following description, S101 to S105 are processes that the CPU 10 repeatedly executes after the image forming apparatus 100 is powered on and before a printing operation is executed. Furthermore, S111 to S132 are processes that the CPU 10 repeatedly executes during printing.

[0045] The CPU 10 determines whether there are any changes to the settings of the user-defined sheet described with reference to FIGS. 4A and 4B (S101). If there are any changes (S101: Y), the changes are reflected in the current user-defined sheet settings (S102). Note that changes to the user-defined sheet settings may include creating a user-defined sheet, deleting a created user-defined sheet, or changing the media characteristics and image formation conditions. When S102 is executed, the CPU 10 determines whether the job-common settings shown in FIGS. 7A and 7B have been changed (S103). Note that if there are no changes to the user-defined sheet settings (S101: N), the CPU 10 executes S103 without executing S102. If there are any changes to the job-common sheet settings (S103: Y), the CPU 10 reflects the changes (S104) and determines whether a print start operation instruction has been issued as an image formation command from the operation unit 13 or the like (S105). If there is no change in the job-common sheet setting (S103: N), the CPU 10 executes S105 without executing S104. S101 to S105 are processes before the execution of a print operation. In this embodiment, when the user presses the job-common setting button for the automatic sheet setting mode displayed on the operation unit 13 before the execution of a print operation, the display screen for the automatic sheet setting mode shown in FIGS. 7(a) and 7(b) is displayed. Also, in order to enable the user to set the sheet type individually for each job, the display screen in FIG. 7(b) always displays a check button 714 corresponding to "Set individually for each job" together with check buttons 711 to 713.

[0046] If there is no print start operation instruction (S105: N), the CPU 10 executes S101 again. If there is a print start operation instruction (S105: Y), the CPU 10 causes the image forming apparatus 100 to start a print operation and feed paper (S111). In the paper feeding process, the CPU 10 feeds sheets one by one from the specified paper feed slot. Next, the CPU 10 determines whether the automatic sheet setting mode is set (S112). If the automatic sheet setting mode is not set (S112: N), the CPU 10 selects the sheet type manually set by the user via the operation unit 13 (S113) and executes printing under image formation conditions corresponding to the selected sheet type (S131). If the automatic sheet setting mode is set (S112: Y), the CPU 10 detects the media characteristics of the fed sheet using the media sensor 14 to detect the media characteristics (S114). In this way, the sheet category is determined based on the detection result of the media characteristics. The CPU 10 then determines whether or not there are multiple sheet types that correspond to the determined category (S115). Note that S114 to S125 are sheet discrimination controls when the automatic sheet setting mode is set, and particularly S117 to S125 are sheet discrimination controls when there are multiple sheets that correspond to the detected category.

[0047] If there is only one sheet type corresponding to the determined category (S115: N), the CPU 10 selects the corresponding sheet type (S116). This process corresponds to the case where thin paper 601 is detected in FIG. 6. Then, the CPU 10 executes S131 described above. If there are multiple sheet types corresponding to the determined category (S115: Y), the CPU 10 determines whether a single sheet type can be identified from among the sheet types set corresponding to the determined category. This determination can be made by any method. For example, if a sheet type set by the user is included among the multiple sheet types set corresponding to the category, the CPU 10 may preferentially identify a single sheet type from among the sheet types set by the user. Alternatively, the CPU 10 may record a history of sheet types set by the user and, based on that history, identify a sheet type that is frequently set as the single sheet type. In this embodiment, the CPU 10 determines whether there is only one corresponding user-defined sheet type (S117). If there is only one user-defined sheet corresponding to the determined category (S117: Y), CPU 10 selects that user-defined sheet as a single sheet type (S118) and executes S131, which corresponds to the case where cardboard 603 is detected in the example of FIG.

[0048] If there are two or more user-defined sheets as sheet types corresponding to the determined category (S117: N), the CPU 10 determines that a single sheet type cannot be identified. Thereafter, the CPU 10 determines whether or not to use the job-individual settings by referring to the user's selection input via the display screen of FIG. 7(b) in the process prior to executing the print operation (S119). If the user inputs a selection not to use the job-individual settings (S119: N), the CPU 10 selects the job-common settings. This corresponds to the case where the user has already selected one of the check buttons 711 to 713 for selecting a job-common sheet in FIG. 7(b). In this case, the CPU 10 selects the sheet type of the sheet job-common settings selected by the user for the determined category (S120) and executes S131.

[0049] If the user selects to use the job individual settings (S119: Y), this corresponds to the case where the user has already selected the check button 714 corresponding to "Job Individual Settings" in FIG. 7B. In this case, the CPU 10 determines whether image formation is to be performed on the first page of the sheet on which an image is to be formed in the current print job (S121). This determination can be made by any method, for example, using a counter (not shown) provided in the image forming apparatus 100. If it is the first page (S121: Y), the CPU 10 displays on the operation unit 13 a screen for accepting the user's selection of a sheet type for the current job. This allows the CPU 10 to accept the user's selection of a sheet type in the job individual settings (S122). In this embodiment, in S112, check buttons 721 to 723 corresponding to sheet types such as plain paper_default, as shown in FIG. 7C, are displayed to accept the user's selection.

[0050] Furthermore, the CPU 10 displays on the operation unit 13 a screen for accepting a user's selection as to whether or not the sheet type selected in the job individual settings is also used as the sheet type in the job common settings for sheet types in the same category. As a result, the CPU 10 determines whether or not to reflect the sheet type selected in the job individual settings in the job common settings (S123). This display may be displayed together with the screen for accepting the user's selection of the job individual sheet for the current job in S122, or may be displayed after the user's selection of the job individual sheet has been accepted.

[0051] In the example of FIG. 7(c), a check button 724 corresponding to "Set as job common" is displayed together with a screen for accepting a user's selection of job individual settings for the current job. If the check button 724 is not selected, it means that the user has selected not to reflect the settings of the job individual sheet in the job common settings (S123: N). In this case, the user selects the sheet type of the sheet job individual settings selected by the user (S125), and S131 is executed. On the other hand, if the check button 724 corresponding to "Set as job common" is selected by the user in the example of FIG. 7(c), it means that the user has selected to reflect the settings of the job individual sheet in the job common settings (S123: Y). In this case, the CPU 10 does not require job individual settings for the category determined by detecting the media characteristics in S114.

[0052] Thereafter, the CPU 10 reflects the sheet type in the job individual settings selected by the user in S122 in the job common settings in S103 (S124), and then selects the sheet type in the sheet job individual settings selected by the user (S125).Then, the CPU 10 executes S131, and performs print control based on the image formation conditions for the selected sheet type.

[0053] Returning to S121, if the page on which image formation is to be performed is not the first page (S121: N), image formation will be performed on the second page and onward. Therefore, CPU 10 selects the sheet type of the job-individual settings already selected for the first page and executes S131. Thereafter, CPU 10 determines whether the printing operation for the final page is complete (S132). If it is not complete (S132: N), it executes S111 and subsequent steps again. If it is complete (S132: Y), the processing ends. Note that the control executed by CPU 10 in this embodiment is merely an example, and the present invention is not limited to this. For example, a job-individual sheet may be set for each printing operation, or a job-common sheet may be set for each paper feed slot.

[0054] As described above, according to this embodiment, in the automatic sheet setting mode, when there are multiple sheet types that match the characteristics detected by the media sensor, the user can set the sheet type to be selected. This allows the user to select the appropriate sheet type even when there are multiple matching sheet types, thereby obtaining high-quality printed matter. Furthermore, it is possible to select an appropriate sheet setting even when there are multiple sheet settings that match the characteristics detected by the media sensor, without compromising the convenience of automatic sheet setting using the media sensor.

Claims

1. a conveying means for conveying the sheet along a conveying path; an image forming unit that forms an image on the sheet conveyed by the conveying unit based on image forming conditions; a detection unit for detecting the type of the sheet conveyed through the conveyance path; A setting means; a control means; the detection means is capable of detecting at least a first type of sheet and a second type different from the first type, The first type includes at least a first subtype and a second subtype different from the first subtype, even among the same type of sheet; the setting means sets, when the first type is detected by the detection means, which of a plurality of subtypes is to be preferentially set before the detection is performed by the detection means; when the detecting means detects the first type, the control means controls the image forming conditions based on the sheet subtype set by the setting means; a receiving means for receiving user instruction information instructing which of the plurality of subtypes should be given priority; the setting means sets which of the plurality of subtypes is to be prioritized based on the user instruction information received from the receiving means. Image forming device.

2. a conveying means for conveying the sheet along a conveying path; an image forming unit that forms an image on the sheet conveyed by the conveying unit based on image forming conditions; a detection unit for detecting the type of the sheet conveyed through the conveyance path; A setting means; a control means; the detection means is capable of detecting at least a first type of sheet and a second type different from the first type, The first type includes at least a first subtype and a second subtype different from the first subtype, even among the same type of sheet; when the first type is detected by the detection means, the setting means sets which of a plurality of subtypes is to be preferentially set after the detection is performed by the detection means; when the detecting means detects the first type, the control means controls the image forming conditions based on the sheet subtype set by the setting means; a receiving means for receiving user instruction information instructing which of the plurality of subtypes should be given priority; the setting means sets which of the plurality of subtypes is to be prioritized based on the user instruction information received from the receiving means. Image forming device.

3. the detection unit detects the first type and the second type by detecting physical characteristics of the sheet transported on the transport path; 3. The image forming apparatus according to claim 1.

4. When the setting means receives an image formation command, it executes a presentation process to present a screen for selecting one subtype from the plurality of subtypes for the first type of sheet to a user through the receiving means; setting a subtype of sheet designated by the user instruction information received through the receiving means as a type of sheet to be selected in common with the first type of sheet; the control means controls the image forming means to form an image on the sheet in accordance with the image forming conditions. The image forming apparatus according to claim 1 .

5. when it is possible to identify a single subtype from among the plurality of subtypes for the first type of sheet, the setting means sets image forming conditions of the image forming means in accordance with the identified single subtype without executing the process of presenting a screen for selection; When it is not possible to identify the single subtype, the image forming conditions are set by executing the process of presenting a screen for selection. The image forming apparatus according to claim 4 .

6. When the first type of sheet includes only one subtype defined by a user, the control unit sets the image forming conditions based on the subtype defined by the user.

3. The image forming apparatus according to claim 1.

7. When image forming conditions corresponding to the same subtype are set for the type of sheet detected by the detection means a predetermined number of times in succession, the control means sets image forming conditions corresponding to the same subtype for the type of sheet detected by the detection means.

3. The image forming apparatus according to claim 1.

8. When it is not possible to identify the single subtype, the setting means presents the plurality of subtypes to the user as candidates to be individually set for each image formation command, identifies the subtype selected by the user as the single subtype, and sets the image formation conditions for the image formation command. The image forming apparatus according to claim 5 .

9. the control means executes the presentation before performing image formation of the first page of the sheet in response to the image formation command, and controls the image formation conditions based on the specified subtype without executing the presentation in image formation of the second page and subsequent pages of the sheet. The image forming apparatus according to claim 8 .

10. When the first type detected by the detection means includes a sheet type defined by the user, the control means identifies the single sheet type from the sheet types defined by the user. The image forming apparatus according to claim 5 .

11. The detection means detects the type of the sheet from the basis weight or surface property of the sheet.

3. The image forming apparatus according to claim 1.

12. The setting means a first image forming condition in which a first setting screen that allows a user to set any one of the sheet types before forming the image is displayed on a receiving means that receives user instruction information regarding the sheet type, and the sheet type set via the first setting screen is selected to form the image; a second setting screen is displayed on the receiving means, which allows a user to set one of the plurality of sheet types corresponding to the sheet type detected by the detection means, and a second image forming condition is selected to form the image by selecting the sheet type set through the second setting screen; and one of the first image forming conditions and the second image forming conditions is selected based on the user instruction information.

3. The image forming apparatus according to claim 1.

13. a plurality of paper feed means for feeding the sheets to the conveyance path; the control unit sets either the first image forming condition or the second image forming condition for each of the paper feed units, The image forming apparatus according to claim 12.

14. A conveying means for conveying a sheet along a conveying path; an image forming unit that forms an image on the sheet conveyed by the conveying unit based on image forming conditions; a detection unit for detecting the type of the sheet conveyed through the conveyance path; A setting means; a control means; the detection means is capable of detecting at least a first type of sheet and a second type different from the first type, The first type includes at least a first subtype and a second subtype different from the first subtype, even among the same type of sheet; the setting means sets, when the first type is detected by the detection means, which of a plurality of subtypes is to be preferentially set before the detection is performed by the detection means; when the detecting means detects the first type, the control means controls the image forming conditions based on the sheet subtype set by the setting means; When image forming conditions corresponding to the same subtype are set for the type of sheet detected by the detection means a predetermined number of times in succession, the control means sets image forming conditions corresponding to the same subtype for the type of sheet detected by the detection means. Image forming device.

15. A conveying means for conveying a sheet along a conveying path; an image forming unit that forms an image on the sheet conveyed by the conveying unit based on image forming conditions; a detection unit for detecting the type of the sheet conveyed through the conveyance path; A setting means; a control means; the detection means is capable of detecting at least a first type of sheet and a second type different from the first type, The first type includes at least a first subtype and a second subtype different from the first subtype, even among the same type of sheet; when the first type is detected by the detection means, the setting means sets which of a plurality of subtypes is to be preferentially set after the detection is performed by the detection means; when the detecting means detects the first type, the control means controls the image forming conditions based on the sheet subtype set by the setting means; When image forming conditions corresponding to the same subtype are set for the type of sheet detected by the detection means a predetermined number of times in succession, the control means sets image forming conditions corresponding to the same subtype for the type of sheet detected by the detection means. Image forming device.

Images